Sample records for handle nonuniform arrays

  1. Field emission from non-uniform carbon nanotube arrays.

    Dall'agnol, Fernando F; den Engelsen, Daniel


    Regular arrays of carbon nanotubes (CNTs) are frequently used in studies on field emission. However, non-uniformities are always present like dispersions in height, radius, and position. In this report, we describe the effect of these non-uniformities in the overall emission current by simulation. We show that non-uniform arrays can be modeled as a perfect array multiplied by a factor that is a function of the CNTs spacing.

  2. Resistor array infrared nonuniformity correction based on sparse grid

    He, Xudong; Qiu, Jiang; Zhang, Qiao; Du, Huijie; Zhao, Hongming


    Resistor array plays a vital role in emulation of the IR control and guide system. However, its serious nonuniformity confines the range of its application. Therefore, in order to obtain an available IR image, nonuniformity correction (NUC) is necessary. The traditional method is sparse grid and flood which only take the array's nonuniformity into account. In this paper we present an improved sparse grid method which considers the whole system which affects the array's nonuniformity by dividing the NUC process into different gray levels. In each gray level, we can take two points or several points to calculate the nonuniformity of every block which is divided before correction. After that, we can have several characteristic curves which will be operated with curve fitting. By this means, we will correct the nonuniformity. At last, through the experiment of a number of images, we find the residual nonuniformity associated with random noise is about 0.2% after the correction.

  3. Nonuniformity compensation for IR focal plane array sensors

    Venkateswarlu, Ronda; Er, Meng H.; Gan, Yu H.; Fong, Yew C.


    Recent reports indicate that cooled and uncooled IR focal plane array sensors are progressing to a field-worthy level for commercial and defense applications. They offer higher sensitivity, amenability to signal processing and mechanical simplicity. However these sensors contain large detector-to- detector dark current (offset) and responsivity (gain) variations. These variations result in a severe problem called fixed pattern noise that can mask/distort the image obtained from the sensor. The correction process is generally termed as nonuniformity compensation. Conventional two-point compensation techniques are accurate enough, but require built-in controllable temperature references along with mechanical and electro-optical shutters. Therefore this compensation technique detracts the mechanical simplicity of using IR focal plane arrays. Scene-based nonuniformity techniques dispenses with the requirement of temperature references and shutters, but are not accurate enough for certain applications. This paper discusses two-point and scene-based nonuniformity compensation algorithms and proposes an empirical formula to automatically calculate the scene constants, which is an essential step towards practical applications. This paper reports the analyzed results of testing the algorithms on a number of IR images. A practical problem of 'artifacts' which arise when using scene-based nonuniformity compensation is also discussed. A common hardware scheme to implement both the algorithms is also presented in this paper.

  4. Combined Approach for Nonuniformity Correction in Infrared Focal Plane Array

    XUE Hui


    A new algorithm of nonuniformity correction for infrared focal plane array(IRFPA) is reported,which is a combined algorithm based on both the two-point correction and artificial neural networks correction.The combined algorithm is calibrated by two-point correction,and the calibrated correction coefficients are automatically modified by BP algorithm.So it is not only calibrated,but also real-time processed.In adaptive nonuniformity correction algorithm,the phenomena ghost artifact and target fade-out are avoided by edge extraction.In order to get intensified image,the modified median filters are adopted.The simulated data indicates the proposed scheme is an effective algorithm.

  5. Beam pattern improvement by compensating array nonuniformities in a guided wave phased array

    Kwon, Hyu-Sang; Lee, Seung-Seok; Kim, Jin-Yeon


    This paper presents a simple data processing algorithm which can improve the performance of a uniform circular array based on guided wave transducers. The algorithm, being intended to be used with the delay-and-sum beamformer, effectively eliminates the effects of nonuniformities that can significantly degrade the beam pattern. Nonuniformities can arise intrinsically from the array geometry when the circular array is transformed to a linear array for beam steering and extrinsically from unequal conditions of transducers such as element-to-element variations of sensitivity and directivity. The effects of nonuniformities are compensated by appropriately imposing weight factors on the elements in the projected linear array. Different cases are simulated, where the improvements of the beam pattern, especially the level of the highest sidelobe, are clearly seen, and related issues are discussed. An experiment is performed which uses A0 mode Lamb waves in a steel plate, to demonstrate the usefulness of the proposed method. The discrepancy between theoretical and experimental beam patterns is explained by accounting for near-field effects.

  6. Research of improved sparse grid non-uniformity correction technologies for infrared resistor array

    Du, Hui-jie; Zhao, Hong-ming; Gao, Yang; Yu, Hong; Zhang, Yi


    Infrared resistor arrays perform a vital role in the hardware in the loop testing of infrared seekers. Infrared resistor arrays composed of large numbers of suspended resistor elements are commonly used to produce dynamic two-dimensional images of infrared radiation. Due to inconsistencies in the fabrication process of the resistor arrays, the temperature each resistor elements reaches for a given input voltage is variable and this leads to more significant radiance differences, these differences result in spatially-distributed radiance non-uniformity. Therefore, in order to obtain an available infrared image, non-uniformity correction (NUC) is necessary. In this paper, the non-uniformity characters of the infrared resistor arrays are analyzed base on measured data and then an improved sparse grid method for engineering are discussed and analyzed. First of all, the NUC camera has a strong influence on the effectiveness of the infrared resistor arrays NUC procedure. According to the actual fact and the laboratory condition, we presented an alternative method for collecting resistor arrays intended to reduce the influence causing by the NUC camera. Secondly, based on the measured non-uniformity data, we obtain the response characteristics of the infrared resistor arrays. In each gray level, we take two points or several points correction algorithm to calculate the gain data and the offset data, and then the linear look-up table is established. Finally, through MATLAB we develop the correction software, and we can obtain the driving output conveniently. The result shows that the image quality has a remarkable improvement after non-uniformity correction, the non-uniformity correction flow and algorithm preferably satisfies the requirement of the high confidence infrared imaging simulation.

  7. Locally adaptive regression filter-based infrared focal plane array non-uniformity correction

    Li, Jia; Qin, Hanlin; Yan, Xiang; Huang, He; Zhao, Yingjuan; Zhou, Huixin


    Due to the limitations of the manufacturing technology, the response rates to the same infrared radiation intensity in each infrared detector unit are not identical. As a result, the non-uniformity of infrared focal plane array, also known as fixed pattern noise (FPN), is generated. To solve this problem, correcting the non-uniformity in infrared image is a promising approach, and many non-uniformity correction (NUC) methods have been proposed. However, they have some defects such as slow convergence, ghosting and scene degradation. To overcome these defects, a novel non-uniformity correction method based on locally adaptive regression filter is proposed. First, locally adaptive regression method is used to separate the infrared image into base layer containing main scene information and the detail layer containing detailed scene with FPN. Then, the detail layer sequence is filtered by non-linear temporal filter to obtain the non-uniformity. Finally, the high quality infrared image is obtained by subtracting non-uniformity component from original image. The experimental results show that the proposed method can significantly eliminate the ghosting and the scene degradation. The results of correction are superior to the THPF-NUC and NN-NUC in the aspects of subjective visual and objective evaluation index.

  8. Tunable pinning effects produced by non-uniform antidot arrays in YBCO thin films

    George, J.; Jones, A.; Al-Qurainy, M. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); Fedoseev, S.A. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); Centre for Medical Radiation Physics, University of Wollongong, NSW (Australia); Rosenfeld, A. [Centre for Medical Radiation Physics, University of Wollongong, NSW (Australia); Pan, A.V. [Institute for Superconducting and Electronic Materials, University of Wollongong, NSW (Australia); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)


    Uniform, graded and spaced arrays of 3 μm triangular antidots in pulsed laser deposited YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) superconducting thin films are compared by examining the improvements in the critical current density J{sub c} they produced. The comparison is made to establish the role of their lithographically defined (non-)uniformity and the effectiveness to control and/or enhance the critical current density. It is found that almost all types of non-uniform arrays, including graded ones enhance J{sub c} over the broad applied magnetic field and temperature range due to the modified critical state. Whereas uniform arrays of antidots either reduce or produce no effect on J{sub c} compared to the original (as-deposited) thin films. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. An improved retina-like nonuniformity correction for infrared focal-plane array

    Yu, Hui; Zhang, Zhi-jie; Wang, Chen-sheng


    The non-uniform response in infrared focal plane array (IRFPA) detectors produces corrupted images with nonuniformity noise. This paper mainly proposes an improved adaptive nonuniformity correction (NUC) method based on the retina-like neural network approach. The main purpose of NUC method is to obtain reliable estimations of gain and offset parameters. In this paper the two correction parameters are updated with two different learning rates respectively for the purpose of updating these two parameters synchronously. And then more accurate estimations of the two correction parameters can be obtained. Again, in order to reduce the ghost artifacts normally introduced by the strong edge effectively, the proposed algorithm employs the non-local means (NLM) method to estimate the desired target value of each detector. The proposed NUC method has been tested by applying it to the IR sequence of frames with simulated nonuniformity noise and real nonuniformity noise, respectively. The performance comparisons are implemented with the well-established scene-based NUC techniques. And the experimental results show the efficiency of the proposed method.

  10. Reference-free nonuniformity compensation for IR imaging arrays

    Narendra, P. M.


    Multi-detector IR imaging focal plane arrays possess large detector-to-detector dark current (offset) and responsivity (gain) variations which can completely mask the useful thermal signatures in IR scenes. Conventional detector compensation techniques require uniform temperature references of constant radiance over the entire field of view and a mechanical/electro-optical shutter. This detracts from the mechanical simplicity of multi-detector staring focal planes (which require no scanning). This paper describes a real-time offset and responsivity (gain) compensation technique which dispenses with temperature references and shutters in staring focal planes. The technique makes use of the IR scene itself for calibration and continuously updates the compensation coefficients without interrupting the field of view with a shutter or a temperature reference. The results of real-time simulations of this technique with a number of sensors are presented. Real-time hardware implementation considerations suggest that the technique can be implemented with the addition of very little hardware to a conventional compensation technique requiring temperature references. The technique is also suitable for multi-detector scanning focal planes and for the removal of shading in TV sensors as well.

  11. Direction of Arrival Estimation Based on MUSIC Algorithm Using Uniform and Non-Uniform Linear Arrays

    Eva Kwizera


    Full Text Available In signal processing, the direction of arrival (DOA estimation denotes the direction from which a propagating wave arrives at a point, where a set of antennas is located. Using the array antenna has an advantage over the single antenna in achieving an improved performance by applying Multiple Signal Classification (MUSIC algorithm. This paper focuses on estimating the DOA using uniform linear array (ULA and non-uniform linear array (NLAof antennas to analyze the performance factors that affect the accuracy and resolution of the system based on MUSIC algorithm. The direction of arrival estimation is simulated on a MATLAB platform with a set of input parameters such as array elements, signal to noise ratio, number of snapshots and number of signal sources. An extensive simulation has been conducted and the results show that the NLA with DOA estimation for co-prime array can achieve an accurate and efficient DOA estimation

  12. Flood Nonuniformity Measurement Resistor Arrays%电阻阵列Flood非均匀性测试

    杨春伟; 王仕成; 苏德伦; 廖守亿; 张金生


    Resistor array has been the hot research area during the late 20 years in the field of hard-ware-in-the-loop(HWIL), of which the radiance non-uniformity is a negative effect to the scene fidelity. The resistor array non-uniformity must be measured precisely in order to correct it. The functional diagram of resistor array Flood non-uniformity measurement method was introduced; the reasons for Moire fringes appearance was analyzed; the resistor array non-uniformity Flood measurement method based on the prediction of Moire fringes was proposed towards the Moire fringes. The simulation results indicate that the method achieves good effect in the mapping ratio less than 1:1.%在红外成像半实物仿真领域,电阻阵列一直是近20多年的研究热点,但其固有的辐射非均匀性对成像的保真度有着很大的负面影响.为了对电阻阵列进行非均匀性校正,必须对电阻阵列的非均匀性进行精确的测量.给出了电阻阵列Flood非均匀性测试法系统模型;分析了莫尔条纹的产生原因;针对非1∶1映射比例下Flood非均匀性测试方法产生的莫尔条纹,提出了基于莫尔条纹预测的电阻阵列Flood非均匀性测试方法.仿真结果表明,该方法在小于1∶1映射比例下可以取得很好的效果.

  13. Performance limitations and practical considerations associated with resistive emitter array nonuniformity correction (NUC)

    Moore, Douglas K.; Stanek, Clay J.; Peterson, Curt


    Resistive array technology is finding increasing application in representing synthetic infrared targets and backgrounds. Pixel-to-pixel radiance nonuniformity is the prominent noise source from resistive arrays and must be compensated or otherwise mitigated for high-fidelity testing of infrared imaging sensors. Any imaging method for measuring and correcting nonuniformity noise is subject to theoretical performance limitations due to sensor measurement noise, geometrical resolution, background offset, and optical resolution. We derive general performance bounds as functions of sensor parameters, which are equally applicable to staring and scanning nonuniformity correction (NUC) sensors. A thorough understanding of the theoretical limitations of the process allows intelligent specification of the NUC sensor, procedures, algorithms, and processing power required for any scene projection application. We describe the NUC approach developed for the US Army's Dynamic Infrared Scene Projector (DIRSP). We also exhibit the features of our software package, which calculates emitter calibration curves from automatically collected laboratory data. We show how the code deals with practical considerations such as detector fill factor, incorrect magnification, rotation between emitter array and NUC sensor, optics anisoplanity, dead pixels, data overload, and automatic detection of emitter signals. The paper concludes by showing a glimpse of procedures, algorithms, and sensor to be used in the DIRSP.

  14. Adaptive broadband beamformer for nonuniform linear array based on second order cone programming

    Chen Peng; Hou Chaohuan; Ma Xiaochuan; Cao Zhiqian; Liang Yicong; Yan Sheng


    Adaptive broadband beamforming is a key issue in array applications. The adaptive broadband beamformer with tapped delay line (TDL) structure for nonuniform linear array (NLA) is designed according to the rule of minimizing the beamformer's output power while keeping the distortionless response (DR) in the direction of desired signal and keeping the constant beamwidth (CB) with the prescribed sidelobe level over the whole operating band. This kind of beamforming problem can be solved with the interior-point method after being converted to the form of standard second order cone programming (SOCP). The computer simulations are presented which illustrate the effectiveness of our bearaformer.

  15. Adaptive scene-based nonuniformity correction method for infrared-focal plane arrays

    Torres, Sergio N.; Vera, Esteban M.; Reeves, Rodrigo A.; Sobarzo, Sergio K.


    The non-uniform response in infrared focal plane array (IRFPA) detectors produces corrupted images with a fixed-pattern noise. In this paper we present an enhanced adaptive scene-based non-uniformity correction (NUC) technique. The method simultaneously estimates detector's parameters and performs the non-uniformity compensation using a neural network approach. In addition, the proposed method doesn't make any assumption on the kind or amount of non-uniformity presented on the raw data. The strength and robustness of the proposed method relies in avoiding the presence of ghosting artifacts through the use of optimization techniques in the parameter estimation learning process, such as: momentum, regularization, and adaptive learning rate. The proposed method has been tested with video sequences of simulated and real infrared data taken with an InSb IRFPA, reaching high correction levels, reducing the fixed pattern noise, decreasing the ghosting, and obtaining an effective frame by frame adaptive estimation of each detector's gain and offset.

  16. A dynamic resistance nonuniformity compensation circuit for uncooled microbolometer detector arrays

    Yildirim, Omer Ozgur; Akin, Tayfun


    This paper presents a new approach for compensating resistance nonuniformity of uncooled microbolometers by adjusting the bias currents of both detector and reference pixels. Contrary to conventional nonuniformity compensation circuits, this approach eliminates the need for digital-to-analog converters (DACs), which usually occupy a large area, dissipate high power, and require complicated external circuitry with high frequency data transfer to the microbolometer chip. The proposed circuit uses a feedback structure that dynamically changes the bias currents of the reference and detector pixels and does not need complicated external circuitry. A special feature of the circuit is that it provides continuous compensation for the detector and reference resistances due to temperature changes over time. The circuit is implemented in a 0.6μm 5V CMOS process and occupies an area of only 160μm × 630μm. Test results of the prototype circuit show that the circuit reduces the offset current due to resistance nonuniformity about 2.35% of its uncompensated value, i.e., an improvement of about 42.5 times is achieved, independent of the nonuniformity amount. The circuit achieves this compensation in 12μsec. Considering its simplicity and low cost, this approach is suitable for large array commercial infrared imaging systems.

  17. Nonuniformity compensation methods for the thermal imager based on uncooled focal plane array

    Wu, Cheng; Su, Junhong


    Because of the detector material, manufacturing technology and optical system, there is a obvious signal responsivity variation in sensor elements of uncooled focal plane array (UFPA), that is same as the cooled FPA. This variations results in a severe fixed pattern noise. There have been a lot of varied ways to compensate the nonuniformity of FPA detectors now. This paper briefly describes several main nonuniformity compensation (NUC) methods discussed below, and considering the properties of UFPA detectors, the precision and rate of NUC, a practical NUC methods applying to UFPA is given. The aim is to simplify the hardware and software of NUC for UFPA, and to satisfy the requests of use in the real world simultaneously.

  18. Static scene statistical algorithm for nonuniformity correction in focal-plane arrays

    Catarius, Adrian M.; Seal, Michael D.


    A static scene statistical nonuniformity correction (S3NUC) method was developed based on the higher-order moments of a linear statistical model of a photodetection process. S3NUC relieves the requirement for calibrated targets or a moving scene for NUC by utilizing two data sets of different intensities but requires low scene intensity levels. The first-, second-, and third-order moments of the two data sets are used to estimate the gain and bias values for the detectors in a focal-plane array (FPA). These gain and bias values may then be used to correct the nonuniformities between detectors or to initialize other continuous calibration methods. S3NUC was successfully applied to simulated data as well as measured data at visible wavelengths.

  19. Modeling and reconfiguration of solar photovoltaic arrays under non-uniform shadow conditions

    Nguyen, Dung Duc

    Mass production and use of electricity generated from solar energy has become very common recently because of the environmental threats arising from the production of electricity from fossil fuels and nuclear power. The obvious benefits of solar energy are clean energy production and infinite supply of daylight. The main disadvantage is the high cost. In these photovoltaic systems, semiconductor materials convert the solar light into electrical energy. Current versus voltage characteristics of the solar cells are nonlinear, thus leading to technical control challenges. In the first order approximation, output power of a solar array is proportional to the irradiance of sunlight. However, in many applications, such as solar power plants, building integrated photovoltaic or solar tents, the solar photovoltaic arrays might be illuminated non-uniformly. The cause of non-uniform illumination may be the shadow of clouds, the trees, booms, neighbor's houses, or the shadow of one solar array on the other, etc. This further leads to nonlinearities in characteristics. Because of the nature of the electrical characteristics of solar cells, the maximum power losses are not proportional to the shadow, but magnify nonlinearly [1]. Further, shadows of solar PV array can cause other undesired effects: (1) The power actually generated from the solar PV array is much less than designed. At some systems, the annual losses because of the shadow effects can be reached 10%. Thus, the probability for "loss of load" increases [2]. (2) The local hot spot in the shaded part of the solar PV array can damage the solar cells. The shaded solar cells may be work on the negative voltage region and become a resistive load and absorb power. Bypass diodes are sometimes connected parallel to solar cells to protect them from damage. However, in most cases, just one diode is connected in parallel to group of solar cells [3], and this hidden the potential power output of the array. This proposed research

  20. Test stand for non-uniformity correction of microbolometer focal plane arrays used in thermal cameras

    Krupiński, Michał; Bareła, Jaroslaw; Firmanty, Krzysztof; Kastek, Mariusz


    Uneven response of particular detectors (pixels) to the same incident power of infrared radiation is an inherent feature of microbolometer focal plane arrays. As a result an image degradation occurs, known as Fixed Pattern Noise (FPN), which distorts the thermal representation of an observed scene and impairs the parameters of a thermal camera. In order to compensate such non-uniformity, several NUC correction methods are applied in digital data processing modules implemented in thermal cameras. Coefficients required to perform the non-uniformity correction procedure (NUC coefficients) are determined by calibrating the camera against uniform radiation sources (blackbodies). Non-uniformity correction is performed in a digital processing unit in order to remove FPN pattern in the registered thermal images. Relevant correction coefficients are calculated on the basis of recorded detector responses to several values of radiant flux emitted from reference IR radiation sources (blackbodies). The measurement of correction coefficients requires specialized setup, in which uniform, extended radiation sources with high temperature stability are one of key elements. Measurement stand for NUC correction developed in Institute of Optoelectronics, MUT, comprises two integrated extended blackbodies with the following specifications: area 200×200 mm, stabilized absolute temperature range +15 °C÷100 °C, and uniformity of temperature distribution across entire surface +/-0.014 °C. Test stand, method used for the measurement of NUC coefficients and the results obtained during the measurements conducted on a prototype thermal camera will be presented in the paper.

  1. Optical sensitivity non-uniformity analysis and optimization of a tilt optical readout focal plane array

    Fu, Jianyu; Shang, Haiping; Shi, Haitao; Li, Zhigang; Ou, Yi; Chen, Dapeng; Zhang, Qingchuan


    An optical readout focal plane array (FPA) usually has a differently tilted reflector/absorber at the initial state due to the micromachining technique. The angular deviation of the reflector/absorber has a strong impact on the optical sensitivity non-uniformity, which is a key factor which affects the imaging uniformity. In this study, a theoretical analysis has been developed, and it is found that the stress matching in SiO2-Aluminum (Al) bilayer leg could make a contribution towards reducing the optical sensitivity non-uniformity. Ion implantation of phosphorus (P) has been utilized to control the stress in SiO2 film. By controlling the implantation energy and dose, the stress and stress stability are modified. The optical readout FPA has been successfully fabricated with the stress-control technique based on P+ implantation. It is demonstrated that the gray response non-uniformity of optical readout FPA has decreased from 25.69% to 10.7%.

  2. Bacterial handling under the influence of non-uniform electric fields: dielectrophoretic and electrohydrodynamic effects

    Flavio H. Fernádez-Morales


    Full Text Available This paper describes the modeling and experimental verification of a castellated microelectrode array intended tohandle biocells, based on common dielectrophoresis. The proposed microsystem was developed employing platinumelectrodes deposited by lift-off, silicon micromachining, and photoresin patterning techniques. Having fabricated the microdevice it was tested employing Escherichia coli as bioparticle model. Positive dielectrophoresis could be verified with the selected cells for frequencies above 100 kHz, and electrohydrodynamic effects were observed as the dominant phenomena when working at lower frequencies. As a result, negative dielectrophoresis could not be observed because its occurrence overlaps with electrohydrodynamic effects; i.e. the viscous drag force acting on the particles is greater than the dielectrophoretic force at frequencies where negative dielectrophoresis should occur. The experiments illustrate the convenience of this kind of microdevices to micro handling biological objects, opening the possibility for using these microarrays with other bioparticles. Additionally, liquid motion as a result of electrohydrodynamic effects must be taken into account when designing bioparticle micromanipulators, and could be used as mechanism to clean the electrode surfaces, that is one of the most important problems related to this kind of devices.Este artigo descreve a modelagem e teste experimental de uma rede de microeletrodos em cremalheira cujo objetivo é o manuseio de células biológicas, com base em dieletroforese comum. O microsistema proposto foi desenvolvido empregando eletrodos de platina depositados por técnicas de 'lift-off', micro-usinagem em silício e litografia com foto-resina. Uma vez fabricado o microdispositivo, este foi testado utilizando a Escherichia coli como modelo de biopartículas. Dieletroforese positiva pode ser observada com as células selecionadas para freqüências acima de 100kHz, e efeitos eletro

  3. Non-local means-based nonuniformity correction for infrared focal-plane array detectors

    Yu, Hui; Zhang, Zhi-jie; Chen, Fu-sheng; Wang, Chen-sheng


    The infrared imaging systems are normally based on the infrared focal-plane array (IRFPA) which can be considered as an array of independent detectors aligned at the focal plane of the imaging system. Unfortunately, every detector on the IRFPA may have a different response to the same input infrared signal which is known as the nonuniformity problem. Then we can observe the fixed pattern noise (FPN) from the resulting images. Standard nonuniformity correction (NUC) methods need to be recalibrated after a short period of time due the temporal drift of the FPN. Scene-based nonuniformity correction (NUC) techniques eliminate the need for calibration by correction coefficients based on the scene being viewed. However, in the scene-based NUC method the problem of ghosting artifacts widely seriously decreases the image quality, which can degrade the performance of many applications such as target detection and track. This paper proposed an improved scene-based method based on the retina-like neural network approach. The method incorporates the use of non-local means (NLM) method into the estimation of the gain and the offset of each detector. This method can not only estimates the accurate correction coefficient but also restrict the ghosting artifacts efficiently. The proposed method relies on the use of NLM method which is a very successful image denoising method. And then the NLM used here can preserve the image edges efficiently and obtain a reliable spatial estimation. We tested the proposed NUC method by applying it to an IR sequence of frames. The performance of the proposed method was compared the other well-established adaptive NUC techniques.

  4. Nonuniformity correction of cryogenic 512(2) emitter arrays: the five-minute 5% NUC using FIESTA

    Thomas, Matthew C.; Newman, Donald D.; Frolli, Mark; Pritchett, Donald G.; Peterson, Curt


    In this paper we report on effects to correct the spatial radiance nonuniformities in four infrared emitter arrays in the mid-wave infrared. Using a table-top setup in which a 512 X 512 NODDS array was driven by the MRC FIESTA 8500 drive electronics, and the output radiance from the emitter array was captured by a 100% fill-factor InSb focal plane array with fast frame storage capabilities, we were able to improve the emitter radiance nonuniformities by up to a factor of six while collecting the emitter radiances using the sparse grid approach in only 5 minutes. We report on the custom FIESTA operating system we developed, paying particular attention to the real-time nonuniformity correction capabilities since this enabled the emitter nonuniformities to be minimized while the emitter movie was played at frame rates up to 180 Hz. We also report on the custom emitter data processing software we developed which enabled us to determine the radiance from four emitters and write out new, calibrated movies which displayed radiances with only 2% nonuniformity.

  5. An uncooled microbolometer focal plane array using heating based resistance nonuniformity compensation

    Tepegoz, Murat; Oguz, Alp; Toprak, Alperen; Senveli, S. Ufuk; Canga, Eren; Tanrikulu, M. Yusuf; Akin, Tayfun


    This paper presents the performance evaluation of a unique method called heating based resistance nonuniformity compensation (HB-RNUC). The HB-RNUC method utilizes a configurable bias heating duration for each pixel in order to minimize the readout integrated circuit (ROIC) output voltage distribution range. The outputs of each individual pixel in a resistive type microbolometer differ from each other by a certain amount due to the resistance non-uniformity throughout the focal plane array (FPA), which is an inevitable result of the microfabrication process. This output distribution consumes a considerable portion of the available voltage headroom of the ROIC unless compensated properly. The conventional compensation method is using on-chip DACs to apply specific bias voltages to each pixel such that the output distribution is confined around a certain point. However, on-chip DACs typically occupy large silicon area, increase the output noise, and consume high power. The HB-RNUC method proposes modifying the resistances of the pixels instead of the bias voltages, and this task can be accomplished by very simple circuit blocks. The simplicity of the required blocks allows utilizing a low power, low noise, and high resolution resistance nonuniformity compensation operation. A 9-bit HB-RNUC structure has been designed, fabricated, and tested on a 384x288 microbolometer FPA ROIC on which 35μm pixel size detectors are monolithically implemented, in order to evaluate its performance. The compensation operation reduces the standard deviation of the ROIC output distribution from 470 mV to 9 mV under the same readout gain and bias settings. The analog heating channels of the HB-RNUC block dissipate around 4.1 mW electrical power in this condition, and the increase in the output noise due to these blocks is lower than 10%.

  6. An Improved Scene-based Nonuniformity Correction Algorithm for Infrared Focal Plane Arrays Using Neural Networks

    SUI Jing; JIN Wei-qi; DONG Li-quan; WANG Xia; GUO Hong


    The improved scene-based adaptive nonuniformity correction (NUC) algorithms using a neural network (NNT) approach for infrared image sequences are presented and analyzed. The retina-like neural networks using steepest descent model was the first proposed infrared focal plane arrays (IRFPA) nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term,regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij ( n ) is proposed as an alternative value of desired network output of neuron Xij ( n ), denoted as Tij ( n ), which is the local spatial average of Xij ( n ) in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence.Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences (several hundred frames) subjected to the dense impulse noises with a number of dead or saturated pixels.

  7. Pattern Synthesis of Planar Nonuniform Circular Antenna Arrays Using a Chaotic Adaptive Invasive Weed Optimization Algorithm

    Huaning Wu


    Full Text Available A novel invasive weed optimization (IWO variant called chaotic adaptive invasive weed optimization (CAIWO is proposed and applied for the optimization of nonuniform circular antenna arrays. A chaotic search method has been combined into the modified IWO with adaptive dispersion, where the seeds produced by a weed are dispersed in the search space with standard deviation specified by the fitness value of the weed. To evaluate the performance of CAIWO, several representative benchmark functions are minimized using various optimization algorithms. Numerical results demonstrate that the proposed approach improves the performance of the algorithm significantly, in terms of both the convergence speed and exploration ability. Moreover, the scheme of CAIWO is employed to find out an optimal set of weights and antenna element separation to obtain a radiation pattern with maximum side-lobe level (SLL reduction with different numbers of antenna element under two cases with different purposes. The design results obtained by CAIWO have comfortably outperformed the published results obtained by other state-of-the-art metaheuristics in a statistically meaningful way.

  8. Guided filter and adaptive learning rate based non-uniformity correction algorithm for infrared focal plane array

    Sheng-Hui, Rong; Hui-Xin, Zhou; Han-Lin, Qin; Rui, Lai; Kun, Qian


    Imaging non-uniformity of infrared focal plane array (IRFPA) behaves as fixed-pattern noise superimposed on the image, which affects the imaging quality of infrared system seriously. In scene-based non-uniformity correction methods, the drawbacks of ghosting artifacts and image blurring affect the sensitivity of the IRFPA imaging system seriously and decrease the image quality visibly. This paper proposes an improved neural network non-uniformity correction method with adaptive learning rate. On the one hand, using guided filter, the proposed algorithm decreases the effect of ghosting artifacts. On the other hand, due to the inappropriate learning rate is the main reason of image blurring, the proposed algorithm utilizes an adaptive learning rate with a temporal domain factor to eliminate the effect of image blurring. In short, the proposed algorithm combines the merits of the guided filter and the adaptive learning rate. Several real and simulated infrared image sequences are utilized to verify the performance of the proposed algorithm. The experiment results indicate that the proposed algorithm can not only reduce the non-uniformity with less ghosting artifacts but also overcome the problems of image blurring in static areas.

  9. Array illumination with minimal non-uniformity based on generalized phase contrast

    Palima, Darwin; Glückstad, Jesper


    The generalized phase contrast method (GPC) has been previously shown to be an efficient technique for generating array illumination and is thus highly suitable for such applications as dynamic multiple beam trapping and optical micromanipulation. However, projected arrays usually exhibit intensity...... roll-offs that may be undesirable for some applications. We show that the uniformity of GPC-generated array illuminations can be improved using intuitive corrections to the input spatial phase modulation, by increasing or decreasing it to respectively raise or lower the intensity of the corresponding...... output spots to improve uniformity. This is combined with matching corrections to the phase shift introduced by the phase contrast filter. Results from numerical experiments show that the array illumination uniformity error improves from over 40% to less than 1% while maintaining the efficiency prior...

  10. Synthesis Study of a 6-Element Non-Uniform Array with Tilted Elements for CLARREO Project

    Jamnejad, Vahraz; Hoorfar, Ahmad


    This paper presents the results of a preliminary study of the gain/pattern properties of a 6-element Radio Occultation (RO) array for the proposed CLARREO (Climate Absolute Radiance and Refractivity Observatory (CLARREO) Project. CLARREO is one of the 4 highest priority missions recommended in the National Research Council Earth Science Decadal Survey.

  11. Hybrid antenna arrays with non-uniform Electromagnetic Band Gap lattices for wireless communication networks

    Mourtzios, Ch.; Siakavara, K.


    A method to design hybrid antenna configurations with very low profile, suitable for smart and Multiple Input-Multiple Output antenna systems is proposed. The antennas are incorporated with novel Electromagnetic Band Gap (EBG) surfaces with non-similar cells. These non-uniform EBG surfaces have been properly designed to cause focusing, of the incident waves, thus enhancing the characteristics of operation of antenna elements positioned in close proximity to the surface and also to increase the isolation between them. Theoretical analysis of the reflection mechanism of this type of lattices as well as the prediction of the resulting performance of the antenna is presented. All these considerations are validated with implementation and simulation of the hybrid structures inside the Universal Mobile Telecommunications System frequency band. The results show that increment of the gain and isolation between the antenna elements can be obtained. Moreover, results for the correlation coefficient between the elements, for Gaussian distribution of the incoming waves have been received and the tolerance of the antennas to the variation of the polarization characteristics of the incoming waves has been investigated. A Genetic Algorithm has been constructed and applied to find the proper geometry of the hybrid antennas in order the correlation coefficient to be minimized and get almost independent from the polarization of incident waves.

  12. Non-Uniform Microstrip Antenna Array for DSRC in Single-Lane Structures

    Tiago Varum


    Full Text Available Vehicular communications have been subject to a great development in recent years, with multiple applications, such as electronic payments, improving the convenience and comfort of drivers. Its communication network is supported by dedicated short range communications (DSRC, a system composed of onboard units (OBU and roadside units (RSU. A recently conceived different set-up for the tolling infrastructures consists of placing them in highway access roads, allowing a number of benefits over common gateway infrastructures, divided into several lanes and using complex systems. This paper presents an antenna array whose characteristics are according to the DSRC standards. Additionally, the array holds an innovative radiation pattern adjusted to the new approach requirements, with an almost uniform wide beamwidth along the road width, negligible side lobes, and operating in a significant bandwidth.

  13. Heat transfer and bubble detachment in subcooled pool boiling from a downward-facing microheater array in a nonuniform electric field.

    Liu, Zan; Herman, Cila; Kim, Jungho


    The effects of a nonuniform electric field on vapor bubble detachment and heat transfer in subcooled pool boiling from a microheater array are investigated. The heater array faced downward to simulate a -1 g gravity condition and to eliminate the dominant masking effect of the buoyancy force. Experiments were conducted at different subcooling levels for various wall temperatures and electric field magnitudes. A dielectric fluid, FC-72, was used as the working fluid at ambient pressure. The array of 3 x 3 independently controlled microheaters was maintained at constant temperature and the rate of heat transfer from each heater was measured. Bubble images were recorded using a high-speed camera. The electric field was applied between the horizontal downward-facing microheater array, which was grounded, and a spherical, off-axis electrode beneath it. Boiling heat transfer results with and without the electric field are presented in this study. In the absence of the nonuniform electric field, compared to the same bulk fluid temperature and wall superheat settings in the +1 g situation, a much larger primary bubble was formed on the heater array, due to the coalescence of the secondary bubbles that nucleated on the heater array. The vapor bubble remained on the heater array surface and no bubble detachment was observed. With the nonuniform electric field applied, bubbles were lifted and sheared off from the heater array surface. The electric field was able to break up the primary bubble into several smaller bubbles--considerably greater heat transfer enhancement was measured than under similar conditions in +1 g.

  14. Nonuniform $(\\mu,\

    Bento, António J G


    We obtain a local stable manifold theorem for perturbations of nonautonomous linear difference equations possessing a very general type of nonuniform dichotomy, possibly with different growth rates in the uniform and nonuniform parts. We note that we consider situations were the classical Lyapunov exponents can be zero. Additionally, we study how the manifolds decay along the orbit of a point as well as the behavior under perturbations and give examples of nonautonomous linear difference equations that admit the dichotomies considered.

  15. SEMICONDUCTOR DEVICES Novel multi-bit non-uniform channel charge trapping memory device with virtual-source NAND flash array

    Haiming, Gu; Liyang, Pan; Peng, Zhu; Dong, Wu; Zhigang, Zhang; Jun, Xu


    In order to overcome the bit-to-bit interference of the traditional multi-level NAND type device, this paper firstly proposes a novel multi-bit non-uniform channel charge trapping memory (NUC-CTM) device with virtual-source NAND-type array architecture, which can effectively restrain the second-bit effect (SBE) and provide 3-bit per cell capability. Owing to the n- buffer region, the SBE induced threshold voltage window shift can be reduced to less than 400 mV and the minimum threshold voltage window between neighboring levels is larger than 750 mV for reliable 3-bit operation. A silicon-rich SiON is also investigated as a trapping layer to improve the retention reliability of the NUC-CTM.

  16. Resistor Array Non-uniformity Test Based on PSF Estimation%基于PSF估计的电阻阵列非均匀性测试

    苏德伦; 廖守亿; 张金生


    电阻阵列的非均匀性是一种固定模式的空间噪声,是影响红外图像质量的主要因素。测试数据的准确性对非均匀性校正效果是至关重要的,全屏测试时辐射能量的扩散是导致测试误差的重要原因。分析了经典图像复原方法的局限性,提出一种新的基于PSF粗估计的迭代测试方法。分析了不同PSF估计误差对新方法收敛速度和测试精度的影响,评估了不同PSF条件下的测试效果。数值仿真结果表明,新的方法计算量更低,收敛速度更快,且能够适应更宽的平滑因子参数范围。新方法可有效地从退化图像中复原电阻阵列的实际非均匀性图像,取得较好的校正效果。%The non-uniformity of resistor array dynamic infrared scene projector is a kind of fixed pattern spatial noise which makes a great impact on the quality of the output infrared image. The accuracy of the test data is vitally important for the non-uniformity correction. The spread of the radiant energy is a main source of error in flood test. The limitation of classical image restoration method was analyzed. A new iterative test method based on PSF rough estimation was presented. The impact of estimation error on convergence speed and test accuracy was analyzed and the method effect under different PSF condition was evaluated. Numerical simulation indicates that the new method has features of reducing calculation complexity, fast convergence speed and adaptability of more widely range of smooth factors. The new method can effectively restore the degraded image to extract the true non-uniformity image and attain good correction result.

  17. Combined Nonuniformity Correction Algorithm of Infrared Focal Plane Arrays%红外焦平面联合非均匀性校正算法

    洪闻青; 杨南生; 王晓东; 苏俊波; 苏兰; 胡志斌


    分别分析了红外焦平面阵列(IRFPA)基于定标的非均匀性校正(NUC)算法和基于场景的NUC算法的优势和问题.在此基础上提出了联合NUC算法,其中利用基于定标的两点校正法来初步消除探测器的非均匀性,然后再采用基于场景的时域高通校正法和新型自适应滤波校正法来抑制探测器非均匀性参数漂移的影响,同时减弱系统噪声对成像质量的破坏.实验结果表明,与两点法、时域高通法以及传统自适应滤波法等具有较大工程应用价值的NUC算法相比,联合NUC算法具有稳定而且性能更为优良的校正效果.%The advantages and disadvantages in nonuniformity correction (NUC) algorithms based on calibration and scene of infrared focal plane arrays (IRFPA) are analysed separately. The combined NUC algorithm is presented.Two-point NUC algorithm based on calibration is adopted to remove the nonuniformity of the detector simply. The influences of detectors' NUC parameters which will change with time are weakened by using the scene-based temporal high-pass filter algorithm and new-style adaptive filter algorithm. The disadvantages for image quality introduced by ynoises are weakened too. The experimental results show that the combined NUC algorithm is more stable and better than some NUC algorithms with great value in project applications, such as two point NUC algorithm, temporal highpass filter NUC algorithm and former adaptive filter NUC algorithm.

  18. 基于非均匀阵列天线的MUSIC算法性能分析%Performance Analysis of MUSIC Algorithm Based on Non-uniform Spaced Linear Arrays

    杨桂芹; 房琪; 胡滢


    在非均匀线阵上应用MUSIC算法进行测向.阵列模型采用最小冗余阵列,排除了测向模糊的影响.本文通过仿真,分析了信噪比、快拍数、阵元数等因素对MUSIC算法的影响,同时表明,非均匀阵列的测向分辨率精度高于均匀阵列的分辨率精度.%MUSIC algorithm is used to estimate the Direction-of-Arrival (DOA) in non-uniform arrays. To achieve unambiguous DOA estimation,the minimum-redundant linear array is applied to the array model. Through the simulation,the influence of SNR,number of snapshots and array elements on MUSIC,is analyzed and the result proves that higher resolution can be achieved in the non-uniform arrays.

  19. Phased array ultrasonic debond testing of non-uniform thickness compound%不等厚复合构件相控阵超声脱粘检测技术仿真研究

    赵霞; 王召巴; 陈友兴


    Due to the special structure, there is no effective testing method for adhesive interface of non-uniform thick-ness metal and nonmetallic compound components. The phased array ultrasonic detection technique using auto-focused mode can provide a new idea. This article describes the ultrasonic phased array technique to realize quality detection of interface bonding. The sound field of ultrasonic phased array transducer is established. Based on it, the possibility of using ultrasonic phased array method to detect component with non-uniform thickness is studied. The simulation results show that it is possible to control the radiation beam focused at every desired point by calculating the time delay. This can ensure the amplitude of reflected signal from the interface is almost same. The results indicate that the technique of applying phased array to ultrasonic detection can be used to detect the interface debond of non-uniform thickness metal and nonmetallic compound structure.%鉴于不等厚复合构件结构的特殊性,采用传统超声检测技术检测此类构件的粘接质量是非常困难的。采用超声相控阵技术实现界面粘接质量的检测。分析研究了不等厚复合构件脱粘检测的特殊性。建立了相控阵超声换能器的辐射声场模型,基于仿真得到的声场,研究了采用超声相控阵技术检测不等厚复合构件界面脱粘的可行性。仿真结果表明,通过控制相控延时,可使检测声束在检测区域内聚焦到任意位置处,保证在厚度变化的界面处回波信号幅度的一致性,可用于此类构件的界面脱粘检测。

  20. Maximum Power Point tracking algorithm based on I-V characteristic of PV array under uniform and non-uniform conditions

    Kouchaki, Alireza; Iman-Eini, H.; Asaei, B.


    This paper presents a new algorithm based on characteristic equation of solar cells to determine the Maximum Power Point (MPP) of PV modules under partially shaded conditions (PSC). To achieve this goal, an analytic condition is introduced to determine uniform or non-uniform atmospheric condition...... to verify the accuracy and validity of the proposed method, different simulations are carried out in MATLAB-Simulink environment for various atmospheric conditions. © 2012 IEEE....

  1. 非均匀噪声稀疏均匀圆阵的二维DOA估计%2-D DOA Estimation for Sparse Uniform Circular Array in Presence of Unknown Nonuniform Noise

    潘捷; 周建江; 汪飞


    Uniform circular arrays (UCAs) are widely used in airborne radar and communication applications. This article addresses the 2-D DOA estimation for sparse UCA in the presence of unknown nonuniform noise. First of all, the beamspace likelihood function for sparse UCA in the nonuniform noise is constructed by means of the modified phase-mode principle.Then, based on an analysis of the beamspace likelihood function of sparse UCA in the nonuniform noise, Burg's inverse iteration algorithm is modified to estimate the noise covariance matrix of the nonuniform noise on the sparse UCA. Finally, by deriving the gradient and the asymptotic Hessian matrix of the likelihood function in the nonuniform noise, the angle parameters are estimated based on the (Modified Variable Projection, MVP) method. The simulation results show that the proposed method has better performance than sparse UCA root-MUSiC and the traditional maximum-likelihood algorithm. This method can deal with coherent sources as well.%针对在机载雷达、通信等领域有着广泛应用的均匀圆阵(UCA),研究了非均匀噪声下稀疏均匀圆阵的二维波达方向(DOA)估计.首先采用改进的相位模式方法构造非均匀噪卢稀疏均匀圆阵的波柬空间似然函数;之后,在分析非均匀噪声稀疏均匀圆阵的波束空间似然函数特点的基础上,修改了Burg的逆迭代算法以适应稀疏均匀圆阵下非均匀噪声自相关矩阵的估计;最后,经过推导非均匀噪声下似然函数的梯度与近似Hessian矩阵,实现了基于修正的变换投影(MVP)方法的非均匀噪声下目标二维DOA估计.仿真结果表明,在非均匀噪声环境下,该方法估计精度优于稀疏均匀圆阵求根MUSIC和传统均匀噪声最大似然估计方法,对于相于信号源亦具有良好的估计性能.

  2. Quality assessment and data handling methods for Affymetrix Gene 1.0 ST arrays with variable RNA integrity

    Viljoen Katie S


    Full Text Available Abstract Background RNA and microarray quality assessment form an integral part of gene expression analysis and, although methods such as the RNA integrity number (RIN algorithm reliably asses RNA integrity, the relevance of RNA integrity in gene expression analysis as well as analysis methods to accommodate the possible effects of degradation requires further investigation. We investigated the relationship between RNA integrity and array quality on the commonly used Affymetrix Gene 1.0 ST array platform using reliable within-array and between-array quality assessment measures. The possibility of a transcript specific bias in the apparent effect of RNA degradation on the measured gene expression signal was evaluated after either excluding quality-flagged arrays or compensation for RNA degradation at different steps in the analysis. Results Using probe-level and inter-array quality metrics to assess 34 Gene 1.0 ST array datasets derived from historical, paired tumour and normal primary colorectal cancer samples, 7 arrays (20.6%, with a mean sample RIN of 3.2 (SD = 0.42, were flagged during array quality assessment while 10 arrays from samples with RINs Conclusions Here, we demonstrate an effective array-quality assessment strategy, which will allow the user to recognize lower quality arrays that can be included in the analysis once appropriate measures are applied to account for known or unknown sources of variation, such as array quality- and batch- effects, by implementing ComBat or Surrogate Variable Analysis. This approach of quality control and analysis will be especially useful for clinical samples with variable and low RNA qualities, with RIN scores ≥ 2.

  3. 基于PM扩散的红外焦平面阵列神经网络非均匀校正算法%Neural Network Non-uniformity Correction for Infrared Focal Plane Array Based on Perona Malik Diffusion

    杨硕; 赵保军; 毛二可; 唐林波


    该文针对红外图像中含有非均匀性噪声和高斯噪声的退化模型,提出了一种基于各向异性(Perona Malik, PM)扩散的神经网络非均匀校正(PM-NN-NUC)算法。建立了关于非均匀校正的极小化模型。通过对新模型的最陡下降方程和偏微分方程的推导,可以看出PM-NN-NUC算法利用了神经网络校正和PM扩散在滤波过程中的相似性,不仅直接用于产生神经网络校正的期望值,还作用于计算迭代步长,而校正系数又反作用于PM的扩散过程,更好地将 PM 扩散和神经网络校正统一地结合在一起。通过对实际含噪红外图像进行实验,证明新模型可抑制非均匀噪声,并防止图像产生退化。%A new Neural Network Non-Uniformity Correction (PM-NN-NUC) algorithm is proposed for InfraRed Focal Plane Array (IRFPA) based on Perona Malik (PM) diffusion for the situation of degradation model both containing fix pattern noise and Gaussian noise in infrared image. A minimize model is established concerning Non-Uniformity Correction (NUC). It can be seen that PM-NN-NUC uses a similarity in the filtering process on Neural Network Non-Uniformity Correction and PM diffusion, and not only generates the expectation directly but also calculates the iterative step. Correction coefficient reacts on PM diffusion process and combines with PM diffusion and Neural Network Non-Uniformity Correction uniformly. The results of real infrared thermal image show that the proposed algorithm eliminates the fixed pattern noise effectively, but also has excellent performance for the image degraded with fade-out.

