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Sample records for traditional filtered back-projection

  1. Coronary CT angiography: image quality, diagnostic accuracy, and potential for radiation dose reduction using a novel iterative image reconstruction technique - comparison with traditional filtered back projection

    International Nuclear Information System (INIS)

    To compare image noise, image quality and diagnostic accuracy of coronary CT angiography (cCTA) using a novel iterative reconstruction algorithm versus traditional filtered back projection (FBP) and to estimate the potential for radiation dose savings. Sixty five consecutive patients (48 men; 59.3 ± 7.7 years) prospectively underwent cCTA and coronary catheter angiography (CCA). Full radiation dose data, using all projections, were reconstructed with FBP. To simulate image acquisition at half the radiation dose, 50% of the projections were discarded from the raw data. The resulting half-dose data were reconstructed with sinogram-affirmed iterative reconstruction (SAFIRE). Full-dose FBP and half-dose iterative reconstructions were compared with regard to image noise and image quality, and their respective accuracy for stenosis detection was compared against CCA. Compared with full-dose FBP, half-dose iterative reconstructions showed significantly (p = 0.001 - p = 0.025) lower image noise and slightly higher image quality. Iterative reconstruction improved the accuracy of stenosis detection compared with FBP (per-patient: accuracy 96.9% vs. 93.8%, sensitivity 100% vs. 100%, specificity 94.6% vs. 89.2%, NPV 100% vs. 100%, PPV 93.3% vs. 87.5%). Iterative reconstruction significantly reduces image noise without loss of diagnostic information and holds the potential for substantial radiation dose reduction from cCTA. (orig.)

  2. Filtered back projection inversion of turntable ISAR data

    Science.gov (United States)

    Lopez, Jaime X.; Qiao, Zhijun

    2011-06-01

    In this paper, an inversion scheme for near-field inverse synthetic aperture radar (ISAR) data is derived for both two and three dimensions from a scalar wave equation model. The proposed data inversion scheme motivates the use of a filtered back projection (FBP) imaging algorithm. The paper provides a derivation of the the general imaging filter needed for FBP, which will be shown to reduce to a familiar result for near-field ISAR imaging.

  3. Improvement of wavelet threshold filtered back-projection image reconstruction algorithm

    Science.gov (United States)

    Ren, Zhong; Liu, Guodong; Huang, Zhen

    2014-11-01

    Image reconstruction technique has been applied into many fields including some medical imaging, such as X ray computer tomography (X-CT), positron emission tomography (PET) and nuclear magnetic resonance imaging (MRI) etc, but the reconstructed effects are still not satisfied because original projection data are inevitably polluted by noises in process of image reconstruction. Although some traditional filters e.g., Shepp-Logan (SL) and Ram-Lak (RL) filter have the ability to filter some noises, Gibbs oscillation phenomenon are generated and artifacts leaded by back-projection are not greatly improved. Wavelet threshold denoising can overcome the noises interference to image reconstruction. Since some inherent defects exist in the traditional soft and hard threshold functions, an improved wavelet threshold function combined with filtered back-projection (FBP) algorithm was proposed in this paper. Four different reconstruction algorithms were compared in simulated experiments. Experimental results demonstrated that this improved algorithm greatly eliminated the shortcomings of un-continuity and large distortion of traditional threshold functions and the Gibbs oscillation. Finally, the availability of this improved algorithm was verified from the comparison of two evaluation criterions, i.e. mean square error (MSE), peak signal to noise ratio (PSNR) among four different algorithms, and the optimum dual threshold values of improved wavelet threshold function was gotten.

  4. Filtered back-projection algorithm for Compton telescopes

    Science.gov (United States)

    Gunter, Donald L. (Lisle, IL)

    2008-03-18

    A method for the conversion of Compton camera data into a 2D image of the incident-radiation flux on the celestial sphere includes detecting coincident gamma radiation flux arriving from various directions of a 2-sphere. These events are mapped by back-projection onto the 2-sphere to produce a convolution integral that is subsequently stereographically projected onto a 2-plane to produce a second convolution integral which is deconvolved by the Fourier method to produce an image that is then projected onto the 2-sphere.

  5. PET reconstruction artifact can be minimized by using sinogram correction and filtered back-projection technique

    OpenAIRE

    Jha, Ashish Kumar; Purandare, Nilendu C.; Shah, Sneha; Agrawal, Archi; Puranik, Ameya D.; Rangarajan, Venkatesh

    2014-01-01

    Filtered Back-Projection (FBP) has become an outdated image reconstruction technique in new-generation positron emission tomography (PET)/computed tomography (CT) scanners. Iterative reconstruction used in all new-generation PET scanners is a much improved reconstruction technique. Though a well-calibrated PET system can only be used for clinical imaging in few situations like ours, when compromised PET scanner with one PET module bypassed was used for PET acquisition, FBP with sinogram corre...

  6. Research of inverse synthetic aperture imaging lidar based on filtered back-projection tomography technique

    Science.gov (United States)

    Liu, Zhi-chao; Yang, Jin-hua

    2014-07-01

    In order to obtain clear two-dimensional image under the conditions without using heterodyne interferometry by inverse synthetic aperture lidar(ISAL), designed imaging algorithms based on filtered back projection tomography technique, and the target "A" was reconstructed with simulation algorithm by the system in the turntable model. Analyzed the working process of ISAL, and the function of the reconstructed image was given. Detail analysis of the physical meaning of the various parameters in the process of echo data, and its parameters affect the reconstructed image. The image in test area was reconstructed by the one-dimensional distance information with filtered back projection tomography technique. When the measured target rotated, the sum of the echo light intensity at the same distance was constituted by the different position of the measured target. When the total amount collected is large enough, multiple equations can be solved change. Filtered back-projection image of the ideal image is obtained through MATLAB simulation, and analyzed that the angle intervals affected the reconstruction of image. The ratio of the intensity of echo light and loss light affected the reconstruction of image was analyzed. Simulation results show that, when the sampling angle is smaller, the resolution of the reconstructed image of measured target is higher. And the ratio of the intensity of echo light and loss light is greater, the resolution of the reconstructed image of measured target is higher. In conclusion after some data processing, the reconstructed image basically meets be effective identification requirements.

  7. Characterization of filters applied in filtered back-projection reconstruction for absorption and differential phase-contrast imaging

    International Nuclear Information System (INIS)

    In computed X-ray tomography, window functions like ''Ram-Lak'' and ''Hamming'' (absorption) or the ''Hilbert filter'' (phase-contrast) are commonly used for correct tomographic reconstruction and improvement of image quality in the back-projection process. Choosing the appropriate filter, i.e. the adequate weight of the spatial frequencies, is not obvious. For instance, the noise spectrum of phase-contrast tomography differs considerably from absorption tomography. Existing literature does not provide a clear comparison and characterization, neither of absorption nor of differential phase-contrast (DPC) filters corresponding to the target application. In this study, we examine the modulation transfer function (MTF) of a simulated phantom in contrast to its tomographic reconstructions, obtained by forward- and filtered back-projection with different filters. We thereby optimize the reconstruction with respect to sharpness of edges as well as to remaining noise. Those parameters are especially studied using the ''Hilbert filter'' in order to improve frequency weighting, considering amongst others the half-pixel shift method introduced in earlier studies. As a result, we provide a set of rules to facilitate the choice of the appropriate filter for both, absorption and DPC tomography. In biomedical imaging, this filter selection allows for individual contrast enhancement depending on the structure of interest (e.g. bones, soft tissue).

  8. Characterization of filters applied in filtered back-projection reconstruction for absorption and differential phase-contrast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Karin; Chabior, Michael; Pfeiffer, Franz [TUM, Muenchen (Germany)

    2013-07-01

    In computed X-ray tomography, window functions like ''Ram-Lak'' and ''Hamming'' (absorption) or the ''Hilbert filter'' (phase-contrast) are commonly used for correct tomographic reconstruction and improvement of image quality in the back-projection process. Choosing the appropriate filter, i.e. the adequate weight of the spatial frequencies, is not obvious. For instance, the noise spectrum of phase-contrast tomography differs considerably from absorption tomography. Existing literature does not provide a clear comparison and characterization, neither of absorption nor of differential phase-contrast (DPC) filters corresponding to the target application. In this study, we examine the modulation transfer function (MTF) of a simulated phantom in contrast to its tomographic reconstructions, obtained by forward- and filtered back-projection with different filters. We thereby optimize the reconstruction with respect to sharpness of edges as well as to remaining noise. Those parameters are especially studied using the ''Hilbert filter'' in order to improve frequency weighting, considering amongst others the half-pixel shift method introduced in earlier studies. As a result, we provide a set of rules to facilitate the choice of the appropriate filter for both, absorption and DPC tomography. In biomedical imaging, this filter selection allows for individual contrast enhancement depending on the structure of interest (e.g. bones, soft tissue).

  9. 2D and 3D ISAR image reconstruction through filtered back projection

    Science.gov (United States)

    Ray, Timothy; Cao, Yufeng; Qiao, Zhijun; Chen, Genshe

    2012-06-01

    This paper presents a 3D ltered inversion scheme for turntable inverse synthetic aperture radar (ISAR) data from a scalar wave equation model. The proposed inversion scheme targets at the use of ltered back projection (FBP) and convolution back projection (CBP) imaging algorithms. In the paper, we also provide a derivation of a general imaging lter for the near-elds FBP and CBP imaging algorithms.

  10. Comparison of adaptive statistical iterative and filtered back projection reconstruction techniques in brain CT

    International Nuclear Information System (INIS)

    Purpose: To compare image quality and visualization of normal structures and lesions in brain computed tomography (CT) with adaptive statistical iterative reconstruction (ASIR) and filtered back projection (FBP) reconstruction techniques in different X-ray tube current–time products. Materials and methods: In this IRB-approved prospective study, forty patients (nineteen men, twenty-one women; mean age 69.5 ± 11.2 years) received brain scan at different tube current–time products (300 and 200 mAs) in 64-section multi-detector CT (GE, Discovery CT750 HD). Images were reconstructed with FBP and four levels of ASIR-FBP blending. Two radiologists (please note that our hospital is renowned for its geriatric medicine department, and these two radiologists are more experienced in chronic cerebral vascular disease than in neoplastic disease, so this research did not contain cerebral tumors but as a discussion) assessed all the reconstructed images for visibility of normal structures, lesion conspicuity, image contrast and diagnostic confidence in a blinded and randomized manner. Volume CT dose index (CTDIvol) and dose-length product (DLP) were recorded. All the data were analyzed by using SPSS 13.0 statistical analysis software. Results: There was no statistically significant difference between the image qualities at 200 mAs with 50% ASIR blending technique and 300 mAs with FBP technique (p > .05). While between the image qualities at 200 mAs with FBP and 300 mAs with FBP technique a statistically significant difference (p < .05) was found. Conclusion: ASIR provided same image quality and diagnostic ability in brain imaging with greater than 30% dose reduction compared with FBP reconstruction technique

  11. Rapid mapping of visual receptive fields by filtered back projection: application to multi-neuronal electrophysiology and imaging

    OpenAIRE

    Johnston, Jamie; Ding, Huayu; Seibel, Sofie H.; Esposti, Federico; Lagnado, Leon

    2014-01-01

    Neurons in the visual system vary widely in the spatiotemporal properties of their receptive fields (RFs), and understanding these variations is key to elucidating how visual information is processed. We present a new approach for mapping RFs based on the filtered back projection (FBP), an algorithm used for tomographic reconstructions. To estimate RFs, a series of bars were flashed across the retina at pseudo-random positions and at a minimum of five orientations. We apply this method to ret...

  12. Comprehensive analysis of high-performance computing methods for filtered back-projection

    OpenAIRE

    Mendl, Christian B.

    2013-01-01

    This paper provides an extensive runtime, accuracy, and noise analysis of Computed To-mography (CT) reconstruction algorithms using various High-Performance Computing (HPC) frameworks such as: “conventional” multi-core, multi threaded CPUs, Compute Unified Device Architecture (CUDA), and DirectX or OpenGL graphics pipeline programming. The proposed algorithms exploit various built-in hardwired features of GPUs such as rasterization and texture filtering. We compare implementations of the ...

  13. Evaluation of dose reduction and image quality in CT colonography: Comparison of low-dose CT with iterative reconstruction and routine-dose CT with filtered back projection

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Koichi [Kameda Medical Center, Department of Radiology, Kamogawa, Chiba (Japan); Jichi Medical University, Department of Radiology, Tochigi (Japan); National Cancer Center, Cancer Screening Technology Division, Research Center for Cancer Prevention and Screening, Tokyo (Japan); Fujiwara, Masanori; Mogi, Tomohiro; Iida, Nao [Kameda Medical Center Makuhari, Department of Radiology, Chiba (Japan); Kanazawa, Hidenori; Sugimoto, Hideharu [Jichi Medical University, Department of Radiology, Tochigi (Japan); Mitsushima, Toru [Kameda Medical Center Makuhari, Department of Gastroenterology, Chiba (Japan); Lefor, Alan T. [Jichi Medical University, Department of Surgery, Tochigi (Japan)

    2015-01-15

    To prospectively evaluate the radiation dose and image quality comparing low-dose CT colonography (CTC) reconstructed using different levels of iterative reconstruction techniques with routine-dose CTC reconstructed with filtered back projection. Following institutional ethics clearance and informed consent procedures, 210 patients underwent screening CTC using automatic tube current modulation for dual positions. Examinations were performed in the supine position with a routine-dose protocol and in the prone position, randomly applying four different low-dose protocols. Supine images were reconstructed with filtered back projection and prone images with iterative reconstruction. Two blinded observers assessed the image quality of endoluminal images. Image noise was quantitatively assessed by region-of-interest measurements. The mean effective dose in the supine series was 1.88 mSv using routine-dose CTC, compared to 0.92, 0.69, 0.57, and 0.46 mSv at four different low doses in the prone series (p < 0.01). Overall image quality and noise of low-dose CTC with iterative reconstruction were significantly improved compared to routine-dose CTC using filtered back projection. The lowest dose group had image quality comparable to routine-dose images. Low-dose CTC with iterative reconstruction reduces the radiation dose by 48.5 to 75.1 % without image quality degradation compared to routine-dose CTC with filtered back projection. (orig.)

  14. Evaluation of dose reduction and image quality in CT colonography: Comparison of low-dose CT with iterative reconstruction and routine-dose CT with filtered back projection

    International Nuclear Information System (INIS)

    To prospectively evaluate the radiation dose and image quality comparing low-dose CT colonography (CTC) reconstructed using different levels of iterative reconstruction techniques with routine-dose CTC reconstructed with filtered back projection. Following institutional ethics clearance and informed consent procedures, 210 patients underwent screening CTC using automatic tube current modulation for dual positions. Examinations were performed in the supine position with a routine-dose protocol and in the prone position, randomly applying four different low-dose protocols. Supine images were reconstructed with filtered back projection and prone images with iterative reconstruction. Two blinded observers assessed the image quality of endoluminal images. Image noise was quantitatively assessed by region-of-interest measurements. The mean effective dose in the supine series was 1.88 mSv using routine-dose CTC, compared to 0.92, 0.69, 0.57, and 0.46 mSv at four different low doses in the prone series (p < 0.01). Overall image quality and noise of low-dose CTC with iterative reconstruction were significantly improved compared to routine-dose CTC using filtered back projection. The lowest dose group had image quality comparable to routine-dose images. Low-dose CTC with iterative reconstruction reduces the radiation dose by 48.5 to 75.1 % without image quality degradation compared to routine-dose CTC with filtered back projection. (orig.)

  15. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

    International Nuclear Information System (INIS)

    Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic

  16. Coronary CT angiography: Comparison of a novel iterative reconstruction with filtered back projection for reconstruction of low-dose CT—Initial experience

    International Nuclear Information System (INIS)

    Objective: To prospectively compare subjective and objective image quality in 20% tube current coronary CT angiography (cCTA) datasets between an iterative reconstruction algorithm (SAFIRE) and traditional filtered back projection (FBP). Materials and methods: Twenty patients underwent a prospectively ECG-triggered dual-step cCTA protocol using 2nd generation dual-source CT (DSCT). CT raw data was reconstructed using standard FBP at full-dose (Group1a) and 80% tube current reduced low-dose (Group1b). The low-dose raw data was additionally reconstructed using iterative raw data reconstruction (Group2). Attenuation and image noise were measured in three regions of interest and signal-to-noise-ratio (SNR) as well as contrast-to-noise-ratio (CNR) was calculated. Subjective diagnostic image quality was evaluated using a 4-point Likert scale. Results: Mean image noise of group2 was lowered by 22% on average when compared to group1b (p 2 compared to group1b (p 2 (1.88 ± 0.63) was also rated significantly higher when compared to group1b (1.58 ± 0.63, p = 0.004). Conclusions: Image quality of 80% tube current reduced iteratively reconstructed cCTA raw data is significantly improved when compared to standard FBP and consequently may improve the diagnostic accuracy of cCTA

  17. Rapid mapping of visual receptive fields by filtered back projection: application to multi-neuronal electrophysiology and imaging.

    Science.gov (United States)

    Johnston, Jamie; Ding, Huayu; Seibel, Sofie H; Esposti, Federico; Lagnado, Leon

    2014-11-15

    Neurons in the visual system vary widely in the spatiotemporal properties of their receptive fields (RFs), and understanding these variations is key to elucidating how visual information is processed. We present a new approach for mapping RFs based on the filtered back projection (FBP), an algorithm used for tomographic reconstructions. To estimate RFs, a series of bars were flashed across the retina at pseudo-random positions and at a minimum of five orientations. We apply this method to retinal neurons and show that it can accurately recover the spatial RF and impulse response of ganglion cells recorded on a multi-electrode array. We also demonstrate its utility for in vivo imaging by mapping the RFs of an array of bipolar cell synapses expressing a genetically encoded Ca(2+) indicator. We find that FBP offers several advantages over the commonly used spike-triggered average (STA): (i) ON and OFF components of a RF can be separated; (ii) the impulse response can be reconstructed at sample rates of 125 Hz, rather than the refresh rate of a monitor; (iii) FBP reveals the response properties of neurons that are not evident using STA, including those that display orientation selectivity, or fire at low mean spike rates; and (iv) the FBP method is fast, allowing the RFs of all the bipolar cell synaptic terminals in a field of view to be reconstructed in under 4 min. Use of the FBP will benefit investigations of the visual system that employ electrophysiology or optical reporters to measure activity across populations of neurons. PMID:25172952

  18. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

    Energy Technology Data Exchange (ETDEWEB)

    Katsura, Masaki, E-mail: mkatsura-tky@umin.ac.jp [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2013-02-15

    Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P < 0.01) and FBP images (26.52 ± 5.8, P < 0.01). Significant improvements in streak artifacts of the cervicothoracic region were observed with the use of MBIR (P < 0.001 each for MBIR vs. the other two image data sets for both readers), while no significant difference was observed between ASIR and FBP (P > 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic.

  19. Coronary CT angiography: Comparison of a novel iterative reconstruction with filtered back projection for reconstruction of low-dose CT—Initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Takx, Richard A.P. [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Maastricht University Medical Centre, Maastricht (Netherlands); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Moscariello, Antonio [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Policlinico Universitario Campus Bio-Medico, Rome (Italy); Das, Marco [Department of Radiology, Maastricht University Medical Centre, Maastricht (Netherlands); Rowe, Garrett [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoenberg, Stefan O.; Fink, Christian [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany); Henzler, Thomas [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University (Germany)

    2013-02-15

    Objective: To prospectively compare subjective and objective image quality in 20% tube current coronary CT angiography (cCTA) datasets between an iterative reconstruction algorithm (SAFIRE) and traditional filtered back projection (FBP). Materials and methods: Twenty patients underwent a prospectively ECG-triggered dual-step cCTA protocol using 2nd generation dual-source CT (DSCT). CT raw data was reconstructed using standard FBP at full-dose (Group{sub 1}a) and 80% tube current reduced low-dose (Group{sub 1}b). The low-dose raw data was additionally reconstructed using iterative raw data reconstruction (Group{sub 2}). Attenuation and image noise were measured in three regions of interest and signal-to-noise-ratio (SNR) as well as contrast-to-noise-ratio (CNR) was calculated. Subjective diagnostic image quality was evaluated using a 4-point Likert scale. Results: Mean image noise of group{sub 2} was lowered by 22% on average when compared to group{sub 1}b (p < 0.0001–0.0033), while there were no significant differences in mean attenuation within the same anatomical regions. The lower image noise resulted in significantly higher SNR and CNR ratios in group{sub 2} compared to group{sub 1}b (p < 0.0001–0.0232). Subjective image quality of group{sub 2} (1.88 ± 0.63) was also rated significantly higher when compared to group{sub 1}b (1.58 ± 0.63, p = 0.004). Conclusions: Image quality of 80% tube current reduced iteratively reconstructed cCTA raw data is significantly improved when compared to standard FBP and consequently may improve the diagnostic accuracy of cCTA.

  20. Why do commercial CT scanners still employ traditional, filtered back-projection for image reconstruction?

    International Nuclear Information System (INIS)

    Despite major advances in x-ray sources, detector arrays, gantry mechanical design and especially computer performance, one component of computed tomography (CT) scanners has remained virtually constant for the past 25 years—the reconstruction algorithm. Fundamental advances have been made in the solution of inverse problems, especially tomographic reconstruction, but these works have not been translated into clinical and related practice. The reasons are not obvious and seldom discussed. This review seeks to examine the reasons for this discrepancy and provides recommendations on how it can be resolved. We take the example of field of compressive sensing (CS), summarizing this new area of research from the eyes of practical medical physicists and explaining the disconnection between theoretical and application-oriented research. Using a few issues specific to CT, which engineers have addressed in very specific ways, we try to distill the mathematical problem underlying each of these issues with the hope of demonstrating that there are interesting mathematical problems of general importance that can result from in depth analysis of specific issues. We then sketch some unconventional CT-imaging designs that have the potential to impact on CT applications, if the link between applied mathematicians and engineers/physicists were stronger. Finally, we close with some observations on how the link could be strengthened. There is, we believe, an important opportunity to rapidly improve the performance of CT and related tomographic imaging techniques by addressing these issues. (topical review)

  1. Results of clinical receiver operating characteristic study comparing ordered subset expectation maximization and filtered back projection images in FDG PET studies of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    The aims of this study is to validate the usefulness of ordered subset expectation maximization (OSEM) comparing with filtered back projection in terms of diagnostic ability for hepatocellular carcinoma (HCC). The data of fifty seven patients with HCC and 62 patients with normal liver was reconstructed using both OSEM and FBP. Mean age of the patients group was 54.4±1.5 year. All patient underwent whole body and liver scan after the injection of 10 mCi of (F-18)FDG using dedicated whole body PET camera (GE, Advance). Interpretation of PET images were performed by 3 observers with random exposure of normal and diseased cases. Receiver operator characteristic (ROC) study was used for the validation of results. The area of ROC curve. Az was represented as below and this results revealed statistical differences (p<0.05). In PET studies of patients with HCC, OSEM showed better results that those of conventional FBP in terms of lesion detectability

  2. Investigation of the quantitative accuracy of 3D iterative reconstruction algorithms in comparison to filtered back projection method: a phantom study

    Science.gov (United States)

    Abuhadi, Nouf; Bradley, David; Katarey, Dev; Podolyak, Zsolt; Sassi, Salem

    2014-03-01

    Introduction: Single-Photon Emission Computed Tomography (SPECT) is used to measure and quantify radiopharmaceutical distribution within the body. The accuracy of quantification depends on acquisition parameters and reconstruction algorithms. Until recently, most SPECT images were constructed using Filtered Back Projection techniques with no attenuation or scatter corrections. The introduction of 3-D Iterative Reconstruction algorithms with the availability of both computed tomography (CT)-based attenuation correction and scatter correction may provide for more accurate measurement of radiotracer bio-distribution. The effect of attenuation and scatter corrections on accuracy of SPECT measurements is well researched. It has been suggested that the combination of CT-based attenuation correction and scatter correction can allow for more accurate quantification of radiopharmaceutical distribution in SPECT studies (Bushberg et al., 2012). However, The effect of respiratory induced cardiac motion on SPECT images acquired using higher resolution algorithms such 3-D iterative reconstruction with attenuation and scatter corrections has not been investigated. Aims: To investigate the quantitative accuracy of 3D iterative reconstruction algorithms in comparison to filtered back projection (FBP) methods implemented on cardiac SPECT/CT imaging with and without CT-attenuation and scatter corrections. Also to investigate the effects of respiratory induced cardiac motion on myocardium perfusion quantification. Lastly, to present a comparison of spatial resolution for FBP and ordered subset expectation maximization (OSEM) Flash 3D together with and without respiratory induced motion, and with and without attenuation and scatter correction. Methods: This study was performed on a Siemens Symbia T16 SPECT/CT system using clinical acquisition protocols. Respiratory induced cardiac motion was simulated by imaging a cardiac phantom insert whilst moving it using a respiratory motion motor inducing cyclical elliptical motion of the apex of the cardiac insert. Results: Our analyses revealed that the use of the Flash 3-D reconstruction algorithm without scatter or attenuation correction has improved Spatial Resolution by 30% relative to FBP. Reduction in Spatial Resolution due to respiratory induced motion was 12% and 38% for FBP and Flash 3-D respectively. The implementation of scatter correction has resulted in a reduction in resolution by up to 6%. The application of CT-based attenuation correction has resulted in 13% and 26% reduction in spatial resolution for SPECT images reconstructed using FBP and Flash 3-D algorithms respectively. Conclusion: We conclude that iterative reconstruction (Flash-3D) provides significant improvement in image spatial resolution, however as a result the effects of respiratory induced motion have become more evident and correction of this is required before the full potential of these algorithms can be realised for myocardial perfusion imaging. Attenuation and scatter correction can improve image contrast, but may have significant detrimental effect on spatial resolution.

  3. Half-dose abdominal CT with sinogram-affirmed iterative reconstruction technique in children - comparison with full-dose CT with filtered back projection

    International Nuclear Information System (INIS)

    Iterative reconstruction can be helpful to reduce radiation dose while maintaining image quality. However, this technique has not been fully evaluated in children during abdominal CT. To compare objective and subjective image quality between half-dose images reconstructed with iterative reconstruction at iteration strength levels 1 to 5 (half-S1 to half-S5 studies) and full-dose images reconstructed with filtered back projection (full studies) in pediatric abdominal CT. Twenty-one children (M:F = 13:8; mean age 8.2 ± 5.7 years) underwent dual-source abdominal CT (mean effective dose 4.8 ± 2.1 mSv). The objective image quality was evaluated as noise. Subjective image quality analysis was performed comparing each half study to the full study for noise, sharpness, artifact and diagnostic acceptability. Both objective and subjective image noise decreased with increasing iteration strength. Half-S4 and -S5 studies showed objective image noise similar to or lower than that of full studies. The half-S2 and -S3 studies produced the greatest sharpness and the half-S5 studies were the worst from a blocky appearance. Full and half studies did not differ in artifacts. Half-S3 studies showed the best diagnostic acceptability. Half-S4 and -S5 studies objectively and half-S3 studies subjectively showed comparable image quality to full studies in pediatric abdominal CT. (orig.)

  4. Standard dose versus low-dose abdominal and pelvic CT: Comparison between filtered back projection versus adaptive iterative dose reduction 3D

    International Nuclear Information System (INIS)

    Purpose: To compare the dose and image quality of a standard dose abdominal and pelvic CT with Filtered Back Projection (FBP) to low-dose CT with Adaptive Iterative Dose Reduction 3D (AIDR 3D). Materials and methods: We retrospectively examined the images of 21 patients in the portal phase of an abdominal and pelvic CT scan before and after implementation of AIDR 3D iterative reconstruction. The acquisition length, dose and evaluations of the image quality were compared between standard dose FBP images and low-dose images reconstructed with AIDR 3D and FBP using the Wilcoxon test. Results: The mean acquisition length was similar for both CT scans. There was a significant dose reduction of 49.5% with low-dose CT compared to standard dose CT (mean DLP of 451 mGy.cm versus 892 mGy.cm, P < 0.001). There were no differences in image quality scores between standard dose FBP and low-dose AIDR 3D images (4.6 ± 0.6 versus 4.4 ± 0.6 respectively, P = 0.147). Conclusion: AIDR 3D iterative reconstruction enables a significant reduction in dose of 49.5% to be achieved with abdominal CT scan compared to FBP, whilst maintaining equivalent image quality. (authors)

  5. Quantitative analysis of emphysema and airway measurements according to iterative reconstruction algorithms: comparison of filtered back projection, adaptive statistical iterative reconstruction and model-based iterative reconstruction

    International Nuclear Information System (INIS)

    To evaluate filtered back projection (FBP) and two iterative reconstruction (IR) algorithms and their effects on the quantitative analysis of lung parenchyma and airway measurements on computed tomography (CT) images. Low-dose chest CT obtained in 281 adult patients were reconstructed using three algorithms: FBP, adaptive statistical IR (ASIR) and model-based IR (MBIR). Measurements of each dataset were compared: total lung volume, emphysema index (EI), airway measurements of the lumen and wall area as well as average wall thickness. Accuracy of airway measurements of each algorithm was also evaluated using an airway phantom. EI using a threshold of -950 HU was significantly different among the three algorithms in decreasing order of FBP (2.30 %), ASIR (1.49 %) and MBIR (1.20 %) (P < 0.01). Wall thickness was also significantly different among the three algorithms with FBP (2.09 mm) demonstrating thicker walls than ASIR (2.00 mm) and MBIR (1.88 mm) (P < 0.01). Airway phantom analysis revealed that MBIR showed the most accurate value for airway measurements. The three algorithms presented different EIs and wall thicknesses, decreasing in the order of FBP, ASIR and MBIR. Thus, care should be taken in selecting the appropriate IR algorithm on quantitative analysis of the lung. (orig.)