  4. 基于焦平面归一化响应特性的红外非均匀性校正%Nonuniformity Correction Based on Unified Photoresponse Characteristics of Infrared Focal Plane Arrays

    左超; 陈钱; 顾国华


    The nonuniformity in the infrared focal plane array limits the quality of infrared imaging system. A new nonuniformity correction procedure based on the unified photoresponse characteristics of infrared focal plane arrays and the correction ratio based on the chi-square histogram were presented. The correction output of each detector took both its observed value and the average response of the focal plane array into account. The correction parameters were obtained by establishing the relationship between the difference of the observed value and its ideal response and the average response of the focal plane array. The proposed correction ratio took into account of both spatial and temporal response characteristics of focal plane arrays, thus it gave more reasonable results on the measurement of the degree of nonuniformity. Experimental results show that its performance is better than that of the two-point correction and the quadratic curve fitting correction using the input values, and has excellent correction capability to the pixels with abnormal responses. In addition, the algorithm has the advantages of high correction precision, less correction factors and easy to real-time processing, which enhances its utility value.%红外焦平面阵列的非均匀性噪音是制约红外成像质量的主要因素,非均匀性校正是红外焦平面器件应用的一个关键技术.本文提出了一种基于焦平面归一化响应特性且易于实现的非均匀性校正算法,并基于像元分布的卡方直方图提出一种新的图像非均匀性评估方法,即校正比例.该方法的校正输出考虑了每个像元的观测值与焦平面的响应信号的平均值,校正参量通过将像元的输出与其理想校正结果之间的偏差用焦平面响应的平均值建立联系而计算得到.提出的校正比例兼顾考虑了焦平面响应的时间与空间特性,比现有的图像非均匀性评估方法更能合理衡量焦

  5. MVDR based unambiguous direction finding method for non-uniform sparse array%无方位模糊的非均匀稀疏阵MVDR测向方法

    李倩茹; 宋志杰; 王良; 杨晴


    稀疏阵能够获得更大的阵列孔径,但常规波束形成(Conventional Beam-Forming, CBF)对非均匀稀疏阵测向时会出现方位模糊.提出了一种基于最小方差无畸变响应(Minimal Variance Distortionless Response, MVDR)同局部非稀疏的非均匀稀疏阵(Non-Uniform Sparse Array, NUSA)的设计相结合来抑制方位模糊的方法(NUSA+MVDR),对其无方位模糊现象进行了理论分析,表明 MVDR 这一非线性处理方法对伪峰有很好的抑制能力.针对一种典型的NUSA(Typical NUSA, TNUSA),进行了TNUSA+MVDR数值仿真实验,其结果和理论分析一致,表明:① MVDR有很强的 NUSA 检测能力,在所给仿真条件下,等效阵元间距为 50 倍波长时,仍能很好地抑制方位模糊;② TNUSA+MVDR较阵元数相同的均匀非稀疏阵列的CBF和MVDR有更高的方位分辨力;③阵元数一定, TNUSA+MVDR 方位分辨力随着等效间距增加而提高,最小可分辨角度反比于等效间距;④ 等效间距一定, TNUSA+MVDR 方位分辨力随阵元数增加而增加.海上实验在等效阵元间距为 10 倍波长条件下部分验证了NUSA+MVDR的检测性能.%Sparse array can get large aperture, but it will also lead to azimuth ambiguity if conventional beam-forming (CBF) is used for non-uniform sparse array. In order to solve this problem, the method called NUSA+MVDR is pre-sented, in which minimal variance distortionless response (MVDR) is applied to non-uniform sparse array with local non-sparse element distribution(NUSA), and theoretical analysis indicates that false peaks could be suppressed by this method. For a typical NUSA(TNUSA), numerical simulations are carried out, and the results, which are in good agreement with theoretical analysis, show that: 1. MVDR has great detection performance, as the equivalent element spacing reaches to 50 times of the wavelength under the simulation condition given in this paper, TNUSA+MVDR can still suppress azimuth ambiguity perfectly; 2. Azimuth

  6. A Joint Criterion for Reachability and Observability of Nonuniformly Sampled Discrete Systems

    Fúster-Sabater, Amparo


    A joint characterization of reachability (controllability) and observability (constructibility) for linear SISO nonuniformly sampled discrete systems is presented. The work generalizes to the nonuniform sampling the criterion known for the uniform sampling. Emphasis is on the nonuniform sampling sequence, which is believed to be an additional element for analysis and handling of discrete systems.

  7. Maximum Power Point tracking algorithm based on I-V characteristic of PV array under uniform and non-uniform conditions

    Kouchaki, Alireza; Iman-Eini, H.; Asaei, B.


    quickly. This paper also proposes an effective and quick response technique to find the MPP of PV array among Global Peak (GP) and local peaks when PSC occurs based on the analytic condition. It also can perform in a manner like conventional MPPT method when the insolation conditions are uniform. In order...

  8. 基于衬底温度的红外焦平面联合非均匀性校正%Combined nonuniformity correction algorithm of infrared focal plane arrays based on substrate temperature

    唐艳秋; 孙强; 赵建; 姚凯男


    The advantages and disadvantages in nonuniformity correction (NUC) algorithms based on calibration and scene of infrared focal plane arrays(IRFPA) were analysed separately. The combined NUC algorithm was presented. The thermal imaging system extracted the gain and offset factor from the FLASH which storged beforehand according to the substrate temperature of the IRFPA at the moment of power on. These factor was adopted to remove the nonuniformity of the detector simply. Based on the analysis of the characteristic of residual noise after initial correction, the P-M filter was used to replace the linear spatial average filter in the Neural Network nonuniformity correction algorithm (NN-NUC), which could preserve the image edge. Experimental results show that the proposed algorithm can accelerate the rate of convergence, reduces the correction error largely, and avoids the image degradation caused by the response drift of IRFPA.%分别分析了红外焦平面阵列(IRFPA)基于定标的非均匀性校正法(NUC)和基于场景的NUC算法各自的优势和问题,在此基础上提出了联合非均匀性校正方法。根据上电时刻焦平面衬底的温度值,从FLASH中提取事先存储的对应温度区间的增益和偏置校正参数,初步消除探测器的非均匀性。通过分析初步校正后图像残余非均匀性噪声的特性,提出了用具有保边缘特性的P-M滤波取代传统神经网络算法中的四邻域均值滤波来获得期望图像,从而减小了图像边缘误差。实验结果表明,该算法收敛速度快,校正精度高,有效避免了因红外焦平面响应特性漂移而引起的图像降质。

  9. Nonuniformity correction algorithm for infrared focalplane arrays based on adaptive-filter%基于自适应滤波的红外焦平面阵列非均匀性校正算法

    周慧鑫; 拜丽萍; 秦翰林; 赖睿; 王炳健; 刘群昌


    The performance of nonuniformity correction(NUC) would be deteriorated by time shift in the response of detectors in infrared focal plane arrays(IRFPAs). Therefore, a scene-based NUC algorithm is presented. In this algorithm, an adaptive filter bank is applied to estimate NUC parameters for every detector in IRFPAs. And the parameters are renewed by utilizing current imaging information to reduce the influence imposed by response drift on NUC. For an image with a nonuniformity of 26.12%, nonuniformities after 1 h correction are 3.122% for two-point NUC algorithm, 1.893% for Kalman-filter NUC algorithm and around 1.856% for the presented algorithm, which means the presented algorithm can achieve the best NUC effect steadily.%红外探测器响应漂移特性会降低红外焦平面阵列(IRFPA)非均匀性校正的精度.针对该问题提出了一种基于场景的IRFPA非均匀性校正算法.该算法利用所获得的序列成像场景信息,采用一种基于快速自适应滤波器的最优化递归估计方法来获得非均匀性校正参数,并利用当前的成像信息来更新校正参数,以此降低探测器响应漂移特性对非均匀性校正的影响.算法仿真实验显示,对非线性参数为26.12%的同一图像,使用该算法、两点校正算法和卡尔曼滤波校正算法校正1 h后,可分别将非线性参数降至1.856%,3.122%和1.893%,说明该算法可获得稳定而较好的非均匀性校正效果.

  10. Handling complex source structures in global EM induction studies: from C-responses to new arrays of transfer functions

    Puethe, Christoph; Kuvshinov, Alexey; Olsen, Nils


    approximated by a large-scale symmetric (magnetospheric) ring current, described by a single spherical harmonic. However, there is growing evidence for a more complex structure of this source. In this paper, we investigate the variability of C-responses due to sources different from the dominating large...... functions that relate the components of the magnetic variation to different spherical harmonic coefficients. These transfer functions can handle a complex spatial structure of the magnetospheric source. Compared to C-responses, we observe a significant increase in the coherencies relating input and output...

  11. Handling complex source structures in global EM induction studies: from C-responses to new arrays of transfer functions

    Puethe, Christoph; Kuvshinov, Alexey; Olsen, Nils


    The C-response is a conventional transfer function in global electromagnetic induction research and is traditionally determined from observations of magnetic variations in the vertical and horizontal components. Its interpretation relies on the assumption that the source of the variations is well...... functions that relate the components of the magnetic variation to different spherical harmonic coefficients. These transfer functions can handle a complex spatial structure of the magnetospheric source. Compared to C-responses, we observe a significant increase in the coherencies relating input and output...... quantities of the new transfer functions, especially at high latitudes. This increases the usability of observatory magnetic data for the recovery of global 3-D mantle conductivity structure....

  12. Sequential operation droplet array: an automated microfluidic platform for picoliter-scale liquid handling, analysis, and screening.

    Zhu, Ying; Zhang, Yun-Xia; Cai, Long-Fei; Fang, Qun


    This contribution describes a sequential operation droplet array (SODA) system, a fully automated droplet-based microfluidic system capable of performing picoliter-scale liquid manipulation, analysis, and screening. The SODA system was built using a tapered capillary-syringe pump module and a two-dimensional (2D) oil-covered droplet array installed on an x-y-z translation stage. With the system, we developed a novel picoliter-scale droplet depositing technique for forming a 2D picoliter-droplet array. On this basis, an automated droplet manipulation method with picoliter precision was established using the programmable combination of the capillary-based liquid aspirating-depositing and the moving of the oil-covered droplet array, the so-called "aspirating-depositing-moving" (ADM) method. Differing from the previously reported droplet systems based on microchips, microcapillaries, or digital microfluidics, this method can achieve complete and flexible droplet manipulations, including droplet assembling, generation, indexing, transferring, splitting, and fusion in the picoliter range, endowing the present system with ultralow sample/reagent consumptions and substantial versatility in analysis and screening for multiple different samples. To demonstrate its feasibility and versatility, we applied the SODA system in multiple experiments required in drug screening, including the screening of inhibitors for capases-1 from a chemical library, the measurement of IC50 values for the identified inhibitors, and the screening of the synergistic effect of multiple inhibitors. In the experiments, the consumptions of samples and reagents are only 60-180 pL for each droplet microreactor, which are commonly 3-5 orders of magnitude lower than those of conventional multiwell plate systems, and 1-2 orders of magnitude lower than other droplet-based microfluidic systems for multiple sample screening. The ability of the SODA system in performing complicated and multistep droplet

  13. Non-uniformity Correction of Linear Array Detector Based on FPGA%基于FPGA的线阵探测器非均匀校正的实现

    高文清; 徐世伟; 刘严严; 丁艳艳


      充分利用了FPGA的硬件资源,提出一种采用电路逻辑设计的FPGA来实现两点校正;利用FPGA中的浮点加法器、浮点除法器、浮点乘法器,以及内部RAM、 ROM存储器,可以实时计算校正系数,然后对线阵红外探测器进行非均匀性校正,保证了校正精度。同时,充分利用FPGA并行处理能力强的特点,使系数、图像数据的读取在一个时钟周期内完成%  Based on the FPGA hardware resources, a FPGA in the logic circuit design is presented to achieve the two-point correction. The floating-point adder, floating-point divider, floating-point multiplier and the inter⁃nal RAM, ROM memory in FPGA can be used to calculate the correction factors in real time, and then the non-uni⁃formity correction is completed on the linear array infrared detector, thus the correction accuracy is ensured. At the same time, the coefficient and the reading of image data can be completed in a clock cycle by using the parallel pro⁃cessing ability of the FPGA.

  14. Non-uniform Array Vector-APES Beamforming Algorithm Based on Vector-Hydrophone%基于矢量水听器的非均匀阵列A PES波束形成算法

    张超然; 程锦房; 肖大为


    Since conventional amplitude and phase estimation (APES ) algorithm cannot be applied to a non‐uniform array ,a vector APES(VAPES) based on vector‐hydrophone is proposed .The phase differ‐ence between acoustic pressure and acoustic particle velocity received by vector‐hydrophone is irrelative to the locations of sensors ,thus the pressure and velocity channel can be used as two sub‐arrays ,and ap‐plied to non‐uniform array .The array gain and its stability are analyzed .The simulations indicate that compared to conventional APES algorithm ,the method can be applied to non‐uniform array ,and its array gain is higher ;compared to minimum variance distortionless response (MVDR) algorithm ,the method is more robust ,can handle the coherent situation ,and abtain more accrate signal power .The practical data verifies the validity of VAPES .%针对传统幅度与相位估计(Amplitude and phase estimation ,APES )算法难以应用于非均匀阵列的问题,研究了基于矢量水听器的A PES算法。利用矢量水听器能够同时共点测量声压和质点振速的特点,将矢量水听器的声压和解析振速通道作为两个子阵,两路子阵之间只存在一个相位差,且与阵元位置无关,使得A PES算法能够应用于任意形状的阵列。推导和分析了矢量A PES算法的阵增益及其稳健性。分析和仿真表明:该方法相比于传统A PES算法,具有更高的阵增益,且能适用于非均匀阵列;相比于最小方差无失真响应(Minimum variance distortionless response ,MVDR)算法,具有更好的稳健性,能解决相干问题及能够获得更准确的信号功率,并用实测数据验证了算法的有效性。

  15. Nonuniform Markov models

    Ristad, E S; Ristad, Eric Sven; Thomas, Robert G.


    A statistical language model assigns probability to strings of arbitrary length. Unfortunately, it is not possible to gather reliable statistics on strings of arbitrary length from a finite corpus. Therefore, a statistical language model must decide that each symbol in a string depends on at most a small, finite number of other symbols in the string. In this report we propose a new way to model conditional independence in Markov models. The central feature of our nonuniform Markov model is that it makes predictions of varying lengths using contexts of varying lengths. Experiments on the Wall Street Journal reveal that the nonuniform model performs slightly better than the classic interpolated Markov model. This result is somewhat remarkable because both models contain identical numbers of parameters whose values are estimated in a similar manner. The only difference between the two models is how they combine the statistics of longer and shorter strings. Keywords: nonuniform Markov model, interpolated Markov m...

  16. Kollektiv Handling

    Toubøl, Jonas


    Boganmeldelse af Flemming Ibsen, Laust Høgedahl & Steen Sheuer: Kollektiv Handling. Faglig organisering og skift af fagforening. Nyt fra Samfundsvidenskaberne, Frederiksberg, 2012.......Boganmeldelse af Flemming Ibsen, Laust Høgedahl & Steen Sheuer: Kollektiv Handling. Faglig organisering og skift af fagforening. Nyt fra Samfundsvidenskaberne, Frederiksberg, 2012....

  17. 基于综合孔径辐射计稀疏阵列非均匀采样图像的快速重建%Fast Image Reconstruction for Non-uniform Sampling of Thinned Array of Synthesis Aperture Radiometer

    孙逢林; 张升伟


      某些分时采样干涉式微波辐射计成像系统,通常采用稀疏阵列,如圆环稀疏阵列。由于天线阵列优化设计时天线排布位置受限以及天线物理尺寸等限制,具有非均匀空间频域采样的特点。传统的图像重构方法是将非均匀空间频域点插值到均匀的笛卡尔坐标下,补偿空间频率密度,再进行逆快速傅里叶变换。这些插值方法不可避免地会引入误差或者混叠,并且是以假设空间频域的光滑性为前提的,具有局限性。与传统的插值方法不同的是,该文采用最小最大优化准则,先假设图像,再进行共轭梯度迭代快速非均匀傅里叶变换匹配的算法,绕开了空间频域光滑的假设。模拟实验结果表明此算法能够更加快速精确地重建图像。%Some thinned array, such as circle thinned array, is used by synthetic aperture interferometric radiometer to realize time-shared sampling. The thinned array may take non-uniform sampling of spatial frequencies due to antenna array structure optimization, the limitation of affined area and the physical size of antenna elements as well. In some traditional image reconstruction methods, non-uniform spatial frequency samplings are usually inserted to uniform Cartesian coordinate. And the spatial frequency densities are compensated. However, as the spatial sampling intensity is assumed to be quite smooth, these methods still bring errors and blurring in spite of different interpolation functions. Moreover, iterative methods that adopted straight Fourier transform are time consuming as they applied to non-uniform spatial frequency samplings. In this paper, another fast interactive image reconstruction method is introduced. The kernel of this algorithm is min-max formulation. The specific procedure of this method is as follows: (1)initiating the image; (2)taking non-uniform fast Fourier transform;(3)operating iterative conjugate gradient matched

  18. Sound propagation through nonuniform ducts

    Nayfeh, A. H.


    Methods of determining the transmission and attenuation of sound propagating in nonuniform ducts with and without mean flows are discussed. The approaches reviewed include purely numerical techniques, quasi-one-dimensional approximations, solutions for slowly varying cross sections, solutions for weak wall undulations, approximation of the duct by a series of stepped uniform cross sections, variational methods and solutions for the mode envelopes.

  19. A new nonuniformity correction algorithm for infrared line scanners

    Sui, Jing; Jin, Wei-qi; Dong, Li-quan; Wang, Xia


    Nonuniformity correction (NUC) is a critical task for achieving higher performances in modern infrared imaging systems. The striping fixed pattern noise produced by the scanning-type infrared imaging system can hardly be removed clearly by many scene-based non-uniformity correction methods, which can work effectively for staring focal plane arrays (FPA). We proposed an improved nonuniformity algorithm that corrects the aggregate nonuniformity by two steps for the infrared line scanners (IRLS). The novel contribution in our approach is the integration of local constant statistics (LCS) constraint and neural networks. First, the nonuniformity due to the readout electronics is corrected by treating every row of pixels as one channel and normalizing the channel outputs so that each channel produces pixels with the same mean and standard deviation as median value of the local channels statistics. Second, for IRLS every row is generated by pushbrooming one detector on line sensors, we presume each detector has one neuron with a weight and an offset as correction parameters, which can update column by column recursively at Least Mean Square sense. A one-dimensional median filter is used to produce ideal output of linear neural network and some optimization strategies are added to increase the robustness of learning process. Applications to both simulated and real infrared images demonstrated that this algorithm is self-adaptive and able to complete NUC by only one frames. If the nonuniformity is not so severe then only the first step can obtain a good correction result. Combination of two steps can achieve a higher correction level and remove stripe pattern noise clearly.

  20. Effective electrical conductivity of a nonuniform plasma

    Nichols, L. D.


    A simple nonuniformity model for calculating effective electrical conductivity and Hall parameter is proposed. The model shows that the effective conductivity can be significantly reduced by nonuniformities in the Hall parameter, even if the local conductivity is uniform.



    A necessary condition is given for general nonuniform Gabor frames, which generalizes Benedetto and Walnut's theorem. A sufficient and necessary condition for a class of nonuniform Gabor frames is proved.

  2. Temporal high-pass non-uniformity correction algorithm based on grayscale mapping and hardware implementation

    Jin, Minglei; Jin, Weiqi; Li, Yiyang; Li, Shuo


    In this paper, we propose a novel scene-based non-uniformity correction algorithm for infrared image processing-temporal high-pass non-uniformity correction algorithm based on grayscale mapping (THP and GM). The main sources of non-uniformity are: (1) detector fabrication inaccuracies; (2) non-linearity and variations in the read-out electronics and (3) optical path effects. The non-uniformity will be reduced by non-uniformity correction (NUC) algorithms. The NUC algorithms are often divided into calibration-based non-uniformity correction (CBNUC) algorithms and scene-based non-uniformity correction (SBNUC) algorithms. As non-uniformity drifts temporally, CBNUC algorithms must be repeated by inserting a uniform radiation source which SBNUC algorithms do not need into the view, so the SBNUC algorithm becomes an essential part of infrared imaging system. The SBNUC algorithms' poor robustness often leads two defects: artifacts and over-correction, meanwhile due to complicated calculation process and large storage consumption, hardware implementation of the SBNUC algorithms is difficult, especially in Field Programmable Gate Array (FPGA) platform. The THP and GM algorithm proposed in this paper can eliminate the non-uniformity without causing defects. The hardware implementation of the algorithm only based on FPGA has two advantages: (1) low resources consumption, and (2) small hardware delay: less than 20 lines, it can be transplanted to a variety of infrared detectors equipped with FPGA image processing module, it can reduce the stripe non-uniformity and the ripple non-uniformity.

  3. Handling Metalloproteinases.

    Fridrich, Sven; Karmilin, Konstantin; Stöcker, Walter


    Substrate cleavage by metalloproteinases involves nucleophilic attack on the scissile peptide bond by a water molecule that is polarized by a catalytic metal, usually a zinc ion, and a general base, usually the carboxyl group of a glutamic acid side chain. The zinc ion is most often complexed by imidazole nitrogens of histidine side chains. This arrangement suggests that the physiological pH optimum of most metalloproteinases is in the neutral range. In addition to their catalytic metal ion, many metalloproteinases contain additional transition metal or alkaline earth ions, which are structurally important or modulate the catalytic activity. As a consequence, these enzymes are generally sensitive to metal chelators. Moreover, the catalytic metal can be displaced by adventitious metal ions from buffers or biological fluids, which may fundamentally alter the catalytic function. Therefore, handling, purification, and assaying of metalloproteinases require specific precautions to warrant their stability. Copyright © 2016 John Wiley & Sons, Inc.

  4. EZW coding using nonuniform quantization

    Yin, Che-Yi; Derin, Haluk


    This paper presents an image coder that modifies the EZW coder and provides an improvement in its performance. The subband EZW image coder uses a uniform quantizer with a threshold (deadzone). Whereas, we know that the distribution/histogram of the wavelet tree subband coefficients, all except the lowest subband, tend to be Laplacian. To accommodate for this, we modify the refining procedure in EZW and use a non-uniform quantizer on the coefficients that better fits their distribution. The experimental results show that the new image coder performs better than EZW.

  5. Non-uniform electric field-induced yeast cell electrokinetic behavior

    Flavio Humberto Fernández Morales


    Full Text Available Common dielectrophoresis (c-DEP, i.e. neutral matter motion induced by non-uniform electric fields has become a basic pheno-menon of biochips intended for medical, biological and chemical assays, especially when they imply bioparticle handling. This paper deals with modelling and experimental verification of a castellated, c-DEP-based, microelectrode array intended to handle biological objects. The proposed microsystem was developed employing platinum electrodes patterned by lift-off, silicon micro-machining and photoresin patterning techniques. Saccharomyces cerevisiae were used as test bioparticles for experimental verifi-cation. Yeast cells were repelled toward electrode bays and toward interelectrodic gaps tor frequencies around 20 MHz where there is minimum electric field strength, corresponding to a negative dielectrophoretic phenomenon. Yeast cell agglomerations were observed around electrode edges for frequencies of around 2 MHz where there is maximum electric field strength, thereby verifying the positive dielectrophoretic phenomenon. Bioparticles were separated from the electrode edges when the working fre-quency was reduced and they were dragged towards the electrode centre, remaining there while the frequency was low enough. Such atypical pattern may be explained due to the occurrence of positive dielectrophoresis overlap with electrohydrodynamic effects (i.e. the viscous drag force acting on the particles was greater than the dielectrophoretic force at frequencies where positi-ve dielectrophoresis should occur. The experiments illustrated microsystem convenience in microhandling biological objects, the-reby providing these microarrays’ possible use with other cells. Liquid motion resulting from electrohydrodynamic effects must also be taken into account when designing bioparticle micromanipulators, and could be used as a mechanism for cleaning electrode surfaces.

  6. Tunability of Nonuniform Reflection Holographic Filter

    Shanhong You(游善红); Xinwan Li(李新碗); Jianhong Wu(吴建宏); Zongmin Yin(殷宗敏); Minxue Tang(唐敏学)


    The tunability of nonuniform reflection holographic filter is investigated theoretically and experimentally. It is shown that the reflection holographic filter has not only high optical density and narrow bandwidth, but also good tunability. The coupled wave theoretical model for uniform medium is compared with the model for nonuniform medium. It is identified that the coincidence of the theoretical results of the nonuniform model with the experimental results are better than that of the uniform model.

  7. Non-uniform sediment incipient velocity

    Haitao XU; Jinyou LU; Xiaobin LIU


    Based on the mechanism of non-uniform sediment incipient motion,the dragging force and uplift force coefficient expressions are put forward for the non-uniform bed material exposure and close alignment state.The incipient veiocity formula of the non-uniform sediment is then established.It is shown that the formula structure is reasonable,and fine particles of the non-uniform sediment are more difficult to set into motion than the same sized uniform particles,whereas coarser particles are easier to set into motion than their uniform equivalents.The validity of the formula is verified by field and experiment data.

  8. Face recognition across non-uniform motion blur, illumination, and pose.

    Punnappurath, Abhijith; Rajagopalan, Ambasamudram Narayanan; Taheri, Sima; Chellappa, Rama; Seetharaman, Guna


    Existing methods for performing face recognition in the presence of blur are based on the convolution model and cannot handle non-uniform blurring situations that frequently arise from tilts and rotations in hand-held cameras. In this paper, we propose a methodology for face recognition in the presence of space-varying motion blur comprising of arbitrarily-shaped kernels. We model the blurred face as a convex combination of geometrically transformed instances of the focused gallery face, and show that the set of all images obtained by non-uniformly blurring a given image forms a convex set. We first propose a non-uniform blur-robust algorithm by making use of the assumption of a sparse camera trajectory in the camera motion space to build an energy function with l1 -norm constraint on the camera motion. The framework is then extended to handle illumination variations by exploiting the fact that the set of all images obtained from a face image by non-uniform blurring and changing the illumination forms a bi-convex set. Finally, we propose an elegant extension to also account for variations in pose.

  9. Optimized Local Trigonometric Bases with Nonuniform Partitions

    Qiao Fang LIAN; Yong Ge WANG; Dun Yan YAN


    The authors provide optimized local trigonometric bases with nonuniform partitions which efficiently compress trigonometric functions. Numerical examples demonstrate that in many cases the proposed bases provide better compression than the optimized bases with uniform partitions obtained by Matviyenko.

  10. Terahertz lenses based on nonuniform metasurfaces

    Wang, Zhengbin; Chen, Jinchang; Xue, Manlin


    Nonuniform metasurfaces with varying dielectric thicknesses are introduced to full control the transmitted wavefront. Two-port network model is used to analyze the phase shifts of the transmitted field going through dielectric elements. Then, two terahertz convex lenses are designed by using nonuniform polyimide metasurfaces to realize the required abrupt phase distributions. Full-wave simulations demonstrate their excellent performances in controlling the transmitted waves.

  11. Static Scene Statistical Non-Uniformity Correction


    data set in (a) and the nonuniform set in (b). There are some visible signs of the original source image, or ghosting , that is affecting the accuracy...different ratios of ∆̄KK̄ and thus different degrees of 31 precision over the image. The changing precision manifests itself as the ghosting seen in Figure...nonuniform data set. While there is some residual checkerboard pattern in these images, it should be noted that the amount of error is very small. To

  12. Handling sharps and needles

    ... this page: // Handling sharps and needles To use the sharing features ... Health Administration. OSHA fact sheet: protecting yourself when handling contaminated sharps. Updated January 2011. Available at: www. ...

  13. Waiting on More than 64 Handles


    parameter stuct is comprised of an array of handles with a maximum size of MAX_WAIT_OBJECTS and an integer holding the total quantity. Once all the...GIDEP Operations Center P.O. Box 8000 Corona , CA 91718-8000 UNCLASSIFIED Approved for public release; distribution is unlimited. 4 Patricia Alameda Patricia Alameda Andrew Pskowski

  14. Nonuniform sampling techniques for antenna applications

    Rahmat-Samii, Yahya; Cheung, Rudolf Lap-Tung


    A two-dimensional sampling technique, which can employ irregularly spaced samples (amplitude and phase) in order to generate the complete far-field patterns is presented. The technique implements a matrix inversion algorithm, which depends only on the nonuniform sampled data point locations and with no dependence on the actual field values at these points. A powerful simulation algorithm is presented to allow a real-life simulation of many reflector/feed configurations and to determine the usefulness of the nonuniform sampling technique for the copolar and cross-polar patterns. Additionally, an overlapped window concept and a generalized error simulation model are discussed to identify the stability of the technique for recovering the field data among the nonuniform sampled data. Numerical results are tailored for the pattern reconstruction of a 20-m offset reflector antenna operating at L-band. This reflector is planned to be used in a proposed measurement concept of large antenna aboard the Space Shuttle, whereby it would be almost impractical to accurately control the movement of the Shuttle with respect to the RF source in prescribed directions in order to generate uniform sampled points. Also, application of the nonuniform sampling technique to patterns obtained using near-field measured data is demonstrated. Finally, results of an actual far-field measurement are presented for the construction of patterns of a reflector antenna from a set of nonuniformly distributed measured amplitude and phase data.

  15. Subrandom methods for multidimensional nonuniform sampling.

    Worley, Bradley


    Methods of nonuniform sampling that utilize pseudorandom number sequences to select points from a weighted Nyquist grid are commonplace in biomolecular NMR studies, due to the beneficial incoherence introduced by pseudorandom sampling. However, these methods require the specification of a non-arbitrary seed number in order to initialize a pseudorandom number generator. Because the performance of pseudorandom sampling schedules can substantially vary based on seed number, this can complicate the task of routine data collection. Approaches such as jittered sampling and stochastic gap sampling are effective at reducing random seed dependence of nonuniform sampling schedules, but still require the specification of a seed number. This work formalizes the use of subrandom number sequences in nonuniform sampling as a means of seed-independent sampling, and compares the performance of three subrandom methods to their pseudorandom counterparts using commonly applied schedule performance metrics. Reconstruction results using experimental datasets are also provided to validate claims made using these performance metrics.

  16. Subrandom methods for multidimensional nonuniform sampling

    Worley, Bradley


    Methods of nonuniform sampling that utilize pseudorandom number sequences to select points from a weighted Nyquist grid are commonplace in biomolecular NMR studies, due to the beneficial incoherence introduced by pseudorandom sampling. However, these methods require the specification of a non-arbitrary seed number in order to initialize a pseudorandom number generator. Because the performance of pseudorandom sampling schedules can substantially vary based on seed number, this can complicate the task of routine data collection. Approaches such as jittered sampling and stochastic gap sampling are effective at reducing random seed dependence of nonuniform sampling schedules, but still require the specification of a seed number. This work formalizes the use of subrandom number sequences in nonuniform sampling as a means of seed-independent sampling, and compares the performance of three subrandom methods to their pseudorandom counterparts using commonly applied schedule performance metrics. Reconstruction results using experimental datasets are also provided to validate claims made using these performance metrics.

  17. Single image non-uniformity correction using compressive sensing

    Jian, Xian-zhong; Lu, Rui-zhi; Guo, Qiang; Wang, Gui-pu


    A non-uniformity correction (NUC) method for an infrared focal plane array imaging system was proposed. The algorithm, based on compressive sensing (CS) of single image, overcame the disadvantages of "ghost artifacts" and bulk calculating costs in traditional NUC algorithms. A point-sampling matrix was designed to validate the measurements of CS on the time domain. The measurements were corrected using the midway infrared equalization algorithm, and the missing pixels were solved with the regularized orthogonal matching pursuit algorithm. Experimental results showed that the proposed method can reconstruct the entire image with only 25% pixels. A small difference was found between the correction results using 100% pixels and the reconstruction results using 40% pixels. Evaluation of the proposed method on the basis of the root-mean-square error, peak signal-to-noise ratio, and roughness index (ρ) proved the method to be robust and highly applicable.

  18. Shared aperture array antennas composed of differently sized

    Coman, C.I.


    A novel solution for conceiving wide band (multi-band) array antennas is presented. The solution is based on the concept of interleaving sparse, sub-arrays operating at separate frequencies. Sparse array antennas offer two major advantages, namely: they have non-uniformly distributed elements, with

  19. Nonuniform exponential dichotomies and Lyapunov functions

    Barreira, Luis; Dragičević, Davor; Valls, Claudia


    For the nonautonomous dynamics defined by a sequence of bounded linear operators acting on an arbitrary Hilbert space, we obtain a characterization of the notion of a nonuniform exponential dichotomy in terms of quadratic Lyapunov sequences. We emphasize that, in sharp contrast with previous results, we consider the general case of possibly noninvertible linear operators, thus requiring only the invertibility along the unstable direction. As an application, we give a simple proof of the robustness of a nonuniform exponential dichotomy under sufficiently small linear perturbations.

  20. Generalized nonuniform dichotomies and local stable manifolds

    Bento, António J G


    We establish the existence of local stable manifolds for semiflows generated by nonlinear perturbations of nonautonomous ordinary linear differential equations in Banach spaces, assuming the existence of a general type of nonuniform dichotomy for the evolution operator that contains the nonuniform exponential and polynomial dichotomies as a very particular case. The family of dichotomies considered allow situations for which the classical Lyapunov exponents are zero. Additionally, we give new examples of application of our stable manifold theorem and study the behavior of the dynamics under perturbations.

  1. Robust ASPNET Exception Handling

    Dumond, Lee


    This Wrox Blox will teach you how to unravel the mysteries of exception handling in ASP.NET.   First, you'll get a thorough introduction to structured exception handling in the .NET Framework, learn about the Exception class, the related C# language constructs, and how exceptions propagate up the call stack. Then, you'll delve into a variety of practical topics such as: when, where, and how to properly throw, catch, and handle exceptions in your code; how to employ "defensive programming" techniques to avoid triggering the most common CLR exceptions; adopting exception handling "best practices

  2. Non-uniform sampled scalar diffraction calculation using non-uniform fast Fourier transform

    Shimobaba, Tomoyoshi; Oikawa, Minoru; Okada, Naohisa; Endo, Yutaka; Hirayama, Ryuji; Ito, Tomoyoshi


    Scalar diffraction calculations such as the angular spectrum method (ASM) and Fresnel diffraction, are widely used in the research fields of optics, X-rays, electron beams, and ultrasonics. It is possible to accelerate the calculation using fast Fourier transform (FFT); unfortunately, acceleration of the calculation of non-uniform sampled planes is limited due to the property of the FFT that imposes uniform sampling. In addition, it gives rise to wasteful sampling data if we calculate a plane having locally low and high spatial frequencies. In this paper, we developed non-uniform sampled ASM and Fresnel diffraction to improve the problem using the non-uniform FFT.

  3. Instrumentation for multi-detector arrays

    R K Bhowmik


    The new generation of detector arrays require complex instrumentation and data acquisition system to ensure increased reliability of operation, high degree of integration, software control and faster data handling capability. The main features of some of the existing multi-detector arrays like MSU 4 array, Gammasphere and Eurogam are summarized. The instrumentation for the proposed INGA array in India is discussed.

  4. Numerical Validation of a New Approach to Model Single Junction Low Concentration PV Cells under Non-Uniform Illumination

    Hang Zhou


    Full Text Available This study presents a numerical validation of a new approach to model single junction PV cell under non-uniform illumination for low-concentration solar collectors such as compound parabolic concentrators (CPC. The simulation is achieved by finite element modelling (FEM. To characterize the results, the model is simulated with five different non-uniform illumination profiles. The results indicate that increasing the non-uniformity of concentrated light will introduce more resistive losses and lead to a significant attenuation in the PV cell short-circuit current. The FEM modelling results are then used to validate the array modelling approach, in which a single junction PV cell is considered equivalent to a parallel-connected array of several cell splits. A comparison between the FEM and array modelling approaches shows good agreement. Therefore, the array modelling approach is a fast way to investigate the PV cell performance under non-uniform illumination, while the FEM approach is useful in optimizing design of fingers and bus-bars on a PV.

  5. Radar Doppler Processing with Nonuniform Sampling.

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    Conventional signal processing to estimate radar Doppler frequency often assumes uniform pulse/sample spacing. This is for the convenience of t he processing. More recent performance enhancements in processor capability allow optimally processing nonuniform pulse/sample spacing, thereby overcoming some of the baggage that attends uniform sampling, such as Doppler ambiguity and SNR losses due to sidelobe control measures.

  6. Stone stability under non-uniform flow

    Hoan, N.T.; Booij, R.; Hofland, B.; Stive, M.J.F.; Verhagen, H.J.


    The current research is aimed at finding a dimensionless stability parameter for non-uniform flow in which the effect of turbulence is incorporated. To this end, experiments were carried out in which both the bed response (quantified by a dimensionless entrainment rate) and the flow field (velocity

  7. Nonlinear Boundary Stabilization of Nonuniform Timoshenko Beam

    Qing-xu Yan; Hui-chao Zou; De-xing Feng


    In this paper, the stabilization problem of nonuniform Timoshenko beam by some nonlinear boundary feedback controls is considered. By virtue of nonlinear semigroup theory, energy-perturbed approach and exponential multiplier method, it is shown that the vibration of the beam under the proposed control action decays exponentially or in negative power of time t as t →∞.

  8. Stone Stability in Non-uniform Flow

    Hoan, N.T.; Stive, M.J.F.; Booij, R.; Hofland, B.; Verhagen, H.J.


    This paper presents the results of an experimental study on stone stability under nonuniform turbulent flow, in particular expanding flow. Detailed measurements of both flow and turbulence and the bed stability are described. Than various manners of quantifying the hydraulic loads exerted on the sto

  9. Capacitated Vehicle Routing with Nonuniform Speeds

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath


    is the distance traveled divided by its speed.Our algorithm relies on a new approximate minimum spanning tree construction called Level-Prim, which is related to but different from Light Approximate Shortest-path Trees. We also extend the widely used tour-splitting technique to nonuniform speeds, using ideas from...




    In this paper,we consider the Timoshenko equation of a nonuniform beam,with clamped boundary condition at one end and with feedback controls at the other end.It is proved that the system is backward wellposedness when the feedback controls are weak enough.

  11. Elastic stability of non-uniform columns

    Lee, S. Y.; Kuo, Y. H.


    A simple and efficient method is proposed to investigate the elastic stability of three different tapered columns subjected to uniformly distributed follower forces. The influences of the boundary conditions and taper ratio on critical buckling loads are investigated. The critical buckling loads of columns of rectangular cross section with constant depth and linearly varied width ( T1), constant width and linearly varied depth ( T2) and double taper ( T3) are investigated. Among the three different non-uniform columns considered, taper ratio has the greatest influence on the critical buckling load of column T3 and the lowest influence on that of column T1. The types of instability mechanisms for hinged-hinged and cantilever non-uniform columns are divergence and flutter respectively. However, for clamped-hinged and clamped-clamped non-uniform columns, the type of instability mechanism for column T1 is divergence, while that for columns T2 and T3 is divergence only when the taper ratio of the columns is greater than certain critical values and flutter for the rest value of taper ratio. When the type of instability mechanism changes from divergence to flutter, there is a finite jump for the critical buckling load. The influence of taper ratio on the elastic stability of cantilever column T3 is very sensitive for small values of the taper ratio and there also exist some discontinieties in the critical buckling loads of flutter instability. For a hinged-hinged non-uniform column ( T2 or T3) with a rotational spring at the left end of the column, when the taper ratio is less than the critical value the instability mechanism changes from divergence to flutter as the rotational spring constant is increased. For a clamped-elastically supported non-uniform column, when the taper ratio is greater than the critical value the instability mechanism changes from flutter to divergence as the translational spring constant is increased.

  12. Socialanalyse og handling

    Henriksen, Kirsten; Alminde, Rikke; Stevnsgaard Andersen, Mona

    Social analyse og handling er et redskab beregnet til at inspirere socialarbejdere til at arbejde analytisk, systematisk samt refleksivt med konkrete problemstillinger i socialt arbejde.......Social analyse og handling er et redskab beregnet til at inspirere socialarbejdere til at arbejde analytisk, systematisk samt refleksivt med konkrete problemstillinger i socialt arbejde....

  13. Practices of Handling

    Ræbild, Ulla

    area within fashion research. This paper proposes an understanding of the work process of fashion designers as practices of handling comprising a number of embodied methodologies tied to both spatial and temporal dimensions. The term handling encompasses four meanings. As a verb it is literally...... to touch, pick up, carry, or feel with the hands. Figuratively it is to manage, deal with, direct, train, or control. Additionally, as a noun, a handle is something by which we grasp or open up something. Lastly, handle also has a Nordic root, here meaning to trade, bargain or deal. Together all four...... meanings seem to merge in the fashion design process, thus opening up for an embodied engagement with matter that entails direction giving, organizational management and negotiation. By seeing processes of handling as a key fashion methodological practice, it is possible to divert the discourse away from...

  14. CHR -- Character Handling Routines

    Charles, A. C.; Rees, P. C. T.; Chipperfield, A. J.; Jenness, T.

    This document describes the Character Handling Routine library, CHR, and its use. The CHR library augments the limited character handling facilities provided by the Fortran 77 standard. It offers a range of character handling facilities: from formatting Fortran data types into text strings and the reverse, to higher level functions such as wild card matching, string sorting, paragraph reformatting and justification. The library may be used simply for building text strings for interactive applications or as a basis for more complex text processing applications.

  15. Non-Uniform Tube Representation of Proteins

    Hansen, Mikael Sonne

    Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius...... might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better captures the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  16. Non-uniform tube representation of proteins

    Hansen, Mikael Sonne

    Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius...... might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better capture the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  17. Non-uniform tube representation of proteins

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a proteins $3$d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better capture the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  18. Non-Uniform Tube Representation of Proteins

    Hansen, Mikael Sonne

    might not correctly capture volume exclusion - of crucial importance when trying to understand a protein's 3d-structure. We propose a new reduced model treating the protein as a non-uniform tube with a radius reflecting the positions of atoms. The tube representation is well suited considering X......Treating the full protein structure is often neither computationally nor physically possible. Instead one is forced to consider various reduced models capturing the properties of interest. Previous work have used tubular neighborhoods of the C-alpha backbone. However, assigning a unique radius......-ray crystallographic resolution ~ 3Å while a varying radius accounts for the different sizes of side chains. Such a non-uniform tube better captures the protein geometry and has numerous applications in structural/computational biology from the classification of protein structures to sequence-structure prediction....

  19. Orbital behavior around a nonuniform celestial body

    Rosson, Z.; Hall, F.; Vogel, T.


    To effectively model the orbit around a nonuniform celestial body, detailed information needs to be determined of the perturbations. This research looked at one of the most crucial perturbations: the nonuniform gravitational field of a celestial body. Given an orbiting particle (a satellite), we utilized numerical methods to calculate its orbit in two dimensions around a discretized center mass structure. The gravitational acceleration imposed on the particle due to each mass point sums vectorally as the particle completes each infinitesimal time step of one orbit. There are noticeable effects on the orbit as the conditions of the center mass change. The development of a simulation code allows for the modelling of the orbit about an irregular body with satisfactory accuracy.

  20. Equilibrium bed-concentration of nonuniform sediment


    Knowledge of the equilibrium bed-concentration is vital to mathematical modeling of the river-bed deformation associated with suspended load but previous investigations only dealt with the reference concentration of uniform sediment because of difficulties in observation of the bed-concentration. This work is a first attempt to develop a theoretical formula for the equilibrium bed-concentration of any fraction of nonuniform sediment defined at the bed-surface. The formula is based on a stochastic-mechanistic model for the exchange of nonuniform sediment near the bed, and described as a function of incipient motion probability, non-ceasing probability, pick-up probability, and the ratio of the average single-step continuous motion time to static time. Comparison of bed-concentration calculated from the proposed formula with the measured data showed satisfactory agreement, indicating the present formula can be used for solving the differential equation governing the motion of suspended load.

  1. Research on non-uniform sampling problem when adapting wavenumber algorithm to multiple-receiver synthetic aperture sonar


    The azimuth sampling of multiple-receiver SAS systems is non-uniform,which causes standard wavenumber algorithm(ω—κ) can't be applied to multiple-receiver SAS image reconstruction.To solve the problem,two methods are presented,which can adapt the standardω—κalgorithm to multiple-receiver SAS system.One method named Non-uniform Separate Fourier Transform(NSFFT) converts the Fourier Transform(FT) of the non-uniform samples in azimuth direction into several uniform FTs on the assumption that the sonar array...

  2. Helping Kids Handle Worry

    ... Child What Kids Say About: Handling Stress Anxiety, Fears, and Phobias Community Service: A Family's Guide to Getting Involved ... With Stress Teens Talk About Stress (Video) Anxiety, Fears, and Phobias Childhood Stress How Can I Help My Child ...

  3. Handling Pyrophoric Reagents

    Alnajjar, Mikhail S.; Haynie, Todd O.


    Pyrophoric reagents are extremely hazardous. Special handling techniques are required to prevent contact with air and the resulting fire. This document provides several methods for working with pyrophoric reagents outside of an inert atmosphere.

  4. Single-image-based solution for optics temperature-dependent nonuniformity correction in an uncooled long-wave infrared camera.

    Cao, Yanpeng; Tisse, Christel-Loic


    In this Letter, we propose an efficient and accurate solution to remove temperature-dependent nonuniformity effects introduced by the imaging optics. This single-image-based approach computes optics-related fixed pattern noise (FPN) by fitting the derivatives of correction model to the gradient components, locally computed on an infrared image. A modified bilateral filtering algorithm is applied to local pixel output variations, so that the refined gradients are most likely caused by the nonuniformity associated with optics. The estimated bias field is subtracted from the raw infrared imagery to compensate the intensity variations caused by optics. The proposed method is fundamentally different from the existing nonuniformity correction (NUC) techniques developed for focal plane arrays (FPAs) and provides an essential image processing functionality to achieve completely shutterless NUC for uncooled long-wave infrared (LWIR) imaging systems.

  5. A Multiple Beamforming Network for Unequally Spaced Linear Array Based on CORPS

    Armando Arce


    Full Text Available This paper proposes an alternative and innovative way to design a simpler beamforming network (BFN based on balancing alternated power combiners and dividers, to feed a nonuniformly spaced linear array with Gaussian amplitude and coherent (in-phase signals. Thus, a two-beam design configuration of the feeding network for a nonuniform array with beam steering capability is proposed and analyzed. The nonuniform aperture and the complex inputs of the feeding network are optimized by means of a differential evolution algorithm. In addition, a comparative analysis between a uniform and nonuniform linear array with the proposed feeding network is performed. Simulation results show the advantages and effectiveness of the proposed feeding network exploiting the nonuniformity of the antenna elements, in terms of side lobe level and directivity. Furthermore, research results show an inherent reduction in hardware complexity of the network.

  6. Signal Conditioning For Infrared Staring Arrays

    Helfrich, Richard W.


    Infrared (IR) staring arrays offer significant performance improvements over mechanically scanned systems, if the signals from these focal planes can be conditioned for use by imaging displays or signal processors. IR staring arrays offer the potential for increased sensitivity, wide dynamic range, and short frame time, if the problems associated with the readout of data from these arrays can be solved in an efficient manner. Some of the func-tions included in this signal conditioning are: nonuniformity compensation, local area gain and brightness control, detector integration time control, and multiple frame composition. Nonuniformity compensation and local area gain and brightness control were covered in earlier papers. 1,2,3 This paper deals with integration time control and the resulting multiple frame composition possible with focal plane arrays.


    Groupe ST/HM


    A new EDH document entitled 'Transport/Handling Request' will be in operation as of Monday, 11th February 2002, when the corresponding icon will be accessible from the EDH desktop, together with the application instructions. This EDH form will replace the paper-format transport/handling request form for all activities involving the transport of equipment and materials. However, the paper form will still be used for all vehicle-hire requests. The introduction of the EDH transport/handling request form is accompanied by the establishment of the following time limits for the various services concerned: 24 hours for the removal of office items, 48 hours for the transport of heavy items (of up to 6 metric tons and of standard road width), 5 working days for a crane operation, extra-heavy transport operation or complete removal, 5 working days for all transport operations relating to LHC installation. ST/HM Group, Logistics Section Tel: 72672 - 72202

  8. Non-Equispaced Grid Sampling in Photoacoustics with a Non-Uniform FFT

    Schmid, Julian; Zabihian, Behrooz; Liu, Mengyang; Drexler, Wolfgang; Scherzer, Otmar


    To obtain the initial pressure from the collected data on a planar sensor arrangement in photoacoustic tomography, there exists an exact analytic frequency domain reconstruction formula. An efficient realization of this formula needs to cope with the evaluation of the data's Fourier transform on a non-equispaced mesh. In this paper, we use the non-uniform fast Fourier transform to handle this issue and show its feasibility in 3D experiments with real and synthetic data. This is done in comparison to the standard approach that uses linear, polynomial or nearest neighbor interpolation. Moreover, we investigate the effect and the utility of flexible sensor location to make optimal use of a limited number of sensor points. The computational realization is accomplished by the use of a multi-dimensional non-uniform fast Fourier algorithm, where non-uniform data sampling is performed both in frequency and spatial domain. Examples with synthetic and real data show that both approaches improve image quality.

  9. Advanced Optics Experiments Using Nonuniform Aperture Functions

    Wood, Lowell T


    A method to create instructive, nonuniform aperture functions using spatial frequency filtering is described. The diffraction from a single slit in the Fresnel limit and the interference from a double slit in the Fraunhofer limit are spatially filtered to create electric field distributions across an aperture to produce apodization, inverse apodization or super-resolution, and apertures with phase shifts across their widths. The diffraction effects from these aperture functions are measured and calculated. The excellent agreement between the experimental results and the calculated results makes the experiment ideal for use in an advanced undergraduate or graduate optics laboratory to illustrate experimentally several effects in Fourier optics.

  10. Inwardly rotating spirals in nonuniform excitable media.

    Gao, Xiang; Feng, Xia; Cai, Mei-chun; Li, Bing-wei; Ying, He-ping; Zhang, Hong


    Inwardly rotating spirals (IRSs) have attracted great attention since their observation in an oscillatory reaction-diffusion system. However, IRSs have not yet been reported in planar excitable media. In the present work we investigate rotating waves in a nonuniform excitable medium, consisting of an inner disk part surrounded by an outer ring part with different excitabilities, by numerical simulations of a simple FitzHugh-Nagumo model. Depending on the excitability of the medium as well as the inhomogeneity, we find the occurrence of IRSs, of which the excitation propagates inwardly to the geometrical spiral tip.

  11. Nonuniform Braneworld Stars: AN Exact Solution

    Ovalle, J.

    In this paper the first exact interior solution to Einstein's field equations for a static and nonuniform braneworld star with local and nonlocal bulk terms is presented. It is shown that the bulk Weyl scalar U(r) is always negative inside the stellar distribution, and in consequence it reduces both the effective density and the effective pressure. It is found that the anisotropy generated by bulk gravity effect has an acceptable physical behavior inside the distribution. Using a Reissner-Nördstrom-like exterior solution, the effects of bulk gravity on pressure and density are found through matching conditions.

  12. Scattering characteristics of conducting cylinder coated with nonuniform magnetized ferrite

    Hu Bin-Jie; Edward Yung Kai-Ning; Zhang Jun; Toutain Serge


    An analytical technique, referred to as the scattering matrix method (SMM), is developed to analyse the scattering of a planar wave from a conducting cylinder coated with nonuniform magnetized ferrite. The SMM solution for the nonuniform ferrite coating can be reduced to the expressions for the scattering and penetrated coefficients in four particular cases: nonuniform magnetized ferrite cylinder, uniform magnetized ferrite-coated conducting cylinder, uniform ferrite cylinder as well as homogeneous dielectric-coated conducting cylinder. The resonant condition for the nonuniform ferrite coating is obtained. The distinctive differences in scattering between the nonuniform ferrite coating and the nonuniform dielectric coating are demonstrated. The effects of applied magnetic fields and wave frequencies on the scattering characteristics for two types of the linear profiles are revealed.

  13. Colonic potassium handling

    Sørensen, Mads Vaarby; Matos, Joana E.; Prætorius, Helle


    Homeostatic control of plasma K+ is a necessary physiological function. The daily dietary K+ intake of approximately 100 mmol is excreted predominantly by the distal tubules of the kidney. About 10% of the ingested K+ is excreted via the intestine. K+ handling in both organs is specifically...

  14. Improving coal handling effectiveness

    Walker, S.


    Appropriate coal handling systems are essential for successful coal utilisation. The paper looks at some of the options available, including crushers and hammer mills, wear-resistant liners for chutes and wagons, and dewatering systems. These are individual components within larger systems such as stockyard stacking and reclaiming installations. 5 photos.

  15. Nonquasineutral electron vortices in nonuniform plasmas

    Angus, J. R.; Richardson, A. S.; Swanekamp, S. B.; Schumer, J. W. [Plasma Physics Division, Naval Research Laboratory, Washington, District of Columbia 20375 (United States); Ottinger, P. F. [Engility Corporation, Chantilly, Virginia 20151 (United States)


    Electron vortices are observed in the numerical simulation of current carrying plasmas on fast time scales where the ion motion can be ignored. In plasmas with nonuniform density n, vortices drift in the B × ∇n direction with a speed that is on the order of the Hall speed. This provides a mechanism for magnetic field penetration into a plasma. Here, we consider strong vortices with rotation speeds V{sub ϕ} close to the speed of light c where the vortex size δ is on the order of the magnetic Debye length λ{sub B}=|B|/4πen and the vortex is thus nonquasineutral. Drifting vortices are typically studied using the electron magnetohydrodynamic model (EMHD), which ignores the displacement current and assumes quasineutrality. However, these assumptions are not strictly valid for drifting vortices when δ ≈ λ{sub B}. In this paper, 2D electron vortices in nonuniform plasmas are studied for the first time using a fully electromagnetic, collisionless fluid code. Relatively large amplitude oscillations with periods that correspond to high frequency extraordinary modes are observed in the average drift speed. The drift speed W is calculated by averaging the electron velocity field over the vorticity. Interestingly, the time-averaged W from these simulations matches very well with W from the much simpler EMHD simulations even for strong vortices with order unity charge density separation.

  16. Downsampling Non-Uniformly Sampled Data

    Fredrik Gustafsson


    Full Text Available Decimating a uniformly sampled signal a factor D involves low-pass antialias filtering with normalized cutoff frequency 1/D followed by picking out every Dth sample. Alternatively, decimation can be done in the frequency domain using the fast Fourier transform (FFT algorithm, after zero-padding the signal and truncating the FFT. We outline three approaches to decimate non-uniformly sampled signals, which are all based on interpolation. The interpolation is done in different domains, and the inter-sample behavior does not need to be known. The first one interpolates the signal to a uniformly sampling, after which standard decimation can be applied. The second one interpolates a continuous-time convolution integral, that implements the antialias filter, after which every Dth sample can be picked out. The third frequency domain approach computes an approximate Fourier transform, after which truncation and IFFT give the desired result. Simulations indicate that the second approach is particularly useful. A thorough analysis is therefore performed for this case, using the assumption that the non-uniformly distributed sampling instants are generated by a stochastic process.

  17. The non-uniformity of fossil preservation.

    Holland, Steven M


    The fossil record provides the primary source of data for calibrating the origin of clades. Although minimum ages of clades are given by the oldest preserved fossil, these underestimate the true age, which must be bracketed by probabilistic methods based on multiple fossil occurrences. Although most of these methods assume uniform preservation rates, this assumption is unsupported over geological timescales. On geologically long timescales (more than 10 Myr), the origin and cessation of sedimentary basins, and long-term variations in tectonic subsidence, eustatic sea level and sedimentation rate control the availability of depositional facies that preserve the environments in which species lived. The loss of doomed sediments, those with a low probability of preservation, imparts a secular trend to fossil preservation. As a result, the fossil record is spatially and temporally non-uniform. Models of fossil preservation should reflect this non-uniformity by using empirical estimates of fossil preservation that are spatially and temporally partitioned, or by using indirect proxies of fossil preservation. Geologically, realistic models of preservation will provide substantially more reliable estimates of the origination of clades.This article is part of the themed issue 'Dating species divergences using rocks and clocks'.

  18. Solid waste handling

    Parazin, R.J.


    This study presents estimates of the solid radioactive waste quantities that will be generated in the Separations, Low-Level Waste Vitrification and High-Level Waste Vitrification facilities, collectively called the Tank Waste Remediation System Treatment Complex, over the life of these facilities. This study then considers previous estimates from other 200 Area generators and compares alternative methods of handling (segregation, packaging, assaying, shipping, etc.).

  19. Uranium hexafluoride handling. Proceedings


    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  20. Nonuniform Coverage Control on the Line

    Leonard, Naomi Ehrich


    This paper investigates control laws allowing mobile, autonomous agents to optimally position themselves on the line for distributed sensing in a nonuniform field. We show that a simple static control law, based only on local measurements of the field by each agent, drives the agents to the optimal positions in time which is quadratic in the number of agents. However, we exhibit a dynamic control law which, under slightly stronger assumptions on the capabilities and knowledge of each agent, drives the agents to the optimal positions an order of magnitude faster, namely in time linear in the number of agents. Both algorithms are fully distributed and robust to unpredictable loss and addition of agents.

  1. Non-uniform sampling of NMR relaxation data

    Schwarz-Linnet, Troels; Teilum, Kaare


    The use of non-uniform sampling of NMR spectra may give significant reductions in the data acquisition time. For quantitative experiments such as the measurement of spin relaxation rates, non-uniform sampling is however not widely used as inaccuracies in peak intensities may lead to errors...

  2. Nonuniform exponential unstability of evolution operators in Banach spaces

    Megan, Mihail; Sasu, Adina Luminita; Sasu, Bogdan


    In this paper we consider a nonuniform unsrability concept for evolution operators in Banach spaces. The relationship between this concept and the Perron condition is studied. Generalizations to the nonuniform case of some results of Van Minh, Rabiger and Schnaubelt are obtained. The theory we present here is applicable for general time - varying linear equations in Banach spaces.

  3. The TALE Infill Array

    Bergman, Douglas


    The TALE Infill Array in conjunction with the TALE Tower Detector will provide hybrid coverage of the cosmic ray energy spectrum down to 3x10^16 eV. It will consist of about 100, two square meter scintillators on the surface spaced at 400 m; and 24 buried twelve square meter scintillators. The combination of surface and underground detectors will allow for the determination of the muon content of showers and thus give a handle on cosmic ray composition.

  4. Basics for Handling Food Safely

    ... o a rm ct a s tion Basics for Handling Food Safely Safe steps in food handling, cooking, and storage are essential to prevent foodborne ... and soap for 20 seconds before and after handling food. · Don’t cross-contaminate. Keep raw meat, ...

  5. Students' Strategies for Exception Handling

    Rashkovits, Rami; Lavy, Ilana


    This study discusses and presents various strategies employed by novice programmers concerning exception handling. The main contributions of this paper are as follows: we provide an analysis tool to measure the level of assimilation of exception handling mechanism; we present and analyse strategies to handle exceptions; we present and analyse…

  6. Improvement of brain segmentation accuracy by optimizing non-uniformity correction using N3.

    Zheng, Weili; Chee, Michael W L; Zagorodnov, Vitali


    Smoothly varying and multiplicative intensity variations within MR images that are artifactual, can reduce the accuracy of automated brain segmentation. Fortunately, these can be corrected. Among existing correction approaches, the nonparametric non-uniformity intensity normalization method N3 (Sled, J.G., Zijdenbos, A.P., Evans, A.C., 1998. Nonparametric method for automatic correction of intensity nonuniformity in MRI data. IEEE Trans. Med. Imag. 17, 87-97.) is one of the most frequently used. However, at least one recent study (Boyes, R.G., Gunter, J.L., Frost, C., Janke, A.L., Yeatman, T., Hill, D.L.G., Bernstein, M.A., Thompson, P.M., Weiner, M.W., Schuff, N., Alexander, G.E., Killiany, R.J., DeCarli, C., Jack, C.R., Fox, N.C., 2008. Intensity non-uniformity correction using N3 on 3-T scanners with multichannel phased array coils. NeuroImage 39, 1752-1762.) suggests that its performance on 3 T scanners with multichannel phased-array receiver coils can be improved by optimizing a parameter that controls the smoothness of the estimated bias field. The present study not only confirms this finding, but additionally demonstrates the benefit of reducing the relevant parameter values to 30-50 mm (default value is 200 mm), on white matter surface estimation as well as the measurement of cortical and subcortical structures using FreeSurfer (Martinos Imaging Centre, Boston, MA). This finding can help enhance precision in studies where estimation of cerebral cortex thickness is critical for making inferences.

  7. A hardware Kalman-based offset estimator for nonuniformity correction on IRFPA

    Contreras, Javier; Redlich, Rodolfo; Figueroa, Miguel; Torres, Sergio


    This paper presents a digital hardware filter that estimates the nonuniformity (NU) noise in an Infrared Focal Plane Array (IRFPA) and corrects it in real time. Implementing the algorithm in hardware results in a fast, compact, low-power nonuniformity correction (NUC) system that can be embedded into an intelligent imager at a very low cost. Because it does not use an external reference, our NUC circuit works in real time during normal operation, and can track parameter drift over time. Our NUC system models NU noise as a spatially regular source of additive noise, uses a Kalman filter to estimate the offset in each detector of the array and applies an inverse model to recover the original information captured by the detector. The NUC board uses a low-cost Xilinx Spartan 3E XC3S500E FPGA operating at 75MHz. The NUC circuit consumes 17.3mW of dynamic power and uses only 10% of the logic resources of the FPGA. Despite ignoring the multiplicative effects of nonuniformity, our NUC circuit reaches a Peak Signal-to-Noise Ratio (PSNR) of 35dB in under 50 frames, referenced to two-point calibration using black bodies. This performance lies within 0.35dB of a double-precision Matlab implementation of the algorithm. Without the bandwidth limitations currently imposed by the external RAM that stores the offset estimations, our circuit can correct 320x240-pixel video at up to 1,254 frames per second.

  8. Incorporating Handling Qualities Analysis into Rotorcraft Conceptual Design

    Lawrence, Ben


    This paper describes the initial development of a framework to incorporate handling qualities analyses into a rotorcraft conceptual design process. In particular, the paper describes how rotorcraft conceptual design level data can be used to generate flight dynamics models for handling qualities analyses. Also, methods are described that couple a basic stability augmentation system to the rotorcraft flight dynamics model to extend analysis to beyond that of the bare airframe. A methodology for calculating the handling qualities characteristics of the flight dynamics models and for comparing the results to ADS-33E criteria is described. Preliminary results from the application of the handling qualities analysis for variations in key rotorcraft design parameters of main rotor radius, blade chord, hub stiffness and flap moment of inertia are shown. Varying relationships, with counteracting trends for different handling qualities criteria and different flight speeds are exhibited, with the action of the control system playing a complex part in the outcomes. Overall, the paper demonstrates how a broad array of technical issues across flight dynamics stability and control, simulation and modeling, control law design and handling qualities testing and evaluation had to be confronted to implement even a moderately comprehensive handling qualities analysis of relatively low fidelity models. A key outstanding issue is to how to 'close the loop' with an overall design process, and options for the exploration of how to feedback handling qualities results to a conceptual design process are proposed for future work.

  9. Signal transfer in passive dendrites with nonuniform membrane conductance.

    London, M; Meunier, C; Segev, I


    In recent years it became clear that dendrites possess a host of ion channels that may be distributed nonuniformly over their membrane surface. In cortical pyramids, for example, it was demonstrated that the resting membrane conductance G(m)(x) is higher (the membrane is "leakier") at distal dendritic regions than at more proximal sites. How does this spatial nonuniformity in G(m)(x) affect the input-output function of the neuron? The present study aims at providing basic insights into this question. To this end, we have analytically studied the fundamental effects of membrane non-uniformity in passive cable structures. Keeping the total membrane conductance over a given modeled structure fixed (i.e., a constant number of passive ion channels), the classical case of cables with uniform membrane conductance is contrasted with various nonuniform cases with the following general conclusions. (1) For cylindrical cables with "sealed ends," monotonic increase in G(m)(x) improves voltage transfer from the input location to the soma. The steeper the G(m)(x), the larger the improvement. (2) This effect is further enhanced when the stimulation is distal and consists of a synaptic input rather than a current source. (3) Any nonuniformity in G(m)(x) decreases the electrotonic length, L, of the cylinder. (4) The system time constant tau(0) is larger in the nonuniform case than in the corresponding uniform case. (5) When voltage transients relax with tau(0), the dendritic tree is not isopotential in the nonuniform case, at variance with the uniform case. The effect of membrane nonuniformity on signal transfer in reconstructed dendritic trees and on the I/f relation of the neuron is also considered, and experimental methods for assessing membrane nonuniformity in dendrites are discussed.

  10. Flexural Free Vibrations of Multistep Nonuniform Beams

    Guojin Tan


    Full Text Available This paper presents an exact approach to investigate the flexural free vibrations of multistep nonuniform beams. Firstly, one-step beam with moment of inertia and mass per unit length varying as I(x=α11+βxr+4 and m(x=α21+βxr was studied. By using appropriate transformations, the differential equation for flexural free vibration of one-step beam with variable cross section is reduced to a four-order differential equation with constant coefficients. According to different types of roots for the characteristic equation of four-order differential equation with constant coefficients, two kinds of modal shape functions are obtained, and the general solutions for flexural free vibration of one-step beam with variable cross section are presented. An exact approach to solve the natural frequencies and modal shapes of multistep beam with variable cross section is presented by using transfer matrix method, the exact general solutions of one-step beam, and iterative method. Numerical examples reveal that the calculated frequencies and modal shapes are in good agreement with the finite element method (FEM, which demonstrates the solutions of present method are exact ones.

  11. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    Fu, Wenjie; Guan, Xiaotong; Yan, Yang [THz Research Center, School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)


    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper.

  12. Minimum emittance in storage rings with uniform or nonuniform dipoles

    Chun-xi Wang


    Full Text Available A simple treatment of minimum emittance theory in storage rings is presented, favoring vector and matrix forms for a more concise picture. Both conventional uniform dipoles and nonuniform dipoles with bending radius variation are treated. Simple formulas are given for computing the minimum emittance, optimal lattice parameters, as well as effects of nonoptimal parameters. For nonuniform dipoles, analytical results are obtained for a three-piece sandwich dipole model. Minimization of the effective emittance for light sources is given in detail. Usefulness of gradient and/or nonuniform dipoles for reducing the effective emittance is addressed.

  13. Minimum mean square error method for stripe nonuniformity correction

    Weixian Qian; Qian Chen; Guohua Gu


    @@ Stripe nonuniformity is very typical in line infrared focal plane (IRFPA) and uncooled starring IRFPA.We develop the minimum mean square error (MMSE) method for stripe nonuniformity correction (NUC).The goal of the MMSE method is to determine the optimal NUC parameters for making the corrected image the closest to the ideal image.%Stripe nonuniformity is very typical in line infrared focal plane (IRFPA) and uncooled starring IRFPA.We develop the minimum mean square error (MMSE) method for stripe nonuniformity correction (NUC).The goal of the MMSE method is to determine the optimal NUC parameters for making the corrected image the closest to the ideal image. Moreover, this method can be achieved in one frame, making it more competitive than other scene-based NUC algorithms. We also demonstrate the calibration results of our algorithm using real and virtual infrared image sequences. The experiments verify the positive effect of our algorithm.

  14. Practical Non-Uniform Channelization for Multistandard Base Stations

    Alvaro Palomo Navarro; Rudi Villing; Ronan J. Farrell


    A multistandard software-defined radio base station must perform non-uniform channelization of multiplexed frequency bands. Non-uniform channelization accounts for a significant portion of the digital signal processing workload in the base station receiver and can be difficult to realize in a physical implementation. In non-uniform channelization methods based on generalized DFT filter banks, large prototype filter orders are a significant issue for implementation. In this paper, a multistage filter design is applied to two different non-uniform generalized DFT-based channelizers in order to reduce their filter orders. To evaluate the approach, a TETRA and TEDS base station is used. Experimental results show that the new multistage design reduces both the number of coefficients and operations and leads to a more feasible design and practical physical implementation.

  15. Absolute parametric instability in a nonuniform plane plasma waveguide

    Khaled Hamed El-Shorbagy; Atef Ahmed El-Bendary; Shatha Jameel Monaquel


    The paper reports an analysis of the effect of spatial plasma nonuniformity on absolute parametric instability (API) of electrostatic waves in magnetized plane waveguides subjected to an intense high-frequency (HF) electric field using the separation method. In this case the effect of strong static magnetic field is considered. The problem of strong magnetic field is solved in 1D nonuniform plane plasma waveguide. The equation describing the spatial part of the electric potential is obtained. Also, the growth rates and conditions of the parametric instability for periodic and aperiodic cases are obtained. It is found that the spatial nonuniformity of the plasma exerts a stabilizing effect on the API. It is shown that the growth rates of periodic and aperiodic API in nonuniform plasma are less compared to that of uniform plasma.

  16. Impact of a nonuniform charge distribution on virus assembly

    Li, Siyu; Erdemci-Tandogan, Gonca; Wagner, Jef; van der Schoot, Paul; Zandi, Roya


    Many spherical viruses encapsulate their genomes in protein shells with icosahedral symmetry. This process is spontaneous and driven by electrostatic interactions between positive domains on the virus coat proteins and the negative genomes. We model the effect of the nonuniform icosahedral charge distribution from the protein shell instead using a mean-field theory. We find that this nonuniform charge distribution strongly affects the optimal genome length and that it can explain the experimentally observed phenomenon of overcharging of virus and viruslike particles.

  17. New transport and handling contract

    SC Department


    A new transport and handling contract entered into force on 1.10.2008. As with the previous contract, the user interface is the internal transport/handling request form on EDH: To ensure that you receive the best possible service, we invite you to complete the various fields as accurately as possible and to include a mobile telephone number on which we can reach you. You can follow the progress of your request (schedule, completion) in the EDH request routing information. We remind you that the following deadlines apply: 48 hours for the transport of heavy goods (up to 8 tonnes) or simple handling operations 5 working days for crane operations, transport of extra-heavy goods, complex handling operations and combined transport and handling operations in the tunnel. For all enquiries, the number to contact remains unchanged: 72202. Heavy Handling Section TS-HE-HH 72672 - 160319

  18. Childhood chronic inflammatory demyelinating polyneuropathy with nonuniform pathologic features.

    Luan, Xinghua; Zheng, Riliang; Chen, Bin; Yuan, Yun


    Nonuniform pathologic changes in chronic inflammatory demyelinating polyneuropathy were previously reported only in adult humans. We analyzed the pathologic features of 12 children, aged 2-17 years, with chronic inflammatory demyelinating polyneuropathy. Six patients manifested a preceding illness. Five patients presented a chronic, monophasic course, and seven presented a relapsing-remitting course. Three patients exhibited multiple cranial-nerve involvement. Five of 12 (41.7%) patients presented nonuniform features. Two subtypes of nonuniform lesions were revealed. One exhibited varying myelinated fiber content between nerve fascicles, and one exhibited onion bulbs involving a variable number of fascicles. Macrophages were evident in 11 patients, and the number of CD3-positive T cells in the nonuniform group was greater compared with the uniform group (P = 0.045). Our results demonstrate that childhood chronic inflammatory demyelinating polyneuropathy exhibits pathologically nonuniform features, thus providing more evidence to assist in differential diagnoses of pediatric patients. However, clinical and electrophysiologic features, as well as responses to treatment, were similar in the nonuniform and uniform groups.

  19. Trends in Modern Exception Handling

    Marcin Kuta


    Full Text Available Exception handling is nowadays a necessary component of error proof information systems. The paper presents overview of techniques and models of exception handling, problems connected with them and potential solutions. The aspects of implementation of propagation mechanisms and exception handling, their effect on semantics and general program efficiency are also taken into account. Presented mechanisms were adopted to modern programming languages. Considering design area, formal methods and formal verification of program properties we can notice exception handling mechanisms are weakly present what makes a field for future research.


    Ginns, D.W.


    A means for handling remotely a sample pellet to be irradiated in a nuclear reactor is proposed. It is comprised essentially of an inlet tube extending through the outer shield of the reactor and being inclined so that its outer end is at a higher elevation than its inner end, an outlet tube extending through the outer shield being inclined so that its inner end is at a higher elevation than its outer end, the inner ends of these two tubes being interconnected, and a straight tube extending through the outer shield and into the reactor core between the inlet and outlet tubes and passing through the juncture of said inner ends. A rod-like member is rotatably and slidely operated within the central straight tube and has a receptacle on its inner end for receiving a sample pellet from the inlet tube. The rod member is operated to pick up a sample pellet from the inlet tube, carry the sample pellet into the irradiating position within the core, and return to the receiving position where it is rotated to dump the irradiated pellet into the outlet tube by which it is conveyed by gravity to the outside of the reactor. Stop members are provided in the inlet tube, and electrical operating devices are provided to control the sequence of the operation automatically.

  1. Parallel Handling of Integrity Constraints

    Grefen, P.W.P.J.; Flokstra, Jan; Apers, Peter M.G.


    Integrity constraints form an important part of a data model. Therefore, a complete integrity constraint handling subsystem is considered an important part of any modern DBMS. In implementing an integrity constraint handling subsystem, there are two major problem areas: providing enough functionalit

  2. Assessment of Issue Handling Efficiency

    Luijten, B.; Visser, J.; Zaidman, A.


    We mined the issue database of GNOME to assess how issues are handled. How many issues are submitted and resolved? Does the backlog grow or decrease? How fast are issues resolved? Does issue resolution speed increase or decrease over time? In which subproject are issues handled most efficiently? To

  3. Assessment of Issue Handling Efficiency

    Luijten, B.; Visser, J.; Zaidman, A.


    We mined the issue database of GNOME to assess how issues are handled. How many issues are submitted and resolved? Does the backlog grow or decrease? How fast are issues resolved? Does issue resolution speed increase or decrease over time? In which subproject are issues handled most efficiently? To

  4. Sunflower array antenna for multi-beam satellite applications

    Vigano, M.C.


    Saving space on board, reducing costs and improving the antenna performances are tasks of outmost importance in the field of satellite communication. In this work it is shown how a non-uniformly spaced, direct radiating array designed according to the so called ‘sunflower’ law is able to satisfy str

  5. Imaging of the dynamic magnetic structure in a parallel array of shunted Josephson junctions

    Doderer, T.; Kaplunenko, V. K.; Mygind, Jesper


    is applied to the edge junction of the array. This effect was found to be due to the self-induced magnetic field produced by the edge current. This nonuniform field divides the array into domains each spanning several unit cells and each containing the same number of flux quanta. We report on experimental...

  6. Acetylcholine molecular arrays enable quantum information processing

    Tamulis, Arvydas; Majauskaite, Kristina; Talaikis, Martynas; Zborowski, Krzysztof; Kairys, Visvaldas


    We have found self-assembly of four neurotransmitter acetylcholine (ACh) molecular complexes in a water molecules environment by using geometry optimization with DFT B97d method. These complexes organizes to regular arrays of ACh molecules possessing electronic spins, i.e. quantum information bits. These spin arrays could potentially be controlled by the application of a non-uniform external magnetic field. The proper sequence of resonant electromagnetic pulses would then drive all the spin groups into the 3-spin entangled state and proceed large scale quantum information bits.

  7. Spatial model of the gecko foot hair: functional significance of highly specialized non-uniform geometry

    Filippov, Alexander E.; Gorb, Stanislav N.


    One of the important problems appearing in experimental realizations of artificial adhesives inspired by gecko foot hair is so-called clusterization. If an artificially produced structure is flexible enough to allow efficient contact with natural rough surfaces, after a few attachment–detachment cycles, the fibres of the structure tend to adhere one to another and form clusters. Normally, such clusters are much larger than original fibres and, because they are less flexible, form much worse adhesive contacts especially with the rough surfaces. Main problem here is that the forces responsible for the clusterization are the same intermolecular forces which attract fibres to fractal surface of the substrate. However, arrays of real gecko setae are much less susceptible to this problem. One of the possible reasons for this is that ends of the seta have more sophisticated non-uniformly distributed three-dimensional structure than that of existing artificial systems. In this paper, we simulated three-dimensional spatial geometry of non-uniformly distributed branches of nanofibres of the setal tip numerically, studied its attachment–detachment dynamics and discussed its advantages versus uniformly distributed geometry. PMID:25657843

  8. Nonuniformity correction of infrared cameras by reading radiance temperatures with a spatially nonhomogeneous radiation source

    Gutschwager, Berndt; Hollandt, Jörg


    We present a novel method of nonuniformity correction (NUC) of infrared cameras and focal plane arrays (FPA) in a wide optical spectral range by reading radiance temperatures and by applying a radiation source with an unknown and spatially nonhomogeneous radiance temperature distribution. The benefit of this novel method is that it works with the display and the calculation of radiance temperatures, it can be applied to radiation sources of arbitrary spatial radiance temperature distribution, and it only requires sufficient temporal stability of this distribution during the measurement process. In contrast to this method, an initially presented method described the calculation of NUC correction with the reading of monitored radiance values. Both methods are based on the recording of several (at least three) images of a radiation source and a purposeful row- and line-shift of these sequent images in relation to the first primary image. The mathematical procedure is explained in detail. Its numerical verification with a source of a predefined nonhomogeneous radiance temperature distribution and a thermal imager of a predefined nonuniform FPA responsivity is presented.

  9. Measurements of conductivity nonuniformities and fluctuations in combustion MHD plasmas

    Kowalik, R. M.


    Diagnostics for the characterization of electrical conductivity nonuniformities in combustion magnetohydrodynamic (MHD) plasmas were developed. An initial characterization of nonuniformities in the Stanford M-2 linear generator was obtained and recommendations were made concerning the use of the diagnostics in practical MHD generator configurations. A laser induced fluorescene (LIF) diagnostic for nonintrusive measurements of local conductivity fluctuations was developed. This diagnostic and other line of sight averaged optical nonuniformity diagnostics were successfully demonstrated in several experiments in the Standford M-2 combustion systems. Results were used to characterize the nonuniformities in the M-2 system and to compare and evaluate the diagnostics. Conductivity nonuniformities were found to be predominantly streamers which had relatively long length scales of the order of l m in the axial flow direction. Shortet transverse length scales of the order of 0.1 m were found perpendicular to the flow direction. A combination of LIF and plasma luminosity diagnostics is recommended for future characterizations of conductivity uniformities in combustion MHD plasmas.

  10. Non-uniform sampling of NMR relaxation data

    Linnet, Troels E.; Teilum, Kaare, E-mail: [University of Copenhagen, SBiNLab and the Linderstrøm-Lang Centre for Protein Science, Department of Biology (Denmark)


    The use of non-uniform sampling of NMR spectra may give significant reductions in the data acquisition time. For quantitative experiments such as the measurement of spin relaxation rates, non-uniform sampling is however not widely used as inaccuracies in peak intensities may lead to errors in the extracted dynamic parameters. By systematic reducing the coverage of the Nyquist grid of {sup 15}N Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion datasets for four different proteins and performing a full data analysis of the resulting non-uniform sampled datasets, we have compared the performance of the multi-dimensional decomposition and iterative re-weighted least-squares algorithms in reconstructing spectra with accurate peak intensities. As long as a single fully sampled spectrum is included in a series of otherwise non-uniform sampled two-dimensional spectra, multi-dimensional decomposition reconstructs the non-uniform sampled spectra with high accuracy. For two of the four analyzed datasets, a coverage of only 20 % results in essentially the same results as the fully sampled data. As exemplified by other data, such a low coverage is in general not enough to produce reliable results. We find that a coverage level not compromising the final results can be estimated by recording a single full two-dimensional spectrum and reducing the spectrum quality in silico.

  11. Photovoltaic healing of non-uniformities in semiconductor devices

    Karpov, Victor G.; Roussillon, Yann; Shvydka, Diana; Compaan, Alvin D.; Giolando, Dean M.


    A method of making a photovoltaic device using light energy and a solution to normalize electric potential variations in the device. A semiconductor layer having nonuniformities comprising areas of aberrant electric potential deviating from the electric potential of the top surface of the semiconductor is deposited onto a substrate layer. A solution containing an electrolyte, at least one bonding material, and positive and negative ions is applied over the top surface of the semiconductor. Light energy is applied to generate photovoltage in the semiconductor, causing a redistribution of the ions and the bonding material to the areas of aberrant electric potential. The bonding material selectively bonds to the nonuniformities in a manner such that the electric potential of the nonuniformities is normalized relative to the electric potential of the top surface of the semiconductor layer. A conductive electrode layer is then deposited over the top surface of the semiconductor layer.

  12. LDPC Code Design for Nonuniform Power-Line Channels

    Masoud Ardakani


    Full Text Available We investigate low-density parity-check code design for discrete multitone channels over power lines. Discrete multitone channels are well modeled as nonuniform channels, that is, different bits experience various channel parameters. We propose a coding system for discrete multitone channels that allows for using a single code over a nonuniform channel. The number of code parameters for the proposed system is much greater than the number of code parameters in conventional channel. Therefore, search-based optimization methods are impractical. We first formulate the problem of optimizing the rate of an irregular low-density parity-check code, with guaranteed convergence over a general nonuniform channel, as an iterative linear programming which is significantly more efficient than search-based methods. Then we use this technique for a typical power-line channel. The methodology of this paper is directly applicable to all decoding algorithms for which a density evolution analysis is possible.

  13. LDPC Code Design for Nonuniform Power-Line Channels

    Sanaei Ali


    Full Text Available We investigate low-density parity-check code design for discrete multitone channels over power lines. Discrete multitone channels are well modeled as nonuniform channels, that is, different bits experience various channel parameters. We propose a coding system for discrete multitone channels that allows for using a single code over a nonuniform channel. The number of code parameters for the proposed system is much greater than the number of code parameters in conventional channel. Therefore, search-based optimization methods are impractical. We first formulate the problem of optimizing the rate of an irregular low-density parity-check code, with guaranteed convergence over a general nonuniform channel, as an iterative linear programming which is significantly more efficient than search-based methods. Then we use this technique for a typical power-line channel. The methodology of this paper is directly applicable to all decoding algorithms for which a density evolution analysis is possible.

  14. Modeling and Compensating Temperature-Dependent Non-Uniformity Noise in IR Microbolometer Cameras.

    Wolf, Alejandro; Pezoa, Jorge E; Figueroa, Miguel


    Images rendered by uncooled microbolometer-based infrared (IR) cameras are severely degraded by the spatial non-uniformity (NU) noise. The NU noise imposes a fixed-pattern over the true images, and the intensity of the pattern changes with time due to the temperature instability of such cameras. In this paper, we present a novel model and a compensation algorithm for the spatial NU noise and its temperature-dependent variations. The model separates the NU noise into two components: a constant term, which corresponds to a set of NU parameters determining the spatial structure of the noise, and a dynamic term, which scales linearly with the fluctuations of the temperature surrounding the array of microbolometers. We use a black-body radiator and samples of the temperature surrounding the IR array to offline characterize both the constant and the temperature-dependent NU noise parameters. Next, the temperature-dependent variations are estimated online using both a spatially uniform Hammerstein-Wiener estimator and a pixelwise least mean squares (LMS) estimator. We compensate for the NU noise in IR images from two long-wave IR cameras. Results show an excellent NU correction performance and a root mean square error of less than 0.25 ∘ C, when the array's temperature varies by approximately 15 ∘ C.

  15. Investigation of Nonuniform Dose Voxel Geometry in Monte Carlo Calculations.

    Yuan, Jiankui; Chen, Quan; Brindle, James; Zheng, Yiran; Lo, Simon; Sohn, Jason; Wessels, Barry


    The purpose of this work is to investigate the efficacy of using multi-resolution nonuniform dose voxel geometry in Monte Carlo (MC) simulations. An in-house MC code based on the dose planning method MC code was developed in C++ to accommodate the nonuniform dose voxel geometry package since general purpose MC codes use their own coupled geometry packages. We devised the package in a manner that the entire calculation volume was first divided into a coarse mesh and then the coarse mesh was subdivided into nonuniform voxels with variable voxel sizes based on density difference. We name this approach as multi-resolution subdivision (MRS). It generates larger voxels in small density gradient regions and smaller voxels in large density gradient regions. To take into account the large dose gradients due to the beam penumbra, the nonuniform voxels can be further split using ray tracing starting from the beam edges. The accuracy of the implementation of the algorithm was verified by comparing with the data published by Rogers and Mohan. The discrepancy was found to be 1% to 2%, with a maximum of 3% at the interfaces. Two clinical cases were used to investigate the efficacy of nonuniform voxel geometry in the MC code. Applying our MRS approach, we started with the initial voxel size of 5 × 5 × 3 mm(3), which was further divided into smaller voxels. The smallest voxel size was 1.25 × 1.25 × 3 mm(3). We found that the simulation time per history for the nonuniform voxels is about 30% to 40% faster than the uniform fine voxels (1.25 × 1.25 × 3 mm(3)) while maintaining similar accuracy.

  16. Assessment indices for uniform and non-uniform thermal environments


    Different assessment indices for thermal environments were compared and selected for proper assessment of indoor thermal environments.30 subjects reported their overall thermal sensation,thermal comfort,and thermal acceptability in uniform and non-uniform conditions.The results show that these three assessment indices provide equivalent evaluations in uniform environments.However,overall thermal sensation differs from the other two indices and cannot be used as a proper index for the evaluation of non-uniform environments.The relationship between the percentage and the mean vote for each index is established.

  17. Transverse vibrations of arbitrary non-uniform beams

    郭树起; 杨绍普


    Free and steady state forced transverse vibrations of non-uniform beams are investigated with a proposed method, leading to a series solution. The obtained series is verified to be convergent and linearly independent in a convergence test and by the non-zero value of the corresponding Wronski determinant, respectively. The obtained solution is rigorous, which can be reduced to a classical solution for uniform beams. The proposed method can deal with arbitrary non-uniform Euler-Bernoulli beams in principle, but the methods in terms of special functions or elementary functions can only work in some special cases.

  18. On two-dimensional magnetic reconnection with nonuniform resistivity

    Malyshkin, Leonid M.; Kulsrud, Russell M.


    In this paper, two theoretical approaches for the calculation of the rate of quasi-stationary, two-dimensional magnetic reconnection with nonuniform anomalous resistivity are considered in the framework of incompressible magnetohydrodynamics (MHD). In the first, 'global' equations approach, the MHD equations are approximately solved for a whole reconnection layer, including the upstream and downstream regions and the layer center. In the second, 'local' equations approach, the equations are solved across the reconnection layer, including only the upstream region and the layer center. Both approaches give the same approximate answer for the reconnection rate. Our theoretical model is in agreement with the results of recent simulations of reconnection with spatially nonuniform resistivity.

  19. Longitudinal waves in one dimensional non-uniform waveguides


    Wave approach is used to analyze the longitudinal wave motion in one dimensional non-uniform waveguides.With assumptions of constant wave velocity and no wave conversion,there exist four types of non-uniform rods and corresponding traveling wave solutions are investigated.The obtained results indicate that the kinetic energy is preserved as a constant and the wave amplitude is inversely proportional to square root of the cross-sectional area of the rod.Under certain condition,there exists a cut-off frequ...

  20. Lunar Materials Handling System Project

    National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of lunar soil into and out of process equipment in support of in situ resource utilization...

  1. Tritium handling in vacuum systems

    Gill, J.T. [Monsanto Research Corp., Miamisburg, OH (United States). Mound Facility; Coffin, D.O. [Los Alamos National Lab., NM (United States)


    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  2. Solidex 88: solids handling conference


    Papers are presented under the session headings: BMHB (British Materials Handling Board) - tackling user problems; feeding pneumatic conveying systems - matching the hardware to the product; and solutions to some operational problems.

  3. Lunar Materials Handling System Project

    National Aeronautics and Space Administration — The Lunar Materials Handling System (LMHS) is a method for transfer of bulk materials and products into and out of process equipment in support of lunar and Mars in...

  4. Order Handling in Convergent Environments

    Vrtanoski, Jordan


    The rapid development of IT&T technology had big impact on the traditional telecommunications market, transforming it from monopolistic market to highly competitive high-tech market where new services are required to be created frequently. This paper aims to describe a design approach that puts order management process (as part of enterprise application integration) in function of rapid service creation. In the text we will present a framework for collaborative order handling supporting convergent services. The design splits the order handling processes in convergent environments in three business process groups: order capture, order management and order fulfillment. The paper establishes abstract framework for order handling and provides design guidelines for transaction handling implementation based on the checkpoint and inverse command strategy. The proposed design approach is based in a convergent telecommunication environment. Same principles are applicable in solving problems of collaboration in fun...

  5. Towards integrated microliquid handling systems

    Elwenspoek, M.; Lammerink, T.S.J.; Miyake, R.; Fluitman, J.H.J.


    In this paper we describe components for integrated microliquid handling systems such as fluid injection analysis, and first results of planar integration of components. The components discussed are channels, passive and active valves, actuators for micropumps, micromixers, microflow sensors, optica

  6. Grain Handling and Storage Safety

    Webster, Jill, Ph.D.


    Agricultural Health and Safety Fact Sheet AHS-02 Grain Handling and Storage Safety Jill Webster Ph.D., S. Christian Mariger, Graduate Assistant Agricultural Systems Technology and Education There are several hazards that should be considered when working with grain. Storage structures, handling equipment, and the grain itself have all caused serious injuries and deaths. Storage structures (bins, silos, and granaries), like all confined spaces, have significant hazards associated with them. Be...

  7. Civilsamfundets ABC: H for Handling

    Lund, Anker Brink; Meyer, Gitte


    Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til H for Handling.......Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til H for Handling....

  8. [Ergonomic analysis of the handle of manual instruments for dental hygiene].

    Migliario, Mario; Franchignoni, Marco; Soldati, Libero; Melle, Andrea; Carcieri, Paola; Ferriero, Giorgio


    Work-related musculoskeletal disorders of upper limbs are very common among dental hygienists. To minimize the risk of their occurrence, it is essential that attention be paid to proper ergonomics in the workplace, including the selection of instrumentation. At present there are no specific guidelines but only some indications for the selection of the different hand tools. The main purpose of this study was to make a comparative analysis of different types of handles of hand tools used for root planing (Gracey curettes). Nine dental hygienists were interviewed with a questionnaire aimed to assess three different types of curette handle. The results showed that lightness, being of solid steel, having a cylindrical non-uniform shape with full enlarged cross-section, and being silicon coated with non-slip ends are the preferred characteristics for a curette handle. These considerations may assist both manufacturers in designing new hand instruments and clinicians in selecting the most ergonomic ones to buy.

  9. Visible Genotype Sensor Array

    Takashi Imai


    Full Text Available A visible sensor array system for simultaneous multiple SNP genotyping has been developed using a new plastic base with specific surface chemistry. Discrimination of SNP alleles is carried out by an allele-specific extension reaction using immobilized oligonucleotide primers. The 3’-ends of oligonucleotide primers are modified with a locked nucleic acid to enhance their efficiency in allelic discrimination. Biotin-dUTPs included in the reaction mixture are selectively incorporated into extending primer sequences and are utilized as tags for alkaline phosphatase-mediated precipitation of colored chemical substrates onto the surface of the plastic base. The visible precipitates allow immediate inspection of typing results by the naked eye and easy recording by a digital camera equipped on a commercial mobile phone. Up to four individuals can be analyzed on a single sensor array and multiple sensor arrays can be handled in a single operation. All of the reactions can be performed within one hour using conventional laboratory instruments. This visible genotype sensor array is suitable for “focused genomics” that follows “comprehensive genomics”.

  10. Síndrome HaNDL / HaNDL Syndrome / Síndrome HaNDL

    Camilo Ernesto Barros-Gutiérrez, MD., Esp.


    Full Text Available Introducción: El Síndrome HaNDL (Headache and neurologic deficits with cerebroespinal fluid lymphocytosis por sus siglas en inglés, es una patología que cursa con cefalea, focalización neurológica y linfocitosis en el líquido cefalorraquídeo. Objetivo: este artículo busca presentar un caso de Síndrome de HaNDL, puesto que esta condición nosológica implica un reto diagnóstico. Resultados y conclusiones: Se presenta el caso de un paciente con diagnóstico de síndrome de HaNDL los hallazgos al examen físico y del líquido cefalorraquídeo. [Barros-Gutiérrez CE, Silva-Monsalve E, Gualtero-Trujillo S. Síndrome HaNDL. MedUNAB 2015; 17(3: xx-xx]. Introduction: The syndrome of transient Headache and Neurological Deficits with cerebrospinal fluid Lymphocytosis, is a pathology that presents cephalalgia, neurological focalization and lymphocytes in the cerebrospinal fluid. Objective: This article presents a HaNDL Syndrome case, since this nosological condition implies a diagnostic challenge. Results and conclusions: A case of a patient with HaNDL syndrome diagnosis, physical examination findings and cerebrospinal fluid are presented. [Barros-Gutiérrez CE, Silva-Monsalve E, Gualtero-Trujillo S. HaNDL Syndrome. MedUNAB 2015; 17(3: xx-xx]. Introdução: A síndrome de HaNDL (Headache and neurologic déficits with cerebrospinal fluid lymphocytosis por sua sigla em inglês é uma doença que causa dor de cabeça, foco neurológico e linfocitose no líquido cefalorraquidiano. Objetivo: Este artigo tem como objetivo apresentar um caso de Síndrome de HaNDL, uma vez que esta condição nosológica envolve um desafio diagnóstico. Resultados e conclusões: Apresenta-se o caso de um paciente diagnosticado com a síndrome de HaNDL, o encontrado no exame físico e o líquido cefalorraquidiano. [Barros-Gutiérrez CE, Silva-Monsalve E, Gualtero-Trujillo S. Síndrome HaNDL. MedUNAB 2015; 17(3: xx-xx].

  11. Josephson flux-flow oscillators in nonuniform microwave fields

    Salerno, Mario; Samuelsen, Mogens Rugholm


    We present a simple theory for Josephson flux-flow oscillators in the presence of nonuniform microwave fields. In particular we derive an analytical expression for the I-V characteristic of the oscillator from which we show that satellite steps are spaced around the main flux-flow resonance by only...

  12. Non-uniform Euler-Bernoulli beams’ natural frequencies

    Hugo Aya


    Full Text Available This paper has studied the problem of natural frequencies for Euler-Bernoulli beams having non-uniform cross-section. The numerically-obtained solutions were compared to asymptotic solutions obtained by the Wentzel-Kramers-Brillouin (WKB method. It was established that WKB formula precision was higher than 3% for high frequencies (≥ 4 mode.

  13. Experimental data on Stone Stability under non-uniform flow

    Hoan, N.T.


    Previous research (e.g., Jongeling et al 2003; Hofland 2005) has shown that turbulence has an important influence on stone stability and in non-uniform flow it should be modeled explicitly. The dimensionless entrainment rate should be used to describe the bed response because of its complete

  14. Constructal design for a rectangular body with nonuniform heat generation

    Feng, Huijun; Chen, Lingen; Xie, Zhihui; Sun, Fengrui


    Nonuniform heat generation models with constant and variable cross-section high-conductivity channels (HCCs) are built in this paper. The minimum dimensionless peak temperature (DPT) is taken as the optimization objective. Different from the models with uniform heat generation and constant cross-section HCCs built by Bejan (1997) and Ledezma et al. (1997), the model with nonuniform heat generation and variable cross-section HCC is more practical and can help to improve the heat conduction performance of a thermal system. The results show that for the rectangular first-order assembly (RFOA) with nonuniform heat generation, there exist both the optimal shape of the RFOA and the optimal HCCs width ratio, which lead to the minimum DPT. They are different from those with uniform heat generation. When the heat is nonuniformly generated in the RFOA, the minimum DPT of the RFOA with variable cross-section HCC is reduced by 12.11% compared with that with constant cross-section HCC. Moreover, the numerical results are also verified by the analytical method.