  6. The comparison of ordered subset expectation maximization and filtered back projection technique for RBC blood pool SPECT in detection of liver hemangioma

    International Nuclear Information System (INIS)

    Odered subset expectation maximization (OSEM) is a new iterative reconstruction technique for tomographic images that can reduce the reconstruction time comparing with conventional iteration method. We adopted this method of RBC blood pool SPECT and tried to validate the usefulness of OSEM in detection of liver hemangioma comparing with filtered back projection (FBP). A 64 projection SPECT study was acquired over 360 .deg. C by dual-head cameras after the injection of 750MBq of 99mTc-RBC. OSEM was performed with various condition of subset (1,2,4,8,16 and 32) and iteration number (1,2,4,8 and 16) to obtain the best set for lesion detection. OSEM underwent in 17 lesions of 15 patients with liver hemangioma and compared with FBP images. Two nuclear medicine physicians reviewed these results independently. Best set for images was 4 iteration and 16 subset. In general, OSEM revealed more homogeneous images than FBP. Eighty-eight percent (15/17) of OSEM images were superior or equal to FBP for anatomic resolution. According to the blind review of images 70.5% (12/17) of OSEM was better in contrast (4/17), anatomic detail (4/17) and both (2/17). Two small lesions were detected by OSEM only and another 2 small lesions were failed to depict in both methods. Remaining 3 lesions revealed no difference in image quality. OSEM can provide better image quality as well as better results in detection of liver hemangioma than conventional FBP techniquetional FBP technique

  7. Dose reduction in chest CT: Comparison of the adaptive iterative dose reduction 3D, adaptive iterative dose reduction, and filtered back projection reconstruction techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yoshitake, E-mail: yamada@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Jinzaki, Masahiro, E-mail: jinzaki@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Hosokawa, Takahiro, E-mail: hosokawa@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Tanami, Yutaka, E-mail: tanami@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Sugiura, Hiroaki, E-mail: hsugiura@rad.med.keio.ac.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Abe, Takayuki, E-mail: tabe@z5.keio.jp [Center for Clinical Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan); Kuribayashi, Sachio, E-mail: skuribay@a5.keio.jp [Department of Diagnostic Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 (Japan)

    2012-12-15

    Objectives: To assess the effectiveness of adaptive iterative dose reduction (AIDR) and AIDR 3D in improving the image quality in low-dose chest CT (LDCT). Materials and methods: Fifty patients underwent standard-dose chest CT (SDCT) and LDCT simultaneously, performed under automatic exposure control with noise index of 19 and 38 (for a 2-mm slice thickness), respectively. The SDCT images were reconstructed with filtered back projection (SDCT-FBP images), and the LDCT images with FBP, AIDR and AIDR 3D (LDCT-FBP, LDCT-AIDR and LDCT-AIDR 3D images, respectively). On all the 200 lung and 200 mediastinal image series, objective image noise and signal-to-noise ratio (SNR) were measured in several regions, and two blinded radiologists independently assessed the subjective image quality. Wilcoxon's signed rank sum test with Bonferroni's correction was used for the statistical analyses. Results: The mean dose reduction in LDCT was 64.2% as compared with the dose in SDCT. LDCT-AIDR 3D images showed significantly reduced objective noise and significantly increased SNR in all regions as compared to the SDCT-FBP, LDCT-FBP and LDCT-AIDR images (all, P ? 0.003). In all assessments of the image quality, LDCT-AIDR 3D images were superior to LDCT-AIDR and LDCT-FBP images. The overall diagnostic acceptability of both the lung and mediastinal LDCT-AIDR 3D images was comparable to that of the lung and mediastinal SDCT-FBP images. Conclusions: AIDR 3D is superior to AIDR. Intra-individual comparisons between SDCT and LDCT suggest that AIDR 3D allows a 64.2% reduction of the radiation dose as compared to SDCT, by substantially reducing the objective image noise and increasing the SNR, while maintaining the overall diagnostic acceptability.

  8. Dose reduction in computed tomography of the chest. Image quality of iterative reconstructions at a 50% radiation dose compared to filtered back projection at a 100% radiation dose

    International Nuclear Information System (INIS)

    Purpose: The aim of this study was to evaluate the potential of iterative reconstruction (IR) in chest computed tomography (CT) to reduce radiation exposure. The qualitative and quantitative image quality of standard reconstructions with filtered back projection (FBP) and half dose (HD) chest CT data reconstructed with FBP and IR was assessed. Materials and Methods: 52 consecutive patients underwent contrast-enhanced chest CT on a dual-source CT system at 120 kV and automatic exposure control. The tube current was equally split on both tube detector systems. For the HD datasets, only data from one tube detector system was utilized. Thus, FD and HD data was available for each patient with a single scan. Three datasets were reconstructed from the raw data: standard full dose (FD) images applying FBP which served as a reference, HD images applying FBP and IR. Objective image quality analysis was performed by measuring the image noise in tissue and air. The subjective image quality was evaluated by 2 radiologists according to European guidelines. Additional assessment of artifacts, lesion conspicuity and edge sharpness was performed. Results: Image noise did not differ significantly between HD-IR and FD-FBP (p = 0.254) but increased substantially in HD-FBP (p < 0.001). No statistically significant differences were found for the reproduction of anatomical and pathological structures between HD-IR and FD-FBP, subsegmental bronchi and bronchioli. The image quality of HD-FBP was rated inferior because of increased noise. Conclusion: A 50% dose reduction in contrast-enhanced chest CT is feasible without a loss of diagnostic confidence if IR is used for image data reconstruction. Iterative reconstruction is another powerful tool to reduce radiation exposure and can be combined with other dose-saving techniques. (orig.)

  9. Observer performance for adaptive, image-based denoising and filtered back projection compared to scanner-based iterative reconstruction for lower dose CT enterography

    Science.gov (United States)

    Fletcher, Joel G.; Hara, Amy K.; Fidler, Jeff L.; Silva, Alvin C.; Barlow, John M.; Carter, Rickey E.; Bartley, Adam; Shiung, Maria; Holmes, David R.; Weber, Nicolas K.; Bruining, David H.; Yu, Lifeng; McCollough, Cynthia H.

    2015-01-01

    Purpose The purpose of this study was to compare observer performance for detection of intestinal inflammation for low-dose CT enterography (LD-CTE) using scanner-based iterative reconstruction (IR) vs. vendor-independent, adaptive image-based noise reduction (ANLM) or filtered back projection (FBP). Methods Sixty-two LD-CTE exams were performed. LD-CTE images were reconstructed using IR, ANLM, and FBP. Three readers, blinded to image type, marked intestinal inflammation directly on patient images using a specialized workstation over three sessions, interpreting one image type/patient/session. Reference standard was created by a gastroenterologist and radiologist, who reviewed all available data including dismissal Gastroenterology records, and who marked all inflamed bowel segments on the same workstation. Reader and reference localizations were then compared. Non-inferiority was tested using Jackknife free-response ROC (JAFROC) figures of merit (FOM) for ANLM and FBP compared to IR. Patient-level analyses for the presence or absence of inflammation were also conducted. Results There were 46 inflamed bowel segments in 24/62 patients (CTDIvol interquartile range 6.9–10.1 mGy). JAFROC FOM for ANLM and FBP were 0.84 (95% CI 0.75–0.92) and 0.84 (95% CI 0.75–0.92), and were statistically non-inferior to IR (FOM 0.84; 95% CI 0.76–0.93). Patient-level pooled confidence intervals for sensitivity widely overlapped, as did specificities. Image quality was rated as better with IR and AMLM compared to FBP (p < 0.0001), with no difference in reading times (p = 0.89). Conclusions Vendor-independent adaptive image-based noise reduction and FBP provided observer performance that was non-inferior to scanner-based IR methods. Adaptive image-based noise reduction maintained or improved upon image quality ratings compared to FBP when performing CTE at lower dose levels. PMID:25725794

  10. Dose reduction in chest CT: Comparison of the adaptive iterative dose reduction 3D, adaptive iterative dose reduction, and filtered back projection reconstruction techniques

    International Nuclear Information System (INIS)

    Objectives: To assess the effectiveness of adaptive iterative dose reduction (AIDR) and AIDR 3D in improving the image quality in low-dose chest CT (LDCT). Materials and methods: Fifty patients underwent standard-dose chest CT (SDCT) and LDCT simultaneously, performed under automatic exposure control with noise index of 19 and 38 (for a 2-mm slice thickness), respectively. The SDCT images were reconstructed with filtered back projection (SDCT-FBP images), and the LDCT images with FBP, AIDR and AIDR 3D (LDCT-FBP, LDCT-AIDR and LDCT-AIDR 3D images, respectively). On all the 200 lung and 200 mediastinal image series, objective image noise and signal-to-noise ratio (SNR) were measured in several regions, and two blinded radiologists independently assessed the subjective image quality. Wilcoxon's signed rank sum test with Bonferroni's correction was used for the statistical analyses. Results: The mean dose reduction in LDCT was 64.2% as compared with the dose in SDCT. LDCT-AIDR 3D images showed significantly reduced objective noise and significantly increased SNR in all regions as compared to the SDCT-FBP, LDCT-FBP and LDCT-AIDR images (all, P ? 0.003). In all assessments of the image quality, LDCT-AIDR 3D images were superior to LDCT-AIDR and LDCT-FBP images. The overall diagnostic acceptability of both the lung and mediastinal LDCT-AIDR 3D images was comparable to that of the lung and mediastinal SDCT-FBP images. Conclusions: AIDR 3D is superior to AIDR. Intra-individual comparisons between SDCT and LDCT suggest that AIDR 3D allows a 64.2% reduction of the radiation dose as compared to SDCT, by substantially reducing the objective image noise and increasing the SNR, while maintaining the overall diagnostic acceptability.

  11. Adaptive iterative dose reduction algorithm in CT: Effect on image quality compared with filtered back projection in body phantoms of different sizes

    International Nuclear Information System (INIS)

    To evaluate the impact of the adaptive iterative dose reduction (AIDR) three-dimensional (3D) algorithm in CT on noise reduction and the image quality compared to the filtered back projection (FBP) algorithm and to compare the effectiveness of AIDR 3D on noise reduction according to the body habitus using phantoms with different sizes. Three different-sized phantoms with diameters of 24 cm, 30 cm, and 40 cm were built up using the American College of Radiology CT accreditation phantom and layers of pork belly fat. Each phantom was scanned eight times using different mAs. Images were reconstructed using the FBP and three different strengths of the AIDR 3D. The image noise, the contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) of the phantom were assessed. Two radiologists assessed the image quality of the 4 image sets in consensus. The effectiveness of AIDR 3D on noise reduction compared with FBP were also compared according to the phantom sizes. Adaptive iterative dose reduction 3D significantly reduced the image noise compared with FBP and enhanced the SNR and CNR (p < 0.05) with improved image quality (p < 0.05). When a stronger reconstruction algorithm was used, greater increase of SNR and CNR as well as noise reduction was achieved (p < 0.05). The noise reduction effect of AIDR 3D was significantly greater in the 40-cm phantom than in the 24-cm or 30-cm phantoms (p < 0.05). The AIDR 3D algorithm is effective to reduce the image noise as well as to improve the image-quality parameters compared by FBP algorithm, and its effectiveness may increase as the phantom size increases.

  12. Image quality and radiation dose of low dose coronary CT angiography in obese patients: Sinogram affirmed iterative reconstruction versus filtered back projection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Rui, E-mail: rui_wang1979@yahoo.cn [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC 29425-2260 (United States); Wu, Runze, E-mail: runze.wu@gmail.com [Siemens Healthcare China, 7 Wangjing Zhonghuan Nanlu, 100102 Beijing (China); Reddy, Ryan P., E-mail: reddyr@musc.edu [Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC 29425-2260 (United States); Zhang, Chuanchen, E-mail: zhangchuanchen666@163.com [Department of Radiology, Liaocheng People Hospital, 252000 Shandong (China); Yu, Wei, E-mail: yuwei02@gmail.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Liu, Yi, E-mail: liuyi198311@yahoo.cn [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China); Zhang, Zhaoqi, E-mail: zhaoqi5000@vip.sohu.com [Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, 100029 Beijing (China)

    2012-11-15

    Purpose: To investigate the image quality and radiation dose of low radiation dose CT coronary angiography (CTCA) using sinogram affirmed iterative reconstruction (SAFIRE) compared with standard dose CTCA using filtered back-projection (FBP) in obese patients. Materials and methods: Seventy-eight consecutive obese patients were randomized into two groups and scanned using a prospectively ECG-triggered step-and-shot (SAS) CTCA protocol on a dual-source CT scanner. Thirty-nine patients (protocol A) were examined using a routine radiation dose protocol at 120 kV and images were reconstructed with FBP (protocol A). Thirty-nine patients (protocol B) were examined using a low dose protocol at 100 kV and images were reconstructed with SAFIRE. Two blinded observers independently assessed the image quality of each coronary segment using a 4-point scale (1 = non-diagnostic, 4 = excellent) and measured the objective parameters image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Radiation dose was calculated. Results: The coronary artery image quality scores, image noise, SNR and CNR were not significantly different between protocols A and B (all p > 0.05), with image quality scores of 3.51 {+-} 0.70 versus 3.55 {+-} 0.47, respectively. The effective radiation dose was significantly lower in protocol B (4.41 {+-} 0.83 mSv) than that in protocol A (8.83 {+-} 1.74 mSv, p < 0.01). Conclusion: Compared with standard dose CTCA using FBP, low dose CTCA using SAFIRE can maintain diagnostic image quality with 50% reduction of radiation dose.

  13. Image quality and radiation dose of low dose coronary CT angiography in obese patients: Sinogram affirmed iterative reconstruction versus filtered back projection

    International Nuclear Information System (INIS)

    Purpose: To investigate the image quality and radiation dose of low radiation dose CT coronary angiography (CTCA) using sinogram affirmed iterative reconstruction (SAFIRE) compared with standard dose CTCA using filtered back-projection (FBP) in obese patients. Materials and methods: Seventy-eight consecutive obese patients were randomized into two groups and scanned using a prospectively ECG-triggered step-and-shot (SAS) CTCA protocol on a dual-source CT scanner. Thirty-nine patients (protocol A) were examined using a routine radiation dose protocol at 120 kV and images were reconstructed with FBP (protocol A). Thirty-nine patients (protocol B) were examined using a low dose protocol at 100 kV and images were reconstructed with SAFIRE. Two blinded observers independently assessed the image quality of each coronary segment using a 4-point scale (1 = non-diagnostic, 4 = excellent) and measured the objective parameters image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Radiation dose was calculated. Results: The coronary artery image quality scores, image noise, SNR and CNR were not significantly different between protocols A and B (all p > 0.05), with image quality scores of 3.51 ± 0.70 versus 3.55 ± 0.47, respectively. The effective radiation dose was significantly lower in protocol B (4.41 ± 0.83 mSv) than that in protocol A (8.83 ± 1.74 mSv, p < 0.01). Conclusion: Compared with standard dose CTCA using FBP, low dose CTCA using SAFIRE can maintain diagnostic image quality with 50% reduction of radiation dose.

  14. Impact of adaptive iterative dose reduction (AIDR) 3D on low-dose abdominal CT - Comparison with routine-dose CT using filtered back projection

    International Nuclear Information System (INIS)

    Background: While CT is widely used in medical practice, a substantial source of radiation exposure is associated with an increased lifetime risk of cancer. Therefore, concerns to dose reduction in CT examinations are increasing and an iterative reconstruction algorithm, which allow for dose reduction by compensating image noise in the image reconstruction, has been developed. Purpose: To investigate the performance of low-dose abdominal CT using adaptive iterative dose reduction 3D (AIDR 3D) compared to routine-dose CT using filtered back projection (FBP). Material and Methods: Fifty-eight patients underwent both routine-dose CT scans using FBP and low-dose CT scans using AIDR 3D in the abdomen. The image noise levels, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) of the aorta, portal vein, liver, and pancreas were measured and compared in both scans. Visual evaluations were performed. The volume CT dose index (CTDIvol) was measured. Results: Image noise levels on low-dose CT images using AIDR 3D were significantly lower than, or not significantly different from, routine-dose CT images using FBP in reviewing the data on the basis of all patients and the three BMI groups. SNRs and CNRs on low-dose CT images using AIDR 3D were significantly higher than, or not significantly different from, routine-dose CT images using FBP in reviewing the data on the basis of all patients and the three BMI groups. In visual evaluation of the images, there were no s evaluation of the images, there were no statistically significant differences between the scans in all organs independently of BMI. The average CTDIvol at routine-dose and low dose CT was 21.4 and 10.8 mGy, respectively. Conclusion: Low-dose abdominal CT using AIDR 3D allows for approximately 50 % reduction in radiation dose without a degradation of image quality compared to routine-dose CT using FBP independently of BMI

  15. Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Becce, Fabio [University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Universite Catholique Louvain, Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Ben Salah, Yosr; Berg, Bruno C. vande; Lecouvet, Frederic E.; Omoumi, Patrick [Universite Catholique Louvain, Department of Radiology, Cliniques Universitaires Saint-Luc, Brussels (Belgium); Verdun, Francis R. [University of Lausanne, Institute of Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Meuli, Reto [University of Lausanne, Department of Diagnostic and Interventional Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland)

    2013-07-15

    To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %. (orig.)

  16. Iterative reconstruction technique vs filter back projection: utility for quantitative bronchial assessment on low-dose thin-section MDCT in patients with/without chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Hisanobu; Seki, Shinichiro; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Division of Radiology, Department of Radiology, Kobe, Hyogo (Japan); Ohno, Yoshiharu; Nishio, Mizuho; Matsumoto, Sumiaki; Yoshikawa, Takeshi [Kobe University Graduate School of Medicine, Advanced Biomedical Imaging Research Centre, Kobe (Japan); Kobe University Graduate School of Medicine, Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe (Japan); Sugihara, Naoki [Toshiba Medical Systems Corporation, Ohtawara, Tochigi (Japan)

    2014-08-15

    The aim of this study was to evaluate the utility of the iterative reconstruction (IR) technique for quantitative bronchial assessment during low-dose computed tomography (CT) as a substitute for standard-dose CT in patients with/without chronic obstructive pulmonary disease. Fifty patients (mean age, 69.2; mean % predicted FEV1, 79.4) underwent standard-dose CT (150mAs) and low-dose CT (25mAs). Except for tube current, the imaging parameters were identical for both protocols. Standard-dose CT was reconstructed using filtered back-projection (FBP), and low-dose CT was reconstructed using IR and FBP. For quantitative bronchial assessment, the wall area percentage (WA%) of the sub-segmental bronchi and the airway luminal volume percentage (LV%) from the main bronchus to the peripheral bronchi were acquired in each dataset. The correlation and agreement of WA% and LV% between standard-dose CT and both low-dose CTs were statistically evaluated. WA% and LV% between standard-dose CT and both low-dose CTs were significant correlated (r > 0.77, p < 0.00001); however, only the LV% agreement between SD-CT and low-dose CT reconstructed with IR was moderate (concordance correlation coefficient = 0.93); the other agreement was poor (concordance correlation coefficient <0.90). Quantitative bronchial assessment via low-dose CT has potential as a substitute for standard-dose CT by using IR and airway luminal volumetry techniques. circle Quantitative bronchial assessment of COPD using low-dose CT is possible. (orig.)

  17. Iterative reconstruction technique vs filter back projection: utility for quantitative bronchial assessment on low-dose thin-section MDCT in patients with/without chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the utility of the iterative reconstruction (IR) technique for quantitative bronchial assessment during low-dose computed tomography (CT) as a substitute for standard-dose CT in patients with/without chronic obstructive pulmonary disease. Fifty patients (mean age, 69.2; mean % predicted FEV1, 79.4) underwent standard-dose CT (150mAs) and low-dose CT (25mAs). Except for tube current, the imaging parameters were identical for both protocols. Standard-dose CT was reconstructed using filtered back-projection (FBP), and low-dose CT was reconstructed using IR and FBP. For quantitative bronchial assessment, the wall area percentage (WA%) of the sub-segmental bronchi and the airway luminal volume percentage (LV%) from the main bronchus to the peripheral bronchi were acquired in each dataset. The correlation and agreement of WA% and LV% between standard-dose CT and both low-dose CTs were statistically evaluated. WA% and LV% between standard-dose CT and both low-dose CTs were significant correlated (r > 0.77, p < 0.00001); however, only the LV% agreement between SD-CT and low-dose CT reconstructed with IR was moderate (concordance correlation coefficient = 0.93); the other agreement was poor (concordance correlation coefficient <0.90). Quantitative bronchial assessment via low-dose CT has potential as a substitute for standard-dose CT by using IR and airway luminal volumetry techniques. circle Quantitative bronchial assessment of COPD using low-dose CT is possible. (orig.)

  18. Impact of hybrid iterative reconstruction on Agatston coronary artery calcium scores in comparison to filtered back projection in native cardiac CT; Einfluss der hybriden iterativen Rekonstruktion bei der nativen CT des Herzens auf die Agatston-Kalziumscores der Koronararterien

    Energy Technology Data Exchange (ETDEWEB)

    Obmann, V.C.; Heverhagen, J.T. [Inselspital - University Hospital Bern (Switzerland). University Inst. for Diagnostic, Interventional and Pediatric Radiology; Klink, T. [Wuerzburg Univ. (Germany). Inst. of Diagnostic and Interventional Radiology; Stork, A.; Begemann, P.G.C. [Roentgeninstitut Duesseldorf, Duesseldorf (Germany); Laqmani, A.; Adam, G. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Dept. of Diagnostic and Interventional Radiology

    2015-05-15

    To investigate whether the effects of hybrid iterative reconstruction (HIR) on coronary artery calcium (CAC) measurements using the Agatston score lead to changes in assignment of patients to cardiovascular risk groups compared to filtered back projection (FBP). 68 patients (mean age 61.5 years; 48 male; 20 female) underwent prospectively ECG-gated, non-enhanced, cardiac 256-MSCT for coronary calcium scoring. Scanning parameters were as follows: Tube voltage, 120 kV; Mean tube current time-product 63.67 mAs (50 - 150 mAs); collimation, 2 x 128 x 0.625 mm. Images were reconstructed with FBP and with HIR at all levels (L1 to L7). Two independent readers measured Agatston scores of all reconstructions and assigned patients to cardiovascular risk groups. Scores of HIR and FBP reconstructions were correlated (Spearman). Interobserver agreement and variability was assessed with k-statistics and Bland-Altmann-Plots. Agatston scores of HIR reconstructions were closely correlated with FBP reconstructions (L1, R = 0.9996; L2, R = 0.9995; L3, R = 0.9991; L4, R = 0.986; L5, R = 0.9986; L6, R = 0.9987; and L7, R = 0.9986). In comparison to FBP, HIR led to reduced Agatston scores between 97% (L1) and 87.4% (L7) of the FBP values. Using HIR iterations L1-L3, all patients were assigned to identical risk groups as after FPB reconstruction. In 5.4% of patients the risk group after HIR with the maximum iteration level was different from the group after FBP reconstruction. There was an excellent correlation of Agatston scores after HIR and FBP with identical risk group assignment at levels 1 - 3 for all patients. Hence it appears that the application of HIR in routine calcium scoring does not entail any disadvantages. Thus, future studies are needed to demonstrate whether HIR is a reliable method for reducing radiation dose in coronary calcium scoring.

  19. Fan beam and parallel beam projection and back-projection operators

    International Nuclear Information System (INIS)

    Expressions for the fan beam and parallel beam projection and back-projection operators are given along with an evaluation of the point source response for the back-projection operators. The back-projection operator for the fan beam geometry requires the superposition of projection data measured over 3600. Both the fan beam and parallel beam geometries have back-projection operators with point source responses which are proportional to 1/mod (r-r0), and thus two-dimensional Fourier filter techniques can be used to reconstruct transverse sections from fan beam and parallel beam projection data. The two-dimensional Fourier filter techniques may have the speed over other methods for reconstructing fan beam data, but the reconstructed image requires four times the core storage so that the convolution result of one period does not overlap the convolution result of the succeeding period when implementing the fast Fourier transform. 10 figures

  20. Image reconstruction of simulated specimens using convolution back projection

    Directory of Open Access Journals (Sweden)

    Mohd. Farhan Manzoor

    2001-04-01

    Full Text Available This paper reports about the reconstruction of cross-sections of composite structures. The convolution back projection (CBP algorithm has been used to capture the attenuation field over the specimen. Five different test cases have been taken up for evaluation. These cases represent varying degrees of complexity. In addition, the role of filters on the nature of the reconstruction errors has also been discussed. Numerical results obtained in the study reveal that CBP algorithm is a useful tool for qualitative as well as quantitative assessment of composite regions encountered in engineering applications.

  1. Cigarette smoke cadmium breakthrough from traditional filters: implications for exposure.

    Science.gov (United States)

    Pappas, R Steven; Fresquez, Mark R; Watson, Clifford H

    2015-01-01

    Cadmium, a carcinogenic metal, is highly toxic to renal, skeletal, nervous, respiratory and cardiovascular systems. Accurate and precise quantification of mainstream smoke cadmium levels in cigarette smoke is important because of exposure concerns. The two most common trapping techniques for collecting mainstream tobacco smoke particulate for analysis are glass fiber filters and electrostatic precipitators. We observed that a significant portion of total cadmium passed through standard glass fiber filters that are used to trap particulate matter. We therefore developed platinum traps to collect the cadmium that passed through the filters and tested a variety of cigarettes with different physical parameters for quantities of cadmium that passed though the filters. We found electrostatic precipitators. In contrast, cadmium that passed through 92 mm glass fiber filters on a rotary smoking machine was significantly higher, ranging from 3.5 to 22.9% of total smoke cadmium deliveries. Cadmium passed through 44 mm filters typically used on linear smoking machines to an even greater degree, ranging from 13.6 to 30.4% of the total smoke cadmium deliveries. Differences in the cadmium that passed through from the glass fiber filters and electrostatic precipitator could be explained in part if cadmium resides in the smaller mainstream smoke aerosol particle sizes. Differences in particle size distribution could have toxicological implications and could help explain the pulmonary and cardiovascular cadmium uptake in smokers. PMID:25313385

  2. Tsunami Wave Estimation Using GPS-TEC Back Projection

    Science.gov (United States)

    Ito, T.

    2014-12-01

    Large tsunami generates an acoustic wave and shakes the atmosphere layer around a focal region. The generated acoustic wave propagates to ionosphere layer which is located at about 300km hight and causes a ionospheric disturbance. So, a generated acoustic wave causes the density of total electron content (TEC) inside ionospheric layer to be change. The changing TEC inside ionospheric layer can be measured by dense GPS network, such as GEONET. We focus on a large tsunami such as the 2011 March 11 Tohoku-Oki earthquake (Mw 9.0) , which caused vast damages to the country. Tsunami wave due to the 2011 Tohoku-Oki earthquake generates acoustic wave which propagates to ionospheric layer. The Japanese dense network of GPS detected clear anomaly of ionospheric TEC due to Tsunami wave around the focal region. We assume that acoustic wave cause the ionospheric disturbance and estimate tsunami wave propagation using Back Projection (BP) method of ionospheric disturbance. The Japanese dense array of GPS recorded ionospheric disturbances as changes in TEC due to the 2011 Tohoku-Oki earthquake. In this study, we try to reveal the detail of generating tsunami propagation using changing TEC from GPS observation network. At first, we process GPS-TEC above focal region by 1 sec sampling of GEONET. We remove slant GPS-TEC effects using filter out second degrees polynomial fitting. We try to adapt back projection (BP) method for GPS-TEC time series. The BP product shows the beam formed time history and location of coherent acoustic-wave energy generated by large tsunami observed at ionospheric layer regional arrays and across the GPS Network. BPs are performed by beam forming (stacking) energy to a flat grid around the source region with variable spatial resolution scaled by the magnitude of generating tsunami velocity for each second. In result, we can obtain the generating tsunami wave due to a large earthquake. The method is perfectly new and provide detail of tsunami propagating wave distribution from huge GPS-TEC data. We can obtain in-direct measurement Tsunami wave generation from ionospheric disturbances. So, this result will bring a revolution of tsunami study.

  3. Traditional Medicine Through the Filter of Modernity: A brief historical analysis

    Directory of Open Access Journals (Sweden)

    R. Rabarihoela Razafimandimby

    2014-12-01

    Full Text Available Traditional medicines still prevail in current Malagasy context. A careful historical analysis shows however that Malagasy traditional medicine has been screened through many filters before being accepted in a global context. Traditional medicine in its authentic form has been more or less rejected with the advent of  modern medicine – although not without reaction. This paper will retrace the historical encountering of the modern and traditional to determine the extent to which traditional medicine is acknowledged and used in the current prevailing modern, rational and scientific global context.

  4. Dose reduction in computed tomography of the chest. Image quality of iterative reconstructions at a 50% radiation dose compared to filtered back projection at a 100% radiation dose; Dosisreduktion in der Thorax-CT. Vergleich der Bildqualitaet bei 50% Dosis und iterativer Bildrekonstruktion mit 100% Dosis und gefilterter Rueckprojektion

    Energy Technology Data Exchange (ETDEWEB)

    May, M.S.; Eller, A.; Stahl, C. [University Hospital Erlangen (Germany). Dept. of Radiology; and others

    2014-06-15

    Purpose: The aim of this study was to evaluate the potential of iterative reconstruction (IR) in chest computed tomography (CT) to reduce radiation exposure. The qualitative and quantitative image quality of standard reconstructions with filtered back projection (FBP) and half dose (HD) chest CT data reconstructed with FBP and IR was assessed. Materials and Methods: 52 consecutive patients underwent contrast-enhanced chest CT on a dual-source CT system at 120 kV and automatic exposure control. The tube current was equally split on both tube detector systems. For the HD datasets, only data from one tube detector system was utilized. Thus, FD and HD data was available for each patient with a single scan. Three datasets were reconstructed from the raw data: standard full dose (FD) images applying FBP which served as a reference, HD images applying FBP and IR. Objective image quality analysis was performed by measuring the image noise in tissue and air. The subjective image quality was evaluated by 2 radiologists according to European guidelines. Additional assessment of artifacts, lesion conspicuity and edge sharpness was performed. Results: Image noise did not differ significantly between HD-IR and FD-FBP (p = 0.254) but increased substantially in HD-FBP (p < 0.001). No statistically significant differences were found for the reproduction of anatomical and pathological structures between HD-IR and FD-FBP, subsegmental bronchi and bronchioli. The image quality of HD-FBP was rated inferior because of increased noise. Conclusion: A 50% dose reduction in contrast-enhanced chest CT is feasible without a loss of diagnostic confidence if IR is used for image data reconstruction. Iterative reconstruction is another powerful tool to reduce radiation exposure and can be combined with other dose-saving techniques. (orig.)

  5. Traditional Tracking with Kalman Filter on Parallel Architectures

    CERN Document Server

    Cerati, Giuseppe; Lantz, Steven; MacNeill, Ian; McDermott, Kevin; Riley, Dan; Tadel, Matevz; Wittich, Peter; Wuerthwein, Frank; Yagil, Avi

    2014-01-01

    Power density constraints are limiting the performance improvements of modern CPUs. To address this, we have seen the introduction of lower-power, multi-core processors, but the future will be even more exciting. In order to stay within the power density limits but still obtain Moore's Law performance/price gains, it will be necessary to parallelize algorithms to exploit larger numbers of lightweight cores and specialized functions like large vector units. Example technologies today include Intel's Xeon Phi and GPGPUs. Track finding and fitting is one of the most computationally challenging problems for event reconstruction in particle physics. At the High Luminosity LHC, for example, this will be by far the dominant problem. The most common track finding techniques in use today are however those based on the Kalman Filter. Significant experience has been accumulated with these techniques on real tracking detector systems, both in the trigger and offline. We report the results of our investigations into the p...

  6. An improved back projection algorithm of ultrasound tomography

    Energy Technology Data Exchange (ETDEWEB)

    Xiaozhen, Chen; Mingxu, Su; Xiaoshu, Cai [Institute of Particle and Two-phase Flow Measurement, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2014-04-11

    Binary logic back projection algorithm is improved in this work for the development of fast ultrasound tomography system with a better effect of image reconstruction. The new algorithm is characterized by an extra logical value ‘2’ and dual-threshold processing of collected raw data. To compare with the original algorithm, a numerical simulation was conducted by the verification of COMSOL simulations formerly, and then a set of ultrasonic tomography system is established to perform the experiments of one, two and three cylindrical objects. The object images are reconstructed through the inversion of signals matrix acquired by the transducer array after a preconditioning, while the corresponding spatial imaging errors can obviously indicate that the improved back projection method can achieve modified inversion effect.

  7. Earthquake Characteristics as Imaged by the Back-Projection Method

    OpenAIRE

    Kiser, Eric

    2012-01-01

    This dissertation explores the capability of dense seismic array data for imaging the rupture properties of earthquake sources using a method known as back-projection. Only within the past 10 or 15 years has implementation of the method become feasible through the development of large aperture seismic arrays such as the High Sensitivity Seismograph Network in Japan and the Transportable Array in the United States. Coincidentally, this buildup in data coverage has also been accompanied by a gl...

  8. Filtered backprojection method and the interior problem in 2D tomography

    OpenAIRE

    Bilgot, Anne; Desbat, Laurent; Perrier, Vale?rie

    2009-01-01

    We address here the interior problem in local tomography, by means of Filtered Back Projection (FBP). This algorithm, traditionally used in the context of complete data, is usually not considered as valuable for the interior problem. However, in this article, we prove that as well as more sophisticated methods, the FBP algorithm ensures that the difference between the original and the reconstructed functions is continuous. We verify numerically that the FBP method can supply satisfactory imag...

  9. Imaging Seismic Source Variations Using Back-Projection Methods at El Tatio Geyser Field, Northern Chile

    Science.gov (United States)

    Kelly, C. L.; Lawrence, J. F.

    2014-12-01

    During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and determine variations in source depth and distribution in the conduit and larger geyser field over many eruption cycles.

  10. SAR focusing of P-band ice sounding data using back-projection

    OpenAIRE

    Kusk, Anders; Dall, Jørgen

    2010-01-01

    SAR processing can be applied to ice sounder data to improve along-track resolution and clutter suppression. This paper presents a time-domain back-projection technique for SAR focusing of ice sounder data. With this technique, variations in flight track and ice surface slope can be accurately accommodated at the expense of computation time. The back-projection algorithm can be easily parallelized however, and can advantageously be implemented on a graphics processing unit (GPU). Results from...

  11. A fast marching method based back projection algorithm for photoacoustic tomography in heterogeneous media

    CERN Document Server

    Wang, Tianren

    2015-01-01

    This paper presents a numerical study on a fast marching method based back projection reconstruction algorithm for photoacoustic tomography in heterogeneous media. Transcranial imaging is used here as a case study. To correct for the phase aberration from the heterogeneity (i.e., skull), the fast marching method is adopted to compute the phase delay based on the known speed of sound distribution, and the phase delay is taken into account by the back projection algorithm for more accurate reconstructions. It is shown that the proposed algorithm is more accurate than the conventional back projection algorithm, but slightly less accurate than the time reversal algorithm particularly in the area close to the skull. However, the image reconstruction time for the proposed algorithm can be as little as 124 ms when implemented by a GPU (512 sensors, 21323 pixels reconstructed), which is two orders of magnitude faster than the time reversal reconstruction. The proposed algorithm, therefore, not only corrects for the p...

  12. SAR focusing of P-band ice sounding data using back-projection

    DEFF Research Database (Denmark)

    Kusk, Anders; Dall, JØrgen

    2010-01-01

    SAR processing can be applied to ice sounder data to improve along-track resolution and clutter suppression. This paper presents a time-domain back-projection technique for SAR focusing of ice sounder data. With this technique, variations in flight track and ice surface slope can be accurately accommodated at the expense of computation time. The back-projection algorithm can be easily parallelized however, and can advantageously be implemented on a graphics processing unit (GPU). Results from using the back-projection algorithm on POLARIS ice sounder data from North Greenland shows that the quality of data is improved by the processing, and the performance of the GPU implementation allows for very fast focusing.

  13. Super-resolution Reconstruction Algorithm Based on Patch Similarity and Back-projection Modification

    OpenAIRE

    Wei-long Chen; Li Guo; Wu He; Wei Wu; Xiao-min Yang

    2014-01-01

    We propose an effective super-resolution reconstruction algorithm based on patch similarity and back-projection modification. In the proposed algorithm, we assume patch to be similar in natural images and extract the high-frequency information from the best similar patch to add into goal high-resolution image. In the process of reconstruction, the high-resolution patch is back-projected into the low-resolution patch so as to gain detailed modification. Experiments performed on simulated low-r...

  14. Navigating Earthquake Physics with High-Resolution Array Back-Projection

    Science.gov (United States)

    Meng, Lingsen

    Understanding earthquake source dynamics is a fundamental goal of geophysics. Progress toward this goal has been slow due to the gap between state-of-art earthquake simulations and the limited source imaging techniques based on conventional low-frequency finite fault inversions. Seismic array processing is an alternative source imaging technique that employs the higher frequency content of the earthquakes and provides finer detail of the source process with few prior assumptions. While the back-projection provides key observations of previous large earthquakes, the standard beamforming back-projection suffers from low resolution and severe artifacts. This thesis introduces the MUSIC technique, a high-resolution array processing method that aims to narrow the gap between the seismic observations and earthquake simulations. The MUSIC is a high-resolution method taking advantage of the higher order signal statistics. The method has not been widely used in seismology yet because of the nonstationary and incoherent nature of the seismic signal. We adapt MUSIC to transient seismic signal by incorporating the Multitaper cross-spectrum estimates. We also adopt a "reference window" strategy that mitigates the "swimming artifact," a systematic drift effect in back projection. The improved MUSIC back projections allow the imaging of recent large earthquakes in finer details which give rise to new perspectives on dynamic simulations. In the 2011 Tohoku-Oki earthquake, we observe frequency-dependent rupture behaviors which relate to the material variation along the dip of the subduction interface. In the 2012 off-Sumatra earthquake, we image the complicated ruptures involving orthogonal fault system and an usual branching direction. This result along with our complementary dynamic simulations probes the pressure-insensitive strength of the deep oceanic lithosphere. In another example, back projection is applied to the 2010 M7 Haiti earthquake recorded at regional distance. The high-frequency subevents are located at the edges of geodetic slip regions, which are correlated to the stopping phases associated with rupture speed reduction when the earthquake arrests.

  15. Super-resolution Reconstruction Algorithm Based on Patch Similarity and Back-projection Modification

    Directory of Open Access Journals (Sweden)

    Wei-long Chen

    2014-07-01

    Full Text Available We propose an effective super-resolution reconstruction algorithm based on patch similarity and back-projection modification. In the proposed algorithm, we assume patch to be similar in natural images and extract the high-frequency information from the best similar patch to add into goal high-resolution image. In the process of reconstruction, the high-resolution patch is back-projected into the low-resolution patch so as to gain detailed modification. Experiments performed on simulated low-resolution image and real low-resolution image are proved that the proposed super-resolution reconstruction algorithm is effective and efficient to improve the resolution of image and achieve a better visual performance.

  16. Combining time-domain back-projection and capon beamforming for tomographic SAR processing

    OpenAIRE

    Frey, O.; Meier, E.

    2008-01-01

    Various tomographic processing methods have been investigated in recent years. The quality of the focused tomographic image is usually limited by several factors. In particular, Fourier-based focusing methods are susceptible to irregular and sparse sampling, two problems that are unavoidable in case of multi-pass, multi-baseline SAR data acquired by an airborne system. Neither time-domain back-projection(TDBP) processing, although providing a very accurate processing framework, is able to ove...

  17. Is Back-Projection Methodology Still Relevant for Estimating HIV Incidence from National Surveillance Data?

    OpenAIRE

    Mallitt, Kylie-ann; Wilson, David P.; Mcdonald, Ann; Wand, Handan

    2012-01-01

    Accurate estimates of HIV incidence are crucial to understand the extent of transmission of the infection, evaluate intervention strategies and effectively plan new public health control measures. HIV/AIDS surveillance systems in numerous industrialised countries record the number of known new HIV and/or AIDS diagnoses, which are often used as a surrogate marker for HIV incidence. HIV/AIDS diagnosis data have been used to reconstruct historical HIV incidence trends using modified back-project...

  18. A new approach for estimation of seismic moment from back projection analysis

    Science.gov (United States)

    Honda, R.

    2014-12-01

    Recently, array back projection analysis is used for source process analysis of many earthquakes. The back projection analysis is very useful in analyzing large and/or complex fault processes, however, the physical meaning of obtained image is still not clear. To improve this problem, we introduce a new approach as follows. First, we stack seismic waveforms observed by a seismic array in a frequency range that is lower than the corner frequency of an earthquake of which Mo is known. Second, we calculate energy of stacked waveforms. Comparing Mo and the energy of stacked waveform, we obtain a transfer coefficient between Mo and the energy. If radiation pattern at the source and geometric attenuation on the ray path are corrected, it is expected that this coefficient has a unique value for the array. Once we obtained this transfer coefficient of the array, we can estimate Mo of other earthquakes from the product of the transfer coefficient and energy of stacked waveforms. For higher frequency range, we can calculate the transfer coefficient by using scaling law of earthquakes like w-square model. We will analyze middle class earthquakes by using this approach and report the results.

  19. Depth Estimation of Earthquakes in Southwest Asia using Back Projection of Multiple Seismic Phases

    Science.gov (United States)

    Euler, G. G.; Hartse, H. E.; Randall, G. E.

    2014-12-01

    Depth determination is a powerful discriminant in seismic event monitoring as deep earthquakes share amplitude characteristics of explosions. We explore the use of array back projection of multiple body wave phases from earthquakes located in Southwest Asia to estimate source depth. In particular, we focus our efforts on earthquakes estimated to be less than 100km in depth where depth phases (pP, sP) are difficult to identify. Data consist of vertical component records from IMS arrays at regional to far regional distances and the HiNet array at teleseismic distances. We compare regional and teleseismic results to assess confidence in the depth estimates as extension to small events only detectable at regional distances is a goal of this research.

  20. Visual Effects for Stereoscopic 3D Contents: Experiences from the Don't Look Back-project

    OpenAIRE

    Matilainen, Tapio

    2012-01-01

    Visual effects for stereoscopic 3D contents, experiences from the Don't Look Back-project is a description of workflow and phases I went through by making of visual effects on stereoscopic 3D footage filmed earlier in 2010. Work includes two shots from the Don't Look Back-project, where I had opportunity to make computer generated imagery and visual effects. Stereoscopic three dimensional (s3D) refers in cinema to the films which are seen with specific glasses on. S3D material is create...

  1. A comparative study between matched and mis-matched projection/back projection pairs used with ASIRT reconstruction method

    International Nuclear Information System (INIS)

    For algebraic reconstruction techniques both forward and back projection operators are needed. The ability to perform accurate reconstruction relies fundamentally on the forward projection and back projection methods which are usually, the transpose of each other. Even though the mis-matched pairs may introduce additional errors during the iterative process, the usefulness of mis-matched projector/back projector pairs has been proved in image reconstruction. This work investigates the performance of matched and mis-matched reconstruction pairs using popular forward projectors and their transposes when used in reconstruction tasks with additive simultaneous iterative reconstruction techniques (ASIRT) in a parallel beam approach. Simulated noiseless phantoms are used to compare the performance of the investigated pairs in terms of the root mean squared errors (RMSE) which are calculated between reconstructed slices and the reference in different regions. Results show that mis-matched projection/back projection pairs can promise more accuracy of reconstructed images than matched ones. The forward projection operator performance seems independent of the choice of the back projection operator and vice versa.

  2. A rapid parallelization of cone-beam projection and back-projection operator based on texture fetching interpolation

    Science.gov (United States)

    Xie, Lizhe; Hu, Yining; Chen, Yang; Shi, Luyao

    2015-03-01

    Projection and back-projection are the most computational consuming parts in Computed Tomography (CT) reconstruction. Parallelization strategies using GPU computing techniques have been introduced. We in this paper present a new parallelization scheme for both projection and back-projection. The proposed method is based on CUDA technology carried out by NVIDIA Corporation. Instead of build complex model, we aimed on optimizing the existing algorithm and make it suitable for CUDA implementation so as to gain fast computation speed. Besides making use of texture fetching operation which helps gain faster interpolation speed, we fixed sampling numbers in the computation of projection, to ensure the synchronization of blocks and threads, thus prevents the latency caused by inconsistent computation complexity. Experiment results have proven the computational efficiency and imaging quality of the proposed method.

  3. Images of Gravitational and Magnetic Phenomena Derived from 2D Back-Projection Doppler Tomography of Interacting Binary Stars

    OpenAIRE

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J.

    2014-01-01

    We have used 2D back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries which undergo mass transfer from a magnetically-active star onto a non-magnetic main sequence star. This multi-tiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity ima...

  4. GPU-accelerated back-projection revisited. Squeezing performance by careful tuning

    Energy Technology Data Exchange (ETDEWEB)

    Papenhausen, Eric; Zheng, Ziyi; Mueller, Klaus [Stony Brook Univ., NY (United States). Computer Science Dept.

    2011-07-01

    In recent years, GPUs have become an increasingly popular tool in computed tomography (CT) reconstruction. In this paper, we discuss performance optimization techniques for a GPU-based filtered-backprojection reconstruction implementation. We explore the different optimization techniques we used and explain how those techniques affected performance. Our results show a nearly 50% increase in performance when compared to the current top ranked GPU implementation. (orig.)

  5. Helium-3 MR q-space Imaging with Radial Acquisition and Iterative Highly Constrained Back-Projection

    OpenAIRE

    O Halloran, Rafael L.; Holmes, James H.; Wu, Yu-chien; Alexander, Andrew; Fain, Sean B.

    2010-01-01

    An under-sampled diffusion weighted stack-of-stars acquisition is combined with iterative highly constrained back-projection to perform hyperpolarized He-3 MR q-space imaging with combined regional correction of RF- and T1-related signal loss in a single breath-held scan. The technique is tested in computer simulations and phantom experiments and demonstrated in a healthy human volunteer with whole lung coverage in a 13 s breath-hold. Measures of lung microstructure at 3 different lung volume...

  6. Electrical capacitance tomography two-phase oil-gas pipe flow imaging by the linear back-projection algorithm

    Directory of Open Access Journals (Sweden)

    R. Martin

    2005-12-01

    Full Text Available Electrical Capacitance Tomography (ECT is a novel technology that can deal with the complexity of two-phase gas-oil flow measurement by explicitly deriving the component distributions on two adjacent planes along a pipeline. One of its most promising applications is the visualization of gas-oil flows. ECT offers some advantages over other tomography modalities, such as no radiation, rapid response, low-cost, being non-intrusive and non-invasive, and the ability to withstand high temperature and high pressure. The linear back-projection (LBP algorithm is one of the most popular methods employed to perform image reconstruction in ECT. Despite its relatively poor accuracy, it is a simple and fast procedure capable of real-time operation in many applications, and it has remained a very popular choice. However, since it was first reported it has lacked a clear formal support in the context of this application. Its only justification has been that it was an adaptation of a method normally used in linear X-ray medical tomography, and the fact that it actually does produce useful (albeit only ‘qualitative’ images. In this paper, one illustrative way of interpreting LBP is presented. It is shown how LBP is actually based on the linearisation of a normalised form of the forward problem. More specifically, the normalised forward problem is approximated by means of a series of hyper-planes. The reconstruction matrix used in LBP is found to be a ‘weighted’ transpose of the linear operator (matrix that defines the linearised normalised forward problem. The rows of this latter matrix contain the information of the sensitivity maps used in LBP.

  7. Characterizing trends in HIV infection among men who have sex with men in Australia by birth cohorts: results from a modified back-projection method

    OpenAIRE

    Wand Handan; Wilson David; Yan Ping; Gonnermann Andrea; McDonald Ann; Kaldor John; Law Matthew

    2009-01-01

    Abstract Background We set out to estimate historical trends in HIV incidence in Australian men who have sex with men with respect to age at infection and birth cohort. Methods A modified back-projection technique is applied to data from the HIV/AIDS Surveillance System in Australia, including "newly diagnosed HIV infections", "newly acquired HIV infections" and "AIDS diagnoses", to estimate trends in HIV incidence over both calendar time and age at infection. Results Our results demonstrate ...

  8. Effect of Post-Reconstruction Gaussian Filtering on Image Quality and Myocardial Blood Flow Measurement with N-13 Ammonia PET

    OpenAIRE

    Hyeon Sik Kim; Sang-Geon Cho; Ju Han Kim; Seong Young Kwon; Byeongil Lee; Hee-Seung Bom

    2014-01-01

    Objective(s): In order to evaluate the effect of post-reconstruction Gaussian filtering on image quality and myocardial blood flow (MBF) measurement by dynamic N-13 ammonia positron emission tomography (PET), we compared various reconstruction and filtering methods with image characteristics. Methods: Dynamic PET images of three patients with coronary artery disease (male-female ratio of 2:1; age: 57, 53, and 76 years) were reconstructed, using filtered back projection (FBP) and ordered...

  9. Relationship between High-frequency Radiation and Asperity Ruptures, Revealed by Hybrid Back-projection with a Non-planar Fault Model

    OpenAIRE

    Okuwaki, Ryo; Yagi, Yuji; Hirano, Shiro

    2014-01-01

    High-frequency seismic waves are generated by abrupt changes of rupture velocity and slip-rate during an earthquake. Therefore, analysis of high-frequency waves is crucial to understanding the dynamic rupture process. Here, we developed a hybrid back-projection method that considers variations in focal mechanisms by introducing a non-planar fault model that reflects the subducting slab geometry. We applied it to teleseismic P-waveforms of the Mw 8.8 2010 Chile earthquake to estimate the spati...

  10. Traditional Technology.

    Science.gov (United States)

    Deloria, Vine, Jr.

    1990-01-01

    Discusses the dilemma of American Indian science students as they attempt to integrate the reductionist methodologies of modern science with the holistic approach of traditional beliefs and practices. Suggests that students look to traditional technologies to find the broader meaning underlying the mechanics of nature. (SV)

  11. Development of the code for filter calculation

    International Nuclear Information System (INIS)

    This paper describes a calculation method, which commonly used in the Neutron Physics Department to develop a new neutron filter or to improve the existing neutron filter. This calculation is the first step of the traditional filter development procedure. It allows easy selection of the qualitative and quantitative contents of a composite filter in order to receive the filtered neutron beam with given parameters

  12. Phase space signal filtering

    OpenAIRE

    José Alberto Campos Neves; J. C. Aparício Fernandes; Francisco José de Oliveira Restivo

    2006-01-01

    In this article we propose an approach based on the analysis of phase space of time series, in order to improve the filtering process. In some applications the traditional filtering process can produce results that lead to a insufficient representation of the information contained in the signal. Using phase space we can have a different meaning for noise, its correlation with the signal and a supporting theory for accurate filtering.

  13. Keeping Tradition

    OpenAIRE

    Zenhong, C.; Buwalda, P. L.

    2011-01-01

    Chinese dumplings such as Jiao Zi and Bao Zi are two of the popular traditional foods in Asia. They are usually made from wheat flour dough (rice flour or starch is sometimes used) that contains fillings. They can be steamed, boiled and fried and are consumed either as a main meal or dessert. As these tasty dumplings are easy to prepare, they have become one of Asia's fastest growing products in the frozen and ready-to-eat sector.

  14. Generalized Nonlinear Complementary Attitude Filter

    CERN Document Server

    Jensen, Kenneth

    2011-01-01

    This work describes a family of attitude estimators that are based on a generalization of Mahony's nonlinear complementary filter. This generalization reveals the close mathematical relationship between the nonlinear complementary filter and the more traditional multiplicative extended Kalman filter. In fact, the bias-free and constant gain multiplicative continuous-time extended Kalman filters may be interpreted as special cases of the generalized attitude estimator. The correspondence provides a rational means of choosing the gains for the nonlinear complementary filter and a proof of the near global asymptotic stability of special cases of the multiplicative extended Kalman filter.

  15. High security and robust optical image encryption approach based on computer-generated integral imaging pickup and iterative back-projection techniques

    Science.gov (United States)

    Li, Xiao Wei; Cho, Sung Jin; Kim, Seok Tae

    2014-04-01

    In this paper, a novel optical image encryption algorithm by combining the use of computer-generated integral imaging (CGII) pickup technique and iterative back-projection (IBP) technique is proposed. In this scheme, a color image to be encrypted which is firstly segregated into three channels: red, green, and blue. Each of these three channels is independently captured by using a virtual pinhole array and be computationally transformed as a sub-image array. Then, each of these three sub-image arrays are scrambled by the Fibonacci transformation (FT) algorithm, respectively. These three scrambled sub-image arrays are encrypted by the hybrid cellular automata (HCA), respectively. Ultimately, these three encrypted images are combined to produce the colored encrypted image. In the reconstruction process, because the computational integral imaging reconstruction (CIIR) is a pixel-overlapping reconstruction technique, the interference of the adjacent pixels will decrease the quality of the reconstructed image. To address this problem, we introduce an image super-resolution reconstruction technique, the image can be computationally reconstructed by the IBP technique. Some numerical simulations are made to test the validity and the capability of the proposed image encryption algorithm.

  16. The diffuse ensemble filter

    Directory of Open Access Journals (Sweden)

    X. Yang

    2009-07-01

    Full Text Available A new class of ensemble filters, called the Diffuse Ensemble Filter (DEnF, is proposed in this paper. The DEnF assumes that the forecast errors orthogonal to the first guess ensemble are uncorrelated with the latter ensemble and have infinite variance. The assumption of infinite variance corresponds to the limit of "complete lack of knowledge" and differs dramatically from the implicit assumption made in most other ensemble filters, which is that the forecast errors orthogonal to the first guess ensemble have vanishing errors. The DEnF is independent of the detailed covariances assumed in the space orthogonal to the ensemble space, and reduces to conventional ensemble square root filters when the number of ensembles exceeds the model dimension. The DEnF is well defined only in data rich regimes and involves the inversion of relatively large matrices, although this barrier might be circumvented by variational methods. Two algorithms for solving the DEnF, namely the Diffuse Ensemble Kalman Filter (DEnKF and the Diffuse Ensemble Transform Kalman Filter (DETKF, are proposed and found to give comparable results. These filters generally converge to the traditional EnKF and ETKF, respectively, when the ensemble size exceeds the model dimension. Numerical experiments demonstrate that the DEnF eliminates filter collapse, which occurs in ensemble Kalman filters for small ensemble sizes. Also, the use of the DEnF to initialize a conventional square root filter dramatically accelerates the spin-up time for convergence. However, in a perfect model scenario, the DEnF produces larger errors than ensemble square root filters that have covariance localization and inflation. For imperfect forecast models, the DEnF produces smaller errors than the ensemble square root filter with inflation. These experiments suggest that the DEnF has some advantages relative to the ensemble square root filters in the regime of small ensemble size, imperfect model, and copious observations.

  17. GMTI processing using back projection.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2013-07-01

    Backprojection has long been applied to SAR image formation. It has equal utility in forming the range-velocity maps for Ground Moving Target Indicator (GMTI) radar processing. In particular, it overcomes the problem of targets migrating through range resolution cells.

  18. Design of the polarizing interference filters

    Science.gov (United States)

    Ciosek, Jerzy

    1997-10-01

    Narrow-band polarizing interference filters make the new category of thin layers construction. Due to the compact trends the narrow-band polarizing interference filters eliminate one of two elements used traditionally on separate substrates: narrow-band filter and thin layer polarizer. Considering them as narrow-band interference filters it is possible to project their parameters such as center wavelength or the half bandwidth. The choice of the narrow- band polarizing interference filters design is controlled by the polarizing degree.

  19. Filters with active tuning for power applications

    OpenAIRE

    Phinney, Joshua; Perreault, David J.

    2002-01-01

    Filters for switched-mode power converters have traditionally relied on low-pass networks-with corner frequencies well below the ripple fundamental-to attenuate switching harmonics over a range of frequencies. The filters explored in this report provide extra attenuation at discrete frequencies, easing the filtering requirement of accompanying low-pass networks. When a converter's switching frequency is tuned to a filter resonance using a novel phase-lock control scheme, a resonant filter can...

  20. Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters

    Directory of Open Access Journals (Sweden)

    Gonzalez Juan G

    2002-01-01

    Full Text Available Linear filtering theory has been largely motivated by the characteristics of Gaussian signals. In the same manner, the proposed Myriad Filtering methods are motivated by the need for a flexible filter class with high statistical efficiency in non-Gaussian impulsive environments that can appear in practice. Myriad filters have a solid theoretical basis, are inherently more powerful than median filters, and are very general, subsuming traditional linear FIR filters. The foundation of the proposed filtering algorithms lies in the definition of the myriad as a tunable estimator of location derived from the theory of robust statistics. We prove several fundamental properties of this estimator and show its optimality in practical impulsive models such as the -stable and generalized- . We then extend the myriad estimation framework to allow the use of weights. In the same way as linear FIR filters become a powerful generalization of the mean filter, filters based on running myriads reach all of their potential when a weighting scheme is utilized. We derive the "normal" equations for the optimal myriad filter, and introduce a suboptimal methodology for filter tuning and design. The strong potential of myriad filtering and estimation in impulsive environments is illustrated with several examples.

  1. Rupture Processes of the Mw8.3 Sea of Okhotsk Earthquake and Aftershock Sequences from 3-D Back Projection Imaging

    Science.gov (United States)

    Jian, P. R.; Hung, S. H.; Meng, L.

    2014-12-01

    On May 24, 2013, the largest deep earthquake ever recorded in history occurred on the southern tip of the Kamchatka Island, where the Pacific Plate subducts underneath the Okhotsk Plate. Previous 2D beamforming back projection (BP) of P- coda waves suggests the mainshock ruptured bilaterally along a horizontal fault plane determined by the global centroid moment tensor solution. On the other hand, the multiple point source inversion of P and SH waveforms argued that the earthquake comprises a sequence of 6 subevents not located on a single plane but actually distributed in a zone that extends 64 km horizontally and 35 km in depth. We then apply a three-dimensional MUSIC BP approach to resolve the rupture processes of the manishock and two large aftershocks (M6.7) with no a priori setup of preferential orientations of the planar rupture. The maximum pseudo-spectrum of high-frequency P wave in a sequence of time windows recorded by the densely-distributed stations from US and EU Array are used to image 3-D temporal and spatial rupture distribution. The resulting image confirms that the nearly N-S striking but two antiparallel rupture stages. The first subhorizontal rupture initially propagates toward the NNE direction, while at 18 s later it directs reversely to the SSW and concurrently shifts downward to 35 km deeper lasting for about 20 s. The rupture lengths in the first NNE-ward and second SSW-ward stage are about 30 km and 85 km; the estimated rupture velocities are 3 km/s and 4.25 km/s, respectively. Synthetic experiments are undertaken to assess the capability of the 3D MUSIC BP for the recovery of spatio-temporal rupture processes. Besides, high frequency BP images based on the EU-Array data show two M6.7 aftershocks are more likely to rupture on the vertical fault planes.