  15. Tool handling robot system; Tool handling robot system



    As an example of the delivery of industrial use automation equipment by Meidensha Corp., the paper introduced a tool handling robot system. The system is a tool handling robot of case processing use FMS (flexible manufacturing system). This is a system which exchanges tool automatically according to the From To order from the managing computer using the ceiling running robot between five horizontal type machining centers and more than 800 collective tool stockers. The structure of the system is as follows: tool handling robot (MHR-400), robot controller (meirocs-F), tool hand, robot running unit, tool stocker (for 844 tools), five life tool exchange trucks, tool truck lifting unit, system control panel. (NEDO)

  16. Nonuniform sampling and maximum entropy reconstruction in multidimensional NMR.

    Hoch, Jeffrey C; Maciejewski, Mark W; Mobli, Mehdi; Schuyler, Adam D; Stern, Alan S


    NMR spectroscopy is one of the most powerful and versatile analytic tools available to chemists. The discrete Fourier transform (DFT) played a seminal role in the development of modern NMR, including the multidimensional methods that are essential for characterizing complex biomolecules. However, it suffers from well-known limitations: chiefly the difficulty in obtaining high-resolution spectral estimates from short data records. Because the time required to perform an experiment is proportional to the number of data samples, this problem imposes a sampling burden for multidimensional NMR experiments. At high magnetic field, where spectral dispersion is greatest, the problem becomes particularly acute. Consequently multidimensional NMR experiments that rely on the DFT must either sacrifice resolution in order to be completed in reasonable time or use inordinate amounts of time to achieve the potential resolution afforded by high-field magnets. Maximum entropy (MaxEnt) reconstruction is a non-Fourier method of spectrum analysis that can provide high-resolution spectral estimates from short data records. It can also be used with nonuniformly sampled data sets. Since resolution is substantially determined by the largest evolution time sampled, nonuniform sampling enables high resolution while avoiding the need to uniformly sample at large numbers of evolution times. The Nyquist sampling theorem does not apply to nonuniformly sampled data, and artifacts that occur with the use of nonuniform sampling can be viewed as frequency-aliased signals. Strategies for suppressing nonuniform sampling artifacts include the careful design of the sampling scheme and special methods for computing the spectrum. Researchers now routinely report that they can complete an N-dimensional NMR experiment 3(N-1) times faster (a 3D experiment in one ninth of the time). As a result, high-resolution three- and four-dimensional experiments that were prohibitively time consuming are now practical

  17. Værk som handling

    Jalving, Camilla

    Hvordan kan et kunstværk være en handling? Hvad er performativ billedkunst, og hvad menes der egentlig med ordet ´performativitet´? Det er nogle af de spørgsmål, bogen Værk som handling griber fat i. Mens performativitet i løbet af de sidste ti år er blevet et bredt anvendt begreb i kulturteorien...... mellem værket som objekt og som handling. Bogens værkanalyser orienterer sig derfor både mod, hvad kunstværket er, og hvordan det er: Hvordan virker det, hvordan stiller det sig frem, hvordan producerer det betydning, hvordan skaber det en situation, og ikke mindst hvordan interagerer det med betragteren?...

  18. An exact formulation of k-distribution methods in non-uniform gaseous media and its approximate treatment within the Multi-Spectral framework

    ANDRE, Frédéric; HOU, Longfeng; SOLOVJOV, Vladimir P.


    The main restriction of k-distribution approaches for applications in radiative heat transfer in gaseous media arises from the use of a scaling or correlation assumption to treat non-uniform situations. It is shown that those cases can be handled exactly by using a multidimensional k-distribution that addresses the problem of spectral correlations without using any simplifying assumptions. Nevertheless, the approach cannot be suggested for engineering applications due to its computational cost. Accordingly, a more efficient method, based on the so-called Multi-Spectral Framework, is proposed to approximate the previous exact formulation. The model is assessed against reference LBL calculations and shown to outperform usual k-distribution approaches for radiative heat transfer in non-uniform media.

  19. On the gradient of the Green tensor in two-dimensional elastodynamic problems, and related integrals: Distributional approach and regularization, with application to nonuniformly moving sources

    Pellegrini, Yves-Patrick


    The two-dimensional elastodynamic Green tensor is the primary building block of solutions of linear elasticity problems dealing with nonuniformly moving rectilinear line sources, such as dislocations. Elastodynamic solutions for these problems involve derivatives of this Green tensor, which stand as hypersingular kernels. These objects, well defined as distributions, prove cumbersome to handle in practice. This paper, restricted to isotropic media, examines some of their representations in the framework of distribution theory. A particularly convenient regularization of the Green tensor is introduced, that amounts to considering line sources of finite width. Technically, it is implemented by an analytic continuation of the Green tensor to complex times. It is applied to the computation of regularized forms of certain integrals of tensor character that involve the gradient of the Green tensor. These integrals are fundamental to the computation of the elastodynamic fields in the problem of nonuniformly moving d...

  20. Microfabricated wire arrays for Z-pinch.

    Spahn, Olga Blum; Rowen, Adam M.; Cich, Michael Joseph; Peake, Gregory Merwin; Arrington, Christian L.; Nash, Thomas J.; Klem, John Frederick; Romero, Dustin Heinz


    Microfabrication methods have been applied to the fabrication of wire arrays suitable for use in Z. Self-curling GaAs/AlGaAs supports were fabricated as an initial route to make small wire arrays (4mm diameter). A strain relief structure that could be integrated with the wire was designed to allow displacements of the anode/cathode connections in Z. Electroplated gold wire arrays with integrated anode/cathode bus connections were found to be sufficiently robust to allow direct handling. Platinum and copper plating processes were also investigated. A process to fabricate wire arrays on any substrate with wire thickness up to 35 microns was developed. Methods to handle and mount these arrays were developed. Fabrication of wire arrays of 20mm diameter was demonstrated, and the path to 40mm array fabrication is clear. With some final investment to show array mounting into Z hardware, the entire process to produce a microfabricated wire array will have been demonstrated.

  1. The handling of chemical data

    Lark, P D; Bosworth, R C L


    The Handling of Chemical Data deals with how measurements, such as those arrived at from chemical experimentation, are handled. The book discusses the different kinds of measurements and their specific dimensional characteristics by starting with the origin and presentation of chemical data. The text explains the units, fixed points, and relationships found between scales, the concept of dimensions, the presentation of quantitative data (whether in a tabular or graphical form), and some uses of empirical equations. The book also explains the relationship between two variables, and how equatio

  2. How Retailers Handle Complaint Management

    Hansen, Torben; Wilke, Ricky; Zaichkowsky, Judy


    as to the links between CM and redress of consumers’ complaints. The results suggest that retailers who attach large negative consequences to consumer dissatisfaction are more likely than other retailers to develop a positive strategic view on customer complaining, but at the same time an increase in perceived......This article fills a gap in the literature by providing insight about the handling of complaint management (CM) across a large cross section of retailers in the grocery, furniture, electronic and auto sectors. Determinants of retailers’ CM handling are investigated and insight is gained...... negative consequences of customer dissatisfaction leads to a more negative view on interacting with complaining customers....

  3. Flexible Electrostatic Technologies for Capture and Handling, Phase 1

    Bryan, Thomas


    Fundamental to many of NASA's in-space transportation missions is the capture and handling of various objects and vehicles in various orbits for servicing, debris disposal, sample retrieval, and assembly without the benefit of sufficient grapple fixtures and docking ports. To perform similar material handling tasks on Earth, pincher grippers, suction grippers, or magnetic chucks are used, but are unable to reliably grip aluminum and composite spacecraft, insulation, radiators, solar arrays, or extra-terrestrial objects in the vacuum of outer space without dedicated handles in the right places. The electronic Flexible Electrostatic Technologies for space Capture and Handling (FETCH) will enable reliable and compliant gripping (soft dock) of practically any object in various orbits or surfaces without dedicated mechanical features, very low impact capture, and built-in proximity sensing without any conventional actuators. Originally developed to handle semiconductor and glass wafers during vacuum chamber processing without contamination, the normal rigid wafer handling chucks are replaced with thin metal foil segments laminated in flexible insulation driven by commercial off-the-shelf solid state, high-voltage power supplies. Preliminary testing in NASA Marshall Space Flight Center's (MSFC's) Flat Floor Robotics Lab demonstrated compliant alignment and gripping with a full-sized, 150-lb microsat mockup and translation before a clean release with a flip of a switch. The flexible electrostatic gripper pads can be adapted to various space applications with different sizes, shapes, and foil electrode layouts even with openings through the gripper pads for addition of guidance sensors or injection of permanent adhesives. With gripping forces estimated between 0.5 and 2.5 lb/in2 or 70-300 lb/ft2 of surface contact, the FETCH can turn on and off rapidly and repeatedly to enable sample handling, soft docking, in-space assembly, precision relocation, and surface translation

  4. Assessing materials handling and storage capacities in port terminals

    Dinu, O.; Roşca, E.; Popa, M.; Roşca, M. A.; Rusca, A.


    Terminals constitute the factual interface between different modes and, as a result, buffer stocks are unavoidable whenever transport flows with different discontinuities meet. This is the reason why assessing materials handling and storage capacities is an important issue in the course of attempting to increase operative planning of logistic processes in terminals. Proposed paper starts with a brief review of the compatibilities between different sorts of materials and corresponding transport modes and after, a literature overview of the studies related to ports terminals and their specialization is made. As a methodology, discrete event simulation stands as a feasible technique for assessing handling and storage capacities at the terminal, taking into consideration the multi-flows interaction and the non-uniform arrivals of vessels and inland vehicles. In this context, a simulation model, that integrates the activities of an inland water terminal and describes the essential interactions between the subsystems which influence the terminal capacity, is developed. Different scenarios are simulated for diverse sorts of materials, leading to bottlenecks identification, performance indicators such as average storage occupancy rate, average dwell or transit times estimations, and their evolution is analysed in order to improve the transfer operations in the logistic process

  5. 21 CFR 820.140 - Handling.


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Handling. 820.140 Section 820.140 Food and Drugs... QUALITY SYSTEM REGULATION Handling, Storage, Distribution, and Installation § 820.140 Handling. Each..., contamination, or other adverse effects to product do not occur during handling. ...

  6. 7 CFR 58.443 - Whey handling.


    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Whey handling. 58.443 Section 58.443 Agriculture... Procedures § 58.443 Whey handling. (a) Adequate sanitary facilities shall be provided for the handling of... objectionable odors. (b) Whey or whey products intended for human food shall at all times be handled in a...

  7. Seven Ways to Handle Pressure



    1.Take care of your body.Exercise, eat healthily,and get plenty of sleep.You’ll handle stress much better. 2.Take down your thoughts.Recording your thoughts in a diary will help you choose your feelings and relieve~* stress. 3.Talk about it.If possible,find someone

  8. The Dφ Data Handling System

    V.White; D.Adams; 等


    In this paper we highlight strategies and choices that make the Dφ Data Handling system markedly different from many other experiments' systems,We emphasize how far the Dφ system has come in innovating and implementing a Dφ-specific Data Grid system.We discuss experiences during the first months of detector commissioning and give some future plans for the system.

  9. Handling nu eller skru ned

    Kjærsgaard, Poul Søren


    Søgningen til fremmedsprogstudier er faldende, samtidig med at Region Syddanmark har lanceret en plan, der forudsætter et sprogligt beredskab. Hvis regionen skal klare sig i konkurrencen, må den og det regionale universitet handle, så at der er sproguddannelser. Ellers må regionen og universitetet...

  10. Data Handling and Parameter Estimation

    Sin, Gürkan; Gernaey, Krist


    literature that are mostly based on the ActivatedSludge Model (ASM) framework and their appropriate extensions (Henze et al., 2000).The chapter presents an overview of the most commonly used methods in the estimation of parameters from experimental batch data, namely: (i) data handling and validation, (ii...

  11. At skabe handling og forandring


    ” (Investigation-Vision-Action-Change, på dansk Undersøgelse-Vision-Handling-Forandring). Forskning i anvendelsen af IVAC i pædagogiske udviklingsprojekter i skoler viser, at lærere kan tilpasse IVAC det konkrete sundhedsemne, de beskæftiger sig med, ligesom metoden kan afpasses pensumkravene, klassetrin og...

  12. TNO reticle handling test platform

    Crowcombe, W.E.; Hollemans, C.L.; Fritz, E.C.; Donck, J.C.J. van der; Koster, N.B.


    Particle free handling of EUV reticles is a major concern in industry. For reaching economically feasible yield levels, it is reported that Particle-per-Reticle-Pass (PRP) levels should be better than 0.0001 for particles larger than 18 nm. Such cleanliness levels are yet to be reported for current

  13. Cargo handling know-how

    Bachman, T.; Fischer, M. [Liebherr-Werk Nenzing GmbH (Austria)


    The paper reviews recent bulk handling crane orders from Liebherr. These include mobile harbour cranes at the Port of Dunkirk, a four-rope grab crane at Phu My Port, Vietnam and CBG cranes at Balikpapan Coal Terminal, Indonesia. 4 figs.

  14. Non-Uniform Heat Transfer in Thermal Regenerators

    Jensen, Jesper Buch

    This thesis presents investigations on the heat transfer in complex heat ex- changers in general and in regenerative heat exchangers (regenerators) in par- ticular. The motivation for this work is a result of inconsistencies obeserved in the results from a series of experiments on active magnetic...... regenerators (AMRs) with parallel plates. The results suggest that random variations in the regenerator geometries causes maldistributed fluid flow inside the regener- ators, which affects the regenerator performance. In order to study the heat transfer processes in regenerators with non-uniform geometries......, a numerical model, which simulates a single-blow operation in a parallel-plate regenerator, was developed and used to model the heat transfer under various conditions. In addition to the modeling of the heat transfer, a series of experiments on passive regenerators with non-uniform, but precisely controlled...



    A semi-analytical method in time domain is presented for analysis of the transient response of nonuniform transmission lines. In this method, the telegraph equations in time domain is differenced in space domain first, and is transformed into a set of first-order differential equations of voltage and current with respect to time. By integrating these differential equations with respect to time, and precise computation, the solution of these differential equations can be obtained. This method can solve the transient response of various kinds of transmission lines with arbitrary terminal networks. Particularly, it can analyze the nonuniform lines with initial conditions, for which there is no existing effective method to analyze the time response so far. The results obtained with this method are stable and accurate. Two examples are given to illustrate the application of this method.

  16. Computation of nonuniform transmission lines using the FDTD method

    Miranda, G.C.; Paulino, J.O.S. [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). School of Engineering


    Calculation of lightning overvoltages on transmission lines has been described. Lightning induced overvoltages are of great significance under certain conditions because of the main characteristics of the phenomena. The lightning channel model is one of the most important parameters essential to obtaining the generated electromagnetic fields. In this study, nonuniform transmission line equations were solved using the finite difference method and the leap-frog scheme, the Finite Difference Time Domain (FDTD) method. The subroutine was interfaced with the Electromagnetic Transients Program (EMTP). Two models were used to represent the characteristic impedance of the nonuniform lines used to model the transmission line towers and the lightning main channel. The advantages of the FDTD method was the much smaller code and faster processing time. 35 refs., 5 figs.

  17. X-ray Flashes from Off-axis Nonuniform Jets

    Zhi-Ping Jin; Da-Ming Wei


    It has been widely believed that the outflows in gamma-ray bursts are jetted and some jets may have structures like ∈(θ) ∝θ-κ. We check the possibility that X-ray flashes come from such jets. Both qualitative and quantitative analyses have shown that this model can reproduce most of the observational features of both X-ray flashes and gamma-ray bursts. Using the usual parameters of gamma-ray bursts, we have carried out numerical calculations for both uniform and nonuniform jets, of their fluxes, spectra and peak energies. It seems that nonuniform jets are more appropriate to these observational properties than uniform jets. We have also shown that in our model the observational ratio of gamma-ray bursts to X-ray flashes is about a few units.

  18. Capacitated Vehicle Routing with Non-Uniform Speeds

    Gortz, Inge Li; Nagarajan, Viswanath; Ravi, R


    The capacitated vehicle routing problem (CVRP) involves distributing (identical) items from a depot to a set of demand locations, using a single capacitated vehicle. We study a generalization of this problem to the setting of multiple vehicles having non-uniform speeds (that we call Heterogenous CVRP), and present a constant-factor approximation algorithm. The technical heart of our result lies in achieving a constant approximation to the following TSP variant (called Heterogenous TSP). Given a metric denoting distances between vertices, a depot r containing k vehicles with possibly different speeds, the goal is to find a tour for each vehicle (starting and ending at r), so that every vertex is covered in some tour and the maximum completion time is minimized. This problem is precisely Heterogenous CVRP when vehicles are uncapacitated. The presence of non-uniform speeds introduces difficulties for employing standard tour-splitting techniques. In order to get a better understanding of this technique in our con...

  19. Modified Richardson Number in Non-Uniform Saturated Moist Flow

    YANG Shuai; GAO Shou-Ting


    @@ As a useful index, I.e. The Richardson number Ri, is modified in non-uniform saturated moist flow, based on the fact that liquid water is partially dropped out in parcel air. This is more realistic in real moist atmosphere,especially in the rainfall process. The modified Ri presents adequately the influence of numerator, I.e. Brunt-Vaisala frequency (BVF), on instability. Compared to several former formulae generalized by Durran and Klemp,the modified Ri evidently decreases the stability in rainy regions. In theory, the modified BVF and Ri fix the discontinuity of latent heat release in the transition areas between saturated and unsaturated air by introducing the condensation probability function. Furthermore, the diagnostic analysis of the modilied Ri validates the rationality of its application in the non-uniform saturated moist process.

  20. Binary fish passage models for uniform and nonuniform flows

    Neary, Vincent S [ORNL


    Binary fish passage models are considered by many fisheries managers to be the best 21 available practice for culvert inventory assessments and for fishway and barrier design. 22 Misunderstandings between different binary passage modeling approaches often arise, 23 however, due to differences in terminology, application and presentation. In this paper 24 one-dimensional binary fish passage models are reviewed and refined to clarify their 25 origins and applications. For uniform flow, a simple exhaustion-threshold (ET) model 26 equation is derived that predicts the flow speed threshold in a fishway or velocity barrier 27 that causes exhaustion at a given maximum distance of ascent. Flow speeds at or above 28 the threshold predict failure to pass (exclusion). Flow speeds below the threshold predict 29 passage. The binary ET model is therefore intuitive and easily applied to predict passage 30 or exclusion. It is also shown to be consistent with the distance-maximizing model. The 31 ET model s limitation to uniform flow is addressed by deriving a passage model that 32 accounts for nonuniform flow conditions more commonly found in the field, including 33 backwater profiles and drawdown curves. Comparison of these models with 34 experimental observations of volitional passage for Gambusia affinis in uniform and 35 nonuniform flows indicates reasonable prediction of binary outcomes (passage or 36 exclusion) if the flow speed is not near the threshold flow velocity. More research is 37 needed on fish behavior, passage strategies under nonuniform flow regimes and 38 stochastic methods that account for individual differences in swimming performance at or 39 near the threshold flow speed. Future experiments should track and measure ground 40 speeds of ascending fish to test nonuniform flow passage strategies and to improve model 41 predictions. Stochastic models, such as Monte-Carlo techniques, that account for 42 different passage performance among individuals and allow

  1. On random flights with non-uniformly distributed directions

    De Gregorio, Alessandro


    This paper deals with a new class of random flights $\\underline{\\bf X}_d(t),t>0,$ defined in the real space $\\mathbb{R}^d, d\\geq 2,$ characterized by non-uniform probability distributions on the multidimensional sphere. These random motions differ from similar models appeared in literature which take directions according to the uniform law. The family of angular probability distributions introduced in this paper depends on a parameter $\

  2. Non-uniform plastic deformation of micron scale objects

    Niordson, Christian Frithiof; Hutchinson, J. W.


    Significant increases in apparent flow strength are observed when non-uniform plastic deformation of metals occurs at the scale ranging from roughly one to ten microns. Several basic plane strain problems are analyzed numerically in this paper based on a new formulation of strain gradient plastic...... in the numerical analysis of the higher order gradient theory will be discussed and related to prior formulations having some of the same features....

  3. Using Nonuniform Fiber to Generate Slow Light via SBS

    Wenhai Li


    Full Text Available The data pulse delay based on slow light induced by stimulated Brillouin scattering (SBS in a nonuniform dispersion decreasing fiber (DDF is demonstrated experimentally, and the distortions of data pulses at different beat frequencies are studied. We found that a delay exceeding a pulse width can be achieved at particular beat frequency, and the DDF has larger delay versus gain slope coefficient with much better output pulse quality than single-mode fiber.

  4. Non-Uniform Electromagnetic Fields in the SAMURAI TPC

    Estee, J.; Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Gilbert, J.; Lu, F.; Lynch, W. G.; Shane, R.; Tsang, M. B.; McIntosh, A. B.; Yennello, S. J.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration


    A Time Projection Chamber (TPC) is being developed for the SAMURAI dipole magnet at RIKEN. The main scientific objective for the TPC is to provide constraints on the nuclear symmetry at supra-saturation density. The poster presentation will discuss the design of the TPC field cage and the external electrodes that shape the high electric fields near the cathode. Garfield calculations of the electric field as well as TOSCA calculations of the magnetic field of the SAMURAI dipole will be shown and the impact of the non-uniformity of both fields on electron transport will be discussed. These non-uniformities can introduce components into the electron drift velocity in directions other than the expected vertical direction. This poster presentation will discuss the initial design of a laser calibration system, which will be used to calibrate away the influence of these non-uniformities in the electric and magnetic fields. This work is supported by the DOE under Grant DE-SC0004835.

  5. Forced unraveling of chromatin fibers with nonuniform linker DNA lengths

    Ozer, Gungor; Collepardo-Guevara, Rosana; Schlick, Tamar


    The chromatin fiber undergoes significant structural changes during the cell's life cycle to modulate DNA accessibility. Detailed mechanisms of such structural transformations of chromatin fibers as affected by various internal and external conditions such as the ionic conditions of the medium, the linker DNA length, and the presence of linker histones, constitute an open challenge. Here we utilize Monte Carlo (MC) simulations of a coarse grained model of chromatin with nonuniform linker DNA lengths as found in vivo to help explain some aspects of this challenge. We investigate the unfolding mechanisms of chromatin fibers with alternating linker lengths of 26-62 bp and 44-79 bp using a series of end-to-end stretching trajectories with and without linker histones and compare results to uniform-linker-length fibers. We find that linker histones increase overall resistance of nonuniform fibers and lead to fiber unfolding with superbeads-on-a-string cluster transitions. Chromatin fibers with nonuniform linker DNA lengths display a more complex, multi-step yet smoother process of unfolding compared to their uniform counterparts, likely due to the existence of a more continuous range of nucleosome-nucleosome interactions. This finding echoes the theme that some heterogeneity in fiber component is biologically advantageous.

  6. Continuity of non-uniform recursive subdivision surfaces


    Since Doo-Sabin and Catmull-Clark surfaces were proposed in 1978, eigenstructure, convergence and continuity analyses of stationary subdivision have been performed very well, but it has been very difficult to prove the convergence and continuity of non-uniform recursive subdivision surfaces (NURSSes, for short) of arbitrary topology. In fact, so far a problem whether or not there exists the limit surface as well as G1 continuity of a non-uniform Catmull-Clark subdivision has not been solved yet. Here the concept of equivalent knot spacing is introduced. A new technique for eigenanalysis, convergence and continuity analyses of non-uniform Catmull-Clark surfaces is proposed such that the convergence and G1 continuity of NURSSes at extraordinary points are proved. In addition, slightly improved rules for NURSSes are developed. This offers us one more alternative for modeling free-form surfaces of arbitrary topologies with geometric features such as cusps, sharp edges, creases and darts, while elsewhere maintaining the same order of continuity as B-spline surfaces.

  7. Continuity of non-uniform recursive subdivision surfaces

    秦开怀; 王华维


    Since Doo-Sabin and Catmull-Clark surfaces were proposed in 1978, eigenstructure, convergence and continuity analyses of stationary subdivision have been performed very well, but it has been very difficult to prove the convergence and continuity of non-uniform recursive subdivision surfaces (NURSSes, for short) of arbitrary topology. In fact, so far a problem whether or not there exists the limit surface as well as G1 continuity of a non-uniform Catmull-Clark subdivision has not been solved yet. Here the concept of equivalent knot spacing is introduced. A new technique for eigenanaly-sis, convergence and continuity analyses of non-uniform Catmull-Clark surfaces is proposed such that the convergence and G1 continuity of NURSSes at extraordinary points are proved. In addition, slightly improved rules for NURSSes are developed. This offers us one more alternative for modeling free-form surfaces of arbitrary topologies with geometric features such as cusps, sharp edges, creases and darts, while elsewhere ma

  8. Naturalness preserved enhancement algorithm for non-uniform illumination images.

    Wang, Shuhang; Zheng, Jin; Hu, Hai-Miao; Li, Bo


    Image enhancement plays an important role in image processing and analysis. Among various enhancement algorithms, Retinex-based algorithms can efficiently enhance details and have been widely adopted. Since Retinex-based algorithms regard illumination removal as a default preference and fail to limit the range of reflectance, the naturalness of non-uniform illumination images cannot be effectively preserved. However, naturalness is essential for image enhancement to achieve pleasing perceptual quality. In order to preserve naturalness while enhancing details, we propose an enhancement algorithm for non-uniform illumination images. In general, this paper makes the following three major contributions. First, a lightness-order-error measure is proposed to access naturalness preservation objectively. Second, a bright-pass filter is proposed to decompose an image into reflectance and illumination, which, respectively, determine the details and the naturalness of the image. Third, we propose a bi-log transformation, which is utilized to map the illumination to make a balance between details and naturalness. Experimental results demonstrate that the proposed algorithm can not only enhance the details but also preserve the naturalness for non-uniform illumination images.

  9. Direct Experimental Evidence for Current-Transfer Mode Operation of Nested Tungsten Wire Arrays at 16 19 MA

    Cuneo, M. E.; Sinars, D. B.; Bliss, D. E.; Waisman, E. M.; Porter, J. L.; Stygar, W. A.; Lebedev, S. V.; Chittenden, J. P.; Sarkisov, G. S.; Afeyan, B. B.


    Nested tungsten wire arrays (20-mm on 12-mm diam.) are shown for the first time to operate in a current-transfer mode at 16 19 MA, even for azimuthal interwire gaps of 0.2 mm that are the smallest typically used for any array experiment. After current transfer, the inner wire array shows discrete wire ablation and implosion characteristics identical to that of a single array, such as axially nonuniform ablation, delayed acceleration, and trailing mass and current. The presence of trailing mass from the outer and the inner arrays may play a role in determining nested array performance.

  10. Handling Software Faults with Redundancy

    Carzaniga, Antonio; Gorla, Alessandra; Pezzè, Mauro

    Software engineering methods can increase the dependability of software systems, and yet some faults escape even the most rigorous and methodical development process. Therefore, to guarantee high levels of reliability in the presence of faults, software systems must be designed to reduce the impact of the failures caused by such faults, for example by deploying techniques to detect and compensate for erroneous runtime conditions. In this chapter, we focus on software techniques to handle software faults, and we survey several such techniques developed in the area of fault tolerance and more recently in the area of autonomic computing. Since practically all techniques exploit some form of redundancy, we consider the impact of redundancy on the software architecture, and we propose a taxonomy centered on the nature and use of redundancy in software systems. The primary utility of this taxonomy is to classify and compare techniques to handle software faults.

  11. Enteral Feeding Set Handling Techniques.

    Lyman, Beth; Williams, Maria; Sollazzo, Janet; Hayden, Ashley; Hensley, Pam; Dai, Hongying; Roberts, Cristine


    Enteral nutrition therapy is common practice in pediatric clinical settings. Often patients will receive a pump-assisted bolus feeding over 30 minutes several times per day using the same enteral feeding set (EFS). This study aims to determine the safest and most efficacious way to handle the EFS between feedings. Three EFS handling techniques were compared through simulation for bacterial growth, nursing time, and supply costs: (1) rinsing the EFS with sterile water after each feeding, (2) refrigerating the EFS between feedings, and (3) using a ready-to-hang (RTH) product maintained at room temperature. Cultures were obtained at baseline, hour 12, and hour 21 of the 24-hour cycle. A time-in-motion analysis was conducted and reported in average number of seconds to complete each procedure. Supply costs were inventoried for 1 month comparing the actual usage to our estimated usage. Of 1080 cultures obtained, the overall bacterial growth rate was 8.7%. The rinse and refrigeration techniques displayed similar bacterial growth (11.4% vs 10.3%, P = .63). The RTH technique displayed the least bacterial growth of any method (4.4%, P = .002). The time analysis in minutes showed the rinse method was the most time-consuming (44.8 ± 2.7) vs refrigeration (35.8 ± 2.6) and RTH (31.08 ± 0.6) ( P < .0001). All 3 EFS handling techniques displayed low bacterial growth. RTH was superior in bacterial growth, nursing time, and supply costs. Since not all pediatric formulas are available in RTH, we conclude that refrigerating the EFS between uses is the next most efficacious method for handling the EFS between bolus feeds.

  12. High-resolution microcontact printing and transfer of massive arrays of microorganisms on planar and compartmentalized nanoporous aluminium oxide

    Ingham, C.J.; Bomer, J.; Sprenkels, A.; Berg, van der A.; Vos, de W.M.; Hylckama, van J.


    Handling microorganisms in high throughput and their deployment into miniaturized platforms presents significant challenges. Contact printing can be used to create dense arrays of viable microorganisms. Such "living arrays", potentially with multiple identical replicates, are useful in the selection

  13. High-resolution microcontact printing and transfer of massive arrays of microorganisms on planar and compartmentalized nanoporous aluminium oxide

    Ingham, Colin; Bomer, Johan; Sprenkels, Ad; Berg, van den Albert; Vos, de Willem; Hylckama Vlieg, van Johan


    Handling microorganisms in high throughput and their deployment into miniaturized platforms presents significant challenges. Contact printing can be used to create dense arrays of viable microorganisms. Such "living arrays'', potentially with multiple identical replicates, are useful in the selectio

  14. Orion Entry Handling Qualities Assessments

    Bihari, B.; Tiggers, M.; Strahan, A.; Gonzalez, R.; Sullivan, K.; Stephens, J. P.; Hart, J.; Law, H., III; Bilimoria, K.; Bailey, R.


    The Orion Command Module (CM) is a capsule designed to bring crew back from the International Space Station (ISS), the moon and beyond. The atmospheric entry portion of the flight is deigned to be flown in autopilot mode for nominal situations. However, there exists the possibility for the crew to take over manual control in off-nominal situations. In these instances, the spacecraft must meet specific handling qualities criteria. To address these criteria two separate assessments of the Orion CM s entry Handling Qualities (HQ) were conducted at NASA s Johnson Space Center (JSC) using the Cooper-Harper scale (Cooper & Harper, 1969). These assessments were conducted in the summers of 2008 and 2010 using the Advanced NASA Technology Architecture for Exploration Studies (ANTARES) six degree of freedom, high fidelity Guidance, Navigation, and Control (GN&C) simulation. This paper will address the specifics of the handling qualities criteria, the vehicle configuration, the scenarios flown, the simulation background and setup, crew interfaces and displays, piloting techniques, ratings and crew comments, pre- and post-fight briefings, lessons learned and changes made to improve the overall system performance. The data collection tools, methods, data reduction and output reports will also be discussed. The objective of the 2008 entry HQ assessment was to evaluate the handling qualities of the CM during a lunar skip return. A lunar skip entry case was selected because it was considered the most demanding of all bank control scenarios. Even though skip entry is not planned to be flown manually, it was hypothesized that if a pilot could fly the harder skip entry case, then they could also fly a simpler loads managed or ballistic (constant bank rate command) entry scenario. In addition, with the evaluation set-up of multiple tasks within the entry case, handling qualities ratings collected in the evaluation could be used to assess other scenarios such as the constant bank angle

  15. Two-Dimensional Time-Domain Antenna Arrays for Optimum Steerable Energy Pattern with Low Side Lobes

    Alberto Reyna


    Full Text Available This document presents the synthesis of different two-dimensional time-domain antenna arrays for steerable energy patterns with side lobe levels. The research is focused on the uniform and nonuniform distributions of true-time exciting delays and positions of antenna elements. The uniform square array, random array, uniform concentric ring array, and rotated nonuniform concentric ring array geometries are particularly studied. These geometries are synthesized by using the well-known sequential quadratic programming. The synthesis regards the optimal true-time exciting delays and optimal positions of pulsed antenna elements. The results show the capabilities of the different antenna arrays to steer the beam in their energy pattern in time domain and how their performance is in frequency domain after the synthesis in time domain.

  16. Filter arrays

    Page, Ralph H.; Doty, Patrick F.


    The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

  17. The NOAO KOSMOS Data Handling System

    Seaman, Rob


    KOSMOS and COSMOS are twin high-efficiency imaging spectrographs that have been deployed as NOAO facility instruments for the Mayall 4-meter telescope on Kitt Peak in Arizona and for the Blanco telescope on Cerro Tololo in Chile, respectively. The NOAO Data Handling System (DHS) has seen aggressive use over several years at both the Blanco and Mayall telescopes with NEWFIRM (the NOAO Extremely Wide-Field Infrared Imager) and the Mosaic-1.1 wide-field optical imager. Both of these instruments also rely on the Monsoon array controller and related software, and on instrument-specific versions of the NOAO Observation Control System (NOCS). NOCS, Monsoon and DHS are thus a well-tested software suite that was adopted by the KOSMOS project. This document describes the specifics of the KOSMOS implementation of DHS, in particular in support of the original two-amplifier e2v 2Kx4K CCD detectors with which the instruments were commissioned. The emphasis will be on the general layout of the DHS software components and th...

  18. Tunable nanoparticle arrays at charged interfaces.

    Srivastava, Sunita; Nykypanchuk, Dmytro; Fukuto, Masafumi; Gang, Oleg


    Structurally tunable two-dimensional (2D) arrays of nanoscale objects are important for modulating functional responses of thin films. We demonstrate that such tunable and ordered nanoparticles (NP) arrays can be assembled at charged air-water interfaces from nanoparticles coated with polyelectrolyte chains, DNA. The electrostatic attraction between the negatively charged nonhybridizing DNA-coated gold NPs and a positively charged lipid layer at the interface facilitates the formation of a 2D hexagonally closed packed (HCP) nanoparticle lattice. We observed about 4-fold change of the monolayer nanoparticle density by varying the ionic strength of the subphase. The tunable NP arrays retain their structure reasonably well when transferred to a solid support. The influence of particle's DNA corona and lipid layer composition on the salt-induced in-plane and normal structural evolution of NP arrays was studied in detail using a combination of synchrotron-based in situ surface scattering methods, grazing incidence X-ray scattering (GISAXS), and X-ray reflectivity (XRR). Comparative analysis of the interparticle distances as a function of ionic strength reveals the difference between the studied 2D nanoparticle arrays and analogous bulk polyelectrolyte star polymers systems, typically described by Daoud-Cotton model and power law scaling. The observed behavior of the 2D nanoparticle array manifests a nonuniform deformation of the nanoparticle DNA corona due to its electrostatically induced confinement at the lipid interface. The present study provides insight on the interfacial properties of the NPs coated with charged soft shells.

  19. 7 CFR 1207.307 - Handle.


    ... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE POTATO RESEARCH AND PROMOTION PLAN Potato Research and Promotion Plan Definitions § 1207.307 Handle. Handle means to grade, pack,...

  20. Proper Handling and Storage of Human Milk

    ... Breastfeeding Micronutrient Malnutrition State and Local Programs Proper Handling and Storage of Human Milk Recommend on Facebook ... sure to wash your hands before expressing or handling breast milk. When collecting milk, be sure to ...

  1. 7 CFR 1205.312 - Handle.


    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.312 Handle. Handle means to harvest, gin, warehouse, compress, purchase, market, transport, or otherwise acquire ownership or control of cotton....

  2. HMSRP Hawaiian Monk Seal Handling Data

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains records for all handling and measurement of Hawaiian monk seals since 1981. Live seals are handled and measured during a variety of events...

  3. 7 CFR 983.14 - Handle.


    ... NEW MEXICO Definitions § 983.14 Handle. Handle means to engage in: (a) Receiving pistachios; (b... of interstate or foreign commerce; and/or (d) Placing pistachios into the current of commerce...

  4. Electromechanical effects on multilayered cells in nonuniform rotating fields.

    Sebastián, José Luis; Muñoz, Sagrario; Sancho, Miguel; Martínez, Genoveva; Alvarez, Gabriel


    We use the Maxwell stress tensor to calculate the dielectrophoretic force and electrorotational torque acting on a realistic four-shelled model of the yeast Saccharomyces cerevisiae in a nonuniform rotating electric field generated by four coplanar square electrodes. The comparison of these results with numerical calculations of the dipolar and quadrupolar contributions obtained from an integral equation for the polarization charge density shows the effect of the quadrupole contribution in the proximity of the electrode plane. We also show that under typical experimental conditions the substitution of the multilayered cell by an equivalent cell with homogeneous permittivity underestimates the quadrupole contribution to the force and torque by 1 order of magnitude.

  5. Ionization coefficient approach to modeling breakdown in nonuniform geometries.

    Warne, Larry Kevin; Jorgenson, Roy Eberhardt; Nicolaysen, Scott D.


    This report summarizes the work on breakdown modeling in nonuniform geometries by the ionization coefficient approach. Included are: (1) fits to primary and secondary ionization coefficients used in the modeling; (2) analytical test cases for sphere-to-sphere, wire-to-wire, corner, coaxial, and rod-to-plane geometries; a compilation of experimental data with source references; comparisons between code results, test case results, and experimental data. A simple criterion is proposed to differentiate between corona and spark. The effect of a dielectric surface on avalanche growth is examined by means of Monte Carlo simulations. The presence of a clean dry surface does not appear to enhance growth.


    Zhu Zhenqian; Zhang Zhimin; Wang Yu


    In this paper,a fast algorithm to reconstruct the spectrum of non-uniformly sampled signals is proposed.Compared with the original algorithm,the fast algorithm has a higher computational efficiency,especially when sampling sequence is long.Particularly,a transformation matrix is built,and the reconstructed spectrum is perfectly synthesized from the spectrum of every sampling channel.The fast algorithm has solved efficiency issues of spectrum reconstruction algorithm,and making it possible for the actual application of spectrum reconstruction algorithm in multi-channel Synthetic Aperture Radar (SAR).

  7. Timing-Driven Nonuniform Depopulation-Based Clustering

    Hanyu Liu


    hence improve routability by spreading the logic over the architecture. However, all depopulation-based clustering algorithms to this date increase critical path delay. In this paper, we present a timing-driven nonuniform depopulation-based clustering technique, T-NDPack, that targets critical path delay and channel width constraints simultaneously. T-NDPack adjusts the CLB capacity based on the criticality of the Basic Logic Element (BLE. Results show that T-NDPack reduces minimum channel width by 11.07% while increasing the number of CLBs by 13.28% compared to T-VPack. More importantly, T-NDPack decreases critical path delay by 2.89%.

  8. Nonuniform nuclear structures and QPOs in giant flares

    Sotani, Hajime [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)


    We show that the shear modes in the neutron star crust are quite sensitive to the existence of nonuniform nuclear structures, the so-called 'pasta'. Due to the existence of pasta phase, the frequencies of shear modes are reduced. Since the torsional shear frequencies depend strongly on the structure of pasta phase, through the observations of stellar oscillations, one can probe the pasta structure in the crust. Additionally, considering the effect of pasta phase, we show the possibility to explain all the observed frequencies in the SGR 1806-20 with using only crust torsional oscillations.

  9. Non-uniform impact excitation of a cylindrical bar

    Karp, Baruch; Dorogoy, Avraham; Wang, Zonggang


    An experimental and numerical study of a non-uniform impact excitation of a circular bar is reported. In experiments, nine strikers with different contact area were accelerated against a circular bar. Axial surface strain of the impacted bar was measured at several distances from the impinged end to include the near and the far fields. The same experimental conditions were solved numerically using a commercial finite element code. It was demonstrated that the far-field response is insensitive to both the size and the form of the striker's colliding end. The distance at which such insensitivity is set is estimated to be approximately one and a half bar diameters.

  10. The demagnetizing field of a non-uniform rectangular prism

    Smith, Anders; Nielsen, Kaspar Kirstein; Christensen, Dennis


    is solved by an analytical calculation and the coupling between applied field, the demagnetization tensor field and spatially varying temperature is solved through iteration. We show that the demagnetizing field is of great importance in many cases and that it is necessary to take into account the non......The effect of demagnetization on the magnetic properties of a rectangular ferromagnetic prism under non-uniform conditions is investigated. A numerical model for solving the spatially varying internal magnetic field is developed, validated and applied to relevant cases. The demagnetizing field...

  11. Non-uniform Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state

    Buzdin, A., E-mail: [LOMA, University of Bordeaux, 351 cours de la Liberation, F-33405 Talence (France)


    We provide a general review of the properties of the non-uniform superconducting Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase. Special emphasis is made on the orbital and crystal structure effects which may result in the quantum transitions between the higher Landau level states and should be responsible for the strong modification of the anisotropy of the critical field. The FFLO-type instability may be also expected in ultracold Fermi gases. In these systems it is caused not by the Zeeman interaction but by the tuning of the population imbalance between two lowest hyperfine states of the atoms. We also briefly discuss their properties.

  12. Non-uniform Braneworld Stars: an Exact Solution

    Ovalle, J


    The first exact interior solution to Einstein's field equations for a static and non-uniform braneworld star with local and non-local bulk terms is presented. It is shown that the bulk Weyl scalar ${\\cal U}(r)$ is always negative inside the stellar distribution, in consequence it reduces both the effective density and the effective pressure. It is found that the anisotropy generated by bulk gravity effect has an acceptable physical behaviour inside the distribution. Using a Reissner-N\\"{o}rdstrom-like exterior solution, the effects of bulk gravity on pressure and density are found through matching conditions.

  13. Laser Plasmas : Optical guiding of laser beam in nonuniform plasma

    Tarsem Singh Gill


    A plasma channel produced by a short ionising laser pulse is axially nonuniform resulting from the self-defocusing. Through such preformed plasma channel, when a delayed pulse propagates, the phenomena of diffraction, refraction and self-phase modulation come into play. We have solved the nonlinear parabolic partial differential equation governing the propagation characteristics for an approximate analytical solution using variational approach. Results are compared with the theoretical model of Liu and Tripathi (Phys. Plasmas 1, 3100 (1994)) based on paraxial ray approximation. Particular emphasis is on both beam width and longitudinal phase delay which are crucial to many applications.

  14. MHD-effects in a turbulent medium of nonuniform density

    Vaynshteyn, S.I.


    Turbulence in a medium of nonuniform density, such as the convective solar layer, is analyzed with the assumption that Del rho = rho lambda (exponential stratification). Considered are first the simplest case of a quasi-isotropic turbulence, then addition of a scalar factor such as the temperature, and finally anisotropic turbulence. The magnetic field and MHD-effects are then calculated without diffusion, and with two-dimensional turbulence as a special case. Also the values of the essential parameters in this problem are estimated. 7 references.

  15. Feedstock storage, handling and processing

    Egg, R.P.; Coble, C.G.; Engler, C.R. (Texas A and M Univ., College Station, TX (United States). Dept. of Agricultural Engineering); Lewis, D.H. (Texas A and M Univ., College Station, TX (United States). Dept. of Veterinary Microbiology and Parasitology)


    This paper is a review of the technology and research covering components of a methane from biomass system between the field and the digester. It deals primarily with sorghum as a feedstock and focuses on research conducted by the Texas Agricultural Experiment Station. Subjects included in this paper are harvesting, hay storage, ansiling, materials handling, pumping and hydraulic characteristics, hydraulic conductivity, pressure/density relationship, and biological pretreatment. This paper is not a comprehensive design manual; however, design equations and coefficients for sorghum are presented, where available, along with references describing the development and application of design models. (author)

  16. Logik, mening, handling og tale

    Widell, Peter


    skal ses i relation til sandheds- og meningstilskrivning, sådan som den finder sted ikke i først og fremmest i sproget, men i tanken, sådan som den åbenbarer sig i instrumentelle handling. Det er på baggrund af denne pragmatisering af logikken, talehandlingsbegrebet skal ses: Først og fremmest som den...... instrumentelle handleverdens møde med den sociale verden i assertivet. Dernæst som assertivets nødvendige udspaltninger i normativet og konstativet. Og endelig som de perlokutionære handlinger kommissiv, direktiv og informativ....

  17. 29 CFR 1926.953 - Material handling.


    ... 29 Labor 8 2010-07-01 2010-07-01 false Material handling. 1926.953 Section 1926.953 Labor... Material handling. (a) Unloading. Prior to unloading steel, poles, cross arms and similar material, the... employees exist tag lines or other suitable devices shall be used to control loads being handled by hoisting...

  18. 50 CFR 14.111 - Handling.


    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Handling. 14.111 Section 14.111 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR TAKING, POSSESSION... and Birds to the United States § 14.111 Handling. (a) Care shall be exercised to avoid handling the...

  19. 9 CFR 3.118 - Handling.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Handling. 3.118 Section 3.118 Animals... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Marine Mammals Transportation Standards § 3.118 Handling. (a) Carriers and intermediate handlers moving marine...

  20. 7 CFR 985.152 - Handling report.


    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Handling report. 985.152 Section 985.152 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... HANDLING OF SPEARMINT OIL PRODUCED IN THE FAR WEST Administrative Rules and Regulations § 985.152 Handling...

  1. 9 CFR 3.142 - Handling.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Handling. 3.142 Section 3.142 Animals... WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of... Mammals Transportation Standards § 3.142 Handling. (a) Carriers and intermediate handlers shall move live...

  2. Scheduling of outbound luggage handling at airports

    Barth, Torben C.; Pisinger, David


    This article considers the outbound luggage handling problem at airports. The problem is to assign handling facilities to outbound flights and decide about the handling start time. This dynamic, near real-time assignment problem is part of the daily airport operations. Quality, efficiency and rob...

  3. Investigation of multiple spindle characteristics under non-uniform bearing preload

    Yanfei Zhang


    Full Text Available The non-uniform distribution load during machining and assembly process is crucial for spindle system, especially in complex working conditions. The conception of non-uniform preload adjustment approach was proposed and experimentally investigated in this article. Based on the mechanical equivalent principle, the non-uniform preload was theoretically transformed to the combination of uniform preload and an extra moment. Then, the non-uniform preload of rolling bearing was experimentally measured and analyzed via a spacer with 15-µm wear loss on the end face. The spindle performance factors, such as rotation accuracy, temperature rising, acceleration, and vibration, were all monitored. The rotation center of spindle was deviated in different non-uniform preload conditions. Meanwhile, the temperature and vibration performance of non-uniform preload are superior to those of uniform bearing preload.

  4. Collaborative Filtering in a Non-Uniform World: Learning with the Weighted Trace Norm

    Salakhutdinov, Ruslan


    We show that matrix completion with trace-norm regularization can be significantly hurt when entries of the matrix are sampled non-uniformly. We introduce a weighted version of the trace-norm regularizer that works well also with non-uniform sampling. Our experimental results demonstrate that the weighted trace-norm regularization indeed yields significant gains on the (highly non-uniformly sampled) Netflix dataset.