  2. Characterizing trends in HIV infection among men who have sex with men in Australia by birth cohorts: results from a modified back-projection method

    Directory of Open Access Journals (Sweden)

    Wand Handan

    2009-09-01

    Full Text Available Abstract Background We set out to estimate historical trends in HIV incidence in Australian men who have sex with men with respect to age at infection and birth cohort. Methods A modified back-projection technique is applied to data from the HIV/AIDS Surveillance System in Australia, including "newly diagnosed HIV infections", "newly acquired HIV infections" and "AIDS diagnoses", to estimate trends in HIV incidence over both calendar time and age at infection. Results Our results demonstrate that since 2000, there has been an increase in new HIV infections in Australian men who have sex with men across all age groups. The estimated mean age at infection increased from ~35 years in 2000 to ~37 years in 2007. When the epidemic peaked in the mid 1980s, the majority of the infections (56% occurred among men aged 30 years and younger; 30% occurred in ages 31 to 40 years; and only ~14% of them were attributed to the group who were older than 40 years of age. In 2007, the proportion of infections occurring in persons 40 years or older doubled to 31% compared to the mid 1980s, while the proportion of infections attributed to the group younger than 30 years of age decreased to 36%. Conclusion The distribution of HIV incidence for birth cohorts by infection year suggests that the HIV epidemic continues to affect older homosexual men as much as, if not more than, younger men. The results are useful for evaluating the impact of the epidemic across successive birth cohorts and study trends among the age groups most at risk.

  3. Cold Crystal Reflector Filter Concept

    OpenAIRE

    Muhrer, G.

    2014-01-01

    In this paper the theoretical concept of a cold crystal reflector filter will be presented. The aim of this concept is to balance the shortcoming of the traditional cold polycrystalline reflector filter, which lies in the significant reduction of the neutron flux right above (in energy space) or right below (wavelength space) the first Bragg edge.

  4. Air filter

    International Nuclear Information System (INIS)

    An air filter consists of an upright cylinder of corrugated or pleated filter fabric, joined at its upper end to a tubular right-angled elbow. The open end of the elbow includes an internal lip seal, so the elbow can be slid onto a horizontal spigot in an air filter unit. The filter can be cleaned by subjecting the fabric to a reverse pressure pulse from a nozzle. The construction facilitates removal of the filter into a plastic bag secured round a frame behind a door, when the unit is used to filter radioactive dust from air. (author)

  5. Optimal filtering

    CERN Document Server

    Anderson, Brian D O

    2012-01-01

    This graduate-level text augments and extends beyond undergraduate studies of signal processing, particularly in regard to communication systems and digital filtering theory. Vital for students in the fields of control and communications, its contents are also relevant to students in such diverse areas as statistics, economics, bioengineering, and operations research.Topics include filtering, linear systems, and estimation; the discrete-time Kalman filter; time-invariant filters; properties of Kalman filters; computational aspects; and smoothing of discrete-time signals. Additional subjects e

  6. Survey on Spam Filtering Techniques

    Directory of Open Access Journals (Sweden)

    Saadat Nazirova

    2011-08-01

    Full Text Available In the recent years spam became as a big problem of Internet and electronic communication. There developed a lot of techniques to fight them. In this paper the overview of existing e-mail spam filtering methods is given. The classification, evaluation, and comparison of traditional and learning-based methods are provided. Some personal anti-spam products are tested and compared. The statement for new approach in spam filtering technique is considered.

  7. Data assimilation the ensemble Kalman filter

    CERN Document Server

    Evensen, Geir

    2006-01-01

    Covers data assimilation and inverse methods, including both traditional state estimation and parameter estimation. This text and reference focuses on various popular data assimilation methods, such as weak and strong constraint variational methods and ensemble filters and smoothers.

  8. Ultraviolet filters.

    Science.gov (United States)

    Shaath, Nadim A

    2010-04-01

    The chemistry, photostability and mechanism of action of ultraviolet filters are reviewed. The worldwide regulatory status of the 55 approved ultraviolet filters and their optical properties are documented. The photostabilty of butyl methoxydibenzoyl methane (avobenzone) is considered and methods to stabilize it in cosmetic formulations are presented. PMID:20354639

  9. An area efficient low noise 100 Hz low-pass filter

    OpenAIRE

    Ølgaard, Christian; Sassene, Haoues; Perch-nielsen, Ivan R.

    1996-01-01

    A technique based on scaling a filter's capacitor currents to improve the noise performance of low frequency continuous-time filters is presented. Two 100 Hz low-pass filters have been implemented: a traditional low pass filter (as reference), and a filter utilizing the above mentioned current scaling technique. The two filters utilize approximately the same silicon area. The scaled filter implements the scaling by use of a MOS based current conveyor type CCII. Measurements indicate that the ...

  10. Favorite Family Traditions

    Science.gov (United States)

    2012-12-08

    Students use the text The Relatives Came by Cynthia Rylant as a springboard for discussion about family traditions. After identifying the traditions observed by the relatives, students meet in small groups to brainstorm new traditions that could arise from the families gathering together during the winter. The lesson is concluded by having each student write about their own favorite family tradition and share it with a small group.

  11. Optimal filter systems for photometric redshift estimation

    OpenAIRE

    Benitez, N.; Moles, M.; Aguerri, J. A. L.; Alfaro, E.; Broadhurst, T.; Cabrera, J.; Castander, F. J.; Cepa, J.; Cervino, M.; Cristobal-hornillos, D.; Fernandez-soto, A.; Gonzalez-delgado, R. M.; Infante, L.; Marquez, I.; Martinez, V. J.

    2008-01-01

    In the next years, several cosmological surveys will rely on imaging data to estimate the redshift of galaxies, using traditional filter systems with 4-5 optical broad bands; narrower filters improve the spectral resolution, but strongly reduce the total system throughput. We explore how photometric redshift performance depends on the number of filters n_f, characterizing the survey depth through the fraction of galaxies with unambiguous redshift estimates. For a combination...

  12. Robust filtering for uncertain systems a parameter-dependent approach

    CERN Document Server

    Gao, Huijun

    2014-01-01

    This monograph provides the reader with a systematic treatment of robust filter design, a key issue in systems, control and signal processing, because of the fact that the inevitable presence of uncertainty in system and signal models often degrades the filtering performance and may even cause instability. The methods described are therefore not subject to the rigorous assumptions of traditional Kalman filtering. The monograph is concerned with robust filtering for various dynamical systems with parametric uncertainties, and focuses on parameter-dependent approaches to filter design. Classical filtering schemes, like H2 filtering and H¥ filtering, are addressed, and emerging issues such as robust filtering with constraints on communication channels and signal frequency characteristics are discussed. The text features: ·        design approaches to robust filters arranged according to varying complexity level, and emphasizing robust filtering in the parameter-dependent framework for the first time; ·...

  13. Quality of inverse radon transform-based image reconstruction using various frequency domain filters in parallel beam transmission tomography

    International Nuclear Information System (INIS)

    Inverse Radon Transform (IRT) based image reconstruction is of prime importance in various areas of science and engineering in this paper, we have used Filtered Back-Projection technique to find IRT estimate by employing various filters, namely Ram-Lak, shepp-Logan. Cosine, Hamming and Hanning filers for deblurring and emphasizing high frequency components in the projection domain. The head phantom and the lung phantom have been used for carrying out the simulation of 512 * 512 image size. Best results as reconstructed image have been obtained by using Hanning filter. Various image parameters have been used as quality measures including average error, maximum error, peak signal-to-noise ratio, Euclidean error, mean squared error, average error histogram. Variance histogram, mean squared error histogram. Standard deviation histogram, etc. The FBP technique using Hamming filter has been found as effective as FBP Hanning technique in both cases. (author)

  14. Gadamers verständnis der tradition

    Directory of Open Access Journals (Sweden)

    Radoj?i? Saša

    2009-01-01

    Full Text Available (nema?ki In diesem Aufsatz man Gadamers Verständnis der wichtigen hermeneutischen Begriffe des Vorurteils, der Autorität und der Tradition erörtet. Der Vollzug des Verstehens, in dem die Vorurteile unvermeidlich sind, wird als Prozeß ihre ununterbrechende Korrektion bestimmt. Die positive Auswertung des begrifflichen Paar Autorität-Tradition ist ein karakteristischen Motiv der philosophischen Hermeneutik, für die die Autorität kein negativen Mitklang hat, sondern auf freie und rationelle Annahmung begründet ist. Der Zusammenhang des Verstehens und der Tradition ist eine dynamische Beziehung, in die weder Tradition noch das Subjekt des Verstehens ungeändert bleiben. Daraus führt man zwei Implikationen aus: daß der Sinn eines Textes kann man nie ausschöpfen, und seines Verstehen ein unendlichen Prozeß ist; und daß die Suspension der Vorurteilen nur gelingt, wo die Tradition sie sozusagen 'filtriert'. Der Author stellt eine Spannung aus, zwischen Gadamers Verständnis der hermeneutischen Produktivität der Tradition und des zeitlichen Abstand als Instanz die dem Verstehen beiträgt.

  15. The 3-D alignment of objects in dynamic PET scans using filtered sinusoidal trajectories of sinogram

    International Nuclear Information System (INIS)

    In this study, our goal is to employ a novel 3-D alignment method for dynamic positron emission tomography (PET) scans. Because the acquired data (i.e. sinograms) often contain noise considerably, filtering of the data prior to the alignment presumably improves the final results. In this study, we utilized a novel 3-D stackgram domain approach. In the stackgram domain, the signals along the sinusoidal trajectory signals of the sinogram can be processed separately. In this work, we performed angular stackgram domain filtering by employing well known 1-D filters: the Gaussian low-pass filter and the median filter. In addition, we employed two wavelet de-noising techniques. After filtering we performed alignment of objects in the stackgram domain. The local alignment technique we used is based on similarity comparisons between locus vectors (i.e. the signals along the sinusoidal trajectories of the sinogram) in a 3-D neighborhood of sequences of the stackgrams. Aligned stackgrams can be transformed back to sinograms (Method 1), or alternatively directly to filtered back-projected images (Method 2). In order to evaluate the alignment process, simulated data with different kinds of additive noises were used. The results indicated that the filtering prior to the alignment can be important concerning the accuracy

  16. A nonlinear, image domain filtering method for cardiac PET images

    International Nuclear Information System (INIS)

    An adaptive, nonlinear image domain filtering strategy is described which improves positron emission tomography (PET) images. The method was formulated to improve on the linear, low-pass filtering typically applied to each projection in the filtered back-projection (FBP) reconstruction algorithm. The algorithm is a potential alternative to linear smoothing which reduces noise but degrades resolution; this method uses the FBP algorithm for reconstruction, but aims to incorporate some of the statistical information and nonlinear smoothing utilized in iterative reconstruction algorithms. The approach uses sinogram segmentation to separate the sinogram elements with higher and lower signal-to-noise ratios, and then reconstruct each with FBP using a more appropriate choice of filter and cut-off frequency. Also, this algorithm addresses the radial streak artifacts introduced by FBP. The algorithm was evaluated using simulations and clinical data of cardiac PET studies on an ECAT 931 PET scanner. The initial results suggest that this technique has advantages over the current clinical protocol. Images processed with the method show generally improved visual image quality and reduced radial streaks without the introduction of artifacts. In simulations, increased contrast recovery and resolution are realized without an increase in the background noise of the reconstructed images

  17. African Traditional Religion (ATR)

    Science.gov (United States)

    Isizoh, Chidi Denis.

    The African Traditional Religion (ATR) site which hosts the on Bibliography on African Traditional Religion contains several more items of interest, including articles and documents exploring the contact points of ATR with Islam and Christianity, country-by-country statistics on adherents of ATR, and a number of related links.

  18. Traditional fishing tools

    OpenAIRE

    Stoica, Georgeta

    2009-01-01

    In this paper I present the traditional fishing tools used in the area of the Danube Delta. More precisely, I speak about the village of Sfantu Gheorghe, a traditional fishing village, where the fishing activity has been the main activity along the years and where, lately, there have been major changes due to the decrease of the fish species.

  19. Fault Tolerant Parallel Filters Based On Bch Codes

    Directory of Open Access Journals (Sweden)

    K.Mohana Krishna

    2015-04-01

    Full Text Available Digital filters are used in signal processing and communication systems. In some cases, the reliability of those systems is critical, and fault tolerant filter implementations are needed. Over the years, many techniques that exploit the filters’ structure and properties to achieve fault tolerance have been proposed. As technology scales, it enables more complex systems that incorporate many filters. In those complex systems, it is common that some of the filters operate in parallel, for example, by applying the same filter to different input signals. Recently, a simple technique that exploits the presence of parallel filters to achieve multiple fault tolerance has been presented. In this brief, that idea is generalized to show that parallel filters can be protected using Bose– Chaudhuri–Hocquenghem codes (BCH in which each filter is the equivalent of a bit in a traditional ECC. This new scheme allows more efficient protection when the number of parallel filters is large.

  20. Spectral CT using multiple balanced K-edge filters.

    Science.gov (United States)

    Rakvongthai, Yothin; Worstell, William; El Fakhri, Georges; Bian, Junguo; Lorsakul, Auranuch; Ouyang, Jinsong

    2015-03-01

    Our goal is to validate a spectral computed tomography (CT) system design that uses a conventional X-ray source with multiple balanced K-edge filters. By performing a simultaneously synthetic reconstruction in multiple energy bins, we obtained a good agreement between measurements and model expectations for a reasonably complex phantom. We performed simulation and data acquisition on a phantom containing multiple rods of different materials using a NeuroLogica CT scanner. Five balanced K-edge filters including Molybdenum, Cerium, Dysprosium, Erbium, and Tungsten were used separately proximal to the X-ray tube. For each sinogram bin, measured filtered vector can be defined as a product of a transmission matrix, which is determined by the filters and is independent of the imaging object, and energy-binned intensity vector. The energy-binned sinograms were then obtained by inverting the transmission matrix followed by a multiplication of the filter measurement vector. For each energy bin defined by two consecutive K-edges, a synthesized energy-binned attenuation image was obtained using filtered back-projection reconstruction. The reconstructed attenuation coefficients for each rod obtained from the experiment was in good agreement with the corresponding simulated results. Furthermore, the reconstructed attenuation coefficients for a given energy bin, agreed with National Institute of Standards and Technology reference values when beam hardening within the energy bin is small. The proposed cost-effective system design using multiple balanced K-edge filters can be used to perform spectral CT imaging at clinically relevant flux rates using conventional detectors and integrating electronics. PMID:25252276

  1. Quantitative gated SPECT: the effect of reconstruction filter on calculated left ventricular ejection fractions and volumes

    International Nuclear Information System (INIS)

    Gated SPECT (GSPECT) offers the possibility of obtaining additional functional information from perfusion studies, including calculation of left ventricular ejection fraction (LVEF). The calculation of LVEF relies upon the identification of the endocardial surface, which will be affected by the spatial resolution and statistical noise in the reconstructed images. The aim of this study was to compare LVEFs and ventricular volumes calculated from GSPECT using six reconstruction filters. GSPECT and radionuclide ventriculography (RNVG) were performed on 40 patients; filtered back projection was used to reconstruct the datasets with each filter. LVEFs and volumes were calculated using the Cedars-Sinai QGS package. The correlation coefficient between RNVG and GSPECT ranged from 0.81 to 0.86 with higher correlations for smoother filters. The narrowest prediction interval was 11±2%. There was a trend towards higher LVEF values with smoother filters, the ramp filter yielding LVEFs 2.55±3.10% (p<0.001) lower than the Hann filter. There was an overall fall in ventricular volumes with smoother filters with a mean difference of 13.98±10.15 ml (p<0.001) in EDV between the Butterworth-0.5 and Butterworth-0.3 filters. In conclusion, smoother reconstruction filters lead to lower volumes and higher ejection fractions with the QGS algorithm, with the Butterworth-0.4 filter giving the highest correlation with LVEFs from RNVG. Even if the optimal filter is chosen the uncertainty in thefilter is chosen the uncertainty in the measured ejection fractions is still too great to be clinically acceptable. (author)

  2. Drug Filtering

    Science.gov (United States)

    Lawrence F. Iles

    2010-01-01

    In this math meets health science activity, learners observe a model of exponential decay, and how kidneys filter blood. Learners will calculate the amount of a drug in the body over a period of time. Then, they will make and analyze the graphical representation of this exponential function. This lesson guide includes questions for learners, assessment options, extensions, and reflection questions.

  3. Oral Tradition Journal

    Science.gov (United States)

    2008-01-01

    Stretching back thousands of years, the oral traditions that have enriched and documented human existence remain a subject of much fascination. The Oral Tradition Journal was founded in 1986 in order to "serve as an international and interdisciplinary forum for discussion of worldwide oral traditions and related forms." The journal is based at the University of Missouri, and visitors to the site can search the entire run of the journal on this site by keyword or author. Clicking over to the "Browse the Journal" area, visitors can look over back issues that include special issues on the Serbo-Croatian oral tradition, performance literature, and the performance artistry of Bob Dylan. The site is a real treat for anyone interested in the subject, and visitors can also learn how to submit their own work for possible inclusion in a forthcoming volume.

  4. The "Natural Law Tradition."

    Science.gov (United States)

    Finnis, John

    1986-01-01

    A discussion of natural law outlines some of the theory and tradition surrounding it and examines its relationship to the social science and legal curriculum and to the teaching of jurisprudence. (MSE)

  5. Hybrid Sampling Bayesian Occupancy Filter

    OpenAIRE

    Ne?gre, Amaury; Rummelhard, Lukas; Laugier, Christian

    2014-01-01

    Modeling and monitoring dynamic environments is a complex task but is crucial in the field of intelligent vehicle. A traditional way of addressing these issues is the modeling of moving objects, through Detection And Tracking of Moving Objects (DATMO) methods. An alternative to a classic object model framework is the occupancy grid filtering domain. Instead of segmenting the scene into objects and track them, the environment is represented as a regular grid of occupancy, in which each cell is...

  6. Traditional Chinese Biotechnology

    Science.gov (United States)

    Xu, Yan; Wang, Dong; Fan, Wen Lai; Mu, Xiao Qing; Chen, Jian

    The earliest industrial biotechnology originated in ancient China and developed into a vibrant industry in traditional Chinese liquor, rice wine, soy sauce, and vinegar. It is now a significant component of the Chinese economy valued annually at about 150 billion RMB. Although the production methods had existed and remained basically unchanged for centuries, modern developments in biotechnology and related fields in the last decades have greatly impacted on these industries and led to numerous technological innovations. In this chapter, the main biochemical processes and related technological innovations in traditional Chinese biotechnology are illustrated with recent advances in functional microbiology, microbial ecology, solid-state fermentation, enzymology, chemistry of impact flavor compounds, and improvements made to relevant traditional industrial facilities. Recent biotechnological advances in making Chinese liquor, rice wine, soy sauce, and vinegar are reviewed.

  7. Digital filters

    CERN Document Server

    Hamming, Richard W

    1997-01-01

    Digital signals occur in an increasing number of applications: in telephone communications; in radio, television, and stereo sound systems; and in spacecraft transmissions, to name just a few. This introductory text examines digital filtering, the processes of smoothing, predicting, differentiating, integrating, and separating signals, as well as the removal of noise from a signal. The processes bear particular relevance to computer applications, one of the focuses of this book.Readers will find Hamming's analysis accessible and engaging, in recognition of the fact that many people with the s

  8. Building on tradition

    Directory of Open Access Journals (Sweden)

    John Ebdon

    2001-09-01

    Full Text Available Sheffield University has a long and distinguished tradition of research on polymeric materials and in polymer engineering. However, the University's profile in polymer research was greatly strengthened first by the appointments in 1998 of Tony Ryan and Richard Jones and by the transfer last year of seven polymer chemists, together with their research students, research associates and equipment, from Lancaster University.

  9. Looking beyond Traditional Evaluation

    Science.gov (United States)

    Harriman, Lynda; McKenna, Constance

    1978-01-01

    The article describes the evaluation of the home economics specialized adviser program in Illinois Extension regions, including specific recommendations for program revisions. The evaluation was based on the Provus Discrepancy Evaluation Model, which provides an alternative to traditional evaluation techniques by considering descriptions of…

  10. Making Tradition Healthy

    Centers for Disease Control (CDC) Podcasts

    2007-11-01

    In this podcast, a Latina nutrition educator shows how a community worked with local farmers to grow produce traditionally enjoyed by Hispanic/Latinos.  Created: 11/1/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health.   Date Released: 11/10/2007.

  11. Effect of Post-Reconstruction Gaussian Filtering on Image Quality and Myocardial Blood Flow Measurement with N-13 Ammonia PET

    Directory of Open Access Journals (Sweden)

    Hyeon Sik Kim

    2014-10-01

    Full Text Available Objective(s: In order to evaluate the effect of post-reconstruction Gaussian filtering on image quality and myocardial blood flow (MBF measurement by dynamic N-13 ammonia positron emission tomography (PET, we compared various reconstruction and filtering methods with image characteristics. Methods: Dynamic PET images of three patients with coronary artery disease (male-female ratio of 2:1; age: 57, 53, and 76 years were reconstructed, using filtered back projection (FBP and ordered subset expectation maximization (OSEM methods. OSEM reconstruction consisted of OSEM_2I, OSEM_4I, and OSEM_6I with 2, 4, and 6 iterations, respectively. The images, reconstructed and filtered by Gaussian filters of 5, 10, and 15 mm, were obtained, as well as non-filtered images. Visual analysis of image quality (IQ was performed using a 3-grade scoring system by 2 independent readers, blinded to the reconstruction and filtering methods of stress images. Then, signal-to-noise ratio (SNR was calculated by noise and contrast recovery (CR. Stress and rest MBF and coronary flow reserve (CFR were obtained for each method. IQ scores, stress and rest MBF, and CFR were compared between the methods, using Chi-square and Kruskal-Wallis tests. Results: In the visual analysis, IQ was significantly higher by 10 mm Gaussian filtering, compared to other sizes of filter (PP=0.923 and 0.855 for readers 1 and 2, respectively. SNR was significantly higher in 10 mm Gaussian filter. There was a significant difference in stress and rest MBF between several vascular territories. However CFR was not significantly different according to various filtering methods. Conclusion: Post-reconstruction Gaussian filtering with a filter size of 10 mm significantly enhances the IQ of N-13 ammonia PET-CT, without changing the results of CFR calculation. .

  12. Traditional Medicine in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Takawira Kazembe

    2007-06-01

    Full Text Available This study was carried out to help demystify traditional medical practices in Zimbabwe and assist people in understanding Zimbabwean traditional medicine. The Zimbabwean traditional religion involves a hierarchy of spirit mediums differing in the way they practice traditional medicine, as well as the origin and power of the spirit(s that possess(es them. MaGombwe, mediums of angels of God, occupy the highest level on the hierarchy. The second level is that of maSadunhu, the spirit mediums of the original leaders of clans who look after the interests of members of their clans. The third level is that of maTateguru, the spirits who look after the interests of the families they left behind. These spirits of great grandparents are complimented by spirits of grandparents who possess their mediums only to get a specific thing done and then disappear. The fourth level is occupied by N’angas, the ‘real traditional medical practitioners.’ These mediums may be possessed by spirits from any of the above levels, and differ from mediums at the original level in that they charge clients and the powers of their spirits are lower. The spirits at any of the levels are complimented by maShave, spirits that were created to perform specific tasks. The role of the spirit mediums is to service spiritual and medicinal interests of people. Training at the different levels of spirit mediums involves rigorous and tedious apprenticeship systems, and the mediums are willing to cooperate with other service providers if certain conditions are met.

  13. ??????????? Optimized Cooperative Filtering Algorithm

    Directory of Open Access Journals (Sweden)

    ???

    2011-12-01

    Full Text Available ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????Cooperative Filtering algorithm is one of the most successful technologies in the application of personalized recommendation system. However, the users’ identities and interests are very complicated in the normal network, which results in the inaccuracy of the recommendation. However, the appearance of social network provides users with a relatively green and safe communication platform. This paper in terms of the problems in the personalized recommendation system of social network comes up with the trust-based nearest neighbor algorithm which optimizes the traditional NN algorithm and provides recommendation by analyzing trust between the social network users. The experimental results show that the modified algorithm greatly improves the recommendation accuracy and raises the users’ degree of satisfaction.

  14. Adaptive particle filtering

    Science.gov (United States)

    Stevens, Mark R.; Gutchess, Dan; Checka, Neal; Snorrason, Magnús

    2006-05-01

    Image exploitation algorithms for Intelligence, Surveillance and Reconnaissance (ISR) and weapon systems are extremely sensitive to differences between the operating conditions (OCs) under which they are trained and the extended operating conditions (EOCs) in which the fielded algorithms are tested. As an example, terrain type is an important OC for the problem of tracking hostile vehicles from an airborne camera. A system designed to track cars driving on highways and on major city streets would probably not do well in the EOC of parking lots because of the very different dynamics. In this paper, we present a system we call ALPS for Adaptive Learning in Particle Systems. ALPS takes as input a sequence of video images and produces labeled tracks. The system detects moving targets and tracks those targets across multiple frames using a multiple hypothesis tracker (MHT) tightly coupled with a particle filter. This tracker exploits the strengths of traditional MHT based tracking algorithms by directly incorporating tree-based hypothesis considerations into the particle filter update and resampling steps. We demonstrate results in a parking lot domain tracking objects through occlusions and object interactions.

  15. Oral and literate traditions

    Directory of Open Access Journals (Sweden)

    Pieter J.J. Botha

    1992-03-01

    Full Text Available In this study the importance of research concerning orality and oral traditions for a variety of pressing current issues related to social history, cultural studies, education and science of religion is stressed. It is necessary to take into account the full range of language use as it is spoken and listened to, read and written, to improve our descriptions and analyses of ways of communicating and consequently to uncover the inter-relatedness of language and culture.

  16. Filtering Water

    Science.gov (United States)

    Brieske, Joel A.

    2003-01-01

    The first site related to water filtration is from the US Environmental Agency entitled EPA Environmental Education: Water Filtration (1 ). The two-page document explains the need for water filtration and the steps water treatment plants take to purify water. To further understand the process, a demonstration project is provided that illustrates these purification steps, which include coagulation, sedimentation, filtration, and disinfection. The second site is an interesting Flash animation called Filtration: How Does it Work (2 ) provided by Canada's Prairie Farm Rehabilitation Administration. Visitors will learn various types of filtration procedures and systems and the materials that are used such as carbon and sand. Next, from the National Science Foundation is a learning activity called Get Out the Gunk (3 ). Using just a few simple items from around the house, kids will be able to answer questions like "Does a filter work better with a lot of water rushing through, or a small trickle?" and "Does it make the water cleaner if you pour it through a filter twice?" The fourth Web site, Rapid Sand Filtration (4 ), is provided by Dottie Schmitt and Christie Shinault of Virginia Tech. The authors describe the process, which involves the flow of water through a bed of granular media, normally following settling basins in conventional water treatment trains to remove any particulate matter left over after flocculation and settling. Along with its thorough description, readers can view illustrations and photographs that further explain the process. The Vegetative Buffer Strips for Improved Surface Water Quality (5) Web site is provided by the Iowa State University Extension office. The document explains what vegetative buffer strips are, how they filter contaminants and sediment from surface water, how effective they are, and more. The sixth offering is a file called Infiltration Basins and Trenches (6) that is offered by the University of Wisconsin Extension. These structures are intended to collect water, have it infiltrate into the ground, and have it purified along the way. This document explains how effective they are at removing pollutants, how to install them, design guidelines, maintenance, and more. Next, from a site called Wilderness Survial.net is the Water Filtration Devices (7) page. Visitors read how to make a filtering system out of cloth, sand, crushed rock, charcoal, or a hollow log, although as is stated, the water still has to be purified. The last site, from the US Geological Survey, is called A Visit to a Wastewater-Treatment Plant: Primary Treatment of Wastewater (8). Although geared towards children, the site does a good job of explaining what happens at each stage of the treatment process and how pollutants are removed to help keep water clean. Everything from screening, pumping, aerating, sludge and scum removal, killing bacteria, and what is done with wastewater residuals is covered.

  17. An Adaptive Approach to Mitigate Background Covariance Limitations in the Ensemble Kalman Filter

    KAUST Repository

    Song, Hajoon

    2010-07-01

    A new approach is proposed to address the background covariance limitations arising from undersampled ensembles and unaccounted model errors in the ensemble Kalman filter (EnKF). The method enhances the representativeness of the EnKF ensemble by augmenting it with new members chosen adaptively to add missing information that prevents the EnKF from fully fitting the data to the ensemble. The vectors to be added are obtained by back projecting the residuals of the observation misfits from the EnKF analysis step onto the state space. The back projection is done using an optimal interpolation (OI) scheme based on an estimated covariance of the subspace missing from the ensemble. In the experiments reported here, the OI uses a preselected stationary background covariance matrix, as in the hybrid EnKF–three-dimensional variational data assimilation (3DVAR) approach, but the resulting correction is included as a new ensemble member instead of being added to all existing ensemble members. The adaptive approach is tested with the Lorenz-96 model. The hybrid EnKF–3DVAR is used as a benchmark to evaluate the performance of the adaptive approach. Assimilation experiments suggest that the new adaptive scheme significantly improves the EnKF behavior when it suffers from small size ensembles and neglected model errors. It was further found to be competitive with the hybrid EnKF–3DVAR approach, depending on ensemble size and data coverage.

  18. Non-Traditional Vectors for Paralytic Shellfish Poisoning

    Directory of Open Access Journals (Sweden)

    Sara Watt Longan

    2008-06-01

    Full Text Available Paralytic shellfish poisoning (PSP, due to saxitoxin and related compounds, typically results from the consumption of filter-feeding molluscan shellfish that concentrate toxins from marine dinoflagellates. In addition to these microalgal sources, saxitoxin and related compounds, referred to in this review as STXs, are also produced in freshwater cyanobacteria and have been associated with calcareous red macroalgae. STXs are transferred and bioaccumulate throughout aquatic food webs, and can be vectored to terrestrial biota, including humans. Fisheries closures and human intoxications due to STXs have been documented in several non-traditional (i.e. non-filter-feeding vectors. These include, but are not limited to, marine gastropods, both carnivorous and grazing, crustacea, and fish that acquire STXs through toxin transfer. Often due to spatial, temporal, or a species disconnection from the primary source of STXs (bloom forming dinoflagellates, monitoring and management of such non-traditional PSP vectors has been challenging. A brief literature review is provided for filter feeding (traditional and nonfilter feeding (non-traditional vectors of STXs with specific reference to human effects. We include several case studies pertaining to management actions to prevent PSP, as well as food poisoning incidents from STX(s accumulation in non-traditional PSP vectors.