  5. Noise power spectrum measurements under nonuniform gains and their compensations

    Kim, Dong Sik; Kim, Eun; Shin, Choul Woo


    The fixed pattern noise, which is due to the nonuniform amplifier gains and scintillator sensitivities, should be alleviated in radiography imaging and should have less influence on measuring the noise power spectrum (NPS) of the radiography detector. In order to reduce the influence, background trend removing methods, which are based on low-pass filtering, polynomial fitting, and subtracting the average image of the uniform exposure images, are traditionally employed in the literature. In terms of removing the fixed pattern noise, the subtraction method shows a good performance. However, the number of images to be averaged is practically finite and thus the noise contained in the average image contaminates the image difference and inflates the NPS curve. In this paper, an image formation model considering the nonuniform gain is constructed and two measuring methods, which are based on the subtraction and gain correction, respectively, are considered. In order to accurately measure a normalized NPS (NNPS) in the measuring methods, the number of images to be averaged is considered for NNPS compensations. For several flat-panel radiography detectors, the NNPS measurements are conducted and compared with conventional approaches, which have no compensation stages. Through experiments it is shown that the compensation can provide accurate NNPS measurements less influenced by the fixed pattern noise.

  6. Elastic deformations driven by non-uniform lubrication flows

    Rubin, Shimon; Tulchinsky, Arie; Gat, Amir D.; Bercovici, Moran


    The ability to create dynamic deformations of micron-sized structures is relevant to a wide variety of applications such as adaptable optics, soft robotics, and reconfigurable microfluidic devices. In this work we examine non-uniform lubrication flow as a mechanism to create complex deformation fields in an elastic plate. We consider a Kirchoff-Love elasticity model for the plate and Hele-Shaw flow in a narrow gap between the plate and a parallel rigid surface. Based on linearization of the Reynolds equation, we obtain a governing equation which relates elastic deformations to gradients in non-homogenous physical properties of the fluid (e.g. body forces, viscosity, and slip velocity). We then focus on a specific case of non-uniform Helmholtz-Smoluchowski electroosmotic slip velocity, and provide a method for determining the zeta-potential distribution necessary to generate arbitrary static and quasi-static deformations of the elastic plate. Extending the problem to time-dependent solutions, we analyze transient effects on asymptotically static solutions, and finally provide a closed form solution for a Green's function for time periodic actuations.

  7. Asynchronous signal-dependent non-uniform sampler

    Can-Cimino, Azime; Chaparro, Luis F.; Sejdić, Ervin


    Analog sparse signals resulting from biomedical and sensing network applications are typically non-stationary with frequency-varying spectra. By ignoring that the maximum frequency of their spectra is changing, uniform sampling of sparse signals collects unnecessary samples in quiescent segments of the signal. A more appropriate sampling approach would be signal-dependent. Moreover, in many of these applications power consumption and analog processing are issues of great importance that need to be considered. In this paper we present a signal dependent non-uniform sampler that uses a Modified Asynchronous Sigma Delta Modulator which consumes low-power and can be processed using analog procedures. Using Prolate Spheroidal Wave Functions (PSWF) interpolation of the original signal is performed, thus giving an asynchronous analog to digital and digital to analog conversion. Stable solutions are obtained by using modulated PSWFs functions. The advantage of the adapted asynchronous sampler is that range of frequencies of the sparse signal is taken into account avoiding aliasing. Moreover, it requires saving only the zero-crossing times of the non-uniform samples, or their differences, and the reconstruction can be done using their quantized values and a PSWF-based interpolation. The range of frequencies analyzed can be changed and the sampler can be implemented as a bank of filters for unknown range of frequencies. The performance of the proposed algorithm is illustrated with an electroencephalogram (EEG) signal.

  8. Identification of the material properties in nonuniform nanostructures

    Bao, Gang; Xu, Xiang


    This paper is concerned with addressing two significant challenges arising from quantifying mechanical properties of nanomaterials, namely nonuniformity of the nanomaterial and the high noise level of measurements. For nonuniformity, an explicit solution is derived for the general Euler-Bernoulli equation in terms of the Green function for the Poisson equation. Then, by examining a stochastic source, the systematic error may be removed from measurements, which leads to more accurate estimation of mechanical properties. Based on Itô integral properties, three deterministic Fredholm integral equations can be deduced to extract the stiffness and the structure of the random source from measured data. To overcome ill-posedness and high nonlinearity in solving the Fredholm equations, a Tikhonov regularization method is developed with an a priori strategy of choosing the regularization parameter. Moreover, under a regularity assumption for the stiffness coefficient and structures of the random source, the convergence rate can be obtained in the sense of probability. Numerical examples are presented to illustrate the validity and effectiveness of the novel model and regularization method.

  9. Longitudinal oscillations in a non-uniform spatially dispersive plasma

    Calogeracos, Alex, E-mail:


    Longitudinal oscillations of the electron fluid in the hydrodynamic model of a metal are examined with pressure effects taken into account. It is well-known that this entails spatial dispersion. The equilibrium electron number density is taken to be non-uniform and a non-self-adjoint fourth order differential equation obeyed by the electric potential is derived. A velocity potential necessary for the description of sound waves is introduced in the standard fashion and the generalized version of Bloch orthogonality appropriate to a non-uniform background is deduced. We observe a duality between electric and velocity potentials in the sense that the respective differential operators are adjoint to each other. The spectrum is calculated in the special case of an exponential profile for the equilibrium electron number density. The surface plasmons are connected with the analytic properties of the scattering amplitude in the complex plane. The phase shift at threshold is expressed in terms of the number of surface plasmon modes via an expression reminiscent of Levinson’s statement in quantum mechanics.

  10. Elastic deformations driven by non-uniform lubrication flows

    Rubin, Shimon; Gat, Amir; Bercovici, Moran


    The ability to create dynamic deformations of micron-sized structures is relevant to a wide variety of applications such as adaptable optics, soft robotics, and reconfigurable microfluidic devices. In this work we examine non-uniform lubrication flow as a mechanism to create complex deformation fields in an elastic plate. We consider a Kirchoff-Love elasticity model for the plate and Hele-Shaw flow in a narrow gap between the plate and a parallel rigid surface. Based on linearization of the Reynolds equation, we obtain a governing equation which relates elastic deformations to gradients in non-homogenous physical properties of the fluid (e.g. body forces, viscosity, and slip velocity). We then focus on a specific case of non-uniform Helmholtz-Smoluchowski electroosmotic slip velocity, and provide a method for determining the zeta-potential distribution necessary to generate arbitrary static and quasi-static deformations of the elastic plate. Extending the problem to time-dependent solutions, we analyze transi...

  11. Computational imaging from non-uniform degradation of staggered TDI thermal infrared imager.

    Sun, Tao; Liu, Jian Guo; Shi, Yan; Chen, Wangli; Qin, Qianqing; Zhang, Zijian


    For the Time Delay Integration (TDI) staggered line-scanning thermal infrared imager, a Computational Imaging (CI) approach is developed to achieve higher spatial resolution images. After a thorough analysis of the causes of non-uniform image displacement and degradation for multi-channel staggered TDI arrays, the study aims to approach one-dimensional (1D) sub-pixel displacement estimation and superposition of images from time-division multiplexing scanning lines. Under the assumption that a thermal image is 2D piecewise C(2) smooth, a sparse-and-smooth deconvolution algorithm with L1-norm regularization terms combining the first and second order derivative operators is proposed to restore high frequency components and to suppress aliasing simultaneously. It is theoretically and experimentally demonstrated, with simulation and airborne thermal infrared images, that this is a state-of-the-art practical CI method to reconstruct clear images with higher frequency components from raw thermal images that are subject to instantaneous distortion and blurring.

  12. Growth patterns of the slime mold Physarum on a nonuniform substrate

    Halvorsrud, Ragnhild; Wagner, Geri


    The Myxomycete Physarum polycephalum has been grown on nonuniform substrates, where the nutrients were confined in separated drops of agar medium. Spatial and temporal aspects of the resulting growth structures were studied by time-lapse video techniques and analyzed using image processing software. The growth process on a linear substrate of drops can be described in terms of a searching phase alternating with a feeding phase. On a linear array of drops, the Physarum advanced uniformly after an initial lag phase. On a two-dimensional drop substrate two different growth regimes could be distinguished: branched growth was observed on substrates with small drop diameters and compact growth, similar to growth on uniform substrates, was observed on substrates with larger drop diameters. The drop size is a crucial parameter that mediates characteristic plasmodial morphologies. A crossover from branched to compact growth was observed in some of the experiments. A spatial correlation function was used that could quantitatively distinguish between the different growth regimes.

  13. Advances in iterative non-uniformity correction techniques for infrared scene projection

    Danielson, Tom; Franks, Greg; LaVeigne, Joe; Prewarski, Marcus; Nehring, Brian


    Santa Barbara Infrared (SBIR) is continually developing improved methods for non-uniformity correction (NUC) of its Infrared Scene Projectors (IRSPs) as part of its comprehensive efforts to achieve the best possible projector performance. The most recent step forward, Advanced Iterative NUC (AI-NUC), improves upon previous NUC approaches in several ways. The key to NUC performance is achieving the most accurate possible input drive-to-radiance output mapping for each emitter pixel. This requires many highly-accurate radiance measurements of emitter output, as well as sophisticated manipulation of the resulting data set. AI-NUC expands the available radiance data set to include all measurements made of emitter output at any point. In addition, it allows the user to efficiently manage that data for use in the construction of a new NUC table that is generated from an improved fit of the emitter response curve. Not only does this improve the overall NUC by offering more statistics for interpolation than previous approaches, it also simplifies the removal of erroneous data from the set so that it does not propagate into the correction tables. AI-NUC is implemented by SBIR's IRWindows4 automated test software as part its advanced turnkey IRSP product (the Calibration Radiometry System or CRS), which incorporates all necessary measurement, calibration and NUC table generation capabilities. By employing AI-NUC on the CRS, SBIR has demonstrated the best uniformity results on resistive emitter arrays to date.

  14. Transfer Area Mechanical Handling Calculation

    B. Dianda


    This calculation is intended to support the License Application (LA) submittal of December 2004, in accordance with the directive given by DOE correspondence received on the 27th of January 2004 entitled: ''Authorization for Bechtel SAX Company L.L. C. to Include a Bare Fuel Handling Facility and Increased Aging Capacity in the License Application, Contract Number DE-AC28-01R W12101'' (Arthur, W.J., I11 2004). This correspondence was appended by further Correspondence received on the 19th of February 2004 entitled: ''Technical Direction to Bechtel SAIC Company L.L. C. for Surface Facility Improvements, Contract Number DE-AC28-OIRW12101; TDL No. 04-024'' (BSC 2004a). These documents give the authorization for a Fuel Handling Facility to be included in the baseline. The purpose of this calculation is to establish preliminary bounding equipment envelopes and weights for the Fuel Handling Facility (FHF) transfer areas equipment. This calculation provides preliminary information only to support development of facility layouts and preliminary load calculations. The limitations of this preliminary calculation lie within the assumptions of section 5 , as this calculation is part of an evolutionary design process. It is intended that this calculation is superseded as the design advances to reflect information necessary to support License Application. The design choices outlined within this calculation represent a demonstration of feasibility and may or may not be included in the completed design. This calculation provides preliminary weight, dimensional envelope, and equipment position in building for the purposes of defining interface variables. This calculation identifies and sizes major equipment and assemblies that dictate overall equipment dimensions and facility interfaces. Sizing of components is based on the selection of commercially available products, where applicable. This is not a specific recommendation for the future use

  15. A SQUID series array dc current sensor

    Beyer, J; Drung, D [Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, D-10587 Berlin (Germany)], E-mail:, E-mail:


    Superconducting quantum interference device (SQUID) sensors are used to sense changes in various physical quantities, which can be transformed into changes in the magnetic flux threading the SQUID loop. We have developed a novel SQUID array dc current sensor. The device is based on a series array of identical dc SQUIDs. An input signal current to be measured is coupled tightly but non-uniformly to the SQUID array elements. The input signal coupling to the individual array elements is chosen such that a single-valued, non-periodic overall voltage response is obtained. Flux offsets in the individual SQUIDs which would compromise the sensor voltage response are avoided or can be compensated. We present simulations and experimental results on the SQUID Array for Dc (SQUAD) current sensor current sensor performance. A dc current resolution of <1 nA in a measurement bandwidth of 0-25 Hz is achieved for an input inductance of L{sub In}<3 nH.

  16. MPI Debugging with Handle Introspection

    Brock-Nannestad, Laust; DelSignore, John; Squyres, Jeffrey M.;

    The Message Passing Interface, MPI, is the standard programming model for high performance computing clusters. However, debugging applications on large scale clusters is difficult. The widely used Message Queue Dumping interface enables inspection of message queue state but there is no general...... interface for extracting information from MPI objects such as communicators. A developer can debug the MPI library as if it was part of the application, but this exposes an unneeded level of detail. The Tools Working Group in the MPI Forum has proposed a specification for MPI Handle Introspection....... It defines a standard interface that lets debuggers extract information from MPI objects. Extracted information is then presented to the developer, in a human readable format. The interface is designed to be independent of MPI implementations and debuggers. In this paper, we describe our support...

  17. Liberalisation of municipal waste handling

    Busck, Ole Gunni


    of price reductions in stead of quality demands in both environmental and working environmental terms. A recent study showed major deficits in the capacities of the municipalities to administer qualitative requirements in the tender process and to manage the contracts as an integral part of a scheme...... for improved performance of municipal waste management. The study stresses the need for training and guidance of municipal administrators. Highlighting ‘best practice’ examples the study shows, however, that it is perfectly possible to end up with quality service on contract. It takes a mixture of careful......Liberalisation of municipal waste handling: How are sustainable practices pursued? In the process of liberalization of public services in Europe contracting out the collection of municipal waste has surged. Research in Denmark has shown that municipalities in general have pursued a narrow policy...

  18. Compensation for z-directional non-uniformity of a monopole antenna at 7T MRI

    Kim, Nambeom; Woo, Myung-Kyun; Kang, Chang-Ki


    The research was conducted to find ways to compensate for z-directional non-uniformity at a monopole antenna array (MA) coil by using a tilted optimized non-saturating excitation (TONE) pulse and to evaluate the feasibility of using the MA coil with the TONE pulse for anatomical and angiographic imaging. The sensitivity of a MA coil along the z-direction was measured by using an actual flip angle imaging pulse sequence with an oil phantom to evaluate the flip angle distributions of the MA coil for 7T magnetic resonance imaging (MRI). The effects on the z-directional uniformity were examined by using slow and fast TONE pulses, i.e., TONE SLOW and TONE FAST. T1- and T2* -weighted images of the human brain were also examined. The z-directional profiles of the TONE pulses were analyzed by using the average signal intensity throughout the brain. The effect of the TONE pulses on cerebral vessels was further examined by analyzing maximal intensity projections of T1-weighted images. With increasing the applied flip angles, the sensitivity slope slightly increased (0.044 per degree). For the MA coil, the TONE SLOWpulse yielded a compensated profile along the z-direction while the TONE HIGH pulse, which has a flat excitation profile along the z-direction, exhibited a tilted signal intensity toward the coil end, clearly indicating an intrinsic property of the MA coil. Similar to the phantom study, human brain images revealed z-directional symmetry around the peak value for the averaged signal intensity of the TONE SLOW pulse while the TONE HIGH pulse exhibited a tilted signal intensity toward the coil end. In vascular system imaging, the MA coil also clearly demonstrated a beneficial effect on the cerebral vessels, either with or without the TONE pulses. This study demonstrates that TONE pulses could compensate for the intrinsic z-directional non-uniformity of MA coils that exhibit strong uniformity in the x-y plane. Furthermore, tilted pulses, such as TONE pulses, were

  19. A Single-Chip 64-Channel Ultrasound RX-Beamformer Including Analog Front-End and an LUT for Non-Uniform ADC-Sample-Clock Generation.

    Kim, Yoon-Jee; Cho, Sung-Eun; Um, Ji-Yong; Chae, Min-Kyun; Bang, Jihoon; Song, Jongkeun; Jeon, Taeho; Kim, Byungsub; Sim, Jae-Yoon; Park, Hong-June


    A 64-channel RX digital beamformer was implemented in a single chip for 3-D ultrasound medical imaging using 2-D phased-array transducers. The RX beamformer chip includes 64 analog front-end branches including 64 non-uniform sampling ADCs, a FIFO/Adder, and an on-chip look-up table (LUT). The LUT stores the information on the rising edge timing of the non-uniform ADC sampling clocks. To include the LUT inside the beamformer chip, the LUT size was reduced by around 240 times by approximating an ADC-sample-time profile w.r.t. focal points (FP) along a scanline (SL) for a channel into a piece-wise linear form. The maximum error between the approximated and accurate sample times of ADC is eight times the sample time resolution (Ts) that is 1/32 of the ultrasound signal period in this work. The non-uniform sampling reduces the FIFO size required for digital beamforming by around 20 times. By applying a 9-dot image from Field-II program and 2-D ultrasound phantom images to the fabricated RX beamformer chip, the original images were successfully reconstructed from the measured output. The chip in a 0.13-um CMOS occupies 30.25 [Formula: see text] and consumes 605 mW.

  20. Global Arrays

    Krishnamoorthy, Sriram; Daily, Jeffrey A.; Vishnu, Abhinav; Palmer, Bruce J.


    Global Arrays (GA) is a distributed-memory programming model that allows for shared-memory-style programming combined with one-sided communication, to create a set of tools that combine high performance with ease-of-use. GA exposes a relatively straightforward programming abstraction, while supporting fully-distributed data structures, locality of reference, and high-performance communication. GA was originally formulated in the early 1990’s to provide a communication layer for the Northwest Chemistry (NWChem) suite of chemistry modeling codes that was being developed concurrently.

  1. Effect of Enhancement Technique on Nonuniform and Uniform Ultrasound Images

    Parveen Lehana


    Full Text Available The absence of adequate scientific resources in the area of medical sciences sometimes leads to improper diagnosis of diseases and hence the treatments of such diseases are affected badly. However, with the advancement of technology, the complicacy of various malfunctions inside the human body reduces. Ultrasound imaging is one of the biomedical scanning techniques that let the pathologist make comment reasonably and accurately on the disease or irregularity seen in the scan while low imaging quality lets the diagnosis go wrong. Even a little distortion can route the pathologist away from the main cause of the disease. In this research work, the enhancement of dark ultrasound images has been done. An algorithm is developed using enhancement technique for nonuniform and uniform dark images. Finally, we compared the quality of the processed and unprocessed images. Both ETNUD and mean and median filtering techniques were used for image analysis.

  2. Periodic envelopes of waves over non-uniform depth

    Rajan, Girish K.; Bayram, Saziye; Henderson, Diane M.


    The envelope of narrow-banded, periodic, surface-gravity waves propagating in one dimension over water of finite, non-uniform depth may be modeled by the Djordjević and Redekopp ["On the development of packets of surface gravity waves moving over an uneven bottom," Z. Angew. Math. Phys. 29, 950-962 (1978)] equation (DRE). Here we find five approximate solutions of the DRE that are in the form of Jacobi-elliptic functions and discuss them within the framework of ocean swell. We find that in all cases, the maximum envelope-amplitude decreases/increases when the wave group propagates on water of decreasing/increasing depth. In the limit of the elliptic modulus approaching one, three of the solutions reduce to the envelope soliton solution. In the limit of the elliptic modulus approaching zero, two of the solutions reduce to an envelope-amplitude that is uniform in an appropriate reference frame.

  3. Multifractal analysis of non-uniformly contracting iterated function systems

    Ye, Yuan-Ling


    Let X  =  [0,1]. Given a non-uniformly contracting conformal iterated function system (IFS) ≤ft\\{{{w}j}\\right\\}j=1m and a family of positive Dini continuous potential functions ≤ft\\{ {{p}j}\\right\\}j=1m , the triple system ≤ft(X,≤ft\\{{{w}j}\\right\\}j=1m,≤ft\\{ {{p}j}\\right\\}j=1m\\right) , under some conditions, determines uniquely a probability invariant measure, denoted by μ. In this paper, we study the pressure function of the system and multifractal structure of μ. We prove that the pressure function is Gateaux differentiable and the multifractal formalism holds, if the IFS ≤ft\\{{{w}j}\\right\\}j=1m has non-overlapping.

  4. Vacuum polarisation in some static nonuniform magnetic fields

    Calucci, G. [Trieste Univ. (Italy). Dip. di Fisica Teorica]|[INFN, Trieste (Italy)


    Vacuum polarisation in QED in presence of some configurations of external magnetic fields is investigated. The configuration considered correspond to fields is investigated. The configuration considered correspond to fields lying in a plane and without sources. The motion of a Dirac electron in this field configuration is studied and arguments are found to conclude that the lowest level gives the most important contribution. The result is that the main effect is not very different from the uniform case, the possibilities of calculating the corrections due to the uniformity is explicitly shown. A typical effect of nonuniformity of the field shows out in the refractivity of the field shows out in the refractivity of the vacuum.

  5. A Thermal Field Theory with Non-uniform Chemical Potential

    Arai, Masato; Sasaki, Shin


    We investigate thermal one-loop effective potentials in multi-flavor models with chemical potentials. We study four-dimensional models in which each flavor have different global U(1) charges. Accordingly they have different chemical potentials. We call these "non-uniform chemical potentials," which are organized into a diagonal matrix \\mu. The mass matrix at a vacuum does not commute with \\mu. We find that the effective potential is divided into three parts. The first part is the Coleman-Weinberg potential. The UV divergence resides only in this part. The second is the correction to the Coleman-Weinberg potential that is independent of temperature, and the third depends on both temperature and \\mu. Our result is a generalization of the thermal potentials in previous studies for models with single and multi-flavors with (uniform) chemical potentials and reproduces all the known results correctly.

  6. Higher order mode propagation in nonuniform circular ducts

    Cho, Y. C.; Ingard, K. U.


    This paper presents an analytical investigation of higher order mode propagation in a nonuniform circular duct without mean flow. An approximate wave equation is derived on the assumptions that the duct cross section varies slowly and that mode conversion is negligible. Exact closed form solutions are obtained for a particular class of converging-diverging circular duct which is here referred to as 'circular cosh duct'. Numerical results are presentd in terms of the transmission loss for the various duct shapes and frequencies. The results are applicable to studies of multimodal propagation as well as single mode propagation. The results are also applicable to studies of sound radiation from certain types of contoured inlet ducts, or of sound propagation in a converging-diverging duct of somewhat different shape from a cosh duct.

  7. Langevin Simulation of Non-Uniform Granular Gases

    张端明; 雷雅洁; 潘贵军; 郁伯铭


    We present and study a fractal model of a non-uniform granular system for the first time, based on which we numerically solve the dynamics actions in the system successfully in one-dimensional case. The multi-mixture is composed of N different particles, whose granularity distribution has the fractal characteristic. The particles are subject to inelastic mutual collisions and obey to Langevin equation between collisions. Far from the equilibrium,i.e. the given typical relaxation time T of the driving Brownian process is much larger than the mean collision time Tc, the results of simulation indicate that the degree of inhomogeneity in the granularity distribution signed by the fractal dimension D of size distribution has great influence on the dynamics actions of the system. The velocity distribution deviates obviously from the Gaussian distribution and the particles cluster more pronouncedly with the larger value of D in the system. The velocity distribution and spatial clusterization change with D are presented.

  8. The study of synchronization in the periodic nonuniform folded waveguide

    Xu Ao; Wang Wen-Xiang; Wei Yan-Yu; Gong Yu-Bin


    The periodic nonuniform folded waveguides are special structures, the physical dimension of which is between the periodic folded waveguide and the tapering period folded waveguide. Therefore, the synchronization between the microwave and the electron beam can be maintained in the whole interaction process and the periods are not tapered.In comparison with the tapering period folded waveguide, the theoretical analysis and the technological requirements for this structure are more convenient. In order to study this structure, the space harmonics are analysed, the conditions to make the m-th space harmonic synchronizing with the electron beam in the whole interaction process are present,and the dispersion curve and the coupling impedance curve axe obtained by the simulation software HFSS.

  9. Leveraging Non-Uniform Resources for Parallel Query Processing

    Mayr, Tobias; Bonnet, Philippe; Gehrke, Johannes;


    of existing parallel database systems. We show in this paper that dataflow parallelism alone is ill suited for modular clusters because running the same operation on different subsets of the data can not fully utilize non-uniform hardware resources. We propose and evaluate new load balancing techniques......Modular clusters are now composed of non- uniform nodes with different CPUs, disks or network cards so that customers can adapt the cluster configuration to the changing technologies and to their changing needs. This challenges dataflow parallelism as the primary load balancing technique...... that confirms the feasibility and effectiveness of the new techniques in a parallel execution engine prototype based on the open-source DBMS Predator....

  10. Time-Stampless Adaptive Nonuniform Sampling for Stochastic Signals

    Feizi, Soheil; Goyal, Vivek K.; Medard, Muriel


    In this paper, we introduce a time-stampless adaptive nonuniform sampling (TANS) framework, in which time increments between samples are determined by a function of the $m$ most recent increments and sample values. Since only past samples are used in computing time increments, it is not necessary to save sampling times (time stamps) for use in the reconstruction process. We focus on two TANS schemes for discrete-time stochastic signals: a greedy method, and a method based on dynamic programming. We analyze the performances of these schemes by computing (or bounding) their trade-offs between sampling rate and expected reconstruction distortion for autoregressive and Markovian signals. Simulation results support the analysis of the sampling schemes. We show that, by opportunistically adapting to local signal characteristics, TANS may lead to improved power efficiency in some applications.

  11. Time-Stampless Adaptive Nonuniform Sampling for Stochastic Signals

    Feizi, Soheil; Medard, Muriel


    In this paper, we introduce a time-stampless adaptive nonuniform sampling (TANS) framework, in which time increments between samples are determined by a function of the $m$ most recent increments and sample values. Since only past samples are used in computing time increments, it is not necessary to save sampling times (time stamps) for use in the reconstruction process. We focus on two TANS schemes for discrete-time stochastic signals: a greedy method, and a method based on dynamic programming. We analyze the performances of these schemes by computing (or bounding) their trade-offs between sampling rate and expected reconstruction distortion for autoregressive and Markovian signals. Simulation results support the analysis of the sampling schemes. We show that, by opportunistically adapting to local signal characteristics, TANS may lead to improved power efficiency in some applications.

  12. Highly Deformed Non-uniform Black Strings in Six Dimensions

    Kalisch, Michael


    We construct numerically static non-uniform black string solutions in six dimensions by using pseudo-spectral methods. An appropriately designed adaptation of the methods in regard of the specific behaviour of the field quantities in the vicinity of our numerical boundaries provides us with extremely accurate results, that allows us to get solutions with an unprecedented deformation of the black string horizon. Consequently, we are able to investigate in detail a critical regime within a suitable parameter diagram. In particular, we observe a clearly pronounced maximum in the mass curve, which is in accordance with the results of Kleihaus, Kunz and Radu from 2006. Interestingly, by looking at extremely distorted black strings, we find two further turning points of the mass, resulting in a spiral curve in the black string's phase diagram.


    Line, Michael R. [NASA Ames Research Center, Moffet Field, CA 94035 (United States); Parmentier, Vivien, E-mail: [Department of Astronomy and Astrophysics, University of California–Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)


    We model the impact of nonuniform cloud cover on transit transmission spectra. Patchy clouds exist in nearly every solar system atmosphere, brown dwarfs, and transiting exoplanets. Our major findings suggest that fractional cloud coverage can exactly mimic high mean molecular weight atmospheres and vice versa over certain wavelength regions, in particular, over the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) bandpass (1.1–1.7 μm). We also find that patchy cloud coverage exhibits a signature that is different from uniform global clouds. Furthermore, we explain analytically why the “patchy cloud-high mean molecular weight” degeneracy exists. We also explore the degeneracy of nonuniform cloud coverage in atmospheric retrievals on both synthetic and real planets. We find from retrievals on a synthetic solar composition hot Jupiter with patchy clouds and a cloud-free high mean molecular weight warm Neptune that both cloud-free high mean molecular weight atmospheres and partially cloudy atmospheres can explain the data equally well. Another key finding is that the HST WFC3 transit transmission spectra of two well-observed objects, the hot Jupiter HD 189733b and the warm Neptune HAT-P-11b, can be explained well by solar composition atmospheres with patchy clouds without the need to invoke high mean molecular weight or global clouds. The degeneracy between high molecular weight and solar composition partially cloudy atmospheres can be broken by observing the molecular Rayleigh scattering differences between the two. Furthermore, the signature of partially cloudy limbs also appears as a ∼100 ppm residual in the ingress and egress of the transit light curves, provided that the transit timing is known to seconds.



    We study the effect of electrodes with varying thickness on thickness-twist vibration of a piezoelectric plate resonator of crystals of 6 mm symmetry. An exact theoretical analysis is performed. Results show that non-uniform electrodes have a strong effect on mode shapes, and suggest the possibility of using nonuniform electrodes for strong energy trapping.

  15. Subband image coding using filter banks with non-uniform passband distribution

    Lu, Xiqun; Chen, Li; Chan, KwokPing


    In this paper, subband filter banks with non-uniform passband distribution in frequency domain are studied. Several design examples are presented and compared with conventional uniform bandwidth filter banks. Image coding results show that filter banks with non-uniform bandwidth outperform filter banks with uniform bandwidth, especially in low bit rate coding.

  16. Mathematical simulation application for research of nonuniform distributed-parameter circuit transients

    Kuleshova, E. O.; Plyusnin, A. A.; Shandarova, E. B.; Tikhomirova, O. V.


    This paper considers the simulation capability of nonuniform distributed-parameter circuit transients by using MatLab Simulink. This approach is capable of determining currents and voltages of nodes for power networks of any configurations and modes. The paper contains results of nonuniform line simulations in idle, short-circuit and load modes.

  17. Ergonomics: safe patient handling and mobility.

    Hallmark, Beth; Mechan, Patricia; Shores, Lynne


    This article reviews and investigates the issues surrounding ergonomics, with a specific focus on safe patient handling and mobility. The health care worker of today faces many challenges, one of which is related to the safety of patients. Safe patient handling and mobility is on the forefront of the movement to improve patient safety. This article reviews the risks associated with patient handling and mobility, and informs the reader of current evidence-based practice relevant to this area of care.

  18. Enclosure for handling high activity materials

    Jimeno de Osso, F.


    One of the most important problems that are met at the laboratories producing and handling radioisotopes is that of designing, building and operating enclosures suitable for the safe handling of active substances. With this purpose in mind, an enclosure has been designed and built for handling moderately high activities under a shielding made of 150 mm thick lead. In this report a description is given of those aspects that may be of interest to people working in this field. (Author)

  19. Ergonomic handle for an arthroscopic cutter.

    Tuijthof; van Engelen; Herder; Goossens; Snijders; van Dijk


    From an analysis of the routinely performed meniscectomy procedures, it was concluded that a punch with a side-ways steerable tip would improve the reachability of meniscal tissue. This potentially leads to a safer and more efficient meniscectomy. Furthermore, the current scissors handles of arthroscopic punches are ergonomically not sufficient. An ergonomic handle is designed with one lever that enables opening and closing of the instrument tip, and side-ways steering of the instrument tip. The design of the handle complies with ergonomic guidelines that were found in the literature. A model of the instrument tip was added to the new handle for comparison with conventional handles. Experiments were performed with a knee joint model, using objective and subjective criteria. The results show that the concept of a side-ways steerable punch is promising, since faster task times are achieved without increasing the risk of damaging healthy tissue. The current design of the ergonomic handle incorporates two degrees of freedom in an intuitive way, the handle is more comfortable to hold, and easy to control. The external memory capabilities of the new handle could be improved. Further development of this handle and the addition of a sufficient instrument tip and force transmission are recommended.

  20. Control of fuel target implosion non-uniformity in heavy ion inertial fusion

    Iinuma, T; Kondo, S; Kubo, T; Kato, H; Suzuki, T; Kawata, S; Ogoyski, A I


    In inertial fusion, one of scientific issues is to reduce an implosion non-uniformity of a spherical fuel target. The implosion non-uniformity is caused by several factors, including the driver beam illumination non-uniformity, the Rayleigh-Taylor instability (RTI) growth, etc. In this paper we propose a new control method to reduce the implosion non-uniformity; the oscillating implosion acceleration dg(t) is created by pulsating and dephasing heavy ion beams (HIBs) in heavy ion inertial fusion (HIF). The dg(t) would reduce the RTI growth effectively. The original concept of the non- uniformity control in inertial fusion was proposed in (Kawata, et al., 1993). In this paper it was found that the pulsating and dephasing HIBs illumination provide successfully the controlled dg(t) and that dg(t) induced by the pulsating HIBs reduces well the implosion non-uniformity. Consequently the pulsating HIBs improve a pellet gain remarkably in HIF.

  1. Electromagnetic performance analysis of reflector antennas with non-uniform errors along radius

    Peiyuan Lian; Congsi Wang; Wei Wang; Binbin Xiang


    Based on the works of Greve and Rahmat-Sami , the electromagnetic (EM) performance of the reflector antenna with non-uniform surface errors along radius is further addressed. A mathematical model is developed to describe the weighting func-tion for the non-uniform surface errors along radius. Then, some discussions on the peak gain loss (PGL) and the first sidelobe level increase (SLLI) caused by the non-uniform surface errors are presented and several significant radiation characteristics of the reflector with non-uniform errors are pointed out. Last, based on the proposed model, the weighted root mean square (RMS) value of the surface errors is produced to evaluate the EM performance and several representative cases with different non-uniform errors are presented with good results. Results show that the weighted RMS value should be taken into account for a better quality evalu-ation of the reflector surface.


    Liu Binbin; Bai Dong; Mei Shunliang


    Non-uniform quantization for messages in Low-Density Parity-Check (LDPC) decoding can reduce implementation complexity and mitigate performance loss. But the distribution of messages varies in the iterative decoding. This letter proposes a variable non-uniform quantized Belief Propaga- tion (BP) algorithm. The BP decoding is analyzed by density evolution with Gaussian approximation. Since the probability density of messages can be well approximated by Gaussian distribution, by the unbiased estimation of variance, the distribution of messages can be tracked during the iteration. Thus the non-uniform quantization scheme can be optimized to minimize the distortion. Simulation results show that the variable non-uniform quantization scheme can achieve better error rate performance and faster decoding convergence than the conventional non-uniform quantization and uniform quantization schemes.

  3. Handling S/MAR vectors.

    Hagedorn, Claudia; Baiker, Armin; Postberg, Jan; Ehrhardt, Anja; Lipps, Hans J


    Nonviral episomal vectors represent attractive alternatives to currently used virus-based expression systems. In the late 1990s, it was shown that a plasmid containing an expression cassette linked to a scaffold/matrix attached region (S/MAR) replicates as a low copy number episome in all cell lines tested, as well as primary cells, and can be used for the genetic modification of higher animals. Once established in the cell, the S/MAR vector replicates early during S-phase and, in the absence of selection, is stably retained in the cells for an unlimited period of time. This vector can therefore be regarded as a minimal model system for studying the epigenetic regulation of replication and functional nuclear architecture. In theory, this construct represents an almost "ideal" expression system for gene therapy. In practice, S/MAR-based vectors stably modify mammalian cells with efficiencies far below those of virus-based constructs. Consequently, they have not yet found application in gene therapy trials. Furthermore, S/MAR vector systems are not trivial to handle and several critical technical issues have to be considered when modifying these vectors for various applications.

  4. Compound droplet manipulations on fiber arrays

    Weyer, Floriane; Dreesen, Laurent; Vandewalle, Nicolas


    Recent works demonstrated that fiber arrays may constitue the basis of an open digital microfluidics. Various processes, such as droplet motion, fragmentation, trapping, release, mixing and encapsulation, may be achieved on fiber arrays. However, handling a large number of tiny droplets resulting from the mixing of several liquid components is still a challenge for developing microreactors, smart sensors or microemulsifying drugs. Here, we show that the manipulation of tiny droplets onto fiber networks allows for creating compound droplets with a high complexity level. Moreover, this cost-effective and flexible method may also be implemented with optical fibers in order to develop fluorescence-based biosensor.

  5. Research on Event Handling Models of Java

    WU Yue; WU Jing; ZHOU Ming-tian


    A new event-handling paradigm and its application model are proposed. The working mechanism and principle of event listener model is given in detail. Finally, the launching event mechanisms,the choosing event handling models and the dispatching mechanism are illustrated.

  6. 9 CFR 3.19 - Handling.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Handling. 3.19 Section 3.19 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of Dogs...

  7. 9 CFR 3.41 - Handling.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Handling. 3.41 Section 3.41 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of...

  8. 9 CFR 3.92 - Handling.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Handling. 3.92 Section 3.92 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of...

  9. 9 CFR 3.66 - Handling.


    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Handling. 3.66 Section 3.66 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of...

  10. 29 CFR 1917.18 - Log handling.


    ... 29 Labor 7 2010-07-01 2010-07-01 false Log handling. 1917.18 Section 1917.18 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.18 Log handling. (a) The employer shall ensure that structures (bunks) used to contain logs have rounded corners and rounded structural parts to avoid...

  11. 38 CFR 1.660 - Expeditious handling.


    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Expeditious handling. 1.660 Section 1.660 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS GENERAL PROVISIONS Inventions by Employees of Department of Veterans Affairs § 1.660 Expeditious handling. No patent...

  12. 30 CFR 715.16 - Topsoil handling.


    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Topsoil handling. 715.16 Section 715.16 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS GENERAL PERFORMANCE STANDARDS § 715.16 Topsoil handling. To prevent topsoil from being...

  13. 7 CFR 1219.11 - Handle.


    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HASS AVOCADO PROMOTION, RESEARCH, AND INFORMATION Hass Avocado Promotion, Research, and Information Order Definitions § 1219.11 Handle. Handle means to pack, process, transport, purchase, or in any other way to place or cause Hass...

  14. Information Handling, Organizational Structure, and Power.

    Buckland, Michael K.


    Uses examples from military strategic communications to demonstrate that organizational structures and the distribution of power within organizational structures adapt to changes in information handling capability. It is concluded that delegation and decentralization can be viewed as indicative of inadequate information handling and that improved…

  15. Storage and Handling of Commercially Packaged Foods

    Villalba, Abigail; Boyer, Renee Raiden; Bazemore, Sherry


    Proper selection of foods at the grocery store and appropriate storage and handling practices at home are necessary to maintain the quality and safety of commercially processed foods and perishable foods. This brochure offers some guidelines to follow when buying, handling, and storing packaged foods.

  16. Material Handling Equipment Evaluation for Crater Repair


    material handling equipment with a reduced logistical footprint for use by crater repair teams in airfield damage repair (ADR) scenarios. A market ...compared to currently utilized material handling equipment. This report presents the results of the market survey and equipment evaluations. Results...1 1.2 Objective and scope

  17. Feasibility of Upper Port Plug tube handling

    Koning, J.F.; Elzendoorn, B.S.Q.; Ronden, D.M.S.; Klinkhamer, J.F.F.; Biel, W.; Krasikov, Y.; Walker, C.I.


    Central, retractable tubes are proposed in several Upper Port Plugs (UPPs) designs for ITER, to enable fast exchange of specific components of diagnostics housed in these UPPs. This paper investigates into possible designs to enable the efficient handling of tubes. The feasibility of tube handling i

  18. 7 CFR 765.151 - Handling payments.


    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Handling payments. 765.151 Section 765.151 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DIRECT LOAN SERVICING-REGULAR Borrower Payments § 765.151 Handling payments. (a) Borrower...

  19. Reducing Mouse Anxiety during Handling: Effect of Experience with Handling Tunnels

    Kelly Gouveia; Hurst, Jane L.


    Handling stress is a well-recognised source of variation in animal studies that can also compromise the welfare of research animals. To reduce background variation and maximise welfare, methods that minimise handling stress should be developed and used wherever possible. Recent evidence has shown that handling mice by a familiar tunnel that is present in their home cage can minimise anxiety compared with standard tail handling. As yet, it is unclear whether a tunnel is required in each home c...

  20. Liquid jets injected into non-uniform crossflow

    Tambe, Samir

    An experimental study has been conducted with liquid jets injected transversely into a crossflow to study the effect of non-uniformities in the crossflow velocity distribution to the jet behavior. Two different non-uniform crossflows were created during this work, a shear-laden crossflow and a swirling crossflow. The shear-laden crossflow was generated by merging two independent, co-directional, parallel airstreams creating a shear mixing layer at the interface between them. The crossflow exhibited a quasi-linear velocity gradient across the height of the test chamber. By varying the velocities of the two airstreams, the sense and the slope of the crossflow velocity gradient could be changed. Particle Image Velocimetry (PIV) studies were conducted to characterize the crossflow. The parameter, UR, is defined as the ratio of the velocities of the two streams and governs the velocity gradient. A positive velocity gradient was observed for UR > 1 and a negative velocity gradient for UR 1), jet penetration increased and the Sauter Mean Diameter (SMD) distribution became more uniform. For low UR (designed axial swirlers. Three swirlers were used, with vane exit angles of 30°, 45° and 60°. Laser Doppler Velocimetry (LDV) was used to study the crossflow velocities. The axial (Ux) and the tangential (Utheta) components of the crossflow velocity were observed to decrease with increasing radial distance away from the centerbody. The flow angle of the crossflow was smaller than the vane exit angle, with the difference increasing with the vane exit angle. Water jets were injected from a 0.5 mm diameter orifice located on a cylindrical centerbody. Multi-plane PIV measurements were conducted to study the penetration and droplet velocity distribution of the jets. The jets were observed to follow a path close to the helical trajectory of the crossflow with a flow angle slightly less than the crossflow. This deficit in flow angle is attributed to the centrifugal acceleration

  1. Degradation nonuniformity in the solar diffuser bidirectional reflectance distribution function.

    Sun, Junqiang; Chu, Mike; Wang, Menghua


    The assumption of angular dependence stability of the solar diffuser (SD) throughout degradation is critical to the on-orbit calibration of the reflective solar bands (RSBs) in many satellite sensors. Recent evidence has pointed to the contrary, and in this work, we present a thorough investigative effort into the angular dependence of the SD degradation for the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite and for the twin Moderate-resolution Imaging Spectroradiometer (MODIS) onboard Terra and Aqua spacecrafts. One common key step in the RSB calibration is the use of the SD degradation performance measured by an accompanying solar diffuser stability monitor (SDSM) as a valid substitute for the SD degradation factor in the direction of the RSB view. If SD degradations between these two respective directions do not maintain the same relative relationship over time, then the unmitigated use of the SDSM-measured SD degradation factor in the RSB calibration calculation will generate bias, and consequently, long-term drift in derived science products. We exploit the available history of the on-orbit calibration events to examine the response of the SDSM and the RSB detectors to the incident illumination reflecting off SD versus solar declination angle and show that the angular dependency, particularly at short wavelengths, evolves with respect to time. The generalized and the decisive conclusion is that the bidirectional reflectance distribution function (BRDF) of the SD degrades nonuniformly with respect to both incident and outgoing directions. Thus, the SDSM-based measurements provide SD degradation factors that are biased relative to the RSB view direction with respect to the SD. The analysis also reveals additional interesting phenomena, for example, the sharp behavioral change in the evolving angular dependence observed in Terra MODIS and SNPP VIIRS. For SNPP VIIRS the mitigation for this

  2. Flexible Electrostatic Technology for Capture and Handling Project

    Keys, Andrew; Bryan, Tom; Horwitz, Chris; Rakoczy, John; Waggoner, Jason


    To NASA unfunded & planned missions: This new capability to sense proximity, flexibly align to, and attractively grip and capture practically any object in space without any pre-designed physical features or added sensors or actuators will enable or enhance many of MSFC's strategic emphasis areas in space transportation, and space systems such as: 1. A Flexible Electrostatic gripper can enable the capture, gripping and releasing of an extraterrestrial sample of different minerals or a sample canister (metallic or composite) without requiring a handle or grapple fixture.(B) 2. Flexible self-aligning in-space capture/soft docking or berthing of ISS resupply vehicles, pressurized modules, or nodes for in-space assembly and shielding, radiator, and solar Array deployment for space habitats (C) 3. The flexible electrostatic gripper when combined with a simple steerable extendible boom can grip, position, and release objects of various shapes and materials with low mass and power without any prior handles or physical accommodations or surface contamination for ISS experiment experiments and in-situ repair.(F)(G) 4. The Dexterous Docking concept previously proposed to allow simple commercial resupply ships to station-keep and capture either ISS or an Exploration vehicle for supply or fluid transfer lacked a self-sensing, compliant, soft capture gripper like FETCH that could retract and attach to a CBM. (I) 5. To enable a soft capture and de-orbit of a piece of orbital debris will require self-aligning gripping and holding an object wherever possible (thermal coverings or shields of various materials, radiators, solar arrays, antenna dishes) with little or no residual power while adding either drag or active low level thrust.(K) 6. With the scalability of the FETCH technology, small satellites can be captured and handled or can incorporate FETCH gripper to dock to and handle other small vehicles and larger objects for de-orbiting or mitigating Orbital debris (L) 7. Many of

  3. Further Development of Ko Displacement Theory for Deformed Shape Predictions of Nonuniform Aerospace Structures

    Ko, William L.; Fleischer, Van Tran


    The Ko displacement theory previously formulated for deformed shape predictions of nonuniform beam structures is further developed mathematically. The further-developed displacement equations are expressed explicitly in terms of geometrical parameters of the beam and bending strains at equally spaced strain-sensing stations along the multiplexed fiber-optic sensor line installed on the bottom surface of the beam. The bending strain data can then be input into the displacement equations for calculations of local slopes, deflections, and cross-sectional twist angles for generating the overall deformed shapes of the nonuniform beam. The further-developed displacement theory can also be applied to the deformed shape predictions of nonuniform two-point supported beams, nonuniform panels, nonuniform aircraft wings and fuselages, and so forth. The high degree of accuracy of the further-developed displacement theory for nonuniform beams is validated by finite-element analysis of various nonuniform beam structures. Such structures include tapered tubular beams, depth-tapered unswept and swept wing boxes, width-tapered wing boxes, and double-tapered wing boxes, all under combined bending and torsional loads. The Ko displacement theory, combined with the fiber-optic strain-sensing system, provide a powerful tool for in-flight deformed shape monitoring of unmanned aerospace vehicles by ground-based pilots to maintain safe flights.

  4. Correction of multi-spectral MRI intensity non-uniformity via spatially regularized feature condensing

    Vovk, Uros; Pernus, Franjo; Likar, Bostjan


    In MRI, image intensity non-uniformity is an adverse phenomenon that increases inter-tissue overlapping. The aim of this study was to provide a novel general framework, named regularized feature condensing (RFC), for condensing the distribution of image features and apply it to correct intensity non-uniformity via spatial regularization. The proposed RCF method is an iterative procedure, which consists of four basic steps. First, creation of a feature space, which consists of multi-spectral image intensities and corresponding second derivatives. Second, estimation of the intensity condensing map in feature space, i.e. the estimation of the increase of feature probability densities by a well-established mean shift procedure. Third, regularization of intensity condensing map in image space, which yields the estimation of intensity non-uniformity. Fourth, applying the estimation of non-uniformity correction to the input image. In this way, the intensity distributions of distinct tissues are gradually condensed via spatial regularization. The method was tested on simulated and real MR brain images for which gold standard segmentations were available. The results showed that the method did not induce additional intensity variations in simulated uniform images and efficiently removed intensity non-uniformity in real MR brain images. The proposed RCF method is a powerful fully automated intensity non-uniformity correction method that makes no a prior assumptions on the image intensity distribution and provides non-parametric non-uniformity correction.

  5. Method and apparatus for enhancing vortex pinning by conformal crystal arrays

    Janko, Boldizsar; Reichhardt, Cynthia; Reichhardt, Charles; Ray, Dipanjan


    Disclosed is a method and apparatus for strongly enhancing vortex pinning by conformal crystal arrays. The conformal crystal array is constructed by a conformal transformation of a hexagonal lattice, producing a non-uniform structure with a gradient where the local six-fold coordination of the pinning sites is preserved, and with an arching effect. The conformal pinning arrays produce significantly enhanced vortex pinning over a much wider range of field than that found for other vortex pinning geometries with an equivalent number of vortex pinning sites, such as random, square, and triangular.