  19. Enhanced 3D PET OSEM reconstruction using inter-update Metz filtering

    International Nuclear Information System (INIS)

    We present an enhancement of the OSEM (ordered set expectation maximization) algorithm for 3D PET reconstruction, which we call the inter-update Metz filtered OSEM (IMF-OSEM). The IMF-OSEM algorithm incorporates filtering action into the image updating process in order to improve the quality of the reconstruction. With this technique, the multiplicative correction image - ordinarily used to update image estimates in plain OSEM - is applied to a Metz-filtered version of the image estimate at certain intervals. In addition, we present a software implementation that employs several high-speed features to accelerate reconstruction. These features include, firstly, forward and back projection functions which make full use of symmetry as well as a fast incremental computation technique. Secondly, the software has the capability of running in parallel mode on several processors. The parallelization approach employed yields a significant speed-up, which is nearly independent of the amount of data. Together, these features lead to reasonable reconstruction times even when using large image arrays and non-axially compressed projection data. The performance of IMF-OSEM was tested on phantom data acquired on the GE Advance scanner. Our results demonstrate that an appropriate choice of Metz filter parameters can improve the contrast-noise balance of certain regions of interest relative to both plain and post-filtered OSEM, and to the GE commercial reprojection algorithm software. mmercial reprojection algorithm software. (author)

  20. Research of Collaborative Filtering Recommendation Algorithm based on Network Structure

    OpenAIRE

    Peng, Hui

    2013-01-01

    This paper combines the classic collaborative filtering algorithm with personalized recommendation algorithm based on network structure. For the data sparsity and malicious behavior problems of traditional collaborative filtering algorithm, the paper introduces a new kind of social network-based collaborative filtering algorithm. In order to improve the accuracy of the personalized recommendation technology, we first define empty state in the state space of multi-dimensional semi-Markov proce...

  1. A Kalman filter technique applied for medical image reconstruction

    International Nuclear Information System (INIS)

    Medical images contain information about vital organic tissues inside of human body and are widely used for diagnoses of disease or for surgical purposes. Image reconstruction is essential for medical images for some applications such as suppression of noise or de-blurring the image in order to provide images with better quality and contrast. Due to vital rule of image reconstruction in medical sciences the corresponding algorithms with better efficiency and higher speed is desirable. Most algorithms in image reconstruction are operated on frequency domain such as the most popular one known as filtered back projection. In this paper we introduce a Kalman filter technique which is operated in time domain for medical image reconstruction. Results indicated that as the number of projection increases in both normal collected ray sum and the collected ray sum corrupted by noise the quality of reconstructed image becomes better in terms of contract and transparency. It is also seen that as the number of projection increases the error index decreases.

  2. Traditional sorghum beer "ikigage"

    OpenAIRE

    Lyumugabe Loshima, Franc?ois

    2010-01-01

    Samples of traditional sorghum beer Ikigage was collected in the southern province of Rwanda and analyzed for microbiological and physico-chemical contents. Ikigage contained total aerobic mesophilic bacteria (33.55 x 106 cfu/ml), yeast (10.15 x 106 cfu/ml), lactic acid bacteria (35.35 x 104 cfu/ml), moulds (4.12 x 104 cfu/ml), E. coli (21.90 x 103 cfu/ml), fecal streptococci (22.50 x 103 cfu/ml), Staphylococcus aureus (16.02 x 103 cfu/ml), total coliform (32.30 x 103 cfu/ml), eth...

  3. In the Dirac tradition

    International Nuclear Information System (INIS)

    It was Paul Dirac who cast quantum mechanics into the form we now use, and many generations of theoreticians openly acknowledge his influence on their thinking. When Dirac died in 1984, St. John's College, Cambridge, his base for most of his lifetime, instituted an annual lecture in his memory at Cambridge. The first lecture, in 1986, attracted two heavyweights - Richard Feynman and Steven Weinberg. Far from using the lectures as a platform for their own work, in the Dirac tradition they presented stimulating material on deep underlying questions

  4. HEPA Filter Performance under Adverse Conditions

    International Nuclear Information System (INIS)

    This study involved challenging nuclear grade high-efficiency particulate air (HEPA) filters under a variety of conditions that can arise in Department of Energy (DOE) applications such as: low or high RH, controlled and uncontrolled challenge, and filters with physically damaged media or seals (i.e., leaks). Reported findings correlate filter function as measured by traditional differential pressure techniques in comparison with simultaneous instrumental determination of up and down stream PM concentrations. Additionally, emission rates and failure signatures will be discussed for filters that have either failed or exceeded their usable lifetime. Significant findings from this effort include the use of thermocouples up and down stream of the filter housing to detect the presence of moisture. Also demonstrated in the moisture challenge series of tests is the effect of repeated wetting of the filter. This produces a phenomenon referred to as transient failure before the tensile strength of the media weakens to the point of physical failure. An evaluation of the effect of particle size distribution of the challenge aerosol on loading capacity of filters is also included. Results for soot and two size distributions of KCl are reported. Loading capacities for filters ranged from approximately 70 g of soot to nearly 900 g for the larger particle size distribution of KCl. (authors)

  5. Evaluation of median filtering after reconstruction with maximum likelihood expectation maximization (ML-EM) by real space and frequency space

    International Nuclear Information System (INIS)

    Maximum likelihood expectation maximization (ML-EM) image quality is sensitive to the number of iterations, because a large number of iterations leads to images with checkerboard noise. The use of median filtering in the reconstruction process allows both noise reduction and edge preservation. We examined the value of median filtering after reconstruction with ML-EM by comparing filtered back projection (FBP) with a ramp filter or ML-EM without filtering. SPECT images were obtained with a dual-head gamma camera. The acquisition time was changed from 10 to 200 (seconds/frame) to examine the effect of the count statistics on the quality of the reconstructed images. First, images were reconstructed with ML-EM by changing the number of iterations from 1 to 150 in each study. Additionally, median filtering was applied following reconstruction with ML-EM. The quality of the reconstructed images was evaluated in terms of normalized mean square error (NMSE) values and two-dimensional power spectrum analysis. Median filtering after reconstruction by the ML-EM method provided stable NMSE values even when the number of iterations was increased. The signal element of the image was close to the reference image for any repetition number of iterations. Median filtering after reconstruction with ML-EM was useful in reducing noise, with a similar resolution achieved by reconstruction with FBP and a ramp filter. Especially in images with poor count statistics, median filtering after reount statistics, median filtering after reconstruction with ML-EM is effective as a simple, widely available method. (author)

  6. Miniature wideband filter based on coupled-line sections and quasi-lumped element resonator

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Krozer, Viktor

    2007-01-01

    A new design of a wideband bandpass filter is proposed, based on coupled-line sections and quasi-lumped element resonator, taking advantage of the last one to introduce two transmission zeros and suppress a spurious response. The proposed filter demonstrates significantly improved characteristics in comparison with traditional coupled-line filter and exhibits a very compact structure.

  7. Robot Visual Servo with Fuzzy Particle Filter

    Directory of Open Access Journals (Sweden)

    Jie Ma

    2012-04-01

    Full Text Available This paper proposes a robot visual servo method with an adaptive particle filter based on fuzzy logic theory to online estimate the total Jacobian matrix of a robot visual servo system. A set of fuzzy rules are used to select appropriate numbers of particles according to the filtering estimation errors. When an estimation error is high more particles are used, and when the estimation error is low fewer particles are used. The visual servo results on a two degree-of-freedom robot system show that the proposed fuzzy adaptive particle filter visual servo method needs less time than that of traditional particle filter visual servo method to get a comparative tracking accuracy.

  8. Mica nuclear track filters

    International Nuclear Information System (INIS)

    Mica nuclear track filters are produced by irradiation of mica with energetic heavy ions and subsequent etching. The properties of these filters and the air through-put up to 3000C are reviewed. At an industrial plant mica filters are used to filter 0C hot waste gas containing radioactive aerosols from the production of reactor fuel elements. After filtration the aerosol particles on the filters are examined by different methods for their properties. (orig.)

  9. Spam filter analysis

    CERN Document Server

    Garcia, F D; Basiuk, Vincent; Becoulet, Alain; Coulon, Jean-Pierre; Garcia, Flavio D.; Hoepman, Jaap-Henk; Hutter, Thierry; Saoutic, Vincent

    2004-01-01

    Unsolicited bulk email (aka. spam) is a major problem on the Internet. To counter spam, several techniques, ranging from spam filters to mail protocol extensions like hashcash, have been proposed. In this paper we investigate the effectiveness of several spam filtering techniques and technologies. Our analysis was performed by simulating email traffic under different conditions. We show that genetic algorithm based spam filters perform best at server level and naive Bayesian filters are the most appropriate for filtering at user level.

  10. Optimal Filter Systems for Photometric Redshift Estimation

    Science.gov (United States)

    Benítez, N.; Moles, M.; Aguerri, J. A. L.; Alfaro, E.; Broadhurst, T.; Cabrera-Caño, J.; Castander, F. J.; Cepa, J.; Cerviño, M.; Cristóbal-Hornillos, D.; Fernández-Soto, A.; González Delgado, R. M.; Infante, L.; Márquez, I.; Martínez, V. J.; Masegosa, J.; Del Olmo, A.; Perea, J.; Prada, F.; Quintana, J. M.; Sánchez, S. F.

    2009-02-01

    In the coming years, several cosmological surveys will rely on imaging data to estimate the redshift of galaxies, using traditional filter systems with 4-5 optical broad bands; narrower filters improve the spectral resolution, but strongly reduce the total system throughput. We explore how photometric redshift performance depends on the number of filters nf , characterizing the survey depth by the fraction of galaxies with unambiguous redshift estimates. For a combination of total exposure time and telescope imaging area of 270 hr m2, 4-5 filter systems perform significantly worse, both in completeness depth and precision, than systems with nf gsim 8 filters. Our results suggest that for low nf the color-redshift degeneracies overwhelm the improvements in photometric depth, and that even at higher nf the effective photometric redshift depth decreases much more slowly with filter width than naively expected from the reduction in the signal-to-noise ratio. Adding near-IR observations improves the performance of low-nf systems, but still the system which maximizes the photometric redshift completeness is formed by nine filters with logarithmically increasing bandwidth (constant resolution) and half-band overlap, reaching ~0.7 mag deeper, with 10% better redshift precision, than 4-5 filter systems. A system with 20 constant-width, nonoverlapping filters reaches only ~0.1 mag shallower than 4-5 filter systems, but has a precision almost three times better, ?z = 0.014(1 + z) versus ?z = 0.042(1 + z). We briefly discuss a practical implementation of such a photometric system: the ALHAMBRA Survey.

  11. Additive filters for LES

    Science.gov (United States)

    Germano, Massimo

    2005-11-01

    In the framework of a research devoted to analyze the algebraic properties of the filtering operators and the possible constraints that they impose on the filtered terms, some recent results concerning the additive filters are presented. These filters are produced by summing two or more generic filters and in a sense they are dual of the product filters that have been usefully employed in the dynamic modeling procedures. In this contribution we present particular additive RANS/LES and RANS/DNS filters and their properties are discussed in detail. As regards the possible applications it is interesting to remark that the associated subgrid stresses are derived by mixing filters, and not by mixing models. As such they seem appropriate to the development of controlled hybrid RANS/LES and RANS/DNS filtering procedures that gradually match different computational zones.

  12. Research of EMCCD image filtering method based on noise detection and fuzzy adaptive median filter

    Science.gov (United States)

    Qi, Lei; Zhang, Wenwen; Chen, Qian; Gu, Guohua; Qian, Yuehong

    2013-12-01

    Traditional median filtering algorithm is mainly designed for stationary noise density, which realizes the image smooth but leads to edge fuzzy. The noise density of Electron Multiplying CCD (EMCCD) image varies with the gain. In this paper, a new noise detection and fuzzy adaptive median filter (NDFAMF) is proposed to overcome such drawbacks. First, the noise pixels in the center of the filter window were identified. Secondly, the thresholds were introduced for the detected "noise points". Based on the thresholds and median of the filtering window, the fuzzy membership function of noise points was put forward, using the fuzzy membership function to filter the noise points. Finally, according to the density of noise in the filtering window the filtering window can change the size adaptive. Simulation and experimental results show that the new algorithm is able to remove noise pixels effectively and protect the details well in the image. The performance is better than the other median filters under the condition of low noise density and relatively stable under the condition of high noise density.

  13. Fuzzy Based Median Filtering for Removal of Salt-and-Pepper Noise

    OpenAIRE

    Bhavana Deshpande; Verma, H. K.; Prachi Deshpande

    2012-01-01

    This paper presents a filter for restoration of images that are highly corrupted by salt and pepper noise. By incorporating fuzzy logic after detecting and correcting the noisy pixel, the proposed filter is able to suppress noise and preserve details across a wide range of salt and pepper noise corruption, ranging from 1% to 60%. The proposed filter is tested on different images and is found to produce better results than the Traditional Median Filter.

  14. Fuzzy Adaptive Interacting Multiple Model Nonlinear Filter for Integrated Navigation Sensor Fusion

    OpenAIRE

    Dah-Jing Jwo; Chih-Wen Chang; Chien-Hao Tseng

    2011-01-01

    In this paper, the application of the fuzzy interacting multiple model unscented Kalman filter (FUZZY-IMMUKF) approach to integrated navigation processing for the maneuvering vehicle is presented. The unscented Kalman filter (UKF) employs a set of sigma points through deterministic sampling, such that a linearization process is not necessary, and therefore the errors caused by linearization as in the traditional extended Kalman filter (EKF) can be avoided. The nonlinear filters naturally suff...

  15. Design and realisation of star-geometry dual-mode bandpass filter

    Science.gov (United States)

    Shen, S.; Ramer, R.; Banciu, M. G.; Mansour, R. R.

    2005-11-01

    A design of a planar dual-mode filter is proposed and developed for satellite and wireless communication systems. The novelty of the proposed structure consists of replacing simple diagonal design with a starlike one. This offers the ability of controlling the central frequency and the bandwidth. The filter was implemented on Rogers substrate with 10.8 dielectric constant. The proposed filter structure is 37% smaller in size in comparison with traditional dual mode filters.

  16. HEPA Filter Vulnerability Assessment

    International Nuclear Information System (INIS)

    This assessment of High Efficiency Particulate Air (HEPA) filter vulnerability was requested by the USDOE Office of River Protection (ORP) to satisfy a DOE-HQ directive to evaluate the effect of filter degradation on the facility authorization basis assumptions. Within the scope of this assessment are ventilation system HEPA filters that are classified as Safety-Class (SC) or Safety-Significant (SS) components that perform an accident mitigation function. The objective of the assessment is to verify whether HEPA filters that perform a safety function during an accident are likely to perform as intended to limit release of hazardous or radioactive materials, considering factors that could degrade the filters. Filter degradation factors considered include aging, wetting of filters, exposure to high temperature, exposure to corrosive or reactive chemicals, and exposure to radiation. Screening and evaluation criteria were developed by a site-wide group of HVAC engineers and HEPA filter experts from published empirical data. For River Protection Project (RPP) filters, the only degradation factor that exceeded the screening threshold was for filter aging. Subsequent evaluation of the effect of filter aging on the filter strength was conducted, and the results were compared with required performance to meet the conditions assumed in the RPP Authorization Basis (AB). It was found that the reduction in filter strength due to aging does not affect the filter performance requirements as specified in the AB. A portion of the HEPA filter vulnerability assessment is being conducted by the ORP and is not part of the scope of this study. The ORP is conducting an assessment of the existing policies and programs relating to maintenance, testing, and change-out of HEPA filters used for SC/SS service. This document presents the results of a HEPA filter vulnerability assessment conducted for the River protection project as requested by the DOE Office of River Protection

  17. SAW Filter Performance Improvement

    Directory of Open Access Journals (Sweden)

    Monali R. Dave

    2012-01-01

    Full Text Available Surface acoustic wave (SAW filters have a widerange of applications, including, for example, inmobile/wireless transceivers, radio frequency (RF filters,intermediate frequency (IF filters, resonator-filters, filtersfor mobile and wireless circuits, IF filters in a basetransceiver station (BTS, RF front-end filtersfor mobile/wireless circuitry, multimode frequencyagile oscillators for spread-spectrum securecommunications, nyquist filters for microwave digitalradio, voltage controlled oscillators for first or second stagemixing in mobile transceivers, delay lines for low powertime-diversity wireless receivers, pseudo-noise-coded delaylines for combined code division multiple access/timedivision multiple access (CDMA/TDMA access, clockrecovery filters for fiber-opticscommunication repeater stages, synchronous, spreadspectrum communications, televisions, videorecorders, and many other applications. SAW filters arealso finding increasing use as picture-signal intermediatefrequency (PIF filters, vestigial sideband (VSB filters, andother types of communication filters, and as filters fordigital signal processing [1]. It is, however, supported and leadby various technologies of publiccommunication systems such as fiber optics, digital microwaveand satellites. Various custom SAW devices for publiccommunication systems have been already widely used andstill progress [2].This paper describes various methods to minimize some of thedistortions in SAW filter. It includes bulk wave distortion andfeed through distortion.

  18. The Hausa Lexicographic Tradition

    Directory of Open Access Journals (Sweden)

    Roxana Ma Newman

    2011-10-01

    Full Text Available

    Abstract: Hausa, a major language of West Africa, is one of the most widely studied languagesof Sub-Saharan Africa. It has a rich lexicographic tradition dating back some two centuries. Sincethe first major vocabulary published in 1843 up to the present time, almost 60 lexicographic works— dictionaries, vocabularies, glossaries — have been published, in a range of metalanguages, fromEnglish to Hausa itself. This article traces the historical development of the major studies accordingto their type and function as general reference works, specialized works, pedagogical works, andterminological works. For each work, there is a general discussion of its size, accuracy of the phonological,lexical, and grammatical information, and the adequacy of its definitions and illustrativematerial. A complete list of the lexicographic works is included.

    Keywords: ARABIC, BILINGUAL LEXICOGRAPHY, DIALECTAL VARIANTS, DICTIONARIES,ENGLISH, ETYMOLOGIES, FRENCH, GERMAN, GLOSSARIES, GRAMMATICALCATEGORIES, HAUSA, LANGUAGE LEARNING, LOANWORDS, NEOLOGISMS, NIGER,NIGERIA, ORTHOGRAPHY, PHONETIC TRANSCRIPTION, PHONOLOGY, RUSSIAN, STANDARDDIALECT, STANDARDIZATION, TERMINOLOGY, VOCABULARIES, WEST AFRICA.

    Opsomming: Die leksikografiese tradisie in Hausa. Hausa, 'n belangrike taal vanWes-Afrika, is een van die tale van Afrika suid van die Sahara wat die wydste bestudeer word. Dithet 'n ryk leksikografiese tradisie wat ongeveer twee eeue oud is. Van die eerste groot woordeboekwat in 1843 gepubliseer is tot die hede is ongeveer 60 leksikografiese werke — woordeboeke,naamlyste, woordelyste — gepubliseer in 'n reeks metatale van Engels tot Hausa self. Hierdie artikelgaan die historiese ontwikkeling van die groter studies aan die hand van hulle tipe en funksieas algemene naslaanwerke, gespesialiseerde werke, opvoedkundige werke, en terminologiesewerke na. Vir elke werk is daar 'n algemene bespreking oor sy grootte, akkuraatheid van die fonologiese,leksikale en grammatikale inligting, en die toereikendheid van sy definisies en illustratiewemateriaal. 'n Volledige lys van die leksikografiese werke is ingesluit.

    Sleutelwoorde: AANLEER VAN TAAL, ARABIES, DIALEKTIESE VARIANTE, DUITS,ENGELS, ETIMOLOGIEË, FONETIESE TRANSKRIPSIE, FONOLOGIE, FRANS, GRAMMATIESEKATEGORIEË, HAUSA, LEENWOORDE, NAAMLYSTE, NEOLOGISMES, NIGER,NIGERIË, ORTOGRAFIE, RUSSIES, STANDAARDDIALEK, STANDAARDISERING,

  19. A FUZZY FILTERING MODEL FOR CONTOUR DETECTION

    OpenAIRE

    Rajakumar, T. C.; Arumuga Perumal, S.; Krishnan, N.

    2011-01-01

    Contour detection is the basic property of image processing. Fuzzy Filtering technique is proposed to generate thick edges in two dimensional gray images. Fuzzy logic is applied to extract value for an image and is used for object contour detection. Fuzzy based pixel selection can reduce the drawbacks of conventional methods(Prewitt, Robert). In the traditional methods, filter mask is used for all kinds of images. It may succeed in one kind of image but fail in another one. In this frame work...

  20. Basalt Fiber Based Filters

    International Science & Technology Center (ISTC)

    Development of Highly Effective Filtering Systems on the Basis of a Super-Thin Basalt Fiber for Radioactive Aerosols Purification and Creation of a Work Cycle for Filters Manufacturig with the Purpose of Their Operation at the Nuclear Power Plants

  1. Bag filters for TPP

    Energy Technology Data Exchange (ETDEWEB)

    L.V. Chekalov; Yu.I. Gromov; V.V. Chekalov [JSC ' Kondor-Eko,' Yaroslavl' Oblast' (Russian Federation)

    2007-05-15

    Cleaning of TPP flue gases with bag filters capable of pulsed regeneration is examined. A new filtering element with a three-dimensional filtering material formed from a needle-broached cloth in which the filtration area, as compared with a conventional smooth bag, is increased by more than two times, is proposed. The design of a new FRMI type of modular filter is also proposed. A standard series of FRMI filters with a filtration area ranging from 800 to 16,000 m{sup 2} is designed for an output more than 1 million m{sub 3}/h of with respect to cleaned gas. The new bag filter permits dry collection of sulfur oxides from waste gases at TPP operating on high-sulfur coals. The design of the filter makes it possible to replace filter elements without taking the entire unit out of service.

  2. Simon-nitinol filter

    International Nuclear Information System (INIS)

    This paper discusses a filter that exploits the thermal shape-memory properties of the nitinol alloy to achieve an optimized filter shape and a fine-bore introducer. Experimental methods and materials are given and results are analyzed

  3. MST Filterability Tests

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Duignan, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-03-12

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO2, and NaNO3) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

  4. Filter service system

    Science.gov (United States)

    Sellers, Cheryl L. (Peoria, IL); Nordyke, Daniel S. (Arlington Heights, IL); Crandell, Richard A. (Morton, IL); Tomlins, Gregory (Peoria, IL); Fei, Dong (Peoria, IL); Panov, Alexander (Dunlap, IL); Lane, William H. (Chillicothe, IL); Habeger, Craig F. (Chillicothe, IL)

    2008-12-09

    According to an exemplary embodiment of the present disclosure, a system for removing matter from a filtering device includes a gas pressurization assembly. An element of the assembly is removably attachable to a first orifice of the filtering device. The system also includes a vacuum source fluidly connected to a second orifice of the filtering device.

  5. Optimal filter systems for photometric redshift estimation

    CERN Document Server

    Benítez, N; López-Aguerri, J A; Alfaro, E; Broadhurst, T; Cabrera, J; Castander, F J; Cepa, J; Cerviño, M; Cristobal-Hornillos, D; Fernández-Soto, A; González-Delgado, R M; Infante, L; Márquez, I; Martínez, V J; Masegosa, J; Del Olmo, A; Perea, J; Prada, F; Quintana, J M; Sánchez, S F

    2008-01-01

    In the next years, several cosmological surveys will rely on imaging data to estimate the redshift of galaxies, using traditional filter systems with 4-5 optical broad bands; narrower filters improve the spectral resolution, but strongly reduce the total system throughput. We explore how photometric redshift performance depends on the number of filters n_f, characterizing the survey depth through the fraction of galaxies with unambiguous redshift estimates. For a combination of total exposure time and telescope imaging area of 270 hrs m^2, 4-5 filter systems perform significantly worse, both in completeness depth and precision, than systems with n_f >= 8 filters. Our results suggest that for low n_f, the color-redshift degeneracies overwhelm the improvements in photometric depth, and that even at higher n_f, the effective photometric redshift depth decreases much more slowly with filter width than naively expected from the reduction in S/N. Adding near-IR observations improves the performance of low n_f syste...

  6. Dual filtered backprojection for micro-rotation confocal microscopy

    International Nuclear Information System (INIS)

    Micro-rotation confocal microscopy is a novel optical imaging technique which employs dielectric fields to trap and rotate individual cells to facilitate 3D fluorescence imaging using a confocal microscope. In contrast to computed tomography (CT) where an image can be modelled as parallel projection of an object, the ideal confocal image is recorded as a central slice of the object corresponding to the focal plane. In CT, the projection images and the 3D object are related by the Fourier slice theorem which states that the Fourier transform of a CT image is equal to the central slice of the Fourier transform of the 3D object. In the micro-rotation application, we have a dual form of this setting, i.e. the Fourier transform of the confocal image equals the parallel projection of the Fourier transform of the 3D object. Based on the observed duality, we present here the dual of the classical filtered back projection (FBP) algorithm and apply it in micro-rotation confocal imaging. Our experiments on real data demonstrate that the proposed method is a fast and reliable algorithm for the micro-rotation application, as FBP is for CT application

  7. Traditional Smallpox Vaccines and Atopic Dermatitis

    Science.gov (United States)

    Traditional Smallpox Vaccines and Atopic Dermatitis Frequently Asked Questions What is the traditional smallpox vaccine? The traditional smallpox vaccine is made from a virus called vaccinia, which ...

  8. Modern calorimetry: going beyond tradition

    OpenAIRE

    Jeong, Y. H.

    2001-01-01

    Calorimetry has been a traditional tool for obtaining invaluable thermodynamic information of matter, the free energy. We describe recent efforts to go beyond this traditional calorimetry: After introducing dynamic heat capacity, we present the various experimental methods to measure it. Applications and future prospects are also given.

  9. Bringing Traditional Teachings to Leadership

    Science.gov (United States)

    Washington, Siemthlut Michelle

    2005-01-01

    The purpose of this article is to examine how our Kootegan Yix Meh Towlth (traditional governance) might contribute to the development and implementation of a culturally relevant Sliammon governance model. Our Uk woom he heow (ancestors) lived their everyday lives guided by a complex system of practices and beliefs based on our Ta-ow (traditional

  10. Experimental validation of a single shaped filter approach for CT using variable source-to-filter distance for examination of arbitrary object diameters.

    Science.gov (United States)

    Lück, Ferdinand; Kolditz, Daniel; Hupfer, Martin; Steiding, Christian; Kalender, Willi A

    2014-10-01

    The purpose of this study was to validate the use of a single shaped filter (SF) for computed tomography (CT) using variable source-to-filter distance (SFD) for the examination of different object diameters.A SF was designed by performing simulations with the purpose of achieving noise homogeneity in the reconstructed volume and dose reduction for arbitrary phantom diameters. This was accomplished by using a filter design method thats target is to achieve a homogeneous detector noise, but also uses a correction factor for the filtered back projection process. According to simulation results, a single SF designed for one of the largest phantom diameters meets the requirements for all diameters when SFD can be adjusted. To validate these results, a SF made of aluminium alloy was manufactured. Measurements were performed on a CT scanner with polymethyl methacrylate (PMMA) phantoms of diameters from 40-100?mm. The filter was positioned at SFDs ranging from 97-168?mm depending on the phantom diameter. Image quality was evaluated for the reconstructed volume by assessing CT value accuracy, noise homogeneity, contrast-to-noise ratio weighted by dose (CNRD) and spatial resolution. Furthermore, scatter distribution was determined with the use of a beam-stop phantom. Dose was measured for a PMMA phantom with a diameter of 100?mm using a calibrated ionization chamber.The application of a single SF at variable SFD led to improved noise uniformity and dose reduction: noise homogeneity was improved from 15% down to about 0%, and dose was reduced by about 37%. Furthermore, scatter dropped by about 32%, which led to reduced cupping artifacts and improved CT value accuracy. Spatial resolution and CNRD was not affected by the SF.By means of a single SF with variable SFD designed for CT, significant dose reduction can be achieved and image quality can be improved by reducing noise inhomogeneity as well as scatter-induced artifacts. PMID:25198916

  11. Changing ventilation filters

    International Nuclear Information System (INIS)

    A filter changing unit has a door which interlocks with the door of a filter chamber so as to prevent contamination of the outer surfaces of the doors by radioactive material collected on the filter element and a movable support which enables a filter chamber thereonto to be stored within the unit in such a way that the doors of the unit and the filter chamber can be replaced. The door pivots and interlocks with another door by means of a bolt, a seal around the periphery lip of the first door engages the periphery of the second door to seal the gap. A support pivots into a lower filter element storage position. Inspection windows and glove ports are provided. The unit is releasably connected to the filter chamber by bolts engaging in a flange provided around an opening. (author)

  12. An LLCL Power Filter for Single-Phase Grid-Tied Inverter

    DEFF Research Database (Denmark)

    Wu, Weimin; He, Yuanbin

    2012-01-01

    This paper presents a new topology of higher order power filter for grid-tied voltage-source inverters, named the LLCL filter, which inserts a small inductor in the branch loop of the capacitor in the traditional LCL filter to compose a series resonant circuit at the switching frequency. Particularly, it can attenuate the switching-frequency current ripple components much better than an LCL filter, leading to a decrease in the total inductance and volume. Furthermore, by decreasing the inductance of a grid-side inductor, it raises the characteristic resonance frequency, which is beneficial to the inverter system control. The parameter design criteria of the proposed LLCL filter is also introduced. The comparative analysis and discussions regarding the traditional LCL filter and the proposed LLCL filter have been presented and evaluated through experiment on a 1.8-kW-single-phase grid-tied inverter prototype.

  13. Invariant texture segmentation via circular gabor filter

    OpenAIRE

    Zhang, JianGuo; Tan, Tieniu

    2002-01-01

    In this paper, we focus on invariant texture segmentation, and propose a new method using circular Gabor filters (CGF) for rotation invariant texture segmentation. The traditional Gabor function is modified into a circular symmetric version. The rotation invariant texture features are achieved via the channel output of the CGF. A new scheme of the selection of Gabor parameters is also proposed for texture segmentation. Experiments show the efficacy of this method

  14. Aurorae in Australian Aboriginal Traditions

    CERN Document Server

    Hamacher, Duane W

    2013-01-01

    Transient celestial phenomena feature prominently in the astronomical knowledge and traditions of Aboriginal Australians. In this paper, I collect accounts of the Aurora Australis from the literature regarding Aboriginal culture. Using previous studies of meteors, eclipses, and comets in Aboriginal traditions, I anticipate that the physical properties of aurora, such as their generally red colour as seen from southern Australia, will be associated with fire, death, blood, and evil spirits. The survey reveals this to be the case and also explores historical auroral events in Aboriginal cultures, aurorae in rock art, and briefly compares Aboriginal auroral traditions with other global indigenous groups, including the Maori of New Zealand.

  15. Spatial filtering efficiency of monostatic biaxial lidar: analysis and applications

    OpenAIRE

    Agishev, Ravil R.; Comero?n Tejero, Adolfo

    2002-01-01

    Results of lidar modeling based on spatial-angular filtering efficiency criteria are presented. Their analysis shows that the low spatial-angular filtering efficiency of traditional visible and near-infrared systems is an important cause of low signal background-radiation ratio SBR at the photodetector input. The low SBR may be responsible for considerable measurement errors and ensuing the low accuracy of the retrieval of atmospheric optical parameters. As shown, the most effec...

  16. A New Approach for Cluster Based Collaborative Filters

    OpenAIRE

    R. Venu Babu,; K. Srinivas,; Anjali Devi, S.

    2010-01-01

    In modern E-Commerce it is not easy for customers to find the best suitable goods of their interest as more and more information is placed on line (like movies, audios, books, documents etc...). So in order to provide most suitable information of high value to customers of an e-commerce business system, a customized recommender system is required. Collaborative Filtering has become a popular technique for reducing this information overload. While traditional collaborative filtering systems ha...

  17. Market Risk Beta Estimation using Adaptive Kalman Filter

    OpenAIRE

    Atanu Das,; Tapan Kumar Ghoshal

    2010-01-01

    Market risk of an asset or portfolio is recognized through beta in Capital Asset Pricing Model (CAPM). Traditional estimation techniques emerge poor results when beta in CAPM assumed to be dynamic and follows auto regressive model. Kalman Filter (KF) can optimally estimate dynamic beta where measurement noise covariance and state noise covariance are assumed to be known in a state-space framework. This paper applied Adaptive Kalman Filter (AKF) for beta estimation when the above covariances a...

  18. Ultra accurate collaborative information filtering via directed user similarity

    OpenAIRE

    Guo, Qiang; Song, Wen-jun; Liu, Jian-guo

    2014-01-01

    A key challenge of the collaborative filtering (CF) information filtering is how to obtain the reliable and accurate results with the help of peers' recommendation. Since the similarities from small-degree users to large-degree users would be larger than the ones opposite direction, the large-degree users' selections are recommended extensively by the traditional second-order CF algorithms. By considering the users' similarity direction and the second-order correlations to d...

  19. Sensory Pollution from Bag Filters, Carbon Filters and Combinations

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Clausen, Geo

    2008-01-01

    Used ventilation filters are a major source of sensory pollutants in air handling systems. The objective of the present study was to evaluate the net effect that different combinations of filters had on perceived air quality after 5 months of continuous filtration of outdoor suburban air. A panel of 32 subjects assessed different sets of used filters and identical sets consisting of new filters. Additionally, filter weights and pressure drops were measured at the beginning and end of the operation period. The filter sets included single EU5 and EU7 fiberglass filters, an EU7 filter protected by an upstream pre-filter (changed monthly), an EU7 filter protected by an upstream activated carbon (AC) filter, and EU7 filters with an AC filter either downstream or both upstream and downstream. In addition, two types of stand-alone combination filters were evaluated: a bag-type fiberglass filter that contained AC and a synthetic fiber cartridge filter that contained AC. Air that had passed through used filters was most acceptable for those sets in which an AC filter was used downstream of the particle filter. Comparable air quality was achieved with the stand-alone bag filter that contained AC. Furthermore, its pressure drop changed very little during the 5 months of service, and it had the added benefit of removing a large fraction of ozone from the airstream. If similar results are obtained over a wider variety of soiling conditions, such filters may be a viable solution to a long recognized problem.

  20. Bibliography on African Traditional Religion

    Science.gov (United States)

    Isizoh, Chidi Denis.

    Compiled by Chidi Denis Isizoh, this bibliography contains books, journal articles, and selections from larger works that focus on traditional religions in Africa. Citations include items in French and German as well as English.

  1. Complex Hilbert Transform Filter

    Directory of Open Access Journals (Sweden)

    Hannu Olkkonen

    2011-05-01

    Full Text Available Hilbert transform is a basic tool in constructing analytical signals for a various applications such as amplitude modulation, envelope and instantaneous frequency analysis, quadrature decoding, shift-invariant multi-rate signal processing and Hilbert-Huang decomposition. This work introduces a complex Hilbert transform (CHT filter, where the real and imaginary parts are a Hilbert transform pair. The CHT filtered signal is analytic, i.e. its Fourier transform is zero in negative frequency range. The CHT filter is constructed by half-sample delay operators based on the B-spline transform interpolation and decimation procedure. The CHT filter has an ideal phase response and the magnitude response is maximally flat in the frequency range 0 ? ? ? ?. The CHT filter has integer coefficients and the implementation in VLSI requires only summations and register shifts. We demonstrate the feasibility of the CHT filter in reconstruction of the sign modulated CMOS logic pulses in a fibre optic link.

  2. Preaching in the Lutheran Tradition

    DEFF Research Database (Denmark)

    Lorensen, Marlene Ringgaard

    2010-01-01

      Preaching in the Lutheran tradition The ministry of preaching has traditionally been regarded as the most important characteristic - the sine qua non - of the Lutheran church. Luther characterized preaching as an indispensable means of grace, regarding it central to the church liturgy.  Contemporary Lutheran preachers, however, often find themselves in a dilemma trying to integrate traditional Lutheran ideals with contemporary practical experiences of preaching. The following portrait of preaching in the Lutheran tradition is written from the perspective of the Lutheran Evangelical Church of Denmark. On one hand there is a strong reformed emphasis on the belief that Preadicatio verbi dei est verbum dei - The preaching of the Word of God is the Word of God. On the other hand the majority of preachers cannot easily make themselves advocates for continuing the category, "Word of God", as a homiletical basis. The dialectical theology's attempt of reviving the category, in the middle of the 20th century, led homiletics into too grave difficulties and has been accused of great co-responsibility for the drying out of the church's preaching tradition. The claim that preaching is the Word of God has, in the opinion of many preachers and homileticians, led to too much listener-immune, monological preaching. Yet, Although most preachers struggle to identify with a traditional high homiletics, the continuing study of Luther within Danish theology contributes to a continued consciousness among preachers about the belief that proclamation demands to be understood somehow as the "Word of God".   Udgivelsesdato: October

  3. Kernel Monte Carlo Filter

    OpenAIRE

    Kanagawa, Motonobu; Nishiyama, Yu; Gretton, Arthur; Fukumizu, Kenji

    2013-01-01

    Filtering methods for state-space models have been successfully applied to a wide range of applications. However, standard methods assume that the observation model is explicitly known, at least in a parametric form. This can be a problem for tasks where the observation model cannot be easily obtained. This paper proposes a filtering method for such situations based on the recent nonparametric framework of RKHS embeddings. The proposed kernel Monte Carlo filter combines Mont...

  4. Algorithms for XML filtering

    OpenAIRE

    Silvasti, Panu

    2011-01-01

    In a publish-subscribe system based on XML filtering, the subscriber profiles are usually specified by filters written in the XPath language. The system processes the stream of XML documents and delivers to subscribers a notification or the content of those documents that match the filters. The number of interested subscribers and their stored profiles can be very large, thousands or even millions. In this case, the scalability of the system is critical. In this thesis, we develop severa...

  5. Variational Bayesian Filtering.

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav; Quinn, A.

    2008-01-01

    Ro?. 56, ?. 10 (2008), s. 5020-5030. ISSN 1053-587X R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : Bayesian filtering * particle filtering * Variational Bayes Subject RIV: BC - Control Systems Theory Impact factor: 2.335, year: 2008 http://library.utia.cas.cz/separaty/2008/AS/smidl-variational bayesian filtering.pdf

  6. Creating Filtered, Translated Newsfeeds

    OpenAIRE

    Linn Marks Collins; Martinez, Mark L. B.; Powell, James E.

    2010-01-01

    Google Translate's API creates the possibility to leverage machine translation to both filter global newsfeeds for content regarding a specific topic, and to aggregate filtered feed items as a newsfeed. Filtered items can be translated so that the resulting newsfeed can provide basic information about topic-specific news articles from around the globe in the desired language of the consumer. This article explores a possible solution for inputting alternate words and phrases in the user’s na...

  7. Spam filter analysis

    OpenAIRE

    Garcia, Flavio D.; Hoepman, Jaap-henk

    2004-01-01

    Unsolicited bulk email (aka. spam) is a major problem on the Internet. To counter spam, several techniques, ranging from spam filters to mail protocol extensions like hashcash, have been proposed. In this paper we investigate the effectiveness of several spam filtering techniques and technologies. Our analysis was performed by simulating email traffic under different conditions. We show that genetic algorithm based spam filters perform best at server level and naive Bayesian...

  8. Spot- Zombie Filtering System

    OpenAIRE

    Arathy Rajagopal; B. Geethanjali; Arulprakash. P

    2014-01-01

    A major security challenge on the Internet is the existence of the large number of compromised machines. Such machines have been increasingly used to launch various security attacks including spamming and spreading malware, DDoS, and identity theft. These compromised machines are called “Zombies”. In general E-mail applications and providers uses spam filters to filter the spam messages. Spam filtering is a technique for discriminating the genuine message from the spam message...

  9. Practical alarm filtering

    International Nuclear Information System (INIS)

    An expert system-based alarm filtering method is described which prioritizes and reduces the number of alarms facing an operator. This patented alarm filtering methodology was originally developed and implemented in a pressurized water reactor, and subsequently in a chemical processing facility. Both applications were in LISP and both were successful. In the chemical processing facility, for instance, alarm filtering reduced the quantity of alarm messages by 90%. 6 figs

  10. Nanofiber Filters Eliminate Contaminants

    Science.gov (United States)

    2009-01-01

    With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water filter media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water filter, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water filters, Argonide now produces large-scale nanofiber filters used as part of the reverse osmosis process for industrial water purification.

  11. Filters in nuclear facilities

    International Nuclear Information System (INIS)

    The topics of the nine papers given include the behavior of HEPA filters during exposure to air flows of high humidity as well as of high differential pressure, the development of steel-fiber filters suitable for extreme operating conditions, and the occurrence of various radioactive iodine species in the exhaust air from boiling water reactors. In an introductory presentation the German view of the performance requirements to be met by filters in nuclear facilities as well as the present status of filter quality assurance are discussed. (orig.)

  12. FPGA BASED FIR FILTER

    Directory of Open Access Journals (Sweden)

    SUVARNA JOSHI,

    2010-12-01

    Full Text Available This paper gives brief overview of the basic structure and hardware characteristics of the Finite Impulse Response (FIR digital filter.FIR filter has been designed efficiently using matlab and implemented on Field Programmable Gate Array (FPGA platform. MATLAB FDATool has been used to determine filter coefficients and 4th order 32 bit filter has been prototyped. The design has been prototyped on an XC3S500- 4FG320 in Spartan-3E Platform using Integrated Synthesis Environment (ISE 9.1/10.1 Tools all in one design suit from Xilinx.

  13. FPGA BASED FIR FILTER

    OpenAIRE

    SUVARNA JOSHI,; BHARATI AINAPURE

    2010-01-01

    This paper gives brief overview of the basic structure and hardware characteristics of the Finite Impulse Response (FIR) digital filter.FIR filter has been designed efficiently using matlab and implemented on Field Programmable Gate Array (FPGA) platform. MATLAB FDATool has been used to determine filter coefficients and 4th order 32 bit filter has been prototyped. The design has been prototyped on an XC3S500- 4FG320 in Spartan-3E Platform using Integrated Synthesis Environment (ISE) 9.1/10.1 ...

  14. Paul Rodgersi filter Kohilas

    Index Scriptorium Estoniae

    2000-01-01

    28. I Kohila keskkoolis kohaspetsiifiline skulptuur ja performance "Filter". Kooli 130. aastapäeva tähistava ettevõtmise eesotsas oli skulptor Paul Rodgers ja kaks viimase klassi noormeest ? Marko Heinmäe, Hendrik Karm.

  15. Distortion Parameters Analysis Method Based on Improved Filtering Algorithm

    Directory of Open Access Journals (Sweden)

    ZHANG Shutuan

    2013-10-01

    Full Text Available In order to realize the accurate distortion parameters test of aircraft power supply system, and satisfy the requirement of corresponding equipment in the aircraft, the novel power parameters test system based on improved filtering algorithm is introduced in this paper. The hardware of the test system has the characters of s portable and high-speed data acquisition and processing, and the software parts utilize the software Labwindows/CVI as exploitation software, and adopt the pre-processing technique and adding filtering algorithm. Compare with the traditional filtering algorithm, the test system adopted improved filtering algorithm can help to increase the test accuracy. The application shows that the test system with improved filtering algorithm can realize the accurate test results, and reach to the design requirements.  

  16. Ceramic filters for bulk inoculation of nickel alloy castings

    Directory of Open Access Journals (Sweden)

    F. Binczyk

    2011-07-01

    Full Text Available The work includes the results of research on production technology of ceramic filters which, besides the traditional filtering function, playalso the role of an inoculant modifying the macrostructure of cast nickel alloys. To play this additional role, filters should demonstratesufficient compression strength and ensure proper flow rate of liquid alloy. The role of an inoculant is played by cobalt aluminateintroduced to the composition of external coating in an amount from 5 to 10 wt.% . The required compression strength (over 1MPa isprovided by the supporting layers, deposited on the preform, which is a polyurethane foam. Based on a two-level fractional experiment24-1, the significance of an impact of various technological parameters (independent variables on selected functional parameters of theready filters was determined. Important effect of the number of the supporting layers and sintering temperature of filters after evaporationof polyurethane foam was stated.

  17. An Amplitude Spectral Capon Estimator with a Variable Filter Length

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Smaragdis, Paris

    2012-01-01

    The filter bank methods have been a popular non-parametric way of computing the complex amplitude spectrum. So far, the length of the filters in these filter banks has been set to some constant value independently of the data. In this paper, we take the first step towards considering the filter length as an unknown parameter. Specifically, we derive a very simple and approximate way of determining the optimal filter length in a data-adaptive way. Based on this analysis, we also derive a model averaged version of the forward and the forward-backward amplitude spectral Capon estimators. Through simulations, we show that these estimators significantly improve the estimation accuracy compared to the traditional Capon estimators.

  18. Educational technology and the traditional lecture

    Directory of Open Access Journals (Sweden)

    Gabriel Jacobs

    1994-12-01

    Full Text Available I was recently invited to give a lecture at the opening of a new high-technology lecture theatre at Leeds Metropolitan University. It is one of the best examples of its kind I have seen. Its impressive features include hi-fi surround sound, an enormous back-projected screen giving superb picture quality from either a VCR or directly from a computer for live demonstrations, online facilities, the latest remote-control slide-projection equipment, complete lecturer's control panel, and several nice touches such as automatic dimming of the auditorium lights when Play is pressed on any of the hidden video playback machines. The overhead projectors and their screens are of the best quality and correctly positioned for the clearest possible display. There are also video-link facilities for spill-over into a secondary lecture theatre which itself is well fitted out in presentational equipment.

  19. Traditional botanical medicine: an introduction.

    Science.gov (United States)

    Rosenbloom, Richard A; Chaudhary, Jayesh; Castro-Eschenbach, Diane

    2011-01-01

    The role of traditional medicine in the well-being of mankind has certainly journeyed a long way. From an ancient era, in which knowledge was limited to a few traditional healers and dominated by the use of whole plants or crude drugs, the science has gradually evolved into a complete healthcare system with global recognition. Technologic advancements have facilitated traditional science to deliver numerous breakthrough botanicals with potency equivalent to those of conventional drugs. The renewed interest in traditional medicine is mainly attributed to its ability to prevent disease, promote health, and improve quality of life. Despite the support received from public bodies and research organizations, development of botanical medicines continues to be a challenging process. The present article gives a summarized description of the various difficulties encountered in the development and evaluation of botanical drugs, including isolation of active compounds and standardization of plant ingredients. It indicates a future direction of traditional medicine toward evidence-based evaluation of health claims through well-controlled safety and efficacy studies. PMID:21336093

  20. Neutron Beam Filters

    International Nuclear Information System (INIS)

    The purpose of filters is to transmit neutrons with selected energy, while remove unwanted ones from the incident neutron beam. This reduces the background, and the number of spurious. The types of commonly used now-a-day neutron filters and their properties are discussed in the present work. There are three major types of neutron filters. The first type is filter of selective thermal neutron. It transmits the main reflected neutrons from a crystal monochromate, while reject the higher order contaminations accompanying the main one. Beams coming from the moderator always contain unwanted radiation like fast neutrons and gamma-rays which contribute to experimental background and to the biological hazard potential. Such filter type is called filter of whole thermal neutron spectrum. The third filter type is it transmits neutrons with energies in the resonance energy range (En . 1 KeV). The main idea of such neutron filter technique is the use of large quantities of a certain material which have the deep interference minima in its total neutron cross-section. By transmitting reactor neutrons through bulk layer of such material, one can obtain the quasimonochromatic neutron lines instead of white reactor spectrum.

  1. Tunable LYOT-filters

    Science.gov (United States)

    Donkor, Eric; Kumavor, Patrick D.; Villa, Carlos

    2009-05-01

    An all fiber tunable Lyot filter is experimentally demonstrated. The filter can be configured for narrow band or wide band tuning. It is implemented as a Sagnac loop configuration comprised of polarization controllers, birefringent fibers, and a polarizer. Results are present for band stop tuning and narrow band tuning for the wavelengths ranging between 1500nm to 1600nm.

  2. Sintered composite filter

    Science.gov (United States)

    Bergman, W.

    1986-05-02

    A particulate filter medium formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers is described. Preferred composition is about 40 vol.% quartz and about 60 vol.% stainless steel fibers. The media is sintered at about 1100/sup 0/C to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550/sup 0/C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  3. Sub-micron filter

    Science.gov (United States)

    Tepper, Frederick (Sanford, FL); Kaledin, Leonid (Port Orange, FL)

    2009-10-13

    Aluminum hydroxide fibers approximately 2 nanometers in diameter and with surface areas ranging from 200 to 650 m.sup.2/g have been found to be highly electropositive. When dispersed in water they are able to attach to and retain electronegative particles. When combined into a composite filter with other fibers or particles they can filter bacteria and nano size particulates such as viruses and colloidal particles at high flux through the filter. Such filters can be used for purification and sterilization of water, biological, medical and pharmaceutical fluids, and as a collector/concentrator for detection and assay of microbes and viruses. The alumina fibers are also capable of filtering sub-micron inorganic and metallic particles to produce ultra pure water. The fibers are suitable as a substrate for growth of cells. Macromolecules such as proteins may be separated from each other based on their electronegative charges.

  4. Smoke and pollutant filtering device

    International Nuclear Information System (INIS)

    A smoke and pollutant filtering device comprising a mask having a filter composed of a series of contiguous, serial layers of filtering material. The filter consists of front and rear gas permeable covers, a first filter layer of pressed vegetable matter, a second filter layer comprising a layer of activated charcoal adjacent a layer of aqua filter floss, a third filter comprising a gas permeable cloth situated between layers of pressed vegetable matter, and a fourth filter layer comprising an aqua filter floss. The first through fourth filter layers are sandwiched between the front and rear gas permeable covers. The filtering device is stitched together and mounted within a fireretardant hood shaped to fit over a human head. Elastic bands are included in the hood to maintain the hood snugly about the head when worn

  5. Intraindividual evaluation of the influence of iterative reconstruction and filter kernel on subjective and objective image quality in computed tomography of the brain

    International Nuclear Information System (INIS)

    Objectives: To intraindividually evaluate the potential of 4th generation iterative reconstruction (IR) on brain CT with regard to subjective and objective image quality. Methods: 31 consecutive raw data sets of clinical routine native sequential brain CT scans were reconstructed with IR level 0 (= filtered back projection), 1, 3 and 4; 3 different brain filter kernels (smooth/standard/sharp) were applied respectively. Five independent radiologists with different levels of experience performed subjective image rating. Detailed ROI analysis of image contrast and noise was performed. Statistical analysis was carried out by applying a random intercept model. Results: Subjective scores for the smooth and the standard kernels were best at low IR levels, but both, in particular the smooth kernel, scored inferior with an increasing IR level. The sharp kernel scored lowest at IR 0, while the scores substantially increased at high IR levels, reaching significantly best scores at IR 4. Objective measurements revealed an overall increase in contrast-to-noise ratio at higher IR levels, which was highest when applying the soft filter kernel. The absolute grey-white contrast decreased with an increasing IR level and was highest when applying the sharp filter kernel. All subjective effects were independent of the raters' experience and the patients' age and sex. Conclusion: Different combinations of IR level and filter kernel substantially influence subjective and objective image qunfluence subjective and objective image quality of brain CT. (orig.)

  6. Optimal filters on the sphere

    OpenAIRE

    J. D. McEwen; Hobson, M. P.; Lasenby, A. N.

    2006-01-01

    We derive optimal filters on the sphere in the context of detecting compact objects embedded in a stochastic background process. The matched filter and the scale adaptive filter are derived on the sphere in the most general setting, allowing for directional template profiles and filters. The performance and relative merits of the two optimal filters are discussed. The application of optimal filter theory on the sphere to the detection of compact objects is demonstrated on si...

  7. A Reconfigurable FIR Filter System

    Directory of Open Access Journals (Sweden)

    Guosheng Xu

    2013-07-01

    Full Text Available Introduced a practical reconfigurable FIR filter system. According to the filter specialties, the filter coefficients are calculated by the computer. And the configured coefficients of the multistage FIR filter are downloaded to the chip. The filtering computing is completed by the FPGA. All these make virtual value of voltage and current more accurate and steady, so reseach on FIR filter Algorithms is the emphases and difficulty. The performance testing and application examples are given to verify this system.

  8. A Robust Collaborative Filtering Recommendation Algorithm Based on Multidimensional Trust Model

    OpenAIRE

    Dongyan Jia; Fuzhi Zhang; Sai Liu

    2013-01-01

    Collaborative filtering is one of the widely used technologies in the e-commerce recommender systems. It can predict the interests of a user based on the rating information of many other users. But the traditional collaborative filtering recommendation algorithm has the problems such as lower recommendation precision and weaker robustness. To solve these problems, in this paper we present a robust collaborative filtering recommendation algorithm based on multidimensional trust model. Firstly,...

  9. Editorial: Between Tradition and Modernity

    OpenAIRE

    Editor Al-Jami'ah: Journal of Islamic Studies

    2011-01-01

    The relationship between religious ‘tradition’ and ‘modernity’ is a central theme in various academic debates. Of the heatedly debated topic is concerning religious identity in the face of constantly political, economical, and global changes. As with other religious communities, Muslims have to response to these changes, on the one hand, and to the call for preserving their religious identity, on the other. 

  10. Traditional Pricing or Something Else?

    Science.gov (United States)

    Epple, John H.

    1980-01-01

    It is argued tha alternate pricing methods for college textbooks--including net pricing, net billing, and single copy order pricing--would be detrimental to college bookstores. Publishers are urged to continue with the traditional method, and other publisher practices that could help bookstore managers are suggested. (JMD)

  11. Tribal Colleges and Traditional Knowledge.

    Science.gov (United States)

    Deloria, Vine, Jr.

    1993-01-01

    Compares the recent advances of Western science to ancient views of Native American tribes. Indicates that "advances" such as chaos theory and zoopharmacognosy are long-standing elements of Native American traditional knowledge. Suggests that tribal colleges must assert themselves and become the primary symbols of authority on tribal culture. (MAB)

  12. Africanisms in Gullah Oral Tradition.

    Science.gov (United States)

    Holloway, Joseph E.

    1989-01-01

    The Sea Islands off the coast of South Carolina, Georgia, and Northern Florida retain almost every element of African culture, including language, oral tradition, folklore, and aesthetics. Examines the African influence in the lifestyle of the Gullah people of the Sea Islands, especially in terms of their concept of time. (AF)

  13. Fuzzy Stack Filters for Image Processing

    Directory of Open Access Journals (Sweden)

    Cs. Stupak

    1999-06-01

    Full Text Available This paper is oriented to filtering by fuzzy stack filter of monochromatic images distorted with impulsive noise. Fuzzy stack filter is acquired by extension of stack filters by means of fuzzy logic. Adding some parameters to this filter, that are adjusted by neural adaptation algorithm, is obtained the new class of filters, so-called fuzzy rank-order filters. This class of filters is compared with other well known filters as stack filters and neural stack filters.

  14. Property rights and traditional knowledge

    Scientific Electronic Library Online (English)

    JT, Cross.

    Full Text Available For the past several decades, there has been a push to provide some sort of right akin to an intellectual property right in traditional knowledge and traditional cultural expression. This push has encountered staunch resistance from a number of different quarters. Many of the objections are practica [...] l. However, underlying these practical concerns is a core philosophical concern. A system of traditional knowledge rights, this argument suggests, simply does not satisfy the basic rationale for granting property rights in intangibles like inventions and expressive works. Intellectual property is meant to encourage innovation and creative activity. Most traditional knowledge, by contrast, is not innovative, at least in the same sense as the inventions and works that qualify for patents and copyrights. At present, the "anti-property" camp seems to have the better of the argument, as even the World Intellectual Property Organisation has abandoned the notion of true property rights. This article seeks to refute this philosophical objection to a property model for traditional knowledge. It argues that the classic philosophical argument justifying intellectual "property" namely, that property rights are justified only as a way to spur innovation and other creative activity is incorrect in two ways. First, the argument misstates the main goal of an intellectual property system. While intellectual property may serve as an incentive for innovation, society's primary concern is not the innovation per se, but instead the dissemination of knowledge. Second, there may be policy reasons other than the development of knowledge that can justify intellectual property-like rights. The article then applies these observations to the particular question of traditional knowledge and cultural expression. It demonstrates that a system of property rights could be useful in helping to encourage the dissemination of traditional knowledge, even if that knowledge is not "new" in the classic sense. Second, other important social concerns, especially the goal of ensuring accuracy in knowledge, may justify a system of property rights. While these arguments may not ultimately support a property rights system-after all, the practical concerns remain very real-they do help to refute the underlying philosophical objection.

  15. Ceramic fiber reinforced filter

    Science.gov (United States)

    Stinton, David P. (Knoxville, TN); McLaughlin, Jerry C. (Oak Ridge, TN); Lowden, Richard A. (Powell, TN)

    1991-01-01

    A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.

  16. Application of Unscented Kalman Filter for Sonar Signal Processing

    Directory of Open Access Journals (Sweden)

    Leela Kumari. B , Padma Raju.K

    2012-06-01

    Full Text Available State estimation theory is one of the best mathematical approaches to analyze variants in the states of the system or process. The state of the system is defined by a set of variables that provide a complete representation of the internal condition at any given instant of time. Filtering of Random processes is referred to as Estimation, and is a well defined statistical technique. There are two types of state estimation processes, Linear and Nonlinear. Linear estimation of a system can easily be analyzed by using Kalman Filter (KF and is used to compute the target state parameters with a priori information under noisy environment. But the traditional KF is optimal only when the model is linear and its performance is well defined under the assumptions that the system model and noise statistics are well known. Most of the state estimation problems are nonlinear, thereby limiting the practical applications of the KF. The modified KF, aka EKF, Unscented Kalman filter and Particle filter are best known for nonlinear estimates. Extended Kalman filter (EKF is the nonlinear version of the Kalman filter which linearizes about the current mean and covariance. The EKF has been considered the standard in the theory of nonlinear state estimation. Since linear systems do not really exist, a novel transformation is adopted. Unscented Kalman filter and Particle filter are best known nonlinear estimates. The approach in this paper is to analyze the algorithm for maneuvering target tracking using bearing only measurements where UKF provides better probability of state estimation.

  17. Narrowband polarizing interference filter

    Science.gov (United States)

    Ciosek, Jerzy

    1996-08-01

    The article presents the thin-film stack systems creating the new type of optical elements. The said element substitutes a thin-film plane polarizer and narrow-band interference filter simultaneously for selected wavelength. The comparative analysis of the new construction basic parameters was carried out in the function of beam incidence angle on the system with changes of analogical values for classical narrow-band filter. The narrow-band polarization interference filters for (lambda) equals 1064 nm have been designed and made with application of classical vacuum plant with electron guns.