  6. Novel Method for Optimal Synthesis of 5G Millimeter Wave Linear Antenna Array

    Zarko Rosic


    Full Text Available We will propose a useful method for 5G mm wave antenna array synthesis, based on Genetic Algorithm for the synthesis of linear array with nonuniform interelement spacing. Our design method was used to obtain the optimal position of the elements in order to get the minimum side lobe level and nulls in desired directions. The simulation results verify that proposed method outperforms the previously published methods in terms of suppression side lobe level while maintaining nulls in specified directions. The flexibility of proposed algorithm shows good potential for the antenna array synthesis.

  7. Modified Fruit Fly Optimization Algorithm for Analysis of Large Antenna Array

    Nattaset Mhudtongon


    Full Text Available This research paper deals with the optimization of a large antenna array for maximum directivity using a modified fruit fly optimization algorithm (MFOA with random search of two groups of swarm and adaptive fruit fly swarm population size. The MFOA is utilized to determine three nonlinear mathematical test functions, analysis of the optimal number of elements and optimal element spacing of the large antenna array, and analysis of nonuniform amplitude of antenna array. The numerical results demonstrate that the MFOA is effective in solving all test function and electromagnetic problems. The advantages of the proposed algorithm are ease of implementation, large search range, less processing time, and reduced memory requirement.

  8. Generalized quantum counting algorithm for non-uniform amplitude distribution

    Tan, Jianing; Ruan, Yue; Li, Xi; Chen, Hanwu


    We give generalized quantum counting algorithm to increase universality of quantum counting algorithm. Non-uniform initial amplitude distribution is possible due to the diversity of situations on counting problems or external noise in the amplitude initialization procedure. We give the reason why quantum counting algorithm is invalid on this situation. By modeling in three-dimensional space spanned by unmarked state, marked state and free state to the entire Hilbert space of n qubits, we find Grover iteration can be regarded as improper rotation in the space. This allows us to give formula to solve counting problem. Furthermore, we express initial amplitude distribution in the eigenvector basis of improper rotation matrix. This is necessary to obtain mathematical analysis of counting problem on various situations. Finally, we design four simulation experiments, the results of which show that compared with original quantum counting algorithm, generalized quantum counting algorithm wins great satisfaction from three aspects: (1) Whether initial amplitude distribution is uniform; (2) the diversity of situations on counting problems; and (3) whether phase estimation technique can get phase exactly.

  9. The Non-uniform Fast Fourier Transform in Computed Tomography

    Tang, Junqi


    This project is aimed at designing the fast forward projection algorithm and also the backprojection algorithm for cone beam CT imaging systems with circular X-ray source trajectory. The principle of the designs is based on utilizing the potential computational efficiency which the Fourier Slice Theorem and the Non-uniform Fast Fourier Transform (NUFFT) will bring forth. In this Masters report, the detailed design of the NUFFT based forward projector including a novel 3D (derivative of) Radon space resampling method will be given. Meanwhile the complexity of the NUFFT based forward projector is analysed and compared with the non-Fourier based CT projector, and the advantage of the NUFFT based forward projection in terms of the computational efficiency is demonstrated in this report. Base on the design of the forward algorithm, the NUFFT based 3D direct reconstruction algorithm will be derived. The experiments will be taken to test the performance of the forward algorithm and the backprojection algorithm to sh...

  10. A non-uniform distribution of the nearest brown dwarfs

    Bihain, G


    The census of solar neighbours is still complemented by new discoveries, mainly of very low-mass, faint dwarfs, close to or within the substellar domain. These discoveries contribute to a better understanding of the field population; its origin in terms of Galactic dynamics and (sub)stellar formation and evolution. Also, the nearest stars and brown dwarfs at any given age allow the most precise direct characterization, including the search for planetary companions. We aim to further assess the substellar census on the Galactic plane. We projected the 136 stars and 26 brown dwarfs known at <6.5 pc on the Galactic plane and evaluated their distributions. Stars present a uniform- and brown dwarfs a non-uniform distribution, with 21 objects behind the Sun and only five ahead relative to the direction of rotation of the Galaxy. This substellar configuration has a probability of 0.098$^{+10.878}_{-0.098}$% relative to uniformity. The helio- and geocentric nature of the distribution suggests it might result in pa...

  11. Nonuniform Oxidation on the Surface of Fuel Element in HTR

    Peng Liu


    Full Text Available The graphite oxidation of fuel element has obtained high attention in air ingress accident analysis of high temperature gas-cooled reactor (HTR. The shape function, defined as the relationship between the maximum and the average of the oxidation, is an important factor to estimate the consequence of the accident. There are no detailed studies on the shape function currently except two experiments several decades ago. With the development of computer technology, CFD method is used in the numerical experiment about graphite oxidation in pebble bed of HTR in this paper. Structured packed beds are used in the calculation instead of random packed beds. The result shows the nonuniform distribution of oxidation on the sphere surface and the shape function in the condition of air ingress accident. Furthermore, the sensitive factors of shape function, such as temperature and Re number, are discussed in detail and the relationship between the shape function and sensitive factors is explained. According to the results in this paper, the shape function ranges from 1.05 to 4.7 under the condition of temperature varying from 600°C to 1200°C and Re varying from 16 to 1600.

  12. Nanomagnetic logic with non-uniform states of clocking

    Puliafito, Vito; Giordano, Anna; Azzerboni, Bruno; Finocchio, Giovanni


    Nanomagnetic logic transmits information along a path of nanomagnets. The basic mechanism to drive such a transmission, known as clocking, can be achieved by exploiting the spin-Hall effect (SHE), as recently observed in experiments on Ta/CoFeB/MgO multilayers (Bhowmik et al 2014 Nat. Nano 9 59). This paper shows the fundamental mechanism of the spin-Hall driven clocking by using a full micromagnetic framework and considering two different devices, Ta/CoFeB/MgO and Pt/CoFeB/MgO. The former is used for a direct comparison of the numerical results with the experiments while the latter permits the effect of the Dzyaloshinskii-Moriya interaction (DMI) in the clocking mechanism to be predicted. Results show that the clocking state is non-uniform and it is characterized by the presence of domains separated by Bloch (Néel) domain walls depending on the absence (presence) of the DMI. Our findings point out that for the design of nanomagnetic logic a full micromagnetic approach is necessary.

  13. Buckling of un-stiffened cylindrical shell under non-uniform axial conpressive stress



    This paper provides a review of recent research advances and trends in the area of stability of un-stiffened circular cylindrical shells subjected to general non-uniform axial compressive stresses. Only the more important and interesting aspects of the research, judged from a personal viewpoint, are discussed. They can be crudely classified into four categories: (1) shells subjected to non-uniform loads; (2) shells on discrete supports; (3) shells with intended cutouts/holes; and (4) shells with non-uniform settlements.

  14. On Basic Parameters and Radiation Theory of Non-Uniform Channel DMOS

    LI Ze- hong


    @@ Researching the non-uniform channel DMOS is the basic knowledge of the new generation high voltage power MOS devices and the important domain of the IC, smart power ICs. This dissertation investigates the basic parameters and the radiation theory of non-uniform channel DMOS. The threshold voltage model of micron and deep sub-micron non-uniform channel DMOS, the radiation threshold voltage model,the radiation mobility model and the transient response model of single ion radiation are internationally proposed for the first time.

  15. Buckling analysis of stringer-stiffened laminated cylindrical shells with nonuniform eccentricity

    Sadeghifar, M. [Islamic Azad University, Department of Mechanical Engineering, Nowshahr Branch, Nowshahr (Iran, Islamic Republic of); Bagheri, M. [Sattari Air University, Faculty of Aerospace Engineering, Tehran (Iran, Islamic Republic of); Jafari, A.A. [K.N. Toosi University of Technology, Faculty of Mechanical Engineering, Tehran (Iran, Islamic Republic of)


    In this study, the influence of nonuniformity of eccentricity of stringers on the general axial buckling load of stiffened laminated cylindrical shells with simply supported end conditions is investigated. The critical loads are calculated using Love's First-order Shear Deformation Theory and solved using the Rayleigh-Ritz procedure. The effects of the shell length-to-radius ratio, shell thickness-to-radius ratio, number of stringers, and stringers depth-to-width ratio on the buckling load of nonuniformly eccentric shells, are examined. The research demonstrates that an appropriate nonuniform distribution of eccentricity of stringers leads the buckling load to increase significantly. (orig.)

  16. Decentralized PD Control for Non-uniform Motion of a Hamiltonian Hybrid System

    Mingcong Deng; Hongnian Yu; Akira Inoue


    In this paper, a decentralized proportional-derivative (PD) controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-uniform motion is developed. The structural properties of the system are investigated by means of the theory of Hamiltonian systems. A relationship between the parameters of the system and the parameters of the proposed decentralized PD controller is shown to ensure local stability and tracking performance. Simulation results are included to show the obtained non-uniform motion.

  17. A Method to Reconstruct Nth-Order Periodically Nonuniform Sampled Signals

    ZHANG Yao


    It is well known that nonuniform sampling is usually needed in special signals processing.In this paper, a general method to reconstruct Nth-order periodically nonuniform sampled signals is presented which is also developed to digital domain, and the designs of the digital filters and the synthesis system are given. This paper extends the studies of Kohlenberg, whose work concentrate on the periodically nonuniform sampling of second order, as well as the studies of A.J. Coulson, J.L.Brown,whose work deal with the problems of two-band signals' Nth-order sampling and reconstruction.

  18. Effects of non-uniform core flow on peak cladding temperature: MOXY/SCORE sensitivity calculations

    Chang, S.C.


    The MOXY/SCORE computer program is used to evaluate the potential effect on peak cladding temperature of selective cooling that may result from a nonuniform mass flux at the core boundaries during the blowdown phase of the LOFT L2-4 test. The results of this study indicate that the effect of the flow nonuniformity at the core boundaries will be neutralized by a strong radial flow redistribution in the neighborhood of core boundaries. The implication is that the flow nonuniformity at the core boundaries has no significant effect on the thermal-hydraulic behavior and cladding temperature at the hot plane.

  19. The magnetostriction in a superconductor-magnet system under non-uniform magnetic field

    Li, Xueyi; Jiang, Lang; Wu, Hao; Gao, Zhiwen


    This paper describes a numerical model to examine the magnetostriction of bulk high-temperature superconductor (HTS) under non-uniform magnetic field in conjunction with finite element analysis. Through this model, the magnetostriction of homogeneous and nonhomogeneous HTS can be implemented under non-uniform magnetic field. Further, the effects of critical current density, applied field frequency and amplitude are also considered. The computational study can provide a fundamental mechanistic understanding the effects of non-uniform magnetic field on magnetostriction of HTS.

  20. Anchor handling tug operations: a practical guide to the operation of modern anchor handling tugs engaged in anchor handling and towing operations

    Clark, I.C; Hancox, M


    ... --Turning and manoeuvring modern anchor handling vessels --The AHTS design and towing operations --The dangers of very high speed loads during deep water anchor handling operations --The dangers...

  1. Solid state temperature-dependent NUC (non-uniformity correction) in uncooled LWIR (long-wave infrared) imaging system

    Cao, Yanpeng; Tisse, Christel-Loic


    In uncooled LWIR microbolometer imaging systems, temperature fluctuations of FPA (Focal Plane Array) as well as lens and mechanical components placed along the optical path result in thermal drift and spatial non-uniformity. These non-idealities generate undesirable FPN (Fixed-Pattern-Noise) that is difficult to remove using traditional, individual shutterless and TEC-less (Thermo-Electric Cooling) techniques. In this paper we introduce a novel single-image based processing approach that marries the benefits of both statistical scene-based and calibration-based NUC algorithms, without relying neither on extra temperature reference nor accurate motion estimation, to compensate the resulting temperature-dependent non-uniformities. Our method includes two subsequent image processing steps. Firstly, an empirical behavioral model is derived by calibrations to characterize the spatio-temporal response of the microbolometric FPA to environmental and scene temperature fluctuations. Secondly, we experimentally establish that the FPN component caused by the optics creates a spatio-temporally continuous, low frequency, low-magnitude variation of the image intensity. We propose to make use of this property and learn a prior on the spatial distribution of natural image gradients to infer the correction function for the entire image. The performance and robustness of the proposed temperature-adaptive NUC method are demonstrated by showing results obtained from a 640×512 pixels uncooled LWIR microbolometer imaging system operating over a broad range of temperature and with rapid environmental temperature changes (i.e. from -5°C to 65°C within 10 minutes).

  2. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design.

    Cochran, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This report presents conceptual design information for a system to handle and emplace packages containing radioactive waste, in boreholes 16,400 ft deep or possibly deeper. Its intended use is for a design selection study that compares the costs and risks associated with two emplacement methods: drill-string and wireline emplacement. The deep borehole disposal (DBD) concept calls for siting a borehole (or array of boreholes) that penetrate crystalline basement rock to a depth below surface of about 16,400 ft (5 km). Waste packages would be emplaced in the lower 6,560 ft (2 km) of the borehole, with sealing of appropriate portions of the upper 9,840 ft (3 km). A deep borehole field test (DBFT) is planned to test and refine the DBD concept. The DBFT is a scientific and engineering experiment, conducted at full-scale, in-situ, without radioactive waste. Waste handling operations are conceptualized to begin with the onsite receipt of a purpose-built Type B shipping cask, that contains a waste package. Emplacement operations begin when the cask is upended over the borehole, locked to a receiving flange or collar. The scope of emplacement includes activities to lower waste packages to total depth, and to retrieve them back to the surface when necessary for any reason. This report describes three concepts for the handling and emplacement of the waste packages: 1) a concept proposed by Woodward-Clyde Consultants in 1983; 2) an updated version of the 1983 concept developed for the DBFT; and 3) a new concept in which individual waste packages would be lowered to depth using a wireline. The systems described here could be adapted to different waste forms, but for design of waste packaging, handling, and emplacement systems the reference waste forms are DOE-owned high- level waste including Cs/Sr capsules and bulk granular HLW from fuel processing. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design July 23, 2015 iv ACKNOWLEDGEMENTS This report has

  3. How the NWC handles software as product

    Vinson, D.


    This tutorial provides a hands-on view of how the Nuclear Weapons Complex project should be handling (or planning to handle) software as a product in response to Engineering Procedure 401099. The SQAS has published the document SQAS96-002, Guidelines for NWC Processes for Handling Software Product, that will be the basis for the tutorial. The primary scope of the tutorial is on software products that result from weapons and weapons-related projects, although the information presented is applicable to many software projects. Processes that involve the exchange, review, or evaluation of software product between or among NWC sites, DOE, and external customers will be described.

  4. Handling of bulk solids theory and practice

    Shamlou, P A


    Handling of Bulk Solids provides a comprehensive discussion of the field of solids flow and handling in the process industries. Presentation of the subject follows classical lines of separate discussions for each topic, so each chapter is self-contained and can be read on its own. Topics discussed include bulk solids flow and handling properties; pressure profiles in bulk solids storage vessels; the design of storage silos for reliable discharge of bulk materials; gravity flow of particulate materials from storage vessels; pneumatic transportation of bulk solids; and the hazards of solid-mater

  5. Reducing mouse anxiety during handling: effect of experience with handling tunnels.

    Gouveia, Kelly; Hurst, Jane L


    Handling stress is a well-recognised source of variation in animal studies that can also compromise the welfare of research animals. To reduce background variation and maximise welfare, methods that minimise handling stress should be developed and used wherever possible. Recent evidence has shown that handling mice by a familiar tunnel that is present in their home cage can minimise anxiety compared with standard tail handling. As yet, it is unclear whether a tunnel is required in each home cage to improve response to handling. We investigated the influence of prior experience with home tunnels among two common strains of laboratory mice: ICR(CD-1) and C57BL/6. We compared willingness to approach the handler and anxiety in an elevated plus maze test among mice picked up by the tail, by a home cage tunnel or by an external tunnel shared between cages. Willingness to interact with the handler was much greater for mice handled by a tunnel, even when this was unfamiliar, compared to mice picked up by the tail. Once habituated to handling, C57BL/6 mice were most interactive towards a familiar home tunnel, whereas the ICR strain showed strong interaction with all tunnel handling regardless of any experience of a home cage tunnel. Mice handled by a home cage or external tunnel showed less anxiety in an elevated plus maze than those picked up by the tail. This study shows that using a tunnel for routine handling reduces anxiety among mice compared to tail handling regardless of prior familiarity with tunnels. However, as home cage tunnels can further improve response to handling in some mice, we recommend that mice are handled with a tunnel provided in their home cage where possible as a simple practical method to minimise handling stress.

  6. A design of FPGA based intelligent data handling interfacing card.

    Anandaraj D


    Full Text Available With the increasing demand in the custom built logic for avionics systems, FPGA is used in this proposed interfacing card design. This FPGA based intelligent data handling card (IDHC for the IVHM system, will interface the data from aircraft subsystems to the aircraft digital data bus. This IDHC interfacing card is based on the Virtex-5 FPGA (Field Programmable Gate Array, which provides flexibility by re-programming, so that it can be configured to the required functionality. Fault detection can be done within the FPGA and only the anomalies passed to the computer, so that the bus bandwidth can be utilized effectively and also excessive wiring can be eliminated, that would have been required for multiple individual systems. The work concentrates on designing the schematic using OrCAD.

  7. A Synthesis Instance Pruning Approach Based on Virtual Non-uniform Replacements

    ZHANG Wei; LING Zhenhua; HU Guoping; WANG Renhua


    The employment of non-uniform processes assists greatly in the corpus-based text-to-speech (TTS) system to synthesize natural speech.However,tailoring a TTS voice font,or pruning redundant syn-thesis instances,usually results in loss of non-uniform synthesis instances.In order to solve this problem,we propose the concept of virtual non-uniform instances.According to this concept and the synthesis fre-quency of each instance,the algorithm named StaRp-VPA is constructed to make up for the loss of non-uniform instances.In experimental testing,the naturalness scored by the mean opinion score (MOS) re-mains almost unchanged when less than 50% instances are pruned,and the MOS is only slightly degraded for reduction rates above 50%.The test results show that the algorithm StaRp-VPA is effective.


    WAN Zhengsu; CHEN Guangnan


    In this paper, a difference scheme with nonuniform meshes is established for the initial-boundary problem of the nonlinear parabolic system. It is proved that the difference scheme is second order convergent in spacestep and timestep.

  9. Impact of non-uniform surface magnetic fields on stellar winds

    Holzwarth, V R


    Observations of active stars reveal highly non-uniform surface distributions of magnetic flux. Theoretical models considering magnetised stellar winds however often presume uniform surface magnetic fields, characterised by a single magnetic field strength. The present work investigates the impact of non-uniform surface magnetic field distributions on the stellar mass and angular momentum loss rates. The approach of Weber & Davis (1967) is extended to non-equatorial latitudes to quantify the impact of latitude-dependent magnetic field distributions over a large range of stellar rotation rates and thermal wind properties. The analytically prescribed field patterns are dominated by magnetic flux concentrations at intermediate and high latitudes. The global stellar mass loss rates are found to be rather insensitive to non-uniformities of the surface magnetic field. Depending on the non-uniformity of the field distribution, the angular momentum loss rates deviate in contrast at all rotation rates between -60% ...

  10. Factorization method for difference equations of hypergeometric type on nonuniform lattices

    Alvarez-Nodarse, R. [Departamento de Analisis Matematico, Universidad de Sevilla, Sevilla (Spain); Instituto Carlos I de Fisica Teorica y Computacional, Universidad de Granada, Granada (Spain); Costas-Santos, R.S. [Departamento de Analisis Matematico, Universidad de Sevilla, Sevilla (Spain)


    We study the factorization of the hypergeometric-type difference equation of Nikiforov and Uvarov on nonuniform lattices. An explicit form of the raising and lowering operators is derived and some relevant examples are given. (author)

  11. Excitation of kinetic geodesic acoustic modes by drift waves in nonuniform plasmas

    Qiu, Z. [Inst. Fusion Theory and Simulation, Zhejiang Univ., Hangzhou 310027 (China); Chen, L. [Inst. Fusion Theory and Simulation, Zhejiang Univ., Hangzhou 310027 (China); Dept. Physics and Astronomy, Univ. of California, Irvine, California 92697-4575 (United States); Zonca, F. [Inst. Fusion Theory and Simulation, Zhejiang Univ., Hangzhou 310027 (China); Associazione Euratom-ENEA sulla Fusione, C.P. 65 - I-00044 - Frascati (Italy)


    Effects of system nonuniformities and kinetic dispersiveness on the spontaneous excitation of Geodesic Acoustic Mode (GAM) by Drift Wave (DW) turbulence are investigated based on nonlinear gyrokinetic theory. The coupled nonlinear equations describing parametric decay of DW into GAM and DW lower sideband are derived and then solved both analytically and numerically to investigate the effects on the parametric decay process due to system nonuniformities, such as nonuniform diamagnetic frequency, finite radial envelope of DW pump, and kinetic dispersiveness. It is found that the parametric decay process is a convective instability for typical tokamak parameters when finite group velocities of DW and GAM associated with kinetic dispersiveness and finite radial envelope are taken into account. When, however, nonuniformity of diamagnetic frequency is taken into account, the parametric decay process becomes, time asymptotically, a quasi-exponentially growing absolute instability.

  12. The magnetostriction in a superconductor-magnet system under non-uniform magnetic field

    Li, Xueyi; Jiang, Lang; Wu, Hao [Key Laboratory of Mechanics on Disaster and Environment in Western China attached to the Ministry of Education of China, Lanzhou University, Lanzhou, Gansu 730000 (China); Gao, Zhiwen, E-mail: [Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000 (China)


    Highlights: • We studied firstly magnetostriction in HTS under non-uniform magnetic field. • The superconductors may be homogeneous and nonhomogeneous. • The magnetostrictions response of the HTS is sensitive to the critical current density and amplitude of the applied magnetic field. • The magnetostriction of nonhomogeneous HTS is larger than that of homogeneous HTS. - Abstract: This paper describes a numerical model to examine the magnetostriction of bulk high-temperature superconductor (HTS) under non-uniform magnetic field in conjunction with finite element analysis. Through this model, the magnetostriction of homogeneous and nonhomogeneous HTS can be implemented under non-uniform magnetic field. Further, the effects of critical current density, applied field frequency and amplitude are also considered. The computational study can provide a fundamental mechanistic understanding the effects of non-uniform magnetic field on magnetostriction of HTS.

  13. Nonlinear Response of High Arch Dams to Nonuniform Seismic Excitation Considering Joint Effects

    Masoomeh Akbari


    Full Text Available Nonuniform excitation due to spatially varying ground motions on nonlinear responses of concrete arch dams is investigated. A high arch dam was selected as numerical example, reservoir was modelled as incompressible material, foundation was assumed as mass-less medium, and all contraction and peripheral joints were modelled considering the ability of opening/closing. This study used Monte-Carlo simulation approach for generating spatially nonuniform ground motion. In this approach, random seismic characteristics due to incoherence and wave passage effects were investigated and finally their effects on structural response were compared with uniform excitation at design base level earthquake. Based on the results, nonuniform input leads to some differences than uniform input. Moreover using nonuniform excitation increase, stresses on dam body.

  14. Management of transport and handling contracts

    Rühl, I


    This paper shall outline the content, application and management strategies for the various contracts related to transport and handling activities. In total, the two sections Logistics and Handling Maintenance are in charge of 27 (!) contracts ranging from small supply contracts to big industrial support contracts. The activities as well as the contracts can generally be divided into four main topics "Vehicle Fleet Management"; "Supply, Installation and Commissioning of Lifting and Hoisting Equipment"; "Equipment Maintenance" and "Industrial Support for Transport and Handling". Each activity and contract requires different approaches and permanent adaptation to the often changing CERN's requirements. In particular, the management and the difficulties experienced with the contracts E072 "Maintenance of lifting and hoisting equipment", F420 "Supply of seven overhead traveling cranes for LHC" and S090/S103 "Industrial support for transport and handling" will be explained in detail.

  15. Handling knowledge on osteoporosis - a qualitative study

    Nielsen, Dorthe; Huniche, Lotte; Brixen, Kim


    Scand J Caring Sci; 2012 Handling knowledge on osteoporosis - a qualitative study The aim of this qualitative study was to increase understanding of the importance of osteoporosis information and knowledge for patients' ways of handling osteoporosis in their everyday lives. Interviews were...... performed with 14 patients recruited from two English university hospitals and 12 patients from a Danish university hospital. Critical psychology was used as a theoretical framework for the data analysis, which aimed at shedding light on patients' ways of conducting everyday life with osteoporosis....... The themes that emerged from the analysis showed that life conditions influenced the way in which risk, pain and osteoporosis were handled. Everyday life was also influenced by patients' attitude to treatment. The patients who were experiencing emotional difficulties in handling osteoporosis were not those...

  16. Live-trapping and handling brown bear

    US Fish and Wildlife Service, Department of the Interior — This paper reports techniques developed to live trap and handle brown bears on the Kodiak National Wildlife Refuge. The brown bears (Ursus middendorffi) on the...

  17. Aerobot Sampling and Handling System Project

    National Aeronautics and Space Administration — Honeybee Robotics proposes to: ?Derive and document the functional and technical requirements for Aerobot surface sampling and sample handling across a range of...

  18. 7 CFR 926.9 - Handle.



  19. How Do Search Engines Handle Chinese Queries?

    Hong Cui


    Full Text Available The use of languages other than English has been growing exponentially on the Web. However, the major search engines have been lagging behind in providing indexes and search features to handle these languages. This article explores the characteristics of the Chinese language and how queries in this language are handled by different search engines. Queries were entered in two major search engines (Google and AlltheWeb and two search engines developed for Chinese (Sohu and Baidu. Criteria such as handling word segmentation, number of retrieved documents, and correct display and identification of Chinese characters were used to examine how the search engines handled the queries. The results showed that the performance of the two major search engines was not on a par with that of the search engines developed for Chinese.

  20. GeoLab Sample Handling System Project

    National Aeronautics and Space Administration — Develop  a robotic sample handling/ manipulator system for the GeoLab glovebox. This work leverages from earlier GeoLab work and a 2012 collaboration with a...

  1. 30o inclination in handles of plastic boxes can reduce postural and muscular workload during handling

    Luciana C. C. B. Silva


    Full Text Available BACKGROUND: The handling of materials, which occurs in the industrial sector, is associated with lesions on the lumbar spine and in the upper limbs. Inserting handles in industrial boxes is a way to reduce work-related risks. Although the position and angle of the handles are significant factors in comfort and safety during handling, these factors have rarely been studied objectively. OBJECTIVE: To compare the handling of a commercial box and prototypes with handles and to evaluate the effects on upper limb posture, muscle electrical activity, and perceived acceptability using different grips while handling materials from different heights. METHOD: Thirty-seven healthy volunteers evaluated the handles of prototypes that allowed for changes in position (top and bottom and angle (0°, 15°, and 30°. Wrist, elbow, and shoulder movements were evaluated using electrogoniometry and inclinometry. The muscle electrical activity in the wrist extensors, biceps brachii, and the upper portion of the trapezius was measured using a portable electromyographer. The recorded data on muscle movements and electrical activity were synchronized. Subjective evaluations of acceptability were evaluated using a visual analog scale. RESULTS AND CONCLUSIONS: The prototypes with handles at a 30° angle produced the highest acceptability ratings, more neutral wrist positions, lower levels of electromyographic activity for the upper trapezius, and lower elevation angles for the arms. The different measurement methods were complementary in evaluating the upper limbs during handling.

  2. Development of standard components for remote handling

    Taguchi, Kou; Kakudate, Satoshi; Nakahira, Masataka; Ito, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment


    The core of Fusion Experimental Reactor consists of various components such as superconducting magnets and forced-cooled in-vessel components, which are remotely maintained due to intense of gamma radiation. Mechanical connectors such as cooling pipe connections, insulation joints and electrical connectors are commonly used for maintenance of these components and have to be standardized in terms of remote handling. This paper describes these mechanical connectors developed as the standard component compatible with remote handling and tolerable for radiation. (author)

  3. Safety Training: "Manual Handling" course in September

    Safety Training, HSE Unit


    The next "Manual Handling" course will be given, in French, on 26 September 2016. This course is designed for anyone required to carry out manual handling of loads in the course of their work.   The main objective of this course is to adopt and apply the basic principles of physical safety and economy of effort. There are places available. If you are interested in following this course, please fill an EDH training request via our catalogue. 

  4. Nonuniform blood flow in the canine left ventricle.

    Flynn, A E; Coggins, D L; Austin, R E; Muehrcke, D D; Aldea, G S; Goto, M; Doucette, J W; Hoffman, J I


    In order to investigate the relationship between coronary perfusion pressure and blood flow distribution in the left ventricle (LV), we measured myocardial blood flow in small regions using radioactive microspheres in six anesthetized, open-chest dogs. Mean coronary perfusion pressure (CPP) was controlled with a femoral artery to left main coronary artery shunt which included a pressurized, servo-controlled blood reservoir. In each dog, we measured flow in 192 regions of the LV free wall (mean weight per region = 206 +/- 38 mg) at different perfusion pressures. At CPP = 80 mm Hg, blood flow to individual regions varied fourfold (0.30 to 1.18 ml/min/g; relative dispersion (RD) = 21.8 +/- 2.3%). At CPP = 50 mm Hg, flow varied over sevenfold (0.08 to 0.60 ml/min/g; RD = 42.8 +/- 10%; P less than 0.01 vs 80 mm Hg). This relationship between flow variability and CPP was present within individual LV layers as well between layers and is much higher than the error associated with the microsphere technique. We conclude that blood flow to small regions of the LV is markedly nonuniform. This heterogeneity becomes more profound at lower CPP. These findings suggest that (1) global measurements of coronary flow must be interpreted with caution, and (2) even in hearts with normal coronary arteries some regions of the LV are more susceptible to ischemia than others. In addition, these findings may help explain the patchy nature of myocardial damage that occurs following periods of low coronary pressure or inadequate myocardial protection during cardiopulmonary bypass.

  5. Inhomogeneity Dislocation Interaction of Piezoelectric Materials Under Remote Non-uniform Shear & Electric Field


    The complex potentials method is used to develop a solution for a screw dislocation interacting with an elliptical piezoelectric inhomogeneity in piezoelectric materials under remote non-uniform antiplane shear and non-uniform inplane electric field. The theoretical analysis result is formulated via the conformal mapping and Laurent series expansion in the transformed plane by using complex variable method. The general expression of the complex variables is dirived explicitly in both the elliptical inhomogeneity and the surrounding matrix

  6. Thermal entanglement in a mixed-spin Heisenberg XXZ model under a nonuniform external magnetic field


    The thermal entanglement in (1/2,1) mixed-spin Heisenberg XXZ model is investigated under an external nonuniform magnetic field. In the uniform magnetic field system,the critical magnetic field Bc and critical temperature Tc are increased by increasing the anisotropic parameter k. The degree of magnetic field b plays an important role in improving the critical temperature and enlarging the region of entan-glement in the nonuniform magnetic field system.

  7. Entanglement in Anisotropic Heisenberg Model with Non-Uniform External Fields

    WANG Yuan-Feng; CAO Jun-Peng; WANG Yu-Peng


    @@ We study entanglement properties of the three-qubit anisotropic Heisenberg model with both uniform and nonuniform external magnetic fields. Analytic expressions for the measures of entanglement at the ground state are obtained. We show that the pairwise entanglement and global entanglement of the system at the ground state clearly depend on the strength and configuration of external fields. The entanglement between some pairs can be enhanced by non-uniform external fields.

  8. Resonant-state expansion of light propagation in non-uniform waveguides

    Lobanov, S. V.; Zoriniants, G.; Langbein, W.; Muljarov, E. A.


    A new rigorous approach for precise and efficient calculation of light propagation along non-uniform waveguides is presented. Resonant states of a uniform waveguide, which satisfy outgoing-wave boundary conditions, form a natural basis for expansion of the local electromagnetic field. Using such an expansion at fixed frequency, we convert the light propagation along a non-uniform waveguide into an ordinary second-order matrix differential equation for the expansion coefficients along the wave...

  9. Parallel Programming Methodologies for Non-Uniform Structured Problems in Materials Science


    COVERED 1 10/93 _ Interim 12/01/92 - 09/30/93 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Parallel Programming Methodologies for Non-Uniform Structured...Dear Dr. van Tilborg, Enclosed you will find the annual report for " Parallel Programming Methodolo- gies for Non-Uniform Structured Problems in...Quincy Street Arlington, VA 22217-5660 Dear Dr. van Tilborg, Enclosed you will find the annual report for " Parallel Programming Methodolo- gies for Non

  10. The Timoshenko-Reissner generalized model of a plate highly nonuniform in thickness

    Morozov, N. F.; Tovstik, P. E.; Tovstik, T. P.


    A thin plate fabricated of material that is transversally isotropic and nonuniform in thickness is considered. The model of the monolayer transversally homogeneous isotropic plate, which is approximately equivalent to a thickness-nonuniform plate in the deflection and in the lowest frequencies of free vibrations, is constructed. The range of applicability of the model constructed is very wide. The main result of this study is a formula for calculating the transverse-shear rigidity of an equivalent transversally isotropic plate.

  11. Epidemics of Sirs Model with Nonuniform Transmission on Scale-Free Networks

    Xia, C. Y.; Sun, S. W.; Liu, Z. X.; Chen, Z. Q.; Yuan, Z. Z.

    We investigate the effect of nonuniform transmission on the critical threshold of susceptible-infected-recovered-susceptible (SIRS) epidemic model on scale-free networks. Based on the mean-field theory, it is observed that the epidemic threshold is not only correlated with the topology of underlying networks, but also with the disease transmission mechanism (e.g., nonuniform transmission). The current findings will significantly help us to further understand the real epidemics taking place on social and technological networks.

  12. Influence of Non-Uniform Magnetic Field on Quantum Teleportation in Heisenberg XY Model

    SHAO Bin; YANG Tie-jian; ZHAO Yue-hong; ZOU Jian


    By considering the intrinsic decoherence, the validity of quantum teleportation of a two-qubit 1D Heisenberg XY chain in a non-uniform external magnetic field is studied. The fidelity as the measurement of a possible quantum teleportation is calculated and the effects of the non-uniform magnetic field and the intrinsic decoherence are discussed. It is found that anti-parallel magnetic field is more favorable for teleportation and the fidelity is suppressed by the intrinsic decoherence.


    Fabiana Fonseca Fortes


    Full Text Available This paper aims to identify handling and storage impact in iron ore quality, in their physical and chemical characteristics most important for a mining. It is tried to show the interferences in iron ore quality caused by the handling equipment and stockpiling. The research is restricted to Complexo Vargem Grande (Vale. The timeline was demarcated based on the formation of stockpiling. The fieldwork enables data collection and distinction of the routine procedures of casual operations handling. The quantitative analysis is conducted by the statistical method. As a conclusion, handling and storage identified are able to insert changes in physical and chemical characteristics of iron ore. Storage contributes to reduce variability of silica and alumina concentrations, but contributes too particle size deterioration. The handling induces degradation and segregation. However, there is the possibility to decrease handling of the ore and to establish the ideal size of stocks on the system in study, improving the efficiency of the system and consequent in global costs.

  14. Uniform versus Nonuniform Axial Power Distribution in Rod Bundle CHF Experiments

    Baowen Yang


    Full Text Available Rod bundle experiments with axially uniform and nonuniform heat fluxes are examined to explore the potential limitations of using uniform rod bundle CHF data for CHF correlation development of light water reactors with nonuniform axial power distribution (APD. The case of upstream burnout is presented as an example of unique phenomena associated with nonuniform rod bundle CHF experiments. It is a result from combined effect of axial nonuniform power shape and different interchannel mixing mechanisms. In addition, several key parameters are investigated with respect to their potential impacts on the thermal-hydraulic behaviors between rod bundles with uniform and nonuniform APDs. This type of misrepresentation cannot be amended or compensated through the use of correction factors due to the lack of critical information in the uniform rod bundle CHF testing as well as the fundamental difference in the underlining driving mechanisms. Other potential issues involved with the use of uniform rod bundle CHF data for nonuniform APD system applications also present strong evidence concerning the limitations and inadequacy of using uniform rod bundle CHF data for the correlation, prediction, and design limit calculation for safety analysis.

  15. Experimental and theoretical studies of the effects of nonuniformities in equilibrium MHD generators

    Rosenbaum, M.; Shamma, S.E.; Louis, J.F.


    An experimental study of the effects of thermal and velocity nonuniformities is performed in an equilibrium plasma for a range of Hall parameters. An electrodeless MHD disk generator with radial flow is chosen as the ideal geometry for these experiments. By introducing equally spaced cold blades in the flow, it is possible to create well defined two-dimensional wake nonuniformities with strong variations of the plasma properties in the direction normal to the magnetic field and the flow. This type of nonuniformity is predicted to provide the strongest reduction of Hall coefficient and effective conductivity for high values of Hall parameter. This degradation is controlled by both the level of nonuniformities and the value of the ideal Hall parameter. The former is dependent upon the number of blades (root mean square deviation of the conductivity), and the latter is dependent upon the values of the magnetic field intensities. The results provide basic quantitative information about the effects of conductivity and velocity nonuniformities on the performance of equilibrium MHD generators over a wide range of Hall coefficients, between 2 and 7. Reduction formulae are established between the effective and ideal Hall parameters for different levels of nonuniformities intensities. Theoretical predictions are derived from a detailed two-dimensional electrodynamic analysis and a simplified engineering model based on a generalization of Rosa's layer model. These experiments validate the analytical studies and support the use of the theoretical layer models in describing the effect of boundary layers on the performance of linear generators.

  16. Nonuniform grid implicit spatial finite difference method for acoustic wave modeling in tilted transversely isotropic media

    Chu, Chunlei


    Discrete earth models are commonly represented by uniform structured grids. In order to ensure accurate numerical description of all wave components propagating through these uniform grids, the grid size must be determined by the slowest velocity of the entire model. Consequently, high velocity areas are always oversampled, which inevitably increases the computational cost. A practical solution to this problem is to use nonuniform grids. We propose a nonuniform grid implicit spatial finite difference method which utilizes nonuniform grids to obtain high efficiency and relies on implicit operators to achieve high accuracy. We present a simple way of deriving implicit finite difference operators of arbitrary stencil widths on general nonuniform grids for the first and second derivatives and, as a demonstration example, apply these operators to the pseudo-acoustic wave equation in tilted transversely isotropic (TTI) media. We propose an efficient gridding algorithm that can be used to convert uniformly sampled models onto vertically nonuniform grids. We use a 2D TTI salt model to demonstrate its effectiveness and show that the nonuniform grid implicit spatial finite difference method can produce highly accurate seismic modeling results with enhanced efficiency, compared to uniform grid explicit finite difference implementations. © 2011 Elsevier B.V.

  17. Terabyte IDE RAID-5 Disk Arrays

    Sanders, D A; Eschenburg, V; Godang, R; Lawrence, C N; Riley, C P; Summers, D J; Petravick, D L


    High energy physics experiments are currently recording large amounts of data and in a few years will be recording prodigious quantities of data. New methods must be developed to handle this data and make analysis at universities possible. We examine some techniques that exploit recent developments in commodity hardware. We report on tests of redundant arrays of integrated drive electronics (IDE) disk drives for use in offline high energy physics data analysis. IDE redundant array of inexpensive disks (RAID) prices now are less than the cost per terabyte of million-dollar tape robots! The arrays can be scaled to sizes affordable to institutions without robots and used when fast random access at low cost is important.

  18. Coupling in reflector arrays

    Appel-Hansen, Jørgen


    In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communic...

  19. Solidex 84 - modern technology in bulk solids handling


    Proceedings from Conference on solids handling. Sections which are of interest include coal and ash handling, and flow problems and explosion hazards in bulk handling plant. 14 papers have been abstracted separately.

  20. 7 CFR 948.23 - Handling for special purposes.


    ... Order Regulating Handling Regulation § 948.23 Handling for special purposes. Upon the basis of....77, or any combination thereof, to facilitate handling of potatoes for (a) Relief or charity; (b...

  1. 7 CFR 959.53 - Handling for special purposes.


    ... Regulating Handling Regulations § 959.53 Handling for special purposes. Regulations in effect pursuant to §§ 959.42, 959.52, or 959.60 may be modified, suspended, or terminated to facilitate handling of...

  2. 7 CFR 929.60 - Handling for special purposes.


    ... LONG ISLAND IN THE STATE OF NEW YORK Order Regulating Handling Reports and Records § 929.60 Handling... facilitate handling of excess cranberries for the following purposes: (a) Charitable institutions;...

  3. On the resonance effects due to ground wires in transmission lines with non-uniform soil conductivity and non-uniform tower resistances

    Faria, J.A. B. (Centro de Electrotecnia da Univ. Tecnica de Lisboa, Dept. of Electrical Engineering, Inst. Superior Tecnico, 1096 Lisboa Codex (PT))


    High frequency resonance effects due to shield wires grounding may affect carrier transmission performance at the vicinity of certain critical frequencies. In this paper the authors investigate if non-uniformities in soil conductivity and in tower footing resistances along the power line may lead to the suppression of such resonance effects. The simulation results the authors have obtained point towards a negative conclusion.

  4. Handling Qualities Optimization for Rotorcraft Conceptual Design

    Lawrence, Ben; Theodore, Colin R.; Berger, Tom


    Over the past decade, NASA, under a succession of rotary-wing programs has been moving towards coupling multiple discipline analyses in a rigorous consistent manner to evaluate rotorcraft conceptual designs. Handling qualities is one of the component analyses to be included in a future NASA Multidisciplinary Analysis and Optimization framework for conceptual design of VTOL aircraft. Similarly, the future vision for the capability of the Concept Design and Assessment Technology Area (CD&A-TA) of the U.S Army Aviation Development Directorate also includes a handling qualities component. SIMPLI-FLYD is a tool jointly developed by NASA and the U.S. Army to perform modeling and analysis for the assessment of flight dynamics and control aspects of the handling qualities of rotorcraft conceptual designs. An exploration of handling qualities analysis has been carried out using SIMPLI-FLYD in illustrative scenarios of a tiltrotor in forward flight and single-main rotor helicopter at hover. Using SIMPLI-FLYD and the conceptual design tool NDARC integrated into a single process, the effects of variations of design parameters such as tail or rotor size were evaluated in the form of margins to fixed- and rotary-wing handling qualities metrics as well as the vehicle empty weight. The handling qualities design margins are shown to vary across the flight envelope due to both changing flight dynamic and control characteristics and changing handling qualities specification requirements. The current SIMPLI-FLYD capability and future developments are discussed in the context of an overall rotorcraft conceptual design process.

  5. Cherenkov Telescope Array Data Management

    Lamanna, G; Contreras, J L; Knödlseder, J; Kosack, K; Neyroud, N; Aboudan, A; Arrabito, L; Barbier, C; Bastieri, D; Boisson, C; Brau-Nogué, S; Bregeon, J; Bulgarelli, A; Carosi, A; Costa, A; De Cesare, G; Reyes, R de los; Fioretti, V; Gallozzi, S; Jacquemier, J; Khelifi, B; Kocot, J; Lombardi, S; Lucarelli, F; Lyard, E; Maier, G; Massimino, P; Osborne, J P; Perri, M; Rico, J; Sanchez, D A; Satalecka, K; Siejkowski, H; Stolarczyk, T; Szepieniec, T; Testa, V; Walter, R; Ward, J E; Zoli, A


    Very High Energy gamma-ray astronomy with the Cherenkov Telescope Array (CTA) is evolving towards the model of a public observatory. Handling, processing and archiving the large amount of data generated by the CTA instruments and delivering scientific products are some of the challenges in designing the CTA Data Management. The participation of scientists from within CTA Consortium and from the greater worldwide scientific community necessitates a sophisticated scientific analysis system capable of providing unified and efficient user access to data, software and computing resources. Data Management is designed to respond to three main issues: (i) the treatment and flow of data from remote telescopes; (ii) "big-data" archiving and processing; (iii) and open data access. In this communication the overall technical design of the CTA Data Management, current major developments and prototypes are presented.

  6. Dynamics of Non-Uniformity Loads of Afc Drives

    Dolipski, Marian; Remiorz, Eryk; Sobota, Piotr


    The length of armoured face conveyors currently used in hard coal mines most often ranges between 200 m and 300 m. The machines are equipped with a main and auxiliary drive. Asynchronous motors mounted in conveyor drives feature the capacity of several hundreds of kilowatts. The non-uniform distribution of loads onto individual drives is observed in practice. The numerical value of loads distribution onto the individual armoured face conveyor drives is represented by a drive load distribution factor. It is defined as a ratio between the load of an electric motor installed in a given drive and the total conveyor load. The article presents a physical armoured face conveyor model intended for examining dynamic phenomena influencing the load non-uniformity of drives. Motion in this physical model is described with the system of (4 · j + 5) non-linear ordinary differential quotations of the second order. A mathematical model is obtained by adding functions describing the interwork of sprocket drums with chains and functions approximating the mechanical characteristics of asynchronous motors powered by means of frequency inverters. A large number of computer simulations was performed using this model enabling to study the impact on the load non-uniformity of drives of such parameters as motor slip, motor supply voltage drop, variations in supply voltage frequency, differences in the gear ratio of transmissions and differentiation in the pitch of scraper chain links along the chain contour. Długość przenośników zgrzebłowych ścianowych stosowanych obecnie w kopalniach węgla kamiennego najczęściej mieści się w przedziale od 200 m do 300 m. Maszyny te wyposażone są zawsze w napęd główny i pomocniczy, przy czym pierwszy z nich wyniesiony jest do chodnika podścianowego. Silniki napędowe o mocy kilkuset kilowatów napędzają bęben łańcuchowy przez sprzęgło i przekładnię zębatą. Z kolei bębny łańcuchowe poruszają łańcuch zgrzebłowy, kt

  7. Performance Test of Various Types of Antenna Arrays in Real Propagation Environment

    Budiyanto, Setiyo; Nugraha, Beny; WidiAstuti, Dian


    The research was conducted on various types of antenna arrays namely Uniform Array, Binomial Array, Dolph-Chebyshev Array, and Taylor Array. This research is done in the real propagation environment in order to define precisely the number of antenna elements, the distance between the elements, the angle of the antenna arrays, the side lobe level and the n-bar array distribution. The testing process is done by using Matlab and the Non-Uniform Array Simulation Program. The results obtained for various types of antenna arrays are as follows: On Uniform Array produces Half Power Beam Width (HPBW) of 10.152° and directivity of l0 dB, on Binomial Array generates Half Power Beam Width (HPBW) of 20.245° and directivity of 7.47 dB, on Dolph-Chebyshev Arrayproduces Half Power Beam Width (HPBW) of 20.304° and directivity of 4.0185 dB, and on Taylor Arrayproduces Half Power Beam Width (HPBW) of 12.78° and directivity of 8.9 dB.

  8. Rotorcraft handling-qualities design criteria development

    Aiken, Edwin W.; Lebacqz, J. Victor; Chen, Robert T. N.; Key, David L.


    Joint NASA/Army efforts at the Ames Research Center to develop rotorcraft handling-qualities design criteria began in earnest in 1975. Notable results were the UH-1H VSTOLAND variable stability helicopter, the VFA-2 camera-and-terrain-board simulator visual system, and the generic helicopter real-time mathematical model, ARMCOP. An initial series of handling-qualities studies was conducted to assess the effects of rotor design parameters, interaxis coupling, and various levels of stability and control augmentation. The ability to conduct in-flight handling-qualities research was enhanced by the development of the NASA/Army CH-47 variable-stability helicopter. Research programs conducted using this vehicle include vertical-response investigations, hover augmentation systems, and the effects of control-force characteristics. The handling-qualities data base was judged to be sufficient to allow an update of the military helicopter handling-qualities specification, MIL-H-8501. These efforts, including not only the in-house experimental work but also contracted research and collaborative programs performed under the auspices of various international agreements. The report concludes by reviewing the topics that are currently most in need of work, and the plans for addressing these topics.