  18. EMI filter design

    CERN Document Server

    Ozenbaugh, Richard Lee

    2011-01-01

    With today's electrical and electronics systems requiring increased levels of performance and reliability, the design of robust EMI filters plays a critical role in EMC compliance. Using a mix of practical methods and theoretical analysis, EMI Filter Design, Third Edition presents both a hands-on and academic approach to the design of EMI filters and the selection of components values. The design approaches covered include matrix methods using table data and the use of Fourier analysis, Laplace transforms, and transfer function realization of LC structures. This edition has been fully revised

  19. Venous Thromboembolism After Removal of Retrievable Inferior Vena Cava Filters

    International Nuclear Information System (INIS)

    The purpose of this study was to examine the incidence of new or recurrent venous thromboembolism (VTE) after retrieval of inferior vena cava (IVC) filters and risk factors associated with such recurrence. Between March 2001 and September 2008, at our institution, implanted retrievable vena cava filters were retrieved in 76 patients. The incidence of new or recurrent VTE after retrieval was reviewed and numerous variables were analyzed to assess risk factors for redevelopment of VTE after filter retrieval. In 5 (6.6%) of the 76 patients, redevelopment or worsening of VTE was seen after retrieval of the filter. Three patients (4.0%) had recurrent deep venous thrombosis (DVT) in the lower extremities and 2 (2.6%) had development of pulmonary embolism, resulting in death. Although there was no significant difference in the incidence of new or recurrent VTE related to any risk factor investigated, a tendency for development of VTE after filter retrieval was higher in patients in whom DVT in the lower extremities had been so severe during filter implantation that interventional radiological therapies in addition to traditional anticoagulation therapies were required (40% in patients with recurrent VTE vs. 23% in those without VTE; p = 0.5866 according to Fisher's exact probability test) and in patients in whom DVT remained at the time of filter retrieval (60% in patients with recurrent VTE vs. 37% in those without VTE; p = 0.3637). In conclusion, new or recurrent VTE was r In conclusion, new or recurrent VTE was rare after retrieval of IVC filters but was most likely to occur in patients who had severe DVT during filter implantation and/or in patients with a DVT that remained at the time of filter retrieval. We must point out that the fatality rate from PE after filter removal was high (2.6%).

  20. Esoteric healing traditions: a conceptual overview.

    Science.gov (United States)

    Levin, Jeff

    2008-01-01

    This paper presents, for the first time, a comprehensive scholarly examination of the history and principles of major traditions of esoteric healing. After a brief conceptual overview of esoteric religion and healing, summaries are provided of eight major esoteric traditions, including descriptions of beliefs and practices related to health, healing, and medicine. These include what are termed the kabbalistic tradition, the mystery school tradition, the gnostic tradition, the brotherhoods tradition, the Eastern mystical tradition, the Western mystical tradition, the shamanic tradition, and the new age tradition. Next, commonalities across these traditions are summarized with respect to beliefs and practices related to anatomy and physiology; nosology and etiology; pathophysiology; and therapeutic modalities. Finally, the implications of this survey of esoteric healing are discussed for clinicians, biomedical researchers, and medical educators. PMID:18316053

  1. An improved cone-beam filtered backprojection reconstruction algorithm based on x-ray angular correction and multiresolution analysis

    International Nuclear Information System (INIS)

    With the extensive application of industrial computed tomography in the field of non-destructive testing, how to improve the quality of the reconstructed image is receiving more and more concern. It is well known that in the existing cone-beam filtered backprojection reconstruction algorithms the cone angle is controlled within a narrow range. The reason of this limitation is the incompleteness of projection data when the cone angle increases. Thus the size of the tested workpiece is limited. Considering the characteristic of X-ray cone angle, an improved cone-beam filtered back-projection reconstruction algorithm taking account of angular correction is proposed in this paper. The aim of our algorithm is to correct the cone-angle effect resulted from the incompleteness of projection data in the conventional algorithm. The basis of the correction is the angular relationship among X-ray source, tested workpiece and the detector. Thus the cone angle is not strictly limited and this algorithm may be used to detect larger workpiece. Further more, adaptive wavelet filter is used to make multiresolution analysis, which can modify the wavelet decomposition series adaptively according to the demand for resolution of local reconstructed area. Therefore the computation and the time of reconstruction can be reduced, and the quality of the reconstructed image can also be improved. (author)

  2. Cleaning an air filter

    International Nuclear Information System (INIS)

    A hydrophobic HEPA air filter partially blocked by small ferric oxide and iron particles, such as arise from the plasma arc cutting of iron or steel, is unblocked by subjecting the filter to a flow of a vapour (which term includes droplets), atomised liquid or solution, aerosol or the like, of such concentration and duration as not to block the filter but to dissolve the oxide, which is redistributed to leave gas-conducting voids when the liquid subsequently dries out. The vapour may be a cold water fog produced by solid carbon dioxide and hot water, or an acid or organic solvent may be used. The unblocked filter may be coated with silane-coated glass spheres to facilitate subsequent filtration. A particular application involves plasma cutting of equipment contaminated with plutonium. (author)

  3. Adaptive digital filters

    CERN Document Server

    Kova?evi?, Branko; Milosavljevi?, Milan

    2013-01-01

    “Adaptive Digital Filters” presents an important discipline applied to the domain of speech processing. The book first makes the reader acquainted with the basic terms of filtering and adaptive filtering, before introducing the field of advanced modern algorithms, some of which are contributed by the authors themselves. Working in the field of adaptive signal processing requires the use of complex mathematical tools. The book offers a detailed presentation of the mathematical models that is clear and consistent, an approach that allows everyone with a college level of mathematics knowledge to successfully follow the mathematical derivations and descriptions of algorithms.   The algorithms are presented in flow charts, which facilitates their practical implementation. The book presents many experimental results and treats the aspects of practical application of adaptive filtering in real systems, making it a valuable resource for both undergraduate and graduate students, and for all others interested in m...

  4. Venting filter for LWR

    International Nuclear Information System (INIS)

    1990 two tests have been done successfully in France at the Fuchia-loop with CsOH loading of metal fiber filters. A filter modul is tested with a back flow to see the effect in the efficiency after such an event. The thermal capability has been testet for the time after the venting process with no cooling gas stream. Downstream of the multistage fiber filter unit a second filter unit is used with a binary doped zeolith as the sorbens for elementary iodine removal. Also methyl iodine is retained. The removal efficiency and the catalytic behaviour with regard to the H2/O2-reaction are indicated. The test methods are described. (orig.)

  5. Metalcasting: Filtering Molten Metal

    International Nuclear Information System (INIS)

    A more efficient method has been created to filter cast molten metal for impurities. Read about the resulting energy and money savings that can accrue to many different industries from the use of this exciting new technology

  6. Radiopasteurization of traditional herbal medicine

    International Nuclear Information System (INIS)

    Investigation on the effects of irradiation using pasteurization dose of 500 krad (5kGy) on microbes contaminating traditional herbal medicine, produced by 3 large manufacturers in Indonesia, was carried out. Storage effects on microbial count moisture content of traditional herbal medicine packed in microbe tight packages, were also observed. The results showed that initial bacterial counts varied between 104 and 108 per gram, and mould and yeast counts varied between 0 and 105 per gram. These numbers decreased as much as 2 to 5 log cycles after irradiation with 500 krad. After 6 month storage, bacterial counts of irradiated samples decreased as much as 0 to 103 per gram. Initial moisture content varied from 5 to 12% and after 6 month storage the moisture content of most samples increased as much as 0 to 5%. Irradiated samples were found to be mould free, and most of the surviving microbes consisted of spore forming aerobic bacteria and yeast. (author)

  7. Ginseng in Traditional Herbal Prescriptions

    OpenAIRE

    Park, Ho Jae; Kim, Dong Hyun; Park, Se Jin; Kim, Jong Min; Ryu, Jong Hoon

    2012-01-01

    Panax ginseng Meyer has been widely used as a tonic in traditional Korean, Chinese, and Japanese herbal medicines and in Western herbal preparations for thousands of years. In the past, ginseng was very rare and was considered to have mysterious powers. Today, the efficacy of drugs must be tested through well-designed clinical trials or meta-analyses, and ginseng is no exception. In the present review, we discuss the functions of ginseng described in historical documents and describe how thes...

  8. Software Development: Agile vs. Traditional

    OpenAIRE

    Stoica, Marian; Mircea, Marinela; Ghilic-micu, Bogdan

    2013-01-01

    Organizations face the need to adapt themselves to a complex business environment, in continuous change and transformation. Under these circumstances, organization agility is a key element in gaining strategic advantages and market success. Achieving and maintaining agility requires agile architectures, techniques, methods and tools, able to react in real time to change requirements. This paper proposes an incursion in the software development, from traditional to agile.

  9. Software Development: Agile vs. Traditional

    Directory of Open Access Journals (Sweden)

    Marian STOICA

    2013-01-01

    Full Text Available Organizations face the need to adapt themselves to a complex business environment, in continuous change and transformation. Under these circumstances, organization agility is a key element in gaining strategic advantages and market success. Achieving and maintaining agility requires agile architectures, techniques, methods and tools, able to react in real time to change requirements. This paper proposes an incursion in the software development, from traditional to agile.

  10. Decadence and the English tradition

    OpenAIRE

    Pittock, Murray.

    1986-01-01

    ?The thesis sets out to do two things. It seeks first of all to describe the revival of interest in the Caroline era which defines the nature of an "English Tradition" in the Eighteen Nineties. Secondly, in doing so it seeks to reappraise three significant poets of that era, Ernest Dowson, Lionel Johnson, and Francis Thompson, in terms of their participation in this revival. The first chapter, "Craving Viaticum", deals with the general background of the Eighteen Nine...

  11. Post-traditional corporate governance

    OpenAIRE

    Mason, Michael; O Mahony, Joan

    2007-01-01

    Traditional definitions of corporate governance are narrow, focusing on legal relations between managers and shareholders. More recent definitions extend the boundaries of governance to consider the role that various stakeholders play in shaping the behaviour of firms. While stakeholding theory embraces a broader set of corporate constituencies, our argument in this paper is that even these definitions are too narrow – they lack the analytical capacity to account for the social embeddedness...

  12. Traditional communities, multinationals and biodiversity

    OpenAIRE

    Greissing, Anna; Le Tourneau, François-Michel

    2009-01-01

    The Iratapuru Sustainable Development Reserve is mainly exploited by the community of the São Francisco village. Due to its efforts to organize its members around a production co-operative and to improve their standard of living, but also as a result of massive funding from local and international institutions, this community has become a symbol for the actions of sustainable development undertaken with and in the benefit of « traditional » communities living in protected areas in the Amaz...

  13. TRADITIONAL FERMENTED FOODS OF LESOTHO

    OpenAIRE

    Gadaga, Tendekayi H; Molupe Lehohla; Victor Ntuli

    2013-01-01

    This paper describes the traditional methods of preparing fermented foods and beverages of Lesotho. Information on the preparation methods was obtained through a combination of literature review and face to face interviews with respondents from Roma in Lesotho. An unstructured questionnaire was used to capture information on the processes, raw materials and utensils used. Four products; motoho (a fermented porridge), Sesotho (a sorghum based alcoholic beverage), hopose (sorghum fermented beer...

  14. Augustine and the phenomenological tradition

    OpenAIRE

    Biebighauser, Jeffrey

    2012-01-01

    This essay traces the reception of Augustine in the 20th and 21st century phenomenological tradition. It gives special attention to recent monographs on Augustine by Jean-Luc Marion and Jean-Louis Chrétien, but contextualises these both fore (by examining the earlier work of Edmund Husserl and Martin Heidegger, as well as earlier and less determinative Augustinian engagements by Marion and Chrétien) and aft (by critically considering the philosophical, philological and theological implicati...

  15. Switching power supply filter

    Science.gov (United States)

    Kumar, Prithvi R. (Inventor); Abare, Wayne (Inventor)

    1989-01-01

    A filter for a switching power supply. The filter includes a common mode inductor with coil configurations allowing differential mode current from a dc source to pass through but attenuating common mode noise from the power supply so that the noise does not reach the dc source. The invention also includes the use of feed through capacitors at the switching power supply input terminals to provide further high-frequency noise attenuation.

  16. Bloofi: Multidimensional Bloom Filters

    OpenAIRE

    Crainiceanu, Adina; Lemire, Daniel

    2015-01-01

    Bloom filters are probabilistic data structures commonly used for approximate membership problems in many areas of Computer Science (networking, distributed systems, databases, etc.). With the increase in data size and distribution of data, problems arise where a large number of Bloom filters are available, and all them need to be searched for potential matches. As an example, in a federated cloud environment, each cloud provider could encode the information using Bloom filt...

  17. State space second order filter estimation

    Scientific Electronic Library Online (English)

    J.J, Medel; M. T., Zagaceta.

    2013-06-01

    Full Text Available The second order stochastic filter is based on difference models with uncorrelated innovation conditions structured in state space having stationary properties through a surface with bounded drift around the mean value. This allows building recursive estimation without generality lost and basic prop [...] erties over the stochastic state space surface with unknown gains viewed as a black-box scheme. The spatial region generated gave an approximation to real parametres set with a sufficient convergence rate in a probability sense. The results were applied in adaptive identification states with a high convergence rate, observed in the functional error described illustratively in simulations. This technique was developed over the smooth slide surface having advantages over other traditional filters.

  18. Contactor/filter improvements

    Science.gov (United States)

    Stelman, David (West Hills, CA)

    1989-01-01

    A contactor/filter arrangement for removing particulate contaminants from a gaseous stream includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas filter element, wherein the retention member and the filter element are spaced apart to provide a zone for the passage of granular material therethrough. The housing further includes a gas inlet means, a gas outlet means, and means for moving a body of granular material through the zone. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas filter element, exiting out of the gas outlet means. Disposed on the upstream face of the filter element is a cover screen which isolates the filter element from contact with the moving granular bed and collects a portion of the particulates so as to form a dust cake having openings small enough to exclude the granular material, yet large enough to receive the dust particles. In one embodiment, the granular material is comprised of prous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses.

  19. The dual carrier ABSK system based on a FIR bandpass filter.

    Science.gov (United States)

    Chen, Zhimin; Wu, Lenan; Wang, Jiwu

    2014-01-01

    The special impacting filter (SIF) with IIR structure has been used to demodulate ABSK signals. The key points of SIF, including the resonance circuit's high Q value and the "slope-phase discrimination" character of the filter sideband, are demonstrated in the paper. The FIR narrow-band bandpass filtering system, which can also provide the impact-filtering effect, is proposed. A dual carrier system of ABSK signals is designed with the proposed FIR filter as its receiver. The simulation results show that the FIR filter can work well. Moreover, compared to the traditional SIF, the proposed FIR filter can not only achieve higher spectral efficiency, but also give better demodulation performance. PMID:24658625

  20. The Dual Carrier ABSK System Based on a FIR Bandpass Filter

    Directory of Open Access Journals (Sweden)

    Zhimin Chen

    2014-03-01

    Full Text Available The special impacting filter (SIF with IIR structure has been used to demodulate ABSK signals. The key points of SIF, including the resonance circuit’s high Q value and the “slope-phase discrimination” character of the filter sideband, are demonstrated in the paper. The FIR narrow-band bandpass filtering system, which can also provide the impact-filtering effect, is proposed. A dual carrier system of ABSK signals is designed with the proposed FIR filter as its receiver. The simulation results show that the FIR filter can work well. Moreover, compared to the traditional SIF, the proposed FIR filter can not only achieve higher spectral efficiency, but also give better demodulation performance.

  1. Choosing and using astronomical filters

    CERN Document Server

    Griffiths, Martin

    2014-01-01

    As a casual read through any of the major amateur astronomical magazines will demonstrate, there are filters available for all aspects of optical astronomy. This book provides a ready resource on the use of the following filters, among others, for observational astronomy or for imaging: Light pollution filters Planetary filters Solar filters Neutral density filters for Moon observation Deep-sky filters, for such objects as galaxies, nebulae and more Deep-sky objects can be imaged in much greater detail than was possible many years ago. Amateur astronomers can take

  2. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2013-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehen

  3. Anti-clogging filter system

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Erik P.

    2015-05-19

    An anti-clogging filter system for filtering a fluid containing large particles and small particles includes an enclosure with at least one individual elongated tubular filter element in the enclosure. The individual elongated tubular filter element has an internal passage, a closed end, an open end, and a filtering material in or on the individual elongated tubular filter element. The fluid travels through the open end of the elongated tubular element and through the internal passage and through the filtering material. An anti-clogging element is positioned on or adjacent the individual elongated tubular filter element and provides a fluid curtain that preferentially directs the larger particulates to one area of the filter material allowing the remainder of the filter material to remain more efficient.

  4. An Adjoint-Based Adaptive Ensemble Kalman Filter

    KAUST Repository

    Song, Hajoon

    2013-10-01

    A new hybrid ensemble Kalman filter/four-dimensional variational data assimilation (EnKF/4D-VAR) approach is introduced to mitigate background covariance limitations in the EnKF. The work is based on the adaptive EnKF (AEnKF) method, which bears a strong resemblance to the hybrid EnKF/three-dimensional variational data assimilation (3D-VAR) method. In the AEnKF, the representativeness of the EnKF ensemble is regularly enhanced with new members generated after back projection of the EnKF analysis residuals to state space using a 3D-VAR [or optimal interpolation (OI)] scheme with a preselected background covariance matrix. The idea here is to reformulate the transformation of the residuals as a 4D-VAR problem, constraining the new member with model dynamics and the previous observations. This should provide more information for the estimation of the new member and reduce dependence of the AEnKF on the assumed stationary background covariance matrix. This is done by integrating the analysis residuals backward in time with the adjoint model. Numerical experiments are performed with the Lorenz-96 model under different scenarios to test the new approach and to evaluate its performance with respect to the EnKF and the hybrid EnKF/3D-VAR. The new method leads to the least root-mean-square estimation errors as long as the linear assumption guaranteeing the stability of the adjoint model holds. It is also found to be less sensitive to choices of the assimilation system inputs and parameters.

  5. Cubature Kalman filtering for relative spacecraft attitude and position estimation

    Science.gov (United States)

    Zhang, Lijun; Yang, Huabo; Lu, Heping; Zhang, Shifeng; Cai, Hong; Qian, Shan

    2014-12-01

    A novel relative spacecraft attitude and position estimation approach based on cubature Kalman filter is derived. The integrated sensor suit comprises the gyro sensors on each spacecraft and a vision-based navigation system on the deputy spacecraft. In the traditional algorithm, an assumption that the chief's body frame coincides with its Local Vertical Local Horizontal (LVLH) frame is made to construct the line-of-sight observations for convenience. To solve this problem, two relative quaternions that map the chief's LVLH frame to the deputy and chief body frames are involved. The general relative equations of motion for eccentric orbits are used to describe the positional dynamics. The implementation equations for the cubature Kalman filter are derived. Simulation results indicate that the proposed filter provides more accurate estimates of relative attitude and position over than the extended Kalman filter.

  6. Active pre-filters for dc/dc Boost regulators

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Ramos-Paja

    2014-07-01

    Full Text Available This paper proposes an active pre-filter to mitigate the current harmonics generated by classical dc/dc Boost regulators, which generate current ripples proportional to the duty cycle. Therefore, high output voltage conditions, i.e., high voltage conversion ratios, produce high current harmonics that must be filtered to avoid damage or source losses. Traditionally, these current components are filtered using electrolytic capacitors, which introduce reliability problems because of their high failure rate. The solution introduced in this paper instead uses a dc/dc converter based on the parallel connection of the Boost canonical cells to filter the current ripples generated by the Boost regulator, improving the system reliability. This solution provides the additional benefits of improving the overall efficiency and the voltage conversion ratio. Finally, the solution is validated with simulations and experimental results.

  7. An Implementation of Content Boosted Collaborative Filtering Algorithm

    Directory of Open Access Journals (Sweden)

    Boddu Raja Sarath Kumar,

    2011-04-01

    Full Text Available Collaborative filtering (CF systems have been proven to be very effective for personalized and accurate recommendations. These systems are based on the Recommendations of previous ratings byvarious users and products. Since the present database is very sparse, the missing values are considered first and based on that, a complete prediction dataset are made. In this paper, some standardcomputational techniques are applied within the framework of Content-boosted collaborative filtering with imputational rating data to evaluate and produce CF predictions. The Content-boosted collaborative filtering algorithm uses either naive Bayes or means imputation, depending on the sparsity of the original CF rating dataset. Results are presented and shown that this approach performs better than a traditional content-based predictor and collaborative filters.

  8. Fuzzy Digital Filtering: Signal Interpretation

    OpenAIRE

    Sa?nchez Garci?a, Juan C.; Jesu?s Medel Jua?rez, J.; Garci?a Infante, Juan C.

    2011-01-01

    The paper makes a description of the fuzzy filter properties considering its operational principles. A digital filter interacts with a reference model signal into real process in order to get the best corresponding answer, having the minimum error at the filter output using the mean square criterion. Adding into this filter structure a fuzzy mechanism, to obtain an intelligent filtering because adaptively select and emit a decision answer according with the external reference signal changes, ...

  9. Boolean filters of distributive lattices

    Directory of Open Access Journals (Sweden)

    M. Sambasiva Rao

    2013-07-01

    Full Text Available In this paper we introduce the notion of Boolean filters in a pseudo-complemented distributive lattice and characterize the class of all Boolean filters. Further a set of equivalent conditions are derived for a proper filter to become a prime Boolean filter. Also a set of equivalent conditions is derived for a pseudo-complemented distributive lattice to become a Boolean algebra. Finally, a Boolean filter is characterized in terms of congruences.

  10. Modernism and tradition and the traditions of modernism

    Directory of Open Access Journals (Sweden)

    Kros Džonatan

    2006-01-01

    Full Text Available Conventionally, the story of musical modernism has been told in terms of a catastrophic break with the (tonal past and the search for entirely new techniques and modes of expression suitable to a new age. The resulting notion of a single, linear, modernist mainstream (predicated on the basis of a Schoenbergian model of musical progress has served to conceal a more subtle relationship between past and present. Increasingly, it is being recognized that there exist many modernisms and their various identities are forged from a continual renegotiation between past and present, between tradition(s and the avant-garde. This is especially relevant when attempting to discuss the reception of modernism outside central Europe, where the adoption of (Germanic avant-garde attitudes was often interpreted as being "unpatriotic". The case of Great Britain is examined in detail: Harrison Birtwistle’s opera The Mask of Orpheus (1973–83 forms the focus for a wider discussion of modernism within the context of late/post-modern thought.

  11. Adapting agriculture with traditional knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Swiderska, Krystyna; Reid, Hannah [IIED, London (United Kingdom); Song, Yiching; Li, Jingsong [Centre for Chinese Agriculutral Policy (China); Mutta, Doris [Kenya Forestry Research Institute (Kenya)

    2011-10-15

    Over the coming decades, climate change is likely to pose a major challenge to agriculture; temperatures are rising, rainfall is becoming more variable and extreme weather is becoming a more common event. Researchers and policymakers agree that adapting agriculture to these impacts is a priority for ensuring future food security. Strategies to achieve that in practice tend to focus on modern science. But evidence, both old and new, suggests that the traditional knowledge and crop varieties of indigenous peoples and local communities could prove even more important in adapting agriculture to climate change.

  12. The Magi in Ethiopic Tradition

    OpenAIRE

    Witakowski, Witold

    2013-01-01

    The paper traces various extra–biblical strains of tradition concerning the Magi (MT 2,1–12) in Ge?ez literature. The Magi (mäsägg?lan, säb?a sägäl) are present in various Ethiopic compositions, both translated from other languages and original. The compositions discussed include inter alia apocryphal literature (The life of Adam and Eve, The Miracles of Jesus, The Book of the Birth of Mary, The Miracles of Mary), homiliaries (that for the feasts of Mary, and that for the feasts o...

  13. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Mathias; Haubenreisser, Holger; Schoenberg, Stefan O.; Henzler, Thomas [Heidelberg University, Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany); Raupach, Rainer; Schmidt, Bernhard; Leidecker, Christianne; Allmendinger, Thomas; Flohr, Thomas [Siemens Healthcare, Imaging and Therapy Division, Forchheim (Germany); Lietzmann, Florian; Schad, Lothar R. [Heidelberg University, Computer Assisted Clinical Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Mannheim (Germany)

    2015-01-15

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm{sup 2} removesthe necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p < 0.05). Total effective dose was 63 %/39 % lower for the third generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. (orig.)

  14. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging

    International Nuclear Information System (INIS)

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm2 removesthe necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p < 0.05). Total effective dose was 63 %/39 % lower for the third generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. (orig.)

  15. Low-power implementation of polyphase filters in Quadratic Residue Number System

    DEFF Research Database (Denmark)

    Cardarilli, Gian Carlo; Re, Andrea Del

    2004-01-01

    The aim of this work is the reduction of the power dissipated in digital filters, while maintaining the timing unchanged. A polyphase filter bank in the Quadratic Residue Number System (QRNS) has been implemented and then compared, in terms of performance, area, and power dissipation to the implementation of a polyphase filter bank in the traditional two's complement system (TCS). The resulting implementations, designed to have the same clock rates, show that the QRNS filter is smaller and consumes less power than the TCS one.

  16. Fast algorithm of the robust Gaussian regression filter for areal surface analysis

    International Nuclear Information System (INIS)

    In this paper, the general model of the Gaussian regression filter for areal surface analysis is explored. The intrinsic relationships between the linear Gaussian filter and the robust filter are addressed. A general mathematical solution for this model is presented. Based on this technique, a fast algorithm is created. Both simulated and practical engineering data (stochastic and structured) have been used in the testing of the fast algorithm. Results show that with the same accuracy, the processing time of the second-order nonlinear regression filters for a dataset of 1024*1024 points has been reduced to several seconds from the several hours of traditional algorithms

  17. A New Stateless Packet Classification and Filter against DoS Attacks

    Directory of Open Access Journals (Sweden)

    Guang Jin

    2014-02-01

    Full Text Available Capabilities is a typical scheme of stateless filtering. In order to classify and filter packets effectively, a novel scheme of packet classification and filter based on capabilities is proposed in this paper. In our scheme, a new classifier module is added and a new filter structure is designed. We employ capabilities as verification and introduce new authorization in the communications. All these innovations make packet classification owning good effects in attacking scenario. The experimental results based on large-scale topology datasets and NS2 show that our scheme is better than traditional packet classification algorithms, especially under complex cyber environment.

  18. A new Approach for Kalman filtering on Mobile Robots in the presence of uncertainties

    DEFF Research Database (Denmark)

    Larsen, Thomas Dall; Andersen, Nils Axel

    1999-01-01

    In many practical Kalman filter applications, the quantity of most significance for the estimation error is the process noise matrix. When filters are stabilized or performance is sought to be improved, tuning of this matrix is the most common method. This tuning process cannot be done before the filter is implemented, as it is primarily made necessary by modelling errors. In this paper, two different methods for modelling the process noise are described and evaluated; a traditional one based on Gaussian noise models and a new one based on propagating modelling uncertainties. We discuss which method to use and how to tune the filter to achieve the lowest estimation error.

  19. Design and Implementation for a Non Linear State Filter for LEO Micro Satellite

    Directory of Open Access Journals (Sweden)

    S. Chouraqui

    2009-01-01

    Full Text Available This study preliminarily investigates the numerical application of both Extended Kalman Filter (EKF (which has traditionally been used for non linear estimation and a relatively new filter, Unscented Kalman Filter (UKF to the nonlinear estimation problem. The new method can be applied to nonlinear systems without the linearization process necessary for the EKF and it does not demand a Gaussian distribution of noise and what's more, its ease of implementation and more accurate estimation features enables it to demonstrate its good performance. Present experimental results and analysis indicate that unscented Kalman filtering UKF have shown better performances in presence of the severe nonlinearity in state equations.

  20. TRADITIONAL FERMENTED FOODS OF LESOTHO

    Directory of Open Access Journals (Sweden)

    Tendekayi H. Gadaga

    2013-06-01

    Full Text Available This paper describes the traditional methods of preparing fermented foods and beverages of Lesotho. Information on the preparation methods was obtained through a combination of literature review and face to face interviews with respondents from Roma in Lesotho. An unstructured questionnaire was used to capture information on the processes, raw materials and utensils used. Four products; motoho (a fermented porridge, Sesotho (a sorghum based alcoholic beverage, hopose (sorghum fermented beer with added hops and mafi (spontaneously fermented milk, were found to be the main fermented foods prepared and consumed at household level in Lesotho. Motoho is a thin gruel, popular as refreshing beverage as well as a weaning food. Sesotho is sorghum based alcoholic beverage prepared for household consumption as well as for sale. It is consumed in the actively fermenting state. Mafi is the name given to spontaneously fermented milk with a thick consistency. Little research has been done on the technological aspects, including the microbiological and biochemical characteristics of fermented foods in Lesotho. Some of the traditional aspects of the preparation methods, such as use of earthenware pots, are being replaced, and modern equipment including plastic utensils are being used. There is need for further systematic studies on the microbiological and biochemical characteristics of these these products.

  1. Traditional and Modern Morphometrics: Review

    Directory of Open Access Journals (Sweden)

    Gökhan OCAKO?LU

    2013-01-01

    Full Text Available Morphometrics, a branch of morphology, is the study of the size and shape components of biological forms and their variation in the population. In biological and medical sciences, there is a long history of attempts to quantitatively express the diversity of the size and shape of biological forms. On the basis of historical developments in morphometry, we address several questions related to the shape of organs or organisms that are considered in biological and medical studies. In the field of morphometrics, multivariate statistical analysis is used to rigorously address such questions. Historically, these methods have involved the analysis of collections of distances or angles, but recent theoretical, computational, and other advances have shifted the focus of morphometric procedures to the Cartesian coordinates of anatomical points. In recent years, in biology and medicine, the traditional morphometric studies that aim to analyze shape variation have been replaced by modern morphometric studies. In the biological and medical sciences, morphometric methods are frequently preferred for examining the morphologic structures of organs or organisms with regard to diseases or environmental factors. These methods are also preferred for evaluating and classifying the variation of organs or organisms with respect to growth or allometry time dependently. Geometric morphometric methods are more valid than traditional morphometric methods in protecting more morphological information and in permitting analysis of this information.

  2. Survey of HEPA filter experience

    International Nuclear Information System (INIS)

    A survey of high efficiency particulate air (HEPA) filter applications and experience at Department of Energy (DOE) sites was conducted to provide an overview of the reasons and magnitude of HEPA filter changeouts and failures. Results indicated that approximately 58% of the filters surveyed were changed out in the three year study period, and some 18% of all filters were changed out more than once. Most changeouts (63%) were due to the existence of a high pressure drop across the filter, indicative of filter plugging. Other reasons for changeout included leak-test failure (15%), preventive maintenance service life limit (13%), suspected damage (5%) and radiation buildup (4%). Filter failures occurred with approximately 12% of all installed filters. Of these failures, most (64%) occurred for unknown or unreported reasons. Handling or installation damage accounted for an additional 19% of reported failures. Media ruptures, filter-frame failures and seal failures each accounted for approximately 5 to 6% of the reported failures

  3. Tunable ASE filters

    Science.gov (United States)

    Ma, Eugene Y.; Hazell, John F.; Murano, Robert

    2005-02-01

    The advantages of low cost amplifier solutions in single-channel link extender or loss compensator systems cannot be fully realized unless the ASE noise around the signal peak is removed. Doing so requires a cost-effective solution with high performance, including low insertion loss (<-2.5dB), low PDL (<-0.25dB), low power operation (<200mW), and fast tuning (<1sec). We have successfully fabricated and packaged a tunable ASE filter into a small form-factor 2-port package which meets these requirements. We obtain filter properties at both the chip and package-levels and examine filter performance operating under optically open and closed loop control.

  4. Progressive Gaussian Filtering

    CERN Document Server

    Hanebeck, Uwe D

    2012-01-01

    In this paper, we propose a progressive Bayesian procedure, where the measurement information is continuously included into the given prior estimate (although we perform observations at discrete time steps). The key idea is to derive a system of ordinary first-order differential equations (ODE) by employing a new coupled density representation comprising a Gaussian density and its Dirac Mixture approximation. The ODE is used for continuously tracking the true non-Gaussian posterior by its best matching Gaussian approximation. The performance of the new filter is evaluated in comparison with state-of-the-art filters by means of a canonical benchmark example, the discrete-time cubic sensor problem.

  5. Shifted Linear Interpolation Filter

    Directory of Open Access Journals (Sweden)

    Hannu Olkkonen

    2010-12-01

    Full Text Available Linear interpolation has been adapted in many signal and image processing applications due to its simple implementation and low computational cost. In standard linear interpolation the kernel is the second order B-spline. In this work we show that the interpolation error can be remarkably diminished by using the time-shifted B-spline as an interpolation kernel. We verify by experimental tests that the optimal shift is. In VLSI and microprocessor circuits the shifted linear interpolation (SLI algorithm can be effectively implemented by the z-transform filter. The interpolation error of the SLI filter is comparable to the more elaborate higher order cubic convolution interpolation.

  6. Broadband filter design

    OpenAIRE

    Valero Sarmiento, Jose Manuel

    2010-01-01

    This thesis presents the design of an active filter implemented in a 65nm CMOS technology and based on super source follower. The original filter was 5th order low-pass Chebyshev-type with a cut-off frequency of 160 MHz, but it was to be changed into Butterworth-type because of the results, here both designs are shown. The architecture is fully differential and it is based on Sallen-Key biquad structures with super source follower as an active element and resistors and capacitors as passive e...

  7. Digital filters in spectrometry

    International Nuclear Information System (INIS)

    In this work is presented the development and application of the digital signal processing for different multichannel analysis spectra. The use of the smoothing classic methods in applications of signal processing is illustrated by a filters discussion; autoregressive, mobile average and the ARMA filters. Generally, simple routines of lineal smoothing do not provide appropriate smoothing of the data that show the local ruggedness as the strong discontinuities; however the indicated development algorithms have been enough to leave adapting to this task. Four algorithms were proven: autoregressive, mobile average, ARMA and binomial methods for 5, 7, and 9 of data, everything in the domain of the time and programmed in Mat lab. (Author)

  8. Efficient Iterated Filtering

    DEFF Research Database (Denmark)

    Lindstro?m, Erik; Ionides, Edward

    2012-01-01

    Parameter estimation in general state space models is not trivial as the likelihood is unknown. We propose a recursive estimator for general state space models, and show that the estimates converge to the true parameters with probability one. The estimates are also asymptotically Cramer-Rao efficient. The proposed estimator is easy to implement as it only relies on non-linear filtering. This makes the framework flexible as it is easy to tune the implementation to achieve computational efficiency. This is done by using the approximation of the score function derived from the theory on Iterative Filtering as a building block within the recursive maximum likelihood estimator.

  9. The Promise of Traditional Medicines

    Directory of Open Access Journals (Sweden)

    N.N. Inamdar

    2010-01-01

    Full Text Available The usage of plants, plant extracts or plant-derived pure chemicals to treat disease become a therapeutic modality, which has stood the test of time. Today several pharmacological classes of drugs include a natural product prototype. Aspirin, atropine, ephedrine, digoxin, morphine, quinine, reserpine and tubocurarine are a few examples of modern drugs, which were originally discovered through the study of traditional cures and folk knowledge of indigenous people. A team work amongst ethnobotanists, ethnopharmacologists, physicians and phytochemists is must for the fruitful outcome on medicinal plants research. While the ethnopharmacologists have a greater role in the rationalization of combination of activities, the phytochemist’s role will slightly shift towards standardization of herbal medicines.

  10. Traditional Grammar: An Interactive Book

    Science.gov (United States)

    Is traditional grammar dead? Donald Hardy, a professor of English at Northern Illinois University, doesn't think so. He recently posted this "e-grammar" on the Web to help teach users how to distinguish their nouns from their verbs, their nominative cases from their subjunctives, and their present perfect from their past. The descriptions are clear and concise, while quizzes at the end of each chapter as well as five practice exams allow readers to test their retention and keep track electronically of their score. (We were not convinced, however, that the typical exemplifications of the rules that are the core of each chapter truly constitute an "interactive" aspect of the text as the introduction claims.)

  11. Trust and Traditions in Transitions

    DEFF Research Database (Denmark)

    McQuaid, Sara Dybris

    On New Year’s Eve 2013, months of talks on ‘Dealing with the past’, ‘Flags’ and ‘Parades’ ended without agreement on how to move towards a reconciliation of positions in Northern Ireland. The failure of the talks illustrates the importance of culture and (mis)trust in divided societies, where politics often pivot around whose culture shall be official and whose subordinated, whose history shall be remembered and whose forgotten (Jordan and Weedon 1995). These struggles are particularly intense in times of transition where traditions, power relations and frames of relevant remembrance are reconfigured. Historically, parading traditions have been important cultural carriers of identity in Northern Ireland. (Jarman 1997). Correspondingly, the marching season has been an arena for politico-cultural struggles and resistance, indexing relations of trust between communities, between society and the state and more recently, trust in the peace process. As the contest over meaning is always determined by the context of articulation, this paper examines the role of parades in the current ‘post-conflict’ phase of the peace process. Using theories of cultural and collective memory (Assman 2011, Olick 2011, Bodnar 1994), politics of affect (Hogget and Thompson) and data from republican and loyalist parades in North Belfast it is argued that a) there is fear of memory collapse in particular communities on the margins of the peace process with a conscious doubling of efforts to articulate the hidden recesses of memory in the current transition. And b) that patterns of ‘competitive commemoration’ in parades should be understood in relation to the increasing dissonance between vernacular languages of conflict and the official post-conflict discourses in Northern Ireland.

  12. Filtered Backprojection Reconstruction with Depth-Dependent Filtering*

    OpenAIRE

    Dennerlein, Frank; Kunze, Holger; Noo, Fre?de?ric

    2010-01-01

    A direct filtered-backprojection (FBP) reconstruction algorithm is presented for circular cone-beam computed tomography (CB-CT) that allows the filter operation to be applied efficiently with shift-variant band-pass characteristics on the kernel function. Our algorithm is derived from the ramp-filter based FBP method of Feldkamp et al. and obtained by decomposing the ramp filtering into a convolution involving the Hilbert kernel (global operation) and a subsequent differentiation operation (l...

  13. Benchmarking Compressed Sensing, Super-Resolution, and Filter Diagonalization

    CERN Document Server

    Markovich, Thomas; Sanders, Jacob N; Aspuru-Guzik, Alan

    2015-01-01

    Signal processing techniques have been developed that use different strategies to bypass the Nyquist sampling theorem in order to recover more information than a traditional discrete Fourier transform. Here we examine three such methods: filter diagonalization, compressed sensing, and super-resolution. We apply them to a broad range of signal forms commonly found in science and engineering in order to discover when and how each method can be used most profitably. We find that filter diagonalization provides the best results for Lorentzian signals, while compressed sensing and super-resolution perform better for arbitrary signals.

  14. Direct analysis of air filter samples for alpha emitting isotopes

    International Nuclear Information System (INIS)

    The traditional method for determination of alpha emitting isotopes on air filters has been to process the samples by radiochemical methods. However, this method is too slow for cases of incidents involving radioactive materials where the determination of personnel received dose is urgent. A method is developed to directly analyze the air filters taken from personal and area air monitors. The site knowledge is used in combination with alpha spectral information to identify isotopes. A mathematical function is developed to estimate the activity for each isotope. The strengths and weaknesses of the method are discussed

  15. Fungal decay of traditional fishing craft

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.

    1993-01-01

    , their role in the biodeterioration process, traditional and modern preventive methods, their economics with suggestions for future work. This study becomes important in view of the fishing industry turning towards traditional fishing craft for low energy...

  16. COMPARISION BETWEEN THE CONTENT BASED FILTERING AND COLLABORATIVE FILTERING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Prof. Pragati Chowhan

    2015-04-01

    Full Text Available On the Internet, content filtering (also known as information filtering is the use of a program to screen and exclude from access or availability Web pages or e-mail that is deemed objectionable. Content filtering is used by corporations as part of Internet firewall computers and also by home computer owners, especially by parents to screen the content their children have access to from a computer. Content filtering usually works by specifying character strings that, if matched, indicate undesirable content that is to be screened out. In this paper, we present the combination of the two filtering techniques including the content-based and collaborative filtering. Content-based filtering selects information based on semantic content, whereas collaborative filtering combines the opinions of other users to make a prediction for a target user. In this paper, we describe a new filtering approach that combines the content-based filter and collaborative filter to capitalize on their respective strengths, and thereby achieves a good performance .Finally, we comparing the two filtering techniques and in this two techniques find the result of which one is the best technique.

  17. Spot- Zombie Filtering System

    Directory of Open Access Journals (Sweden)

    Arathy Rajagopal

    2014-01-01

    Full Text Available A major security challenge on the Internet is the existence of the large number of compromised machines. Such machines have been increasingly used to launch various security attacks including spamming and spreading malware, DDoS, and identity theft. These compromised machines are called “Zombies”. In general E-mail applications and providers uses spam filters to filter the spam messages. Spam filtering is a technique for discriminating the genuine message from the spam messages. The attackers send the spam messages to the targeted machine by exalting the filters, which causes the increase in false positives and false negatives. We develop an effective spam zombie detection system named SPOT by monitoring outgoing messages of a network. SPOT focuses on the number of outgoing messages that are originated or forwarded by each computer on a network to identify the presence of Zombies. SPOT is designed based on a powerful statistical tool called Sequential Probability Ratio Test, which has bounded false positive and false negative error rates.

  18. Spectral Ensemble Kalman Filters.

    Czech Academy of Sciences Publication Activity Database

    Mandel, Jan; Kasanický, Ivan; Vejmelka, Martin; Fuglík, Viktor; Tur?i?ová, Marie; Eben, Kryštof; Resler, Jaroslav; Juruš, Pavel

    2014-01-01

    Ro?. 11, - (2014), EMS2014-446. [EMS Annual Meeting /14./ & European Conference on Applied Climatology (ECAC) /10./. 06.10.2014-10.10.2014, Prague] R&D Projects: GA ?R GA13-34856S Grant ostatní: NSF DMS-1216481 Institutional support: RVO:67985807 Keywords : data assimilation * spectral filter Subject RIV: DG - Athmosphere Sciences, Meteorology

  19. Ceramic HEPA Filter Program

    International Nuclear Information System (INIS)

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  20. Enhanced Optical Filter Design

    CERN Document Server

    Cushing, David

    2011-01-01

    This book serves as a supplement to the classic texts by Angus Macleod and Philip Baumeister, taking an intuitive approach to the enhancement of optical coating (or filter) performance. Drawing from 40 years of experience in thin film design, Cushing introduces the basics of thin films, the commonly used materials and their deposition, the major coatings and their applications, and improvement methods for each.

  1. Foam For Filtering

    Science.gov (United States)

    1978-01-01

    Like nature's honeycomb, foam is a structure of many-sided cells, apparently solid but actually only three percent material and 97 percent air. Foam is made by a heat-producing chemical reaction which expands a plastic material in a manner somewhat akin to the heat-induced rising of a loaf of bread. The resulting structure of interconnected cells is flexible yet strong and extremely versatile in applicati6n. Foam can, for example, be a sound absorber in one form, while in another it allows sound to pass through it. It can be a very soft powder puff material and at the same time a highly abrasive scrubber. A sampling of foam uses includes stereo speaker grilles, applying postage meter ink, filtering lawnmower carburetor air; deadening noise in trucks and tractors, applying cosmetics, releasing fabric softener and antistatic agents in home clothes dryers, painting, filtering factory heating and ventilating systems, shining shoes, polishing cars, sponge-mopping floors, acting as pre-operative surgical scrubbers-the list is virtually limitless. The process by which foam is made produces "windows," thin plastic membranes connecting the cell walls. Windowed foam is used in many applications but for certain others-filtering, for example-it is desirable to have a completely open network. Scott Paper Company's Foam Division, Chester, Pennsylvania, improved a patented method of "removing the windows," to create an open structure that affords special utility in filtering applications. NASA technology contributed to Scott's improvement.

  2. Traditional perception of Greeks in Serbian oral tradition

    Directory of Open Access Journals (Sweden)

    Konjik Ivana

    2006-01-01

    Full Text Available Based on material on Greeks from Vuk’s corpus of epic poems, we discuss the construction of ethnic stereotype of Greeks in Serbian language. However, the limitation of the paper’s possible conclusion lies in the nature of the corpus: Vuk had deliberately chosen one material over another, therefore, the corpus relating to Greeks cannot be considered as representative of the whole Serbian folk poems. Therefore, the discussion is limited to certain elements of the stereotype. Nevertheless, these Serbian epic folk poems contain many layers: historical, geographical, sociological, mythological and so on, with a strong foundation in traditional culture; thus, they provide an insight into geo-political situation of the time period, viewpoints, perspectives and experiences of other ethnic groups that Serbs have been into contact with. In particular, the relationship toward Greeks was marked with pronounced patriarchal attitude concerning others: we-others, ours-foreign, good-bad. In this sense, Greeks are portrayed as foreign, and as such, as a potential source of danger. On the other hand, Greeks are Christian Orthodox, which associates them with the category ours. In socio-economic sense, they were traders and wealthy, respected gentlemen. In epical-heroic profile, they were not considered as great heroes, but as "lousy army", and frequently, as unfaithful.

  3. Comparative analysis of the crystal-like and traditional microstrip structures efficiency

    Directory of Open Access Journals (Sweden)

    A. I. Nazarko

    2014-12-01

    Full Text Available Introduction. Microstrip frequency selective devices are widely used in radio systems for various purposes. Crystal-like structures and devices that used for frequency selection of signals problems are described. Crystal-like inhomogeneities. The types of inhomogeneities in microstrip devices are viewed. The limitations of the effectiveness of traditional microstrip structures are analyzed. Electromagnetic crystals efficiency. The efficiency of the EC based on proposed inhomogeneities with traditional solutions based on microstrip line is compared. It is shown that by using three-dimensional inhomogeneities in the EC structure, area is reduced by 40%. Comparison of the devices’ characteristics. On an example of the narrow-band filter efficiency of the proposed three-dimensional low-impedance EC-inhomogeneities from the side of the signal conductor with one-dimensional inhomogeneities of traditional microstrip line are compared. It is shown that the filter width reduced in half. Conclusions. Using the proposed three-dimensional low-and high-impedance EC-inhomogeneities in the structure of EC increases its efficiency in comparison with traditional microstrip line. Thus, value of Tmin decreases from –43 dB to –73 dB for one of the considered ECs. The transition from single- and two-dimensional inhomogeneities to three-dimensional low-impedance inhomogeneities from the side of the signal conductor reduces the width of EC-filter twice.

  4. Filters used in scoliosis radiography

    International Nuclear Information System (INIS)

    The use of X-ray filters during full spinal radiography for scoliosis in adolescent patients is discussed. The filters compensate for differences in body thickness while maintaining optimum image quality. They also help to reduce patient dose

  5. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  6. Infusing Qualitative Traditions in Counseling Research Designs

    Science.gov (United States)

    Hays, Danica G.; Wood, Chris

    2011-01-01

    Research traditions serve as a blueprint or guide for a variety of design decisions throughout qualitative inquiry. This article presents 6 qualitative research traditions: grounded theory, phenomenology, consensual qualitative research, ethnography, narratology, and participatory action research. For each tradition, the authors describe its…

  7. Text Classification for Web Filtering

    OpenAIRE

    Sebastiani, Fabrizio

    2004-01-01

    This talk deals with the application of text classification techniques to Web filtering, with particular emphasis on filtering unsuitable content such as pornographic or violent content. The talk introduces text classification, its tools, techniques, and applications, and then discusses how filtering unsuitable Web content can be seen as the intersection of three different applications: Web page classification, filtering, and detection unsuitable content. The characteristics of these three ap...

  8. Maneuvering target tracking using fuzzy logic-based recursive least squares filter

    Science.gov (United States)

    Fan, En; Xie, Wei-xin; Liu, Zong-xiang

    2014-12-01

    In this paper, a fuzzy logic-based recursive least squares filter (FLRLSF) is presented for maneuvering target tracking (MTT) in situations of observations with unknown random characteristics. In the proposed filter, fuzzy logic is applied in the standard recursive least squares filter (RLSF) by the design of a set of fuzzy if-then rules. Given the observation residual and the heading change in the current prediction, these rules are used to determine the magnitude of the fading factor of RLSF. The proposed filter has an advantage in which the restrictive assumptions of statistical models for process noise, measurement noise, and motion models are relaxed. Moreover, it does not need a maneuver detector when tracking a maneuvering target. The performance of FLRLSF is evaluated by using a simulation and real test experiment, and it is found to be better than those of the traditional RLSF, the fuzzy adaptive ?-? filter (FA?-?F), and the hybrid Kalman filter in tracking accuracy.

  9. The Optimal Design of Weighted Order Statistics Filters by Using Support Vector Machines

    Directory of Open Access Journals (Sweden)

    Yao Chih-Chia

    2006-01-01

    Full Text Available Support vector machines (SVMs, a classification algorithm for the machine learning community, have been shown to provide higher performance than traditional learning machines. In this paper, the technique of SVMs is introduced into the design of weighted order statistics (WOS filters. WOS filters are highly effective, in processing digital signals, because they have a simple window structure. However, due to threshold decomposition and stacking property, the development of WOS filters cannot significantly improve both the design complexity and estimation error. This paper proposes a new designing technique which can improve the learning speed and reduce the complexity of designing WOS filters. This technique uses a dichotomous approach to reduce the Boolean functions from 255 levels to two levels, which are separated by an optimal hyperplane. Furthermore, the optimal hyperplane is gotten by using the technique of SVMs. Our proposed method approximates the optimal weighted order statistics filters more rapidly than the adaptive neural filters.

  10. Spatial Filter with Volume Gratings for High-peak-power Multistage Laser Amplifiers

    CERN Document Server

    Tan, Yi-zhou; Zheng, Guang-wei; Shen, Ben-jian; Pan, Heng-yue; Li, Liu

    2012-01-01

    The regular spatial filters comprised of lens and pinhole are essential component in high power laser systems, such as lasers for inertial confinement fusion, nonlinear optical technology and directed-energy weapon. On the other hand the pinhole is treated as a bottleneck of high power laser due to harmful plasma created by the focusing beam. In this paper we present a spatial filter based on angular selectivity of Bragg diffraction grating to avoid the harmful focusing effect in the traditional pinhole filter. A spatial filter consisted of volume phase gratings in two-pass amplifier cavity were reported. Two-dimensional filter was proposed by using single Pi-phase-shifted Bragg grating, numerical simulation results shown that its angular spectrum bandwidth can be less than 160urad. The angular selectivity of photo-thermo-refractive glass and RUGATE film filters, construction stability, thermal stability and the effects of misalignments of gratings on the diffraction efficiencies under high-pulse-energy laser...

  11. The Rao-Blackwellized Particle Filter: A Filter Bank Implementation

    Directory of Open Access Journals (Sweden)

    Karlsson Rickard

    2010-01-01

    Full Text Available For computational efficiency, it is important to utilize model structure in particle filtering. One of the most important cases occurs when there exists a linear Gaussian substructure, which can be efficiently handled by Kalman filters. This is the standard formulation of the Rao-Blackwellized particle filter (RBPF. This contribution suggests an alternative formulation of this well-known result that facilitates reuse of standard filtering components and which is also suitable for object-oriented programming. Our RBPF formulation can be seen as a Kalman filter bank with stochastic branching and pruning.

  12. Samarium polarising filters at ISIS

    International Nuclear Information System (INIS)

    The status of the programme to develop samarium resonance absorption neutron polarising filters at ISIS is summarised. The results of the most recent measurements of filter performance are described. Some suggestions are made for future development work and the results of calculations of the performance of a proposed chopper spectrometer, incorporating polarising filters are given. (author)

  13. Quick-change filter cartridge

    Science.gov (United States)

    Rodgers, John C. (Santa Fe, NM); McFarland, Andrew R. (College Station, TX); Ortiz, Carlos A. (Bryan, TX)

    1995-01-01

    A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems. The cartridge includes a base through which a vacuum can be applied to draw air through the filter medium which is located on a porous filter support and held there by means of a cap which forms an airtight seal with the base. The base is also adapted for receiving absorbing media so that both particulates and gas-phase samples may be trapped for investigation, the latter downstream of the aerosol filter.

  14. Assessment of ceramic membrane filters

    Science.gov (United States)

    Ahluwalia, Rajesh K.; Geyer, Howard K.; Im, Kwan H.; Zhu, Chao; Shelleman, David; Tressler, Richard E.

    The objectives of this project are (1) to develop analytical models for evaluating the fluid mechanics of membrane coated, dead-end ceramic filters; and (2) to determine the effects of thermal and thermo-chemical aging on the material properties of emerging ceramic hot gas filters. A honeycomb cordierite monolith with a thin ceramic coating and a rigid candle filter were evaluated.

  15. Filter for reactor emergency cooling system

    International Nuclear Information System (INIS)

    The invention describes the design of a filter for the emergency cooling system. The new type of filter can be rinsed by flushing water backwards through the filter. The arrangement will prevent the filter from being silt up

  16. Stability of branched pull-back projective foliations

    OpenAIRE

    Silva, W. Costa e

    2015-01-01

    We prove that, if $n\\geq 3$, a singular foliation $\\mathcal{F}$ on $\\mathbb P^n$ which can be written as pull-back, where $\\mathcal{G}$ is a foliation in $ {\\mathbb P^2}$ of degree $d\\geq2$ with one or three invariant lines in general position and $f:{\\mathbb P^n}--->{\\mathbb P^2}$, $deg(f)=\

  17. Challenging traditional authority in the platinum belt

    Scientific Electronic Library Online (English)

    Boitumelo, Matlala.

    2014-09-01

    Full Text Available Members of the Bakgatla-ba-Kgafela traditional community have attempted to hold their traditional leader to account for decisions affecting the community. This article describes the interactions between some community members, traditional leaders, the state and courts, as members of the community ha [...] ve sought to challenge unilateral action by the traditional leader with regard to how community assets and revenue are managed and accounted for. The article examines the various actions groups and individuals have resorted to in an effort to confront traditional leadership and appeal to politicians, officials and the North West provincial government.

  18. Human Rights and American Traditions

    Directory of Open Access Journals (Sweden)

    Alexandru Boboc-Cojocaru

    2013-05-01

    Full Text Available Since the beginning, the United States has recognized and respected the rights of individuals. Besides serving as custodian of a rich historical and political tradition on human rights, the United States has contributed greatly to the crystallization of International human rights legislation through the establishment of the United Nations Organization and the development of the United Nations Charter. From my perspective, the real dilemma faced by the United States has included so far the issue of solving specific problems related to human rights, the way in which human rights considerations combine with other factors of foreign policy and the way of creating a sustainable public consensus in support of their policy on the realm of human rights. In my opinion it is unlikely that these efforts should ever be entirely solved successfully. That’s why, in this paper, I try to analyze the correlation between moral and pragmatic components of the U.S. policy on human rights in the last 40 years.

  19. Controlling flow conditions of test filters in iodine filters

    International Nuclear Information System (INIS)

    Several different iodine filter and test filter designs and experience gained from their operation are presented. For the flow experiments, an iodine filter system equipped with flow regulating and measuring devices was built. In the experiments the influence of the packing method of the iodine sorption material and the influence of the flow regulating and measuring divices upon the flow conditions in the test filters was studied. On the basis of the experiments it has been shown that the flows through the test filters always can be adjusted to a correct value if there only is a high enough pressure difference available across the test filter ducting. As a result of the research, several different methods are presented with which the flows through the test filters in both operating and future iodine sorption system can easily be measured and adjusted to their correct values. (author)

  20. Inorganic UV filters

    Scientific Electronic Library Online (English)

    Eloísa Berbel, Manaia; Renata Cristina Kiatkoski, Kaminski; Marcos Antonio, Corrêa; Leila Aparecida, Chiavacci.

    2013-06-01

    Full Text Available A preocupação com o câncer de pele hoje em dia vem crescendo cada vez mais principalmente em países tropicais, onde a incidência da radiação UVA/B é maior. O uso correto de protetores solares é a forma mais eficaz de prevenir o aparecimento desta doença. Os ativos utilizados em protetores solares po [...] dem ser filtros orgânicos e inorgânicos. Filtros inorgânicos apresentam muitas vantagens em relação aos orgânicos, tais como fotoestabilidade, ausência de irritabilidade e amplo espectro de proteção. Entretanto, em razão de apresentarem alto índice de refração, os ativos inorgânicos conferem aos protetores solares aparência esbranquiçada, diminuindo sua atratividade estética. Muitas alternativas têm sido desenvolvidas no sentido de resolver este problema e dentre elas pode-se destacar o uso da nanotecnologia. Estima-se que o uso de nanomateriais deve crescer das atuais 2000 para 58000 toneladas até 2020. Neste sentido, este trabalho tem como objetivo fazer a análise crítica abordando diferentes aspectos envolvidos tanto na obtenção de protetores solares inorgânicos (rotas de sínteses propostas nos últimos anos) quanto na permeabilidade, na segurança e em outros aspectos relacionados à nova geração de filtros solares inorgânicos. Abstract in english Nowadays, concern over skin cancer has been growing more and more, especially in tropical countries where the incidence of UVA/B radiation is higher. The correct use of sunscreen is the most efficient way to prevent the development of this disease. The ingredients of sunscreen can be organic and/or [...] inorganic sun filters. Inorganic filters present some advantages over organic filters, such as photostability, non-irritability and broad spectrum protection. Nevertheless, inorganic filters have a whitening effect in sunscreen formulations owing to the high refractive index, decreasing their esthetic appeal. Many techniques have been developed to overcome this problem and among them, the use of nanotechnology stands out. The estimated amount of nanomaterial in use must increase from 2000 tons in 2004 to a projected 58000 tons in 2020. In this context, this article aims to analyze critically both the different features of the production of inorganic filters (synthesis routes proposed in recent years) and the permeability, the safety and other characteristics of the new generation of inorganic filters.

  1. A Short Note on t-filters, II-filters and Extended Filters on Residuated Lattices.

    Czech Academy of Sciences Publication Activity Database

    Víta, Martin

    2015-01-01

    Ro?. 271, 15 July (2015), s. 168-171. ISSN 0165-0114 R&D Projects: GA ?R GAP202/10/1826 Institutional support: RVO:67985807 Keywords : t-filters * II-filters * extended filters * residuated lattices Subject RIV: BA - General Mathematics Impact factor: 1.880, year: 2013

  2. Comparison Types of Filter Used in Viewing Inner Structure of Materials Using X-Ray Computed Tomography

    International Nuclear Information System (INIS)

    The inspection of inner structure of materials plays a very important role in safety and quality elements in industry. This process of inspection needs to be carried out in most accurate and efficient manner. Current practice, region of interest is normally being scanned directly to the radiation detector without filtering added. These procedures are assuming perfectly and accurately for the result image reconstruction without justification. While the process of inspection itself may generate unintentionally defects (artefacts). Besides, safety and quality, the use of several filtering techniques can overcome these deficiencies. X-ray computed tomography is a powerful non-invasive imaging technique for viewing an objects inner structures in 2-D or 3-D cross-section images without the need to physically section it. The invention of CT techniques revolutionised the field of medical diagnostic imaging because it provided more detailed and useful information than any previous non-invasive imaging techniques. The method is increasingly being used in industry, aerospace, geosciences and archaeology. This paper describes the comparison of filtering type (aluminium and copper) in X-ray computed tomography system for imaging and visualising of casting material (rear bracket engine mounting). The theoretical aspects of CT scanner, the system configurations and the adopted algorithm for image reconstruction are discussed. The penetrating rays from a 160 kV/10 mA industrial X-ray machine and a bank of Linear Array