  9. Handling Qualities Implications for Crewed Spacecraft Operations

    Bailey, Randall E.; Jackson, E. Bruce; Arthur, J. J.


    Abstract Handling qualities embody those qualities or characteristics of an aircraft that govern the ease and precision with which a pilot is able to perform the tasks required in support of an aircraft role. These same qualities are as critical, if not more so, in the operation of spacecraft. A research, development, test, and evaluation process was put into effect to identify, understand, and interpret the engineering and human factors principles which govern the pilot-vehicle dynamic system as they pertain to space exploration missions and tasks. Toward this objective, piloted simulations were conducted at the NASA Langley Research Center and Ames Research Center for earth-orbit proximity operations and docking and lunar landing. These works provide broad guidelines for the design of spacecraft to exhibit excellent handling characteristics. In particular, this work demonstrates how handling qualities include much more than just stability and control characteristics of a spacecraft or aircraft. Handling qualities are affected by all aspects of the pilot-vehicle dynamic system, including the motion, visual and aural cues of the vehicle response as the pilot performs the required operation or task. A holistic approach to spacecraft design, including the use of manual control, automatic control, and pilot intervention/supervision is described. The handling qualities implications of design decisions are demonstrated using these pilot-in-the-loop evaluations of docking operations and lunar landings.

  10. Effective Teaching Practices in Handling Non Readers

    Jacklyn S. Dacalos


    Full Text Available The study determined the effective teaching practices in handling nonreaders. This seeks to answer the following objectives: describe the adjustments, effective strategies, and scaffolds utilized by teachers in handling nonreaders; differentiate the teachers’ reading adjustments, strategies and scaffolds in teaching nonreaders; analyze the teaching reading efficiency of nonreaders using effective teaching reading strategies; and find significant correlation of nonreaders’ grades and reading teachers’ reading adjustments, strategies and scaffolds. This study utilized mixed methods of research. Case studies of five public schools teachers were selected as primary subjects, who were interviewed in handling nonreaders in the areas of adjustments, strategies, and reading scaffolds. Actual teaching observation was conducted according to the five subjects’ most convenient time. In ascertaining the nonreaders’ academic performance, the students’ grades in English subject was analyzed using T-Test within subject design. Handling nonreaders in order to read and understand better in the lesson is an arduous act, yet; once done with effectiveness and passion, it yielded a great amount of learning success. Effective teaching practices in handling nonreaders comprised the use of teachers’ adjustments, strategies, and scaffolds to establish reading mastery, exposing them to letter sounds, short stories, and the use of follow-up. WH questions enhanced their reading performance significantly. Variations of reading teachers’ nature as: an enabler, a facilitator, a humanist, a behaviorist, and an expert, as regards to their teaching practices, were proven significant to students’ reading effectiveness.

  11. Command and Data Handling Branch Internship

    Billings, Rachel Mae


    Modular Integrated Stackable Layers (MISL) is a computer system designed for simple, fast, and cost effective flexible reconfiguration in space environments such as the ISS and Orion projects for various uses. Existing applications include wireless and wired communications, data acquisition and instrumentation, and camera systems, and potential applications include bus protocol converters and subsystem control. MISL is based on Texas Instruments (TI)' MSP430 16-bit ultra-low-power microcontroller device. The purpose of my project was to integrate the MISL system with a liquid crystal display (LCD) touchscreen. The LCD, manufactured by Crystalfontz and part number CFAF320240F-035T-TS, is a 320 by 240 RGB resistive color screen including an optional carrier board. The vast majority of the project was done with Altium Designer, a tool for printed circuit board (PCB) schematic capture, 3D design, and FPGA (Field Programmable Gate Array) development. The new PCB was to allow the LCD to directly stack to the rest of MISL. Research was done with datasheets for the TI microcontroller and touchscreen display in order to meet desired hardware specifications. Documentation on prior MISL projects was also utilized. The initial step was to create a schematic for the LCD, power bus, and data bus connections between components. A layout was then designed with the required physical dimensions, routed traces and vias, power and ground planes, layer stacks, and other specified design rules such as plane clearance and hole size. Multiple consultation sessions were held with Hester Yim, the technical discipline lead for the Command and Data Handling Branch, and Christy Herring, the lead PCB layout designer in the Electronic Design and Manufacturing Branch in order to ensure proper configuration. At the moment, the PCB is awaiting revision by the latter-mentioned branch. Afterwards, the board will begin to undergo the manufacturing and testing process. Throughout the internship at




    Full Text Available The method of moments (MoM analysis of thin-wire loop antenna arrays with multiple elements is presented in this paper. The proposed formulation provides simple algorithmic implementation that canbe applied to circular loop arrays as well as more generally shaped arrays using the Pocklington’s integral equation with simplified kernel for arbitrary shaped wires in combination with a superquadriccurve representation. This analysis leads to knowledge of the current distribution, input impedance and other electromagnetic properties of both uniform and non-uniform loop arrays. Numerical results areincluded to exhibit good agreement with various relevant references and simulation software. The data for large square and rectangular loop arrays are presented for the first time in literature.

  13. Spatial noise limited NETD performance of a HgCdTe hybrid focal plane array

    Gopal, Vishnu


    This paper presents a model for theoretically estimating the residual spatial noise in a direct injection readout hybrid focal plane array (FPA) consisting of photovoltaic detectors. The procedure consists of computing the response of the pixels after taking into account the nonlinearity induced by the transfer function in the hybrid configuration and the estimated r.m.s. response nonuniformity from the known input parameters of the detector and readout arrays. A linear two point nonuniformity compensation algorithm is applied to the computed pixel responses to calculate the residual spatial noise. Signal-to-spatial noise ratio is then used to estimate the spatial noise limited NETD performance of MWIR and LWIR Hg 1- x Cd x Te hybrid FPAs.

  14. Assessment of heating rate and non-uniform heating in domestic microwave ovens.

    Pitchai, Krishnamoorthy; Birla, Sohan L; Jones, David; Subbiah, Jeyamkondan


    Due to the inherent nature of standing wave patterns of microwaves inside a domestic microwave oven cavity and varying dielectric properties of different food components, microwave heating produces non-uniform distribution of energy inside the food. Non-uniform heating is a major food safety concern in not-ready-to-eat (NRTE) microwaveable foods. In this study, we present a method for assessing heating rate and non-uniform heating in domestic microwave ovens. In this study a custom designed container was used to assess heating rate and non-uniform heating of a range of microwave ovens using a hedgehog of 30 T-type thermocouples. The mean and standard deviation of heating rate along the radial distance and sector of the container were measured and analyzed. The effect of the location of rings and sectors was analyzed using ANOVA to identify the best location for placing food on the turntable. The study suggested that the best location to place food in a microwave oven is not at the center but near the edge of the turntable assuming uniform heating is desired. The effect of rated power and cavity size on heating rate and non-uniform heating was also studied for a range of microwave ovens. As the rated power and cavity size increases, heating rate increases while non-uniform heating decreases. Sectors in the container also influenced heating rate (p heating rate. In general, sectors close to the magnetron tend to heat slightly faster than sectors away from the magnetron. However, the variation in heating rate among sectors was only 2 degrees C/min and considered not practically important. Overall heating performance such as mean heating rate and non-uniform heating did not significantly vary between the two replications that were performed 4 h apart. However, microwave ovens were inconsistent in producing the same heating patterns between the two replications that were performed 4 h apart.

  15. Outer region scaling using the freestream velocity for nonuniform open channel flow over gravel

    Stewart, Robert L.; Fox, James F.


    The theoretical basis for outer region scaling using the freestream velocity for nonuniform open channel flows over gravel is derived and tested for the first time. Owing to the gradual expansion of the flow within the nonuniform case presented, it is hypothesized that the flow can be defined as an equilibrium turbulent boundary layer using the asymptotic invariance principle. The hypothesis is supported using similarity analysis to derive a solution, followed by further testing with experimental datasets. For the latter, 38 newly collected experimental velocity profiles across three nonuniform flows over gravel in a hydraulic flume are tested as are 43 velocity profiles previously published in seven peer-reviewed journal papers that focused on fluid mechanics of nonuniform open channel over gravel. The findings support the nonuniform flows as equilibrium defined by the asymptotic invariance principle, which is reflective of the consistency of the turbulent structure's form and function within the expanding flow. However, roughness impacts the flow structure when comparing across the published experimental datasets. As a secondary objective, we show how previously published mixed scales can be used to assist with freestream velocity scaling of the velocity deficit and thus empirically account for the roughness effects that extend into the outer region of the flow. One broader finding of this study is providing the theoretical context to relax the use of the elusive friction velocity when scaling nonuniform flows in gravel bed rivers; and instead to apply the freestream velocity. A second broader finding highlighted by our results is that scaling of nonuniform flow in gravel bed rivers is still not fully resolved theoretically since mixed scaling relies to some degree on empiricism. As researchers resolve the form and function of macroturbulence in the outer region, we hope to see the closing of this research gap.

  16. Randomly removing g handles at once

    Borradaile, Glencora; Sidiropoulos, Anastasios


    Indyk and Sidiropoulos (2007) proved that any orientable graph of genus $g$ can be probabilistically embedded into a graph of genus $g-1$ with constant distortion. Viewing a graph of genus $g$ as embedded on the surface of a sphere with $g$ handles attached, Indyk and Sidiropoulos' method gives an embedding into a distribution over planar graphs with distortion $2^{O(g)}$, by iteratively removing the handles. By removing all $g$ handles at once, we present a probabilistic embedding with distortion $O(g^2)$ for both orientable and non-orientable graphs. Our result is obtained by showing that the nimum-cut graph of Erickson and Har Peled (2004) has low dilation, and then randomly cutting this graph out of the surface using the Peeling Lemma of Lee and Sidiropoulos (2009).

  17. DOE handbook: Tritium handling and safe storage



    The DOE Handbook was developed as an educational supplement and reference for operations and maintenance personnel. Most of the tritium publications are written from a radiological protection perspective. This handbook provides more extensive guidance and advice on the null range of tritium operations. This handbook can be used by personnel involved in the full range of tritium handling from receipt to ultimate disposal. Compliance issues are addressed at each stage of handling. This handbook can also be used as a reference for those individuals involved in real time determination of bounding doses resulting from inadvertent tritium releases. This handbook provides useful information for establishing processes and procedures for the receipt, storage, assay, handling, packaging, and shipping of tritium and tritiated wastes. It includes discussions and advice on compliance-based issues and adds insight to those areas that currently possess unclear DOE guidance.

  18. Handling of fuel chips - a health problem

    Stroemquist, L.H.; Blomqvist, G.; Karlsson, E.; Vincent, A.; Lundgren, R.; Eliasson, L.


    An investigation has been made about health problems and occurrence of mold in connection with handling of fuel chips. The investigation was composed of three different parts. First, an inquiry was made to chip stokers about handling, storage etc. of chips as well as possible medical trouble. The answers indicated that symptoms on allergic alveolitis are common among chip stokers, 13% of the answers. Second, a determination of the proportion of living airborne colony-forming mold fungi was made at some chip using units. Third, a pilot study was made to examine the possibilities to improve storability of fuel chips using high-temperature drying.

  19. Enhancement of continuous-flow separation of viable/nonviable yeast cells using a nonuniform alternating current electric field with complex spatial distribution.

    Tada, Shigeru; Nakanishi, Arisa; Eguchi, Masanori; Ochi, Kengo; Baba, Megumi; Tsukamoto, Akira


    The variability in cell response to AC electric fields is selective enough to separate not only the cell types but also the activation states of similar cells. In this work, we use dielectrophoresis (DEP), which exploits the differences in the dielectric properties of cells, to separate nonviable and viable cells. A parallel-plate DEP device consisting of a bottom face with an array of micro-fabricated interdigitated electrodes and a top face with a plane electrode was proposed to facilitate the separation of cells by creating a nonuniform electric field throughout the flow channel. The operation and performance of the device were evaluated using live and dead yeast cells as model biological particles. Further, numerical simulations were conducted for the cell suspensions flowing in a channel with a nonuniform AC electric field, modeled on the basis of the equation of motion of particles, to characterize the separation efficiency by changing the frequency of applied AC voltage. Results demonstrated that dead cells traveling through the channel were focused onto a site around the minimum electric field gradient in the middle of the flow stream, while live cells were trapped on the bottom face. Cells were thus successfully separated under the appropriately tuned frequency of 1 MHz. Predictions showed good agreement with the observation. The proposed DEP device provides a new approach to, for instance, hematological analysis or the separation of different cancer cells for application in circulating tumor cell identification.

  20. The emergence of nonuniform spatiotemporal fractionation schemes within the standard BED model

    Unkelbach, Jan, E-mail:; Papp, Dávid [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)


    Purpose: Nonuniform spatiotemporal radiotherapy fractionation schemes, i.e., delivering distinct dose distributions in different fractions can potentially improve the therapeutic ratio. This is possible if the dose distributions are designed such that similar doses are delivered to normal tissues (exploit the fractionation effect) while hypofractionating subregions of the tumor. In this paper, the authors develop methodology for treatment planning with nonuniform fractions and demonstrate this concept in the context of intensity-modulated proton therapy (IMPT). Methods: Treatment planning is performed by simultaneously optimizing (possibly distinct) IMPT dose distributions for multiple fractions. This is achieved using objective and constraint functions evaluated for the cumulative biologically equivalent dose (BED) delivered at the end of treatment. BED based treatment planning formulations lead to nonconvex optimization problems, such that local gradient based algorithms require adequate starting positions to find good local optima. To that end, the authors develop a combinatorial algorithm to initialize the pencil beam intensities. Results: The concept of nonuniform spatiotemporal fractionation schemes is demonstrated for a spinal metastasis patient treated in two fractions using stereotactic body radiation therapy. The patient is treated with posterior oblique beams with the kidneys being located in the entrance region of the beam. It is shown that a nonuniform fractionation scheme that hypofractionates the central part of the tumor allows for a skin and kidney BED reduction of approximately 10%–20%. Conclusions: Nonuniform spatiotemporal fractionation schemes represent a novel approach to exploit fractionation effects that deserves further exploration for selected disease sites.

  1. Enhanced Efficiencies for High-Concentration, Multijunction PV Systems by Optimizing Grid Spacing under Nonuniform Illumination

    Pratibha Sharma


    Full Text Available The design of a triple junction solar cell’s front contact grid can significantly affect cell conversion efficiency under high concentration. We consider one aspect of grid design, choosing a linear grid within a distributed resistance cell model to optimize finger spacings at concentrations between 500 and 2500 suns under uniform and nonuniform illumination. Optimization for maximum efficiency under Gaussian irradiance profiles is done by SPICE analysis. Relative to the optimized uniform illumination designs, we find enhancements of 0.5% to 2% in absolute efficiencies for uniform spacing. Efficiency enhancement with nonuniform spacing under nonuniform illumination is also evaluated. Our model suggests that, at lower concentrations (<1000 suns, the penalty for using uniformly spaced fingers instead of nonuniformly spaced fingers is <0.1%. However, at a concentration of 2500 suns the penalty increases to 0.3%. Thus, relative to a uniform irradiance optimization, an absolute efficiency increase of 2.3% can be attained for an optimized nonuniform spacing given the Gaussian irradiance profile under consideration.

  2. Space cutter compensation method for five-axis nonuniform rational basis spline machining

    Yanyu Ding


    Full Text Available In view of the good machining performance of traditional three-axis nonuniform rational basis spline interpolation and the space cutter compensation issue in multi-axis machining, this article presents a triple nonuniform rational basis spline five-axis interpolation method, which uses three nonuniform rational basis spline curves to describe cutter center location, cutter axis vector, and cutter contact point trajectory, respectively. The relative position of the cutter and workpiece is calculated under the workpiece coordinate system, and the cutter machining trajectory can be described precisely and smoothly using this method. The three nonuniform rational basis spline curves are transformed into a 12-dimentional Bézier curve to carry out discretization during the discrete process. With the cutter contact point trajectory as the precision control condition, the discretization is fast. As for different cutters and corners, the complete description method of space cutter compensation vector is presented in this article. Finally, the five-axis nonuniform rational basis spline machining method is further verified in a two-turntable five-axis machine.

  3. Effects of Nonuniform Incident Illumination on the Thermal Performance of a Concentrating Triple Junction Solar Cell

    Fahad Al-Amri


    Full Text Available A numerical heat transfer model was developed to investigate the temperature of a triple junction solar cell and the thermal characteristics of the airflow in a channel behind the solar cell assembly using nonuniform incident illumination. The effects of nonuniformity parameters, emissivity of the two channel walls, and Reynolds number were studied. The maximum solar cell temperature sharply increased in the presence of nonuniform light profiles, causing a drastic reduction in overall efficiency. This resulted in two possible solutions for solar cells to operate in optimum efficiency level: (i adding new receiver plate with higher surface area or (ii using forced cooling techniques to reduce the solar cell temperature. Thus, surface radiation exchanges inside the duct and Re significantly reduced the maximum solar cell temperature, but a conventional plain channel cooling system was inefficient for cooling the solar cell at medium concentrations when the system was subjected to a nonuniform light distribution. Nonuniformity of the incident light and surface radiation in the duct had negligible effects on the collected thermal energy.

  4. Low-cost, flexible polymer arrays for long-term neuronal culture.

    Hogan, N Catherine; Talei-Franzesi, Giovanni; Abudayyeh, Omar; Taberner, Andrew; Hunter, Ian


    Conducting polymers are promising materials for fabrication of microelectrode arrays for both neural stimulation and recording. Our ability to engineer the morphology and composition of polypyrrole together with its suitability as an electrically addressable tissue/cell substrate have been used to develop an inexpensive, disposable three-dimensional polymeric array for use in neuronal culture and drug discovery. These arrays could be interfaced with a fixed, parallel stimulation and optical imaging system, amenable to automated handling and data analysis.

  5. Simple, Fast and Effective Correction for Irradiance Spatial Nonuniformity in Measurement of IVs of Large Area Cells at NREL

    Moriarty, Tom


    The NREL cell measurement lab measures the IV parameters of cells of multiple sizes and configurations. A large contributing factor to errors and uncertainty in Jsc, Imax, Pmax and efficiency can be the irradiance spatial nonuniformity. Correcting for this nonuniformity through its precise and frequent measurement can be very time consuming. This paper explains a simple, fast and effective method based on bicubic interpolation for determining and correcting for spatial nonuniformity and verification of the method's efficacy.

  6. Remote-handled transuranic system assessment appendices. Volume 2



    Volume 2 of this report contains six appendices to the report: Inventory and generation of remote-handled transuranic waste; Remote-handled transuranic waste site storage; Characterization of remote-handled transuranic waste; RH-TRU waste treatment alternatives system analysis; Packaging and transportation study; and Remote-handled transuranic waste disposal alternatives.

  7. Remote-handled transuranic system assessment appendices. Volume 2



    Volume 2 of this report contains six appendices to the report: Inventory and generation of remote-handled transuranic waste; Remote-handled transuranic waste site storage; Characterization of remote-handled transuranic waste; RH-TRU waste treatment alternatives system analysis; Packaging and transportation study; and Remote-handled transuranic waste disposal alternatives.

  8. 30 CFR 77.1303 - Explosives, handling and use.


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives, handling and use. 77.1303 Section... MINES Explosives and Blasting § 77.1303 Explosives, handling and use. (a) Persons who use or handle... treated and handled with the same safety precautions as blasting caps and electric detonators. (o) Capped...

  9. Efficient compensation handling via subjective updates

    J. Dedeić (Jovana); J. Pantović (Jovanka); J.A. Pérez Parra (Jorge)


    textabstractProgramming abstractions for compensation handling and dynamic update are crucial in specifying reliable interacting systems, such as Collective Adaptive Systems (CAS). Compensations and updates both specify how a system reacts in response to exceptional events. Prior work showed that


    Shaidatul Shida Razali


    Full Text Available As in many other developing countries, the generation of clinical waste in Malaysia has increased significantly over the last few decades. Even though the serious impact of the clinical waste on human beings and the environment is significant, only minor attention is directed to its proper handling and legal aspects. This study seeks to examine the management of clinical waste in Selangor’s government hospitals as well as problems that arise from the current practice of clinical waste management. A depth interview with the responsible concession who handles the clinical waste management in those hospitals also has been taken. In general, it was found that the consortium’s administration was reasonably aware of the importance of clinical waste management. However, significant voids were presented that need to be addressed in future including efficient segregation, better handling and transfer means, as well as the need for training and awareness programs for the personnel. Other obstacles faced by consortiums were to handle the clinical waste including the operational costs. Waste minimizing and recycling, as well as the alternative treatment methods for incineration are regarded to be major challenges in the future.

  11. Confluence Modulo Equivalence in Constraint Handling Rules

    Christiansen, Henning; Kirkeby, Maja Hanne


    Previous results on confluence for Constraint Handling Rules, CHR, are generalized to take into account user-defined state equivalence relations. This allows a much larger class of programs to enjoy the ad- vantages of confluence, which include various optimization techniques and simplified corre...

  12. Materials handling centre: making business more efficient

    B. Bollen (Brian)


    textabstractThe aim of the Materials Handling Forum at RSM is to narrow the gap between research and practice by promoting and disseminating academic knowledge, sharing innovative ideas, generating research questions, and co-developing new research themes with industry partners.

  13. Biodiesel Handling and Use Guide (Fifth Edition)

    Alleman, Teresa L.; McCormick, Robert L.; Christensen, Earl D.; Fioroni, Gina; Moriarty, Kristi; Yanowitz, Janet


    This document is a guide for those who blend, distribute, and use biodiesel and biodiesel blends. It provides basic information on the proper and safe use of biodiesel and biodiesel blends in engines and boilers, and is intended to help fleets, individual users, blenders, distributors, and those involved in related activities understand procedures for handling and using biodiesel fuels.

  14. Australia: round module handling and cotton classing

    Round modules of seed cotton produced via on-board module building harvesters are the reality of the cotton industry, worldwide. Although round modules have been available to the industry for almost a decade, there is still no consensus on the best method to handle the modules, particularly when th...

  15. Laboratory rearing and handling of cerambycids

    Melody A. Keena


    Lack of suitable rearing and handling techniques has hampered research on the biology and control of many species of cerambycids that feed on host species of economic importance. Furthermore, because cerambycids spend most or all of their pre-adult life cycle inside the host plant, the biology of many is not well-known and would be dif

  16. Intertextuality for Handling Complex Environmental Issues

    Byhring, Anne Kristine; Knain, Erik


    Nowhere is the need for handling complexity more pertinent than in addressing environmental issues. Our study explores students' situated constructs of complexity in unfolding discourses on socio-scientific issues. Students' dialogues in two group-work episodes are analysed in detail, with tools from Systemic Functional Linguistics. We identify…

  17. Railcar handling systems - designs for individual solutions



    The article examines the latest state of the art developments in railcar handling technology, with profiles of leading equipment suppliers in this field and recent projects completed worldwide. Equipment covered includes: railcar discharge systems; rotary dumpers; side discharge dumpers; and railcar loading systems. 2 figs., 7 photos.

  18. 7 CFR 915.10 - Handle.


    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Handle. 915.10 Section 915.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and... prepared for market. In the event a grower sells his avocados to a handler who is not so registered...

  19. 340 Waste handling facility interim safety basis

    Stordeur, R.T.


    This document presents an interim safety basis for the 340 Waste Handling Facility classifying the 340 Facility as a Hazard Category 3 facility. The hazard analysis quantifies the operating safety envelop for this facility and demonstrates that the facility can be operated without a significant threat to onsite or offsite people.

  20. 340 waste handling facility interim safety basis

    VAIL, T.S.


    This document presents an interim safety basis for the 340 Waste Handling Facility classifying the 340 Facility as a Hazard Category 3 facility. The hazard analysis quantifies the operating safety envelop for this facility and demonstrates that the facility can be operated without a significant threat to onsite or offsite people.

  1. Intertextuality for Handling Complex Environmental Issues

    Byhring, Anne Kristine; Knain, Erik


    Nowhere is the need for handling complexity more pertinent than in addressing environmental issues. Our study explores students' situated constructs of complexity in unfolding discourses on socio-scientific issues. Students' dialogues in two group-work episodes are analysed in detail, with tools from Systemic Functional Linguistics. We identify…

  2. Goods handling: tugs, trailers and tractors.

    Grayson, H


    Ease of handling ought to be a priority in any supply and disposal system. Hazel Grayson, senior research officer at the Medical Architecture Research Unit, Polytechnic of North London, suggests that even where driver-operated electric tow tractors cannot be used, other types of electric pulling device should be considered.

  3. 'Safe handling of nanotechnology' ten years on

    Maynard, Andrew D.; Aitken, Robert J.


    In 2006, a group of scientists proposed five grand challenges to support the safe handling of nanotechnology. Ten years on, Andrew Maynard and Robert Aitken -- two of the original authors -- look at where we have come, and where we still need to go.

  4. Caution required for handling genome editing technology.

    Araki, Motoko; Nojima, Kumie; Ishii, Tetsuya


    Genome-editing technology, although a robust tool for genetic engineering, is creating indistinct regulatory boundaries between naturally occurring and modified organisms. However, researchers must act with caution in research and development to avoid misleading society. Furthermore, appropriate regulations should be proactively discussed and established for handling genome-editing technology.

  5. Tips for Handling Gourds this Fall Season

    Bratsch, Tony


    Each year, more direct market and wholesale growers are adding gourds to their fall sales mix, along with pumpkins, ornamental corn and fall mums. Proper harvest timing, handling and curing are important to ensure maximum longevity of gourds once the consumer brings them home.

  6. Instrumentation to handle thermal polarized neutron beams

    Kraan, W.H.


    In this thesis we investigate devices needed to handle the polarization of thermal neutron beams: Ï/2-flippers (to start/stop Larmor precession) and Ï-flippers (to reverse polarization/precession direction) and illustrate how these devices are used to investigate the properties of matter and of the

  7. Ergonomics intervention in manual handling of oxygen

    M Motamedzadeh


    Conclusion: With the implementation of ergonomic intervention is casting unit, the risk of exposure to musculoskeletal disorders caused by manual handling of oxygen cylinders was eliminated and safety of employees against the risk of explosion of the cylinders in comparison with before the intervention was improved.

  8. Handling Sparse Data by Successive Abstraction

    Samuelsson, C


    A general, practical method for handling sparse data that avoids held-out data and iterative reestimation is derived from first principles. It has been tested on a part-of-speech tagging task and outperformed (deleted) interpolation with context-independent weights, even when the latter used a globally optimal parameter setting determined a posteriori.

  9. 7 CFR 920.11 - Handle.


    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Handle. 920.11 Section 920.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE KIWIFRUIT GROWN IN CALIFORNIA...

  10. 7 CFR 955.7 - Handle.


    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Handle. 955.7 Section 955.7 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE VIDALIA ONIONS GROWN IN GEORGIA...

  11. Wet handling of solids using submersible pumps

    Czarnota, Z.; Fahlgren, M.; Grainger, M. [ITT Flygt Slurry Laboratory, Soina (Sweden)


    A complete and efficient concept for handling solids in short distance pumping applications is described. The function of pump, mixer, agitator, and sump have been determined in experimental studies. The major factors that affect pump performance such as impeller design and slurry characteristics are discussed. The results apply to a range of applications in industry and mining. 10 refs., 6 figs.

  12. Kinesin-3 and dynein cooperate in long-range retrograde endosome motility along a nonuniform microtubule array

    Schuster, M.; Kilaru, S.; Fink, G.; Collemare, J.A.R.; Roger, Y.; Steinberg, G.


    The polarity of microtubules (MTs) determines the motors for intracellular motility, with kinesins moving to plus ends and dynein to minus ends. In elongated cells of Ustilago maydis, dynein is thought to move early endosomes (EEs) toward the septum (retrograde), whereas kinesin-3 transports them to

  13. Kinesin-3 and dynein cooperate in long-range retrograde endosome motility along a nonuniform microtubule array

    Schuster, M.; Kilaru, S.; Fink, G.; Collemare, J.A.R.; Roger, Y.; Steinberg, G.


    The polarity of microtubules (MTs) determines the motors for intracellular motility, with kinesins moving to plus ends and dynein to minus ends. In elongated cells of Ustilago maydis, dynein is thought to move early endosomes (EEs) toward the septum (retrograde), whereas kinesin-3 transports them to

  14. A curvature filter and PDE based non-uniformity correction algorithm

    Cheng, Kuanhong; Zhou, Huixin; Qin, Hanlin; Zhao, Dong; Qian, Kun; Rong, Shenghui; Yin, Shimin


    In this paper, a curvature filter and PDE based non-uniformity correction algorithm is proposed, the key point of this algorithm is the way to estimate FPN. We use anisotropic diffusion to smooth noise and Gaussian curvature filter to extract the details of original image. Then combine these two parts together by guided image filter and subtract the result from original image to get the crude approximation of FPN. After that, a Temporal Low Pass Filter (TLPF) is utilized to filter out random noise and get the accurate FPN. Finally, subtract the FPN from original image to achieve non-uniformity correction. The performance of this algorithm is tested with two infrared image sequences, and the experimental results show that the proposed method achieves a better non-uniformity correction performance.

  15. Investigation and modeling of the avalanche effect in MOSFETs with non-uniform finger spacing

    Liu Jun; Sun Lingling; Marissa Condon


    This paper investigates the effect of a non-uniform gate-finger spacing layout structure on the avalanche breakdown performance of RF CMOS technology.Compared with a standard multi-finger device with uniform gate-finger spacing,a device with non-uniform gate-finger spacing represents an improvement of 8.5% for the drain-source breakdown voltage(BVds)and of 20% for the thermally-related drain conductance.A novel compact model is proposed to accurately predict the variation of BVds with the total area of devices,which is dependent on the different finger spacing sizes.The model is verified and validated by the excellent match between the measured and simulated avalanche breakdown characteristics for a set of uniform and non-uniform gate-finger spacing arranged nMOSFETs.

  16. On natural frequencies of non-uniform beams modulated by finite periodic cells

    Xu, Yanlong; Zhou, Xiaoling; Wang, Wei; Wang, Longqi; Peng, Fujun; Li, Bin


    It is well known that an infinite periodic beam can support flexural wave band gaps. However, in real applications, the number of the periodic cells is always limited. If a uniform beam is replaced by a non-uniform beam with finite periodicity, the vibration changes are vital by mysterious. This paper employs the transfer matrix method (TMM) to study the natural frequencies of the non-uniform beams with modulation by finite periodic cells. The effects of the amounts, cross section ratios, and arrangement forms of the periodic cells on the natural frequencies are explored. The relationship between the natural frequencies of the non-uniform beams with finite periodicity and the band gap boundaries of the corresponding infinite periodic beam is also investigated. Numerical results and conclusions obtained here are favorable for designing beams with good vibration control ability.

  17. Computer Simulation of Nonuniform MTLs via Implicit Wendroff and State-Variable Methods

    L. Brancik


    Full Text Available The paper deals with techniques for a computer simulation of nonuniform multiconductor transmission lines (MTLs based on the implicit Wendroff and the statevariable methods. The techniques fall into a class of finitedifference time-domain (FDTD methods useful to solve various electromagnetic systems. Their basic variants are extended and modified to enable solving both voltage and current distributions along nonuniform MTL’s wires and their sensitivities with respect to lumped and distributed parameters. An experimental error analysis is performed based on the Thomson cable whose analytical solutions are known, and some examples of simulation of both uniform and nonuniform MTLs are presented. Based on the Matlab language programme, CPU times are analyzed to compare efficiency of the methods. Some results for nonlinear MTLs simulation are presented as well.

  18. Application of nonlocal criteria for destruction in problems with a nonuniform stress field

    Chevrychkina, A. A.; Gruzdkov, A. A.; Petrov, Yu. V.


    The dependence of the critical load on the degree of nonuniformity of the stress field is considered on the example of polymethylmethacrylate beams and plates with a round hole or a sharp notch. It is proposed to use nonlocal criteria for brittle fracture to describe the behavior of a nonuniformly stressed material. Among the criteria considered, the structural criterion is the most universal, because, in this case, the distance parameter d is least dependent on the test configuration. The distance parameters in problems with a regular concentrator are of the same order of magnitude, as in problems with a singular stress concentrator. A further modification of the criterion that takes into account the properties of the fracture process will probably make it possible to obtain a unique value for the length parameter for any degree of nonuniformity of the stress field.

  19. Basic types of nonuniformities and their manifestation in the galvanomagnetic properties of especially pure silicon

    Ostroborodova, V.V.


    A method is proposed for analyzing the type of nonuniformities in a single-crystalline pure material based on the changes in the asymmetry resistances, determined from the magnitudes of the external potentials on the Hall contacts, in a magnetic field. By comparing their magnetic-field dependences with the analogous dependences of the Hall constant and of the resistivity, measured with different polarities of the voltage applied to the sample, it is shown that the asymmetry resistances are the parameters which are most sensitive to nonuniformity. It was found that nonuniformities of the compensation type, i.e., space-charge regions in which the minority carriers make an appreciable contribution to the Hall constant, are systematically manifested in crystals of especially pure high-resistance silicon. The effective Hall factors were calculated under the conditions of Hall bipolarity of the impurity conductivity and the results are compared with the experimental data.



    Experiments on initiation of motion of different fractions of non-uniform sediment mixtures are reported. Four sediment mixes and reference transport method to define the threshold of bed particle movement are used in this analysis. Factors controlling the initiation of motion are analyzed. It is found that relative size of different grains with respect to a median size greatly affects the initiation of movement. The incipient motion of non-uniform sediment is very much dependent on the absolute size for coarser fractions.Considering the factors controlling the initiation of motion the experimental data sets along with the other available data yield a new relationship for the calculation of critical shear stress of non-uniform sediments. A set of equations have found that all the data points fall into a single line for the finer and for coarser fractions.

  1. Velocity field of streams in nonuniform constant magnetic fields. Part 1: numerical calculations

    Gel' fgat, Yu.M.; Peterson, D.Ye.; Shcherbinin, E.V.


    Steady flow of a conducting fluid through a rectangular pipe in nonuniform magnetic fields of various configurations is analyzed and the results are found to depend on whether the magnetic field is assumed to have only a transverse or also a longitudinal component. Velocity and potential profiles are calculated numerically for each case, according to grids with various step sizes, also for an asymmetrically nonuniform and for a periodically nonuniform magnetic field. The feasibility of establishing practically any desired flow pattern by tailoring the magnetic field has thus been established, but the success of this procedure depends largely on the choice of the computation scheme and on the accuracy of computations, as well as on the assumptions made concerning the distribution of the magnetic field. 9 references, 6 figures.

  2. Vibration of nonuniform carbon nanotube with attached mass via nonlocal Timoshenko beam theory

    Tang, Hai Li; Shen, Zhi Bin; Li, Dao Kui [National University of Defense Technology, Changsha (China)


    This paper studies the vibrational behavior of nonuniform single-walled carbon nanotube (SWCNT) carrying a nanoparticle. A nonuniform cantilever beam with a concentrated mass at the free end is analyzed according to the nonlocal Timoshenko beam theory. A governing equation of a nonuniform SWCNT with attached mass is established. The transfer function method incorporating with the perturbation method is utilized to obtain the resonant frequencies of a vibrating nonlocal cantilever-mass system. The effects of the nonlocal parameter, taper ratio and attached mass on the natural frequencies and frequency shifts are discussed. Obtained results indicate that the sensitivity of the frequency shifts on the attached mass increases when the length-to-diameter ratio decreases. Tapered SWCNT possesses higher fundamental frequencies if the taper ratio becomes larger.

  3. Non-uniform sampling and reconstruction of multi-band signals and its application in wideband spectrum sensing of cognitive radio

    Rashidi, Moslem


    Sampling theories lie at the heart of signal processing devices and communication systems. To accommodate high operating rates while retaining low computational cost, efficient analog-to digital (ADC) converters must be developed. Many of limitations encountered in current converters are due to a traditional assumption that the sampling state needs to acquire the data at the Nyquist rate, corresponding to twice the signal bandwidth. In this thesis a method of sampling far below the Nyquist rate for sparse spectrum multiband signals is investigated. The method is called periodic non-uniform sampling, and it is useful in a variety of applications such as data converters, sensor array imaging and image compression. Firstly, a model for the sampling system in the frequency domain is prepared. It relates the Fourier transform of observed compressed samples with the unknown spectrum of the signal. Next, the reconstruction process based on the topic of compressed sensing is provided. We show that the sampling parame...

  4. Data handling and representation of freeform surfaces

    Steinkopf, Ralf; Dick, Lars; Kopf, Tino; Gebhardt, Andreas; Risse, Stefan; Eberhardt, Ramona


    Freeform surfaces enable innovative optics. They are not limited by axis symmetry and hence they are almost free in design. They are used to reduce the installation space and enhance the performance of optical elements. State of the art optical design tools are computing with powerful algorithms to simulate freeform surfaces. Even new mathematical approaches are under development /1/. In consequence, new optical designs /2/ are pushing the development of manufacturing processes consequently and novel types of datasets have to proceed through the process chain /3/. The complexity of these data is the huge challenge for the data handling. Because of the asymmetrical and 3-dimensional surfaces of freeforms, large data volumes have to be created, trimmed, extended and fitted. All these processes must be performed without losing the accuracy of the original design data. Additionally, manifold types of geometries results in different kinds of mathematical representations of freeform surfaces and furthermore the used CAD/CAM tools are dealing with a set of spatial transport formats. These are all reasons why manufacture-oriented approaches for the freeform data handling are not yet sufficiently developed. This paper suggests a classification of freeform surfaces based on the manufacturing methods which are offered by diamond machining. The different manufacturing technologies, ranging from servo-turning to shaping, require a differentiated approach for the data handling process. The usage of analytical descriptions in form of splines and polynomials as well as the application of discrete descriptions like point clouds is shown in relation to the previously made classification. Advantages and disadvantages of freeform representations are discussed. Aspects of the data handling in between different process steps are pointed out and suitable exchange formats for freeform data are proposed. The described approach offers the possibility for efficient data handling from optical

  5. Clocked combustor can array

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar


    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  6. Axiom turkey genotyping array

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  7. Clocked combustor can array

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar


    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  8. Simulations of beam emittance growth from the collectiverelaxation of space-charge nonuniformities

    Lund, Steven M.; Grote, David P.; Davidson, Ronald C.


    Beams injected into a linear focusing channel typically have some degree of space-charge nonuniformity. For unbunched beams with high space-charge intensity propagating in linear focusing channels, Debye screening of self-field interactions tends to make the transverse density profile flat. An injected particle distribution with a large systematic charge nonuniformity will generally be far from an equilibrium of the focusing channel and the initial condition will launch a broad spectrum of collective modes. These modes can phase-mix and experience nonlinear interactions which result in an effective relaxation to a more thermal-equilibrium-like distribution characterized by a uniform density profile. This relaxation transfers self-field energy from the initial space-charge nonuniformity to the local particle temperature, thereby increasing beam phase space area (emittance growth). Here they employ two-dimensional electrostatic particle in cell (PIC) simulations to investigate the effects of initial transverse space-charge nonuniformities on the equality of beams with high space-charge intensity propagating in a continuous focusing channel. Results are compared to theoretical bounds of emittance growth developed in previous studies. Consistent with earlier theory, it is found that a high degree of initial distribution nonuniformity can be tolerated with only modest emittance growth and that beam control can be maintained. The simulations also provide information on the rate of relaxation and characteristic levels of fluctuations in the relaxed states. This research suggests that a surprising degree of initial space-charge nonuniformity can be tolerated in practical intense beam experiments.

  9. In-situ calibration of nonuniformity in infrared staring and modulated systems

    Black, Wiley T.

    Infrared cameras can directly measure the apparent temperature of objects, providing thermal imaging. However, the raw output from most infrared cameras suffers from a strong, often limiting noise source called nonuniformity. Manufacturing imperfections in infrared focal planes lead to high pixel-to-pixel sensitivity to electronic bias, focal plane temperature, and other effects. The resulting imagery can only provide useful thermal imaging after a nonuniformity calibration has been performed. Traditionally, these calibrations are performed by momentarily blocking the field of view with a at temperature plate or blackbody cavity. However because the pattern is a coupling of manufactured sensitivities with operational variations, periodic recalibration is required, sometimes on the order of tens of seconds. A class of computational methods called Scene-Based Nonuniformity Correction (SBNUC) has been researched for over 20 years where the nonuniformity calibration is estimated in digital processing by analysis of the video stream in the presence of camera motion. The most sophisticated SBNUC methods can completely and robustly eliminate the high-spatial frequency component of nonuniformity with only an initial reference calibration or potentially no physical calibration. I will demonstrate a novel algorithm that advances these SBNUC techniques to support all spatial frequencies of nonuniformity correction. Long-wave infrared microgrid polarimeters are a class of camera that incorporate a microscale per-pixel wire-grid polarizer directly affixed to each pixel of the focal plane. These cameras have the capability of simultaneously measuring thermal imagery and polarization in a robust integrated package with no moving parts. I will describe the necessary adaptations of my SBNUC method to operate on this class of sensor as well as demonstrate SBNUC performance in LWIR polarimetry video collected on the UA mall.

  10. Effects of nonuniform Mach-number entrance on scramjet nozzle flowfield and performance

    Zhang, Pu; Xu, Jinglei; Quan, Zhibin; Mo, Jianwei


    Considering the non-uniformities of nozzle entrance influenced by the upstream, the effects of nonuniform Mach-number coupled with shock and expansion-wave on the flowfield and performances of single expansion ramp nozzle (SERN) are numerically studied using Reynolds-Averaged Navier-Stokes equations. The adopted Reynolds-averaged Navier-Stokes methodology is validated by comparing the numerical results with the cold experimental data, and the average method used in this paper is discussed. Uniform and nonuniform facility nozzles are designed to generate different Mach-number profile for the inlet of SERN, which is direct-connected with different facility nozzle, and the whole flowfield is simulated. Because of the coupling of shock and expansion-wave, flow direction of nonuniform SERN entrance is distorted. Compared with Mach contour of uniform case, the line is more curved for coupling shock-wave entrance (SWE) case, and flatter for the coupling expansion-wave entrance (EWE) case. Wall pressure distribution of SWE case appears rising region, whereas decreases like stairs of EWE case. The numerical results reveal that the coupled shock and expansion-wave play significant roles on nozzle performances. Compared with the SERN performances of uniform entrance case at the same work conditions, the thrust of nonuniform entrance cases reduces by 3-6%, pitch moment decreases by 2.5-7%. The negative lift presents an incremental trend with EWE while the situation is the opposite with SWE. These results confirm that considering the entrance flow parameter nonuniformities of a scramjet nozzle coupled with shock or expansion-wave from the upstream is necessary.

  11. A linear monolithic 4-6 on silicon IR detector array

    Vandamme, J.; Vermeiren, J.; Zogg, H.; Masek, J.; Fabbricotti, M.


    A linear array of monolithically grown PbTe and PbSnSe detectors on (111)-Si for MWIR and TIR imaging applications was designed and processed. The array consists of a staggered row of 2 by 128 detectors on a 100 micrometers pitch. The readout circuitry, integrated on the Si substrate consists of a COS multiplexer with a direct injection input stage, a charge reduction stage and charge to voltage conversion stage for each individual detector. This XDI (MultipeXed Direct Injection) circuit also allows for on-chip nonuniformity compensation with a switched capacitor network.

  12. Body conformable 915 MHz microstrip array applicators for large surface area hyperthermia

    Lee, E.R.; Tarczy-Hornoch, P.; Kapp, S.; Fessenden, P.; Lohrbach, A.W.; Prionas, S.D. (Stanford University Medical Center, CA (United States)); Wilsey, T. (Carian Associates, Palo Alto, CA (United States))


    The optimal treatment with hyperthermia of superficially located tumors which involve large surface areas requires applicators which can physically conform to body contours, and locally alter their power deposition patterns to adjust for nonuniform temperature caused by tissue inhomogeneities and blood flow variations. A series of 915 MHz microstrip array applicators satisfying these criteria have been developed and clinically tested. Clinical and engineering design tradeoffs for practical devices are discussed. Measurements taken in tissue equivalent phantoms and a summary of clinical experiences with these microstrip arrays are presented.

  13. Sensitivity of linear CCD array based film scanners used for film dosimetry.

    Devic, Slobodan; Wang, Yi-Zhen; Tomic, Nada; Podgorsak, Ervin B


    Film dosimetry is commonly performed by using linear CCD array transmission optical densitometers. However, these devices suffer from a variation in response along the detector array. If not properly corrected for, this nonuniformity may lead to significant overestimations of the measured dose as one approaches regions close to the edges of the scanning region. In this note, we present measurements of the spatial response of an AGFA Arcus II document scanner used for radiochromic film dosimetry. Results and methods presented in this work can be generalized to other CCD based transmission scanners used for film dosimetry employing either radiochromic or radiographic films.

  14. Alumina Template-Dependant Growth of Cobalt Nanowire Arrays

    L. Malferrari


    Full Text Available Different electrochemical regimes and porous alumina were applied for template synthesis of cobalt nanowire (nw arrays, revealing several peculiar cases. In contrast to quite uniform filling of sulfuric acid alumina templates by alternating current deposition, nonuniform growth of the Co nw tufts and mushrooms was obtained for the case of oxalic acid templates. We showed herein for the first time that such configurations arise from the spontaneous growth of cobalt nw groups evolving from the cobalt balls at the Al/alumina interface. Nevertheless, the uniform growth of densely packed cobalt nw arrays, up to tens of micrometers in length, was obtained via long-term direct current galvanostatic deposition at low current density using oxalic acid templates one-side coated by conducting layer. The unique point of this regime is the formation of hexagonal lattice Co nws with a preferred (100 growth direction.

  15. Image nonlinearity and non-uniformity corrections using Papoulis - Gerchberg algorithm in gamma imaging systems

    Shemer, A.; Schwarz, A.; Gur, E.; Cohen, E.; Zalevsky, Z.


    In this paper, the authors describe a novel technique for image nonlinearity and non-uniformity corrections in imaging systems based on gamma detectors. The limitation of the gamma detector prevents the producing of high quality images due to the radionuclide distribution. This problem causes nonlinearity and non-uniformity distortions in the obtained image. Many techniques have been developed to correct or compensate for these image artifacts using complex calibration processes. The presented method is based on the Papoulis - Gerchberg(PG) iterative algorithm and is obtained without need of detector calibration, tuning process or using any special test phantom.

  16. Modeling of pancake frying with non-uniform heating source applied to domestic cookers

    Sanz-Serrano, F.; Sagues, C.; Feyissa, Aberham Hailu


    . In this work we propose a model of contact frying of pancakes in domestic cookers, particularly in induction hobs and radiant cookers, in which the heating of the cooking vessels can be non-uniform. This non-uniformity is unavoidable in practice, but it can be reduced by optimizing the design of the cooker......The design of domestic cooking stoves is usually optimized by performing time-consuming cooking experiments, often using frying of pancakes as a standard. Simulation of cooking processes may reduce the number of experiments used in the development of the cooking stoves, saving time and resources...

  17. Fluxon dynamics in long Josephson junctions in the presence of a temperature gradient or spatial nonuniformity

    Krasnov, V.M.; Oboznov, V.A.; Pedersen, Niels Falsig


    for the Josephson vortex motion. ZCFFS's were observed at certain magnetic fields when the critical current in one direction but not the other becomes zero. Possible applications of nonuniform Josephson junctions in flux flow oscillators and as a superconducting diode are discussed....... self-energy (from the cold to the hot end of the junction). A phenomenon, the ''zero crossing flux flow step'' (ZCFFS) with a nonzero voltage at a zero applied current, was observed in nonuniform long Josephson junctions. The phenomenon is due to the existence of a preferential direction...

  18. Distribution of Cathode Spots in Vacuum Arc Under Nonuniform Axial Magnetic Fields

    SHI Zong-qian; JIA Shen-li; WANG Li-jun; LI Xing-wen; WANG Zheng


    Recent results on the distribution of vacuum arc cathode spots (CSs) in nonuniform axial magnetic field (AMF) are presented.Based on previous studies,we deem that two contrary influences of AMF,inward effect and outward effect,are attributed to CSs distribution.With this notion,we have analyzed the controlling effectiveness of nonuniform AMF on CSs distribution. Experiments were conducted in a detachable vacuum chamber with iron-style AMF electrodes.Images of vacuum arc column and the distribution of CSs were photographed with a high-speed charge coupled device (CCD) camera. Experimental results agreed well with the theoretical analysis.

  19. Electromechanical characterization of non-uniform charged ionic polymer-metal composites (IPMC) devices

    Lopes, B; Branco, P J C [Institute Superior Tecnico, DEEC - Energia, Lisboa 1096-001 (Portugal)], E-mail:


    Research on electromechanical characterization of non-uniformly charged IPMCs is quasi-absent. This has limited their use to only those devices where the IPMC is completely covered with electrode surfaces (uniformly charged). In this paper, we develop a theoretical study for electromechanical characterization of non-uniformly charged IPMCs. A continuum model taking into account the gravitational forces, important for large IPMCs, is presented. Based on this approach, FEM analysis of IPMC devices using Comsol Multiphysics is introduced in a very simple way. Three devices have been studied, comparing the analytical model results with those ones obtained from a FEM analysis.

  20. A new adaptive nonuniformity correction algorithm for infrared line scanner based on neural networks

    Jing Sui; Liquan Dong; Weiqi Jin; Yayuan Zhang


    The striping pattern nonuniformity of the infrared line scanner (IRLS) severely limits the system performance. An adaptive nonuniformity correction (NUC) algorithm for IRLS using neural network is proposed.It uses a one-dimensional median filter to generate ideal output of network and can complete NUC by a single frame with a high correction level. Applications to both simulated and real infrared images show that the algorithm can obtain a satisfactory result with low complexity, no need of scene diversity or global motion between consecutive frames. It has the potential to realize real-time hardware-based applications.

  1. Lossy Source Compression of Non-Uniform Binary Sources Using GQ-LDGM Codes

    Cappellari, Lorenzo


    In this paper, we study the use of GF(q)-quantized LDGM codes for binary source coding. By employing quantization, it is possible to obtain binary codewords with a non-uniform distribution. The obtained statistics is hence suitable for optimal, direct quantization of non-uniform Bernoulli sources. We employ a message-passing algorithm combined with a decimation procedure in order to perform compression. The experimental results based on GF(q)-LDGM codes with regular degree distributions yield performances quite close to the theoretical rate-distortion bounds.

  2. Symmetry breaking in noncommutative finite temperature λphi4 theory with a nonuniform ground state

    Hernández, J. M.; Ramírez, C.; Sánchez, M.


    We consider the CJT effective action at finite temperature for a noncommutative real scalar field theory, with noncommutativity among space and time variables. We study the solutions of a stripe type nonuniform background, which depends on space and time. The analysis in the first approximation shows that such solutions appear in the planar limit, but also under normal anisotropic noncommutativity. Further we show that the transition from the uniform ordered phase to the non uniform one is first order and that the critical temperature depends on the nonuniformity of the ground state.

  3. Compression gain of spin wave signals in a magnonic YIG waveguide with thermal non-uniformity

    Kolokoltsev, O.; Gómez-Arista, Ivan; Qureshi, N.; Acevedo, A.; Ordóñez-Romero, César L.; Grishin, A.


    We report on the observation of the compression gain of the signals carried by surface spin waves (MSSWs) in yittrium iron garnet films as a result of non-uniform optical heating of the spin wave medium. Efficient gain takes place if a frequency downshift of the spin wave spectrum induced by the heating is compensated by the corresponding non-uniformity of the bias magnetic field. It is proposed that the effect can be understood in part as an interaction between spin waves and a thermally induced potential well in the sample.

  4. A Knowledge-Based Approach for Selection of Material Handling Equipment and Material Handling System Pre-design

    YAMAN, Ramazan


    For material handling system design, material handling equipment selection is the first stage. Also the material handling system and facility layout design problems are coupled. Solving these problems needs consideration of these three different problems. Right material handling equipment selection and good design of the material handling system and facility layout can increase productivity and reduce investments and operations' costs. In this study, after describing the m...

  5. Impact of biospecimens handling on biomarker research in breast cancer

    Callari Maurizio


    Full Text Available Abstract Background Gene expression profiling is moving from the research setting to the practical clinical use. Gene signatures able to correctly identify high risk breast cancer patients as well as to predict response to treatment are currently under intense investigation. While technical issues dealing with RNA preparation, choice of array platforms, statistical analytical tools are taken into account, the tissue collection process is seldom considered. The time elapsed between surgical tissue removal and freezing of samples for biological characterizations is rarely well defined and/or recorded even for recently stored samples, despite the publications of standard operating procedures for biological sample collection for tissue banks. Methods Breast cancer samples from 11 patients were collected immediately after surgical removal and subdivided into aliquots. One was immediately frozen and the others were maintained at room temperature for respectively 2, 6 and 24 hrs. RNA was extracted and gene expression profile was determined using cDNA arrays. Phosphoprotein profiles were studied in parallel. Results Delayed freezing affected the RNA quality only in 3 samples, which were not subjected to gene profiling. In the 8 breast cancer cases with apparently intact RNA also in sample aliquots frozen at delayed times, 461 genes were modulated simply as a function of freezing timing. Some of these genes were included in gene signatures biologically and clinically relevant for breast cancer. Delayed freezing also affected detection of phosphoproteins, whose pattern may be crucial for clinical decision on target-directed drugs. Conclusion Time elapsed between surgery and freezing of samples appears to have a strong impact and should be considered as a mandatory variable to control for clinical implications of inadequate tissue handling.

  6. Analysis of aircraft longitudinal handling qualities

    Hess, R. A.


    The optimal control model (OCM) of the human pilot is applied to the study of aircraft handling qualities. Attention is focused primarily on longitudinal tasks. The modeling technique differs from previous applications of the OCM in that considerable effort is expended in simplifying the pilot/vehicle analysis. After briefly reviewing the OCM, a technique for modeling the pilot controlling higher order systems is introduced. Following this, a simple criterion for determining the susceptibility of an aircraft to pilot induced oscillations (PIO) is formulated. Finally, a model-based metric for pilot rating prediction is discussed. The resulting modeling procedure provides a relatively simple, yet unified approach to the study of a variety of handling qualities problems.

  7. Energy efficiency in air handling applications

    Fontaine, P. [Australian Baldor (Australia)


    It is estimated that the cost of air handling in a typical office building is $25,000 to $60,000 per 10,000 sq metres. New technologies are now available to reduce this by 50 percent with an investment that is recoverable within two years. Old systems of air handling operated at full speed with flow rates changed by mechanical vanes or dampers. The excess capacity generated is wasting energy which could be saved using modern motor controls that match the system output with actual needs. Comparisons of relative energy consumptions of different fan flow control methods show that the more time a system spends throttled down, the better candidate it is for the more efficient Variable Speed Drive (VSD) device which matches the motor`s speed to actual needs. The use of VSD instead of vanes and dampers reduces operating costs which impacts directly on profitability. 2 tables, 1 fig.

  8. Handling System for Iridium-192 Seeds

    Carpenter, W.; Wodicka, D.


    A complete system is proposed for safe handling of iridium-192 seeds used to internally irradiate malignant growths. A vibratory hopper feeds the seeds onto a transport system for deposit in a magazine or storage area. A circular magazine consisting of segmented plastic tubing with holes in the walls to accommodate the seeds seems feasible. The magazine is indexed to stop and release a seed for calibration and deposition.

  9. NB Power`s fish handling facilities

    Hickman, C. N. [New Brunswick Power, Fredericton, NB (Canada)


    Fish handling facilities at the various hydroelectric power generating stations of New Brunswick Power on the St. John River, were described. The facilities described included the fish hoist at the Beechwood Generating Station , the fish ladder at the Tobique Generating Station and a trap and truck operation at the Mactaquac Station. Details of operating arrangements were provided. Operating issues, solutions and ongoing efforts to improve operations further, were discussed. 4 refs., 4 figs.

  10. Reactions and interactions in handling anticancer drugs.

    D'Arcy, P F


    The clinical toxicity of anticancer drugs has been well documented with regard to the adverse effects of treatment in patients. However, many of these drugs have a direct irritant effect on the skin, eyes, mucous membranes, and other tissues. Handled without due care, especially when being prepared for injection, most cytotoxic drugs can cause local toxic or allergic reactions; they also present hazards of carcinogenicity and mutagenicity. This spectrum of potential risk should be kept in mind by personnel administering or handling these drugs, especially in oncology units where just a few individuals may routinely and frequently reconstitute many doses of cytotoxic agents. This is work in which the hospital pharmacist should and must be involved; indeed, many of the techniques and skills required are identical with those used in standard aseptic procedures for preparing pharmaceutical products. Pharmacy departments should take the initiative in making hospital staff aware of the potential risks of handling neoplastic agents, and they should spearhead a multidisciplinary assessment for producing local guidelines for working with these drugs. This article warns practitioners about the inherent dangers of these practitioner-drug interactions and suggests ways in which they may be reduced. Information is given in tabular form regarding recommended procedures for reconstituting 24 anticancer drugs and precautions to protect the personnel handling them, especially when there is spillage of powdered or liquid drugs. Also, guidelines are given about incompatibilities with admixtures of such drugs, and the literature is reviewed relative to recent developments in hospital pharmacy departments where reconstitution of anticancer drugs has been incorporated into existing intravenous fluid preparation/admixture units. Not only has this been shown to be safer and more effective in terms of time and labor, but also it has cut the cost of injectable cytotoxic drugs by an

  11. Browsing TAP Services with TapHandle

    Louys, M.; Michel, L.; Mantelet, G.; Bonnarel, F.


    TapHandle is a Web application merging multiple services based on the IVOA Table Access Protocol (TAP) in one page. TAP resources are presented in an expandable tree whose leaves represent SQL tables. Both table description and content can be immediately displayed. A smart ADQL editor helps to setup queries on one table. A shopping cart facility allows users to get data of interest. A filter enriches the data layout with anchors pointing to remote services.

  12. Statistical methods for handling incomplete data

    Kim, Jae Kwang


    ""… this book nicely blends the theoretical material and its application through examples, and will be of interest to students and researchers as a textbook or a reference book. Extensive coverage of recent advances in handling missing data provides resources and guidelines for researchers and practitioners in implementing the methods in new settings. … I plan to use this as a textbook for my teaching and highly recommend it.""-Biometrics, September 2014

  13. Development of spent fuel remote handling technology

    Yoon, Ji Sup; Park, B. S.; Park, Y. S.; Oh, S. C.; Kim, S. H.; Cho, M. W.; Hong, D. H


    Since the nation`s policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

  14. High-accuracy infra-red thermography method using reflective marker arrays

    Kirollos, Benjamin; Povey, Thomas


    In this paper, we describe a new method for high-accuracy infra-red (IR) thermography measurements in situations with significant spatial variation in reflected radiation from the surroundings, or significant spatial variation in surface emissivity due to viewing angle non-uniformity across the field of view. The method employs a reflective marker array (RMA) on the target surface—typically, high emissivity circular dots—and an integrated image analysis algorithm designed to require minimal human input. The new technique has two particular advantages which make it suited to high-accuracy measurements in demanding environments: (i) it allows the reflected radiation component to be calculated directly, in situ, and as a function of position, overcoming a key problem in measurement environments with non-uniform and unsteady stray radiation from the surroundings; (ii) using image analysis of the marker array (via apparent aspect ratio of the circular reflective markers), the local viewing angle of the target surface can be estimated, allowing corrections for angular variation of local emissivity to be performed without prior knowledge of the geometry. A third advantage of the technique is that allows for simple focus-stacking algorithms due to increased image entropy. The reflective marker array method is demonstrated for an isothermal, hemispherical object exposed to an external IR source arranged to give a significant non-uniform reflected radiation term. This is an example of a challenging environment, both because of the significant non-uniform reflected radiation term, and also the significant variation in target emissivity due to surface angle variation. We demonstrate that the new RMA IR technique leads to significantly lower error in evaluated surface temperature than conventional IR techniques. The method is applicable to any complex radiative environment.

  15. Remote handling systems for the Pride application



    In this paper is described the development of remote handling systems for use in the pyro processing technology development. Remote handling systems mainly include a BDSM (Bridge transported Dual arm Servo-Manipulator) and a simulator, all of which will be applied to the Pride (Pyro process integrated inactive demonstration facility) that is under construction at KAERI. BDMS that will traverse the length of the ceiling is designed to have two pairs of master-slave manipulators of which each pair of master-slave manipulators has a kinematic similarity and a force reflection. A simulator is also designed to provide an efficient means for simulating and verifying the conceptual design, developments, arrangements, and rehearsal of the pyro processing equipment and relevant devices from the viewpoint of remote operation and maintenance. In our research is presented activities and progress made in developing remote handling systems to be used for the remote operation and maintenance of the pyro processing equipment and relevant devices in the Pride. (Author)

  16. Renal sodium handling and sodium sensitivity

    Alissa A. Frame


    Full Text Available The pathophysiology of hypertension, which affects over 1 billion individuals worldwide, involves the integration of the actions of multiple organ systems, including the kidney. The kidney, which governs sodium excretion via several mechanisms including pressure natriuresis and the actions of renal sodium transporters, is central to long term blood pressure regulation and the salt sensitivity of blood pressure. The impact of renal sodium handling and the salt sensitivity of blood pressure in health and hypertension is a critical public health issue owing to the excess of dietary salt consumed globally and the significant percentage of the global population exhibiting salt sensitivity. This review highlights recent advances that have provided new insight into the renal handling of sodium and the salt sensitivity of blood pressure, with a focus on genetic, inflammatory, dietary, sympathetic nervous system and oxidative stress mechanisms that influence renal sodium excretion. Increased understanding of the multiple integrated mechanisms that regulate the renal handling of sodium and the salt sensitivity of blood pressure has the potential to identify novel therapeutic targets and refine dietary guidelines designed to treat and prevent hypertension.

  17. D0 data handling operational experience

    Lee Lueking et al.


    We report on the production experience of the D0 experiment at the Fermilab Tevatron, using the SAM data handling system with a variety of computing hardware configurations, batch systems, and mass storage strategies. We have stored more than 300 TB of data in the Fermilab Enstore mass storage system. We deliver data through this system at an average rate of more than 2 TB/day to analysis programs, with a substantial multiplication factor in the consumed data through intelligent cache management. We handle more than 1.7 Million files in this system and provide data delivery to user jobs at Fermilab on four types of systems: a reconstruction farm, a large SMP system, a Linux batch cluster, and a Linux desktop cluster. In addition, we import simulation data generated at 6 sites worldwide, and deliver data to jobs at many more sites. We describe the scope of the data handling deployment worldwide, the operational experience with this system, and the feedback of that experience.

  18. Improving Memory Error Handling Using Linux

    Carlton, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Blanchard, Sean P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Debardeleben, Nathan A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    As supercomputers continue to get faster and more powerful in the future, they will also have more nodes. If nothing is done, then the amount of memory in supercomputer clusters will soon grow large enough that memory failures will be unmanageable to deal with by manually replacing memory DIMMs. "Improving Memory Error Handling Using Linux" is a process oriented method to solve this problem by using the Linux kernel to disable (offline) faulty memory pages containing bad addresses, preventing them from being used again by a process. The process of offlining memory pages simplifies error handling and results in reducing both hardware and manpower costs required to run Los Alamos National Laboratory (LANL) clusters. This process will be necessary for the future of supercomputing to allow the development of exascale computers. It will not be feasible without memory error handling to manually replace the number of DIMMs that will fail daily on a machine consisting of 32-128 petabytes of memory. Testing reveals the process of offlining memory pages works and is relatively simple to use. As more and more testing is conducted, the entire process will be automated within the high-performance computing (HPC) monitoring software, Zenoss, at LANL.

  19. Handle-attachments from nubia. A note

    William CULICAN


    Full Text Available Information on the distinctive bronze handle - attachments in the shape of a pair of human hands has been painstakingly collected by Dr. E. Cuadrado in his Refertorio de los Recipientes Rituales metálicos con "Asas de Manos" de la Península Ibérica (Trabajos de Prehistoria XXI, Madrid 1966. There is little room to doubt that metal vessels with this form of handle, whether we regard them as braziers (braserillos in the older terminology or 'ritual vessels' as does Cuadrado, are related to the distribution of Phoenician or Punic trade and influence in the Iberian peninsula. The southerly 'Tartessian' distribution speaks for itself; for the western 'Levantine' distribution (from Murcia, Alicante, Valencia, Teruel, Tarragona, Málaga, Ibiza we can postulate Ibiza, Málaga or Cartagena as a probable distribution centre. The examples in the west central meseta (Sanchorreja, El Berrueco, La Osera come as no surprise in view of the fact that such obviously Phoenician objects as the Sanchorreja belt-buckle, the Berrueco bronzes reached the regions of Avila and Salamanca respectively. Even for the outlying spot on the hand-handle distribution map at Santa Olaya, the cèltic oppidum at the mouth of the River Mondego, a context of Phoenician trade is likely, since pottery of Carmona and later types was found there and is now in the museum at Figueira da Foz.

  20. Vestibule and Cask Preparation Mechanical Handling Calculation

    N. Ambre


    The scope of this document is to develop the size, operational envelopes, and major requirements of the equipment to be used in the vestibule, cask preparation area, and the crane maintenance area of the Fuel Handling Facility. This calculation is intended to support the License Application (LA) submittal of December 2004, in accordance with the directive given by DOE correspondence received on the 27th of January 2004 entitled: ''Authorization for Bechtel SAIC Company L.L.C. to Include a Bare Fuel Handling Facility and Increased Aging Capacity in the License Application, Contract Number DE-AC28-01R W12101'' (Ref. 167124). This correspondence was appended by further correspondence received on the 19th of February 2004 entitled: ''Technical Direction to Bechtel SAIC Company L.L. C. for Surface Facility Improvements, Contract Number DE-AC28-01R W12101; TDL No. 04-024'' (Ref. 16875 1). These documents give the authorization for a Fuel Handling Facility to be included in the baseline. The limitations of this preliminary calculation lie within the assumptions of section 5 , as this calculation is part of an evolutionary design process.

  1. The "Forgotten" Pseudomomenta and Gauge Changes in Generalized Landau Level Problems: Spatially Nonuniform Magnetic and Temporally Varying Electric Fields

    Konstantinou, Georgios; Moulopoulos, Konstantinos


    By perceiving gauge invariance as an analytical tool in order to get insight into the states of the "generalized Landau problem" (a charged quantum particle moving inside a magnetic, and possibly electric field), and motivated by an early article that correctly warns against a naive use of gauge transformation procedures in the usual Landau problem (i.e. with the magnetic field being static and uniform), we first show how to bypass the complications pointed out in that article by solving the problem in full generality through gauge transformation techniques in a more appropriate manner. Our solution provides in simple and closed analytical forms all Landau Level-wavefunctions without the need to specify a particular vector potential. This we do by proper handling of the so-called pseudomomentum ěc {{K}} (or of a quantity that we term pseudo-angular momentum L z ), a method that is crucially different from the old warning argument, but also from standard treatments in textbooks and in research literature (where the usual Landau-wavefunctions are employed - labeled with canonical momenta quantum numbers). Most importantly, we go further by showing that a similar procedure can be followed in the more difficult case of spatially-nonuniform magnetic fields: in such case we define ěc {{K}} and L z as plausible generalizations of the previous ordinary case, namely as appropriate line integrals of the inhomogeneous magnetic field - our method providing closed analytical expressions for all stationary state wavefunctions in an easy manner and in a broad set of geometries and gauges. It can thus be viewed as complementary to the few existing works on inhomogeneous magnetic fields, that have so far mostly focused on determining the energy eigenvalues rather than the corresponding eigenkets (on which they have claimed that, even in the simplest cases, it is not possible to obtain in closed form the associated wavefunctions). The analytical forms derived here for these

  2. The "Forgotten" Pseudomomenta and Gauge Changes in Generalized Landau Level Problems: Spatially Nonuniform Magnetic and Temporally Varying Electric Fields

    Konstantinou, Georgios; Moulopoulos, Konstantinos


    By perceiving gauge invariance as an analytical tool in order to get insight into the states of the "generalized Landau problem" (a charged quantum particle moving inside a magnetic, and possibly electric field), and motivated by an early article that correctly warns against a naive use of gauge transformation procedures in the usual Landau problem (i.e. with the magnetic field being static and uniform), we first show how to bypass the complications pointed out in that article by solving the problem in full generality through gauge transformation techniques in a more appropriate manner. Our solution provides in simple and closed analytical forms all Landau Level-wavefunctions without the need to specify a particular vector potential. This we do by proper handling of the so-called pseudomomentum ěc {{K}} (or of a quantity that we term pseudo-angular momentum L z ), a method that is crucially different from the old warning argument, but also from standard treatments in textbooks and in research literature (where the usual Landau-wavefunctions are employed - labeled with canonical momenta quantum numbers). Most importantly, we go further by showing that a similar procedure can be followed in the more difficult case of spatially-nonuniform magnetic fields: in such case we define ěc {{K}} and L z as plausible generalizations of the previous ordinary case, namely as appropriate line integrals of the inhomogeneous magnetic field - our method providing closed analytical expressions for all stationary state wavefunctions in an easy manner and in a broad set of geometries and gauges. It can thus be viewed as complementary to the few existing works on inhomogeneous magnetic fields, that have so far mostly focused on determining the energy eigenvalues rather than the corresponding eigenkets (on which they have claimed that, even in the simplest cases, it is not possible to obtain in closed form the associated wavefunctions). The analytical forms derived here for these

  3. Effects of Axial Non-uniform Tip Clearances on Aerodynamic Performance of a Transonic Axial Compressor

    Hongwei MA; Baihe LI


    This paper presents a numerical investigation of effects of axial non-uniform tip clearances on the aerodynamic performance of a transonic axial compressor rotor (NASA Rotor 37). The three-dimensional steady flow field within the rotor passage was simulated with the datum tip clearance of 0.356 mm at the design wheel speed of 17188.7 rpm. The simulation results are well consistent with the measurement results, which verified the numeri-cal method. Then the three-dimensional steady flow field within the rotor passage was simulated respectively with different axial non-uniform tip clearances. The calculation results showed that optimal axial non-uniform tip clearances could improve the compressor performance, while the efficiency and the pressure ratio of the com-pressor were increased. The flow mechanism is that the axial non-uniform tip clearance can weaken the tip leak-age vortex, blow down low-energy fluids in boundary layers and reduce both flow blockage and tip loss.

  4. Nonuniform Illumination Correction Algorithm for Underwater Images Using Maximum Likelihood Estimation Method

    Sonali Sachin Sankpal


    Full Text Available Scattering and absorption of light is main reason for limited visibility in water. The suspended particles and dissolved chemical compounds in water are also responsible for scattering and absorption of light in water. The limited visibility in water results in degradation of underwater images. The visibility can be increased by using artificial light source in underwater imaging system. But the artificial light illuminates the scene in a nonuniform fashion. It produces bright spot at the center with the dark region at surroundings. In some cases imaging system itself creates dark region in the image by producing shadow on the objects. The problem of nonuniform illumination is neglected by the researchers in most of the image enhancement techniques of underwater images. Also very few methods are discussed showing the results on color images. This paper suggests a method for nonuniform illumination correction for underwater images. The method assumes that natural underwater images are Rayleigh distributed. This paper used maximum likelihood estimation of scale parameter to map distribution of image to Rayleigh distribution. The method is compared with traditional methods for nonuniform illumination correction using no-reference image quality metrics like average luminance, average information entropy, normalized neighborhood function, average contrast, and comprehensive assessment function.

  5. Multidimensional Local Central Limit Theorem of Some Non-uniformly Hyperbolic Systems

    Hong Qiang XIA


    We consider Young's nonuniformly hyperbolic system (X, T, v) where v is the SRB measure corresponding to the system (X, T), and show that if the components of a Holder observable f : X → Rd are cohomologously independent, then f satisfies the multidimensional central limit theorem. Moreover if f is aperiodic, then f satisfies the local multidimensional central limit theorem.

  6. Negative refraction of ultra-cold atoms in optical lattices with nonuniform artificial gauge fields

    Zhang, Ai-Xia, E-mail:; Xue, Ju-Kui


    We theoretically study the reflection and refraction of ultra-cold atoms in optical lattices exposed to a nonuniform artificial magnetic field. The introduction of the nonuniform artificial magnetic field to the optical lattice for suitable designer magnetic potential barrier can lead to a series of intriguing reflection and refraction phenomena of atoms, including reflection, positive refraction, negative refraction and atomic matter wave splitting. Both the occurrence and the distribution of these reflection and refraction scenarios can be coherently controlled by the nonuniform artificial magnetic field. In particular, the regions close to the boundary of reflection demonstrate two more interesting propagation modes, i.e., a reflected branch of atoms comprising a positive or negative refracted branch of atoms with almost same atom population will be excited simultaneously at the magnetic potential barrier. The results can be a guide for the coherent control of the matter waves in optical lattices and the design of new atom optics devices. - Highlights: • Ultra-cold atoms in OL with nonuniform magnetic field are studied. • Matter wave reflection, refraction and splitting are coherently controlled. • Results provide a guide for the design of new atomic optics devices.

  7. Stress state of thin – walled member of the structure with operation damages under nonuniform loading

    В.В. Астанін


    Full Text Available  The publication is dedicated to determining of stress state in particular the stress concentration factors for thin – walled members of the structures subject to nonuniform tension. A structure member has obtained the operation damage generation by corrosion and other causes.

  8. Photocatalytic oxidation activity of titanium dioxide film enhanced by Mn non-uniform doping

    ZHANG Kai-jian; XU Wei; LI Xin-jun; ZHENG Shao-jian; XU Gang; WANG Jian-hua


    The thin films of TiO2 doped by Mn non-uniformly were prepared by sol-gel method under process control. Each film was characterized by XPS, SEM, UV-vis spectrophotometry and electrochemistry workstation analysis.The activity of the photocatalyst was evaluated by the kinetics of photocatalytic degradation of aqueous methyl orange under the UV radiation. The results show that Mn non-uniform doping evidently enhances the photocatalytic activity of TiO2 thin film. In 80 min, the degradation rates of aqueous methyl orange are 62%, 12% and 34% for Mn non-uniformly doped film (0.7%), the uniformly doped film (0.7%) and pure titanium dioxide film, respectively. The characteristic of PN junction in the film was proved by electrochemical characterization. A mechanism for enhanced photocatalytic activity of Mn non-uniformly doped titanium dioxide film was discussed based on the effective separation of the photon-generated carrier because of the existence of the PN junction.

  9. Novel Approach for Modeling of Nonuniform Slag Layers and Air Gap in Continuous Casting Mold

    Wang, Xudong; Kong, Lingwei; Yao, Man; Zhang, Xiaobing


    Various kinds of surface defects on the continuous casting slab usually originate from nonuniform heat transfer and mechanical behavior, especially during the initial solidification inside the mold. In this article, a model-coupled inverse heat transfer problem incorporating the effect of slag layers and air gap is developed to study the nonuniform distribution of liquid slag, solid slag, and air gap layers. The model considers not only the formation and evolution of slag layers and air gap but also the temperatures in the mold copper as measured by thermocouples. The simulation results from the model and the measured temperatures from experiments are shown to be in good agreement with each other. At the casting speed of 0.65 m/min, the liquid slag film disappears and transforms into solid slag entirely at about 400 mm away from meniscus, and an air gap begins to form. Until the mold exit, the maximum thickness of the solid slag layer and air gap gradually increases to 1.34 and 0.056 mm, respectively. The results illustrate that the magnitude and nonuniform distribution of the slag layers and air gap along the cross direction, correlating with heat flux between the shell and mold, eventually determine the temperature profiles of the mold hot face and slab surface. The proposed model may provide a convenient approach for analyzing nonuniform heat transfer and mechanical behaviors between the mold and slab in the real casting process.

  10. Deformation space of a non-uniform 3-dimensional real hyperbolic lattice in quaternionic hyperbolic plane

    Kim, Inkang


    In this note, we study deformations of a non-uniform real hyperbolic lattice in quaternionic hyperbolic spaces. Specially we show that the representations of the fundamental group of the figure eight knot complement into PU(2,1) cannot be deformed in $PSp(2,1)$ out of PU(2,1) up to conjugacy.

  11. Effect of non-uniform mean flow field on acoustic propagation problems in computational aeroacoustics

    Si, Haiqing; Shen, Wen Zhong; Zhu, Wei Jun


    Acoustic propagation in the presence of a non-uniform mean flow is studied numerically by using two different acoustic propagating models, which solve linearized Euler equations (LEE) and acoustic perturbation equations (APE). As noise induced by turbulent flows often propagates from near field t...

  12. Maximum Likelihood DOA Estimation of Multiple Wideband Sources in the Presence of Nonuniform Sensor Noise

    K. Yao


    Full Text Available We investigate the maximum likelihood (ML direction-of-arrival (DOA estimation of multiple wideband sources in the presence of unknown nonuniform sensor noise. New closed-form expression for the direction estimation Cramér-Rao-Bound (CRB has been derived. The performance of the conventional wideband uniform ML estimator under nonuniform noise has been studied. In order to mitigate the performance degradation caused by the nonuniformity of the noise, a new deterministic wideband nonuniform ML DOA estimator is derived and two associated processing algorithms are proposed. The first algorithm is based on an iterative procedure which stepwise concentrates the log-likelihood function with respect to the DOAs and the noise nuisance parameters, while the second is a noniterative algorithm that maximizes the derived approximately concentrated log-likelihood function. The performance of the proposed algorithms is tested through extensive computer simulations. Simulation results show the stepwise-concentrated ML algorithm (SC-ML requires only a few iterations to converge and both the SC-ML and the approximately-concentrated ML algorithm (AC-ML attain a solution close to the derived CRB at high signal-to-noise ratio.

  13. Phase Transitions in a Non-Uniformly Stressed Iron Borate Single Crystal

    Dzhuraev, D. R.; Niyazov, L. N.; Sokolov, B. Yu.


    Based on the Landau thermodynamic theory, phase transformations observed in a FeBO3 single crystal subject to spatially non-uniform mechanical stresses are analyzed. It is demonstrated that the main results of theoretical consideration of structural and magnetic phase transitions in the examined crystal do not contradict with the available experimental data.

  14. Quantitative multi-pinhole small-animal SPECT : uniform versus non-uniform Chang attenuation correction

    Wu, C.; de Jong, J. R.; van Andel, H. A. Gratama; van der Have, F.; Vastenhouw, B.; Laverman, P.; Boerman, O. C.; Dierckx, R. A. J. O.; Beekman, F. J.


    Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusi

  15. Quantitative multi-pinhole small-animal SPECT: uniform versus non-uniform Chang attenuation correction

    Wu, C.; Jong, J.R. de; Gratama van Andel, H.A.; Have, F. van der; Vastenhouw, B.; Laverman, P.; Boerman, O.C.; Dierckx, R.A.; Beekman, F.J.


    Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusi

  16. Numerical analysis of blood flow in realistic arteries subjected to strong non-uniform magnetic fields

    Kenjeres, S.


    The paper reports on a comprehensive mathematical model for simulations of blood flow under the presence of strong non-uniform magnetic fields. The model consists of a set of Navier–Stokes equations accounting for the Lorentz and magnetisation forces, and a simplified set of Maxwell’s equations (Bio

  17. Reducing the Computational Complexity of Reconstruction in Compressed Sensing Nonuniform Sampling

    Grigoryan, Ruben; Jensen, Tobias Lindstrøm; Arildsen, Thomas


    This paper proposes a method that reduces the computational complexity of signal reconstruction in single-channel nonuniform sampling while acquiring frequency sparse multi-band signals. Generally, this compressed sensing based signal acquisition allows a decrease in the sampling rate of frequency...

  18. Non-uniform sampling in EPR--optimizing data acquisition for HYSCORE spectroscopy.

    Nakka, K K; Tesiram, Y A; Brereton, I M; Mobli, M; Harmer, J R


    Non-uniform sampling combined with maximum entropy reconstruction is a powerful technique used in multi-dimensional NMR spectroscopy to reduce sample measurement time. We adapted this technique to the pulse EPR experiment hyperfine sublevel correlation (HYSCORE) and show that experimental times can be shortened by approximately an order of magnitude as compared to conventional linear sampling with negligible loss of information.

  19. Numerical analysis of blood flow in realistic arteries subjected to strong non-uniform magnetic fields

    Kenjeres, S.


    The paper reports on a comprehensive mathematical model for simulations of blood flow under the presence of strong non-uniform magnetic fields. The model consists of a set of Navier–Stokes equations accounting for the Lorentz and magnetisation forces, and a simplified set of Maxwell’s equations (Bio

  20. Desynchronization boost by non-uniform coordinated reset stimulation in ensembles of pulse-coupled neurons

    Leonhard eLücken


    Full Text Available Several brain diseases are characterized by abnormalneuronal synchronization. Desynchronization of abnormal neural synchronyis theoretically compelling because of the complex dynamical mechanismsinvolved. We here present a novel type of coordinated reset (CR stimulation.CR means to deliver phase resetting stimuli at different neuronalsub-populations sequentially, i.e. at times equidistantly distributedin a stimulation cycle. This uniform timing pattern seems to be intuitiveand actually applies to the neural network models used for the studyof CR so far. CR resets the population to an unstable cluster statefrom where it passes through a desynchronized transient, eventuallyresynchronizing if left unperturbed. In contrast, we show that theoptimal stimulation times are nonuniform. Using the model of weaklypulse-coupled neurons with phase response curves, we provide an approachthat enables to determine optimal stimulation timing patterns thatsubstantially maximize the desynchronized transient time followingthe application of CR stimulation. This approach includes an optimizationsearch for clusters in a low-dimensional pulse coupled map. As a consequence,model-specific non-uniformly spaced cluster states cause considerablylonger desynchronization transients. Intriguingly, such a desynchronizationboost with non-uniform CR stimulation can already be achieved by onlyslight modifications of the uniform CR timing pattern. Our resultssuggest that the non-uniformness of the stimulation times can be amedically valuable parameter in the calibration procedure for CR stimulation,where the latter has successfully been used in clinical and pre-clinicalstudies for the treatment of Parkinson's disease and tinnitus.

  1. Constructing iterative non-uniform B-spline curve and surface to fit data points

    LIN Hongwei; WANG Guojin; DONG Chenshi


    In this paper, based on the idea of profit and loss modification, we present the iterative non-uniform B-spline curve and surface to settle a key problem in computer aided geometric design and reverse engineering, that is, constructing the curve (surface)fitting (interpolating) a given ordered point set without solving a linear system. We start with a piece of initial non-uniform B-spline curve (surface) which takes the given point set as its control point set. Then by adjusting its control points gradually with iterative formula,we can get a group of non-uniform B-spline curves (surfaces) with gradually higher precision. In this paper, using modern matrix theory, we strictly prove that the limit curve (surface) of the iteration interpolates the given point set. The non-uniform B-spline curves (surfaces) generated with the iteration have many advantages, such as satisfying the NURBS standard, having explicit expression, gaining locality, and convexity preserving,etc.

  2. Comparison of photocatalytic activity of TiO2 film doped nonuniformly by Mn and Zn

    XU Wei; LI Xin-jun; ZHENG Shao-jian; WANG Jun-gang; XU Zhong-kui


    The thin films of TiO2, doped by Mn or Zn with nonuniform distribution, were prepared by sol-gel method under process control. The actinic absorption of the catalyst thin films was evaluated by UV-vis spectrophotometry. And the activity of the photocatalyst was evaluated by photocatalytic degradation kinetics of aqueous methyl orange under UV radiation. The results show that the photocatalytic activity of the TiO2 thin film can be evidently enhanced by Mn non-uniformly doping in the bottom layer and can be decreased by Mn doping in the surface layer.The activity of TiO2 thin film can be evidently enhanced by Zn non-uniform doping in either the bottom or the surface layer. But the activity of TiO2 is less affected by uniformly Zn doping. The different mechanisms for enhanced photocatalytic activity of Mn or Zn non-uniformly doped titanium dioxide film were discussed in terms of the separation of photon-generated carrier in the TiO2 films.

  3. Pondermotive absorption of a short intense laser pulse in a non-uniform plasma

    Andreev, A.A.; Platonov, K.Yu. [Inst. for Laser Physics, SC `Vavilov State Optical Inst.` 12, Birzhevaya line, St Petersburg (Russian Federation); Tanaka, K.A.


    An analytical description of the pondermotive absorption mechanism at a short high intense laser pulse interaction with a strong inhomogeneous plasma is presented. The optimal conditions for the maximum of resonance absorption of laser pulse interaction with non-uniform plasma at normal incidence are founded. (author)

  4. Modeling the effect of nonuniform sediment on the dynamics of offshore tidal sandbanks

    Roos, Pieter C.; Wemmenhove, Rik; Hulscher, Suzanne J. M. H.; Hoeijmakers, Harry W. M.; Kruyt, N. P.


    [1] Tidal sandbanks are large-scale bed features present in many shallow shelf seas. Here we investigate the effect of nonuniform sediment on their dynamics, with a particular aim to explain observed surficial grain size variations over tidal sandbanks from a process-based modeling perspective. To t

  5. Calculation of Spark Breakdown or Corona Starting Voltages in Nonuniform Fields

    Pedersen, A.


    The processes leading to a spark breakdown or corona discharge are discussed very briefly. A quantitative breakdown criterion for use in high-voltage design is derived by which spark breakdown or corona starting voltages in nonuniform fields can be calculated. The criterion is applied to the sphere...

  6. Analysis of the origins of content non-uniformity in high-shear wet granulation.

    Oka, Sarang; Smrčka, David; Kataria, Anjali; Emady, Heather; Muzzio, Fernando; Štěpánek, František; Ramachandran, Rohit


    In this study, the origins of granule content non-uniformity in the high-shear wet granulation of a model two-component pharmaceutical blend were investigated. Using acetaminophen as the active pharmaceutical ingredient (API) and microcrystalline cellulose as the excipient, the distribution of the API across the granule size classes was measured for a range of conditions that differed in the duration of the initial dry mixing stage, the overall composition of the blend and the wet massing time. The coarse granule fractions were found to be systematically sub-potent, while the fines were enriched in the API. The extent of content non-uniformity was found to be dependent on two factors - powder segregation during dry mixing and redistribution of the API between the granule size fractions during the wet massing phase. The latter was demonstrated in an experiment where the excipient was pre-granulated, the API was added later and wet massed. The content non-uniformity in this case was comparable to that obtained when both components were present in the granulator from the beginning. With increasing wet massing time, the extent of content non-uniformity decreased, indicating that longer wet massing times might be a solution for systems with a natural tendency for component segregation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Experiments with non-uniform sediment in case of bed-load transport

    Ribberink, J.S.


    An experimental study was carried out in the framework of a research project concerning the development of a mathematical model for morphological computations in rivers in case of non-uniform sediment. The study consists of a series of laboratory experiments in a straight flume under steady, uniform

  8. Evolutionary Multiobjective Design Targeting a Field Programmable Transistor Array

    Aguirre, Arturo Hernandez; Zebulum, Ricardo S.; Coello, Carlos Coello


    This paper introduces the ISPAES algorithm for circuit design targeting a Field Programmable Transistor Array (FPTA). The use of evolutionary algorithms is common in circuit design problems, where a single fitness function drives the evolution process. Frequently, the design problem is subject to several goals or operating constraints, thus, designing a suitable fitness function catching all requirements becomes an issue. Such a problem is amenable for multi-objective optimization, however, evolutionary algorithms lack an inherent mechanism for constraint handling. This paper introduces ISPAES, an evolutionary optimization algorithm enhanced with a constraint handling technique. Several design problems targeting a FPTA show the potential of our approach.


    C.E. Sanders


    This design calculation revises and updates the previous criticality evaluation for the canister handling, transfer and staging operations to be performed in the Canister Handling Facility (CHF) documented in BSC [Bechtel SAIC Company] 2004 [DIRS 167614]. The purpose of the calculation is to demonstrate that the handling operations of canisters performed in the CHF meet the nuclear criticality safety design criteria specified in the ''Project Design Criteria (PDC) Document'' (BSC 2004 [DIRS 171599], Section, the nuclear facility safety requirement in ''Project Requirements Document'' (Canori and Leitner 2003 [DIRS 166275], p. 4-206), the functional/operational nuclear safety requirement in the ''Project Functional and Operational Requirements'' document (Curry 2004 [DIRS 170557], p. 75), and the functional nuclear criticality safety requirements described in the ''Canister Handling Facility Description Document'' (BSC 2004 [DIRS 168992], Sections and 3.2.3). Specific scope of work contained in this activity consists of updating the Category 1 and 2 event sequence evaluations as identified in the ''Categorization of Event Sequences for License Application'' (BSC 2004 [DIRS 167268], Section 7). The CHF is limited in throughput capacity to handling sealed U.S. Department of Energy (DOE) spent nuclear fuel (SNF) and high-level radioactive waste (HLW) canisters, defense high-level radioactive waste (DHLW), naval canisters, multicanister overpacks (MCOs), vertical dual-purpose canisters (DPCs), and multipurpose canisters (MPCs) (if and when they become available) (BSC 2004 [DIRS 168992], p. 1-1). It should be noted that the design and safety analyses of the naval canisters are the responsibility of the U.S. Department of the Navy (Naval Nuclear Propulsion Program) and will not be included in this document. In addition, this calculation is valid for

  10. Waste Handling Equipment Devleopment Test and Evaluation

    R.L. Tome


    The purpose of this study is to identify candidate Monitored Geologic Repository (MGR) surface waste handling equipment for development testing. This study will also identify strategies for performing the development tests. Development testing shall be implemented to support detail design and reduce design risks. Development testing shall be conducted to confirm design concepts, evaluate alternative design concepts, show the availability of needed technology, and provide design documentation. The candidate equipment will be selected from MGR surface waste handling equipment that is the responsibility of the Management and Operating Contractor (M&O) Surface Design Department. The equipment identified in this study is based on Viability Assessment (VA) design. The ''Monitored Geologic Repository Test and Evaluation Plan'' (MGR T&EP), Reference 5.1, was used as a basis for this study. The MGR T&EP reflects the extent of test planning and analysis that can be conducted, given the current status of the MGR requirements and latest VA design information. The MGR T&EP supports the appropriate sections in the license application (LA) in accordance with 10 CFR 60.2 1(c)(14). The MGR T&EP describes the following test activities: site characterization to confirm, by test and analysis, the suitability of the Yucca Mountain site for housing a geologic repository; development testing to investigate and document design concepts to reduce risk; qualification testing to verify equipment compliance with design requirements, specifications, and regulatory requirements; system testing to validate compliance with MGR requirements, which include the receipt, handling, retrieval, and disposal of waste; periodic performance testing to verify preclosure requirements and to demonstrate safe and reliable MGR operation; and performance confirmation modeling, testing, and analysis to verify adherence to postclosure regulatory requirements. Development test activities can be

  11. Electronic Switch Arrays for Managing Microbattery Arrays

    Mojarradi, Mohammad; Alahmad, Mahmoud; Sukumar, Vinesh; Zghoul, Fadi; Buck, Kevin; Hess, Herbert; Li, Harry; Cox, David


    Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together.

  12. Array Antenna Limitations

    Jonsson, B L G; Hussain, N


    This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.

  13. Carbon nanotube nanoelectrode arrays

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi


    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  14. Pacific Array (Transportable Broadband Ocean Floor Array)

    Kawakatsu, Hitoshi; Ekstrom, Goran; Evans, Rob; Forsyth, Don; Gaherty, Jim; Kennett, Brian; Montagner, Jean-Paul; Utada, Hisashi


    Based on recent developments on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry1, together with advances in the seismic analysis methodology, have enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (azimuthal, and hopefully radial), with deployments of ~15 broadband ocean bottom seismometers (BBOBSs). Having ~15 BBOBSs as an array unit for a 2-year deployment, and repeating such deployments in a leap-frog way or concurrently (an array of arrays) for a decade or so would enable us to cover a large portion of the Pacific basin. Such efforts, not only by giving regional constraints on the 1-D structure beneath Pacific ocean, but also by sharing waveform data for global scale waveform tomography, would drastically increase our knowledge of how plate tectonics works on this planet, as well as how it worked for the past 150 million years. International collaborations is essential: if three countries/institutions participate this endeavor together, Pacific Array may be accomplished within five-or-so years.

  15. Self-arraying of charged levitating droplets.

    Kauffmann, Paul; Nussbaumer, Jérémie; Masse, Alain; Jeandey, Christian; Grateau, Henri; Pham, Pascale; Reyne, Gilbert; Haguet, Vincent


    Diamagnetic levitation of water droplets in air is a promising phenomenon to achieve contactless manipulation of chemical or biochemical samples. This noncontact handling technique prevents contaminations of samples as well as provides measurements of interaction forces between levitating reactors. Under a nonuniform magnetic field, diamagnetic bodies such as water droplets experience a repulsive force which may lead to diamagnetic levitation of a single or few micro-objects. The levitation of several repulsively charged picoliter droplets was successfully performed in a ~1 mm(2) adjustable flat magnetic well provided by a centimeter-sized cylindrical permanent magnet structure. Each droplet position results from the balance between the centripetal diamagnetic force and the repulsive Coulombian forces. Levitating water droplets self-organize into satellite patterns or thin clouds, according to their charge and size. Small triangular lattices of identical droplets reproduce magneto-Wigner crystals. Repulsive forces and inner charges can be measured in the piconewton and the femtocoulomb ranges, respectively. Evolution of interaction forces is accurately followed up over time during droplet evaporation.

  16. Experimental validation of an optimized signal processing method to handle non-linearity in swept-source optical coherence tomography.

    Vergnole, Sébastien; Lévesque, Daniel; Lamouche, Guy


    We evaluate various signal processing methods to handle the non-linearity in wavenumber space exhibited by most laser sources for swept-source optical coherence tomography. The following methods are compared for the same set of experimental data: non-uniform discrete Fourier transforms with Vandermonde matrix or with Lomb periodogram, resampling with linear interpolation or spline interpolation prior to fast-Fourier transform (FFT), and resampling with convolution prior to FFT. By selecting an optimized Kaiser-Bessel window to perform the convolution, we show that convolution followed by FFT is the most efficient method. It allows small fractional oversampling factor between 1 and 2, thus a minimal computational time, while retaining an excellent image quality. (c) 2010 Optical Society of America.

  17. Dynamically Reconfigurable Microphone Arrays


    Static + 2 Wireless Using only a standard computer sound card, a robot is limited to binaural inputs. Even when using wireless microphones, the audio...Abstract—Robotic sound localization has traditionally been restricted to either on-robot microphone arrays or embedded microphones in aware...a microphone array has a significant impact on the mathematics of sound source localization. Arrays, for instance, are commonly designed to

  18. Optimal evaluation of array expressions on massively parallel machines

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert; Teng, Shang-Hua


    We investigate the problem of evaluating FORTRAN 90 style array expressions on massively parallel distributed-memory machines. On such machines, an elementwise operation can be performed in constant time for arrays whose corresponding elements are in the same processor. If the arrays are not aligned in this manner, the cost of aligning them is part of the cost of evaluating the expression. The choice of where to perform the operation then affects this cost. We present algorithms based on dynamic programming to solve this problem efficiently for a wide variety of interconnection schemes, including multidimensional grids and rings, hypercubes, and fat-trees. We also consider expressions containing operations that change the shape of the arrays, and show that our approach extends naturally to handle this case.

  19. Integrated avalanche photodiode arrays

    Harmon, Eric S.


    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  20. Solidex 86 - modern technology in bulk solids handling


    A total of 30 papers were presented covering the following topics: coal and ash handling; dust control and explosion hazards; pneumatic conveying; mechanical conveying; storage and wear; and weighing technology and automated materials handling. 15 papers have been abstracted separately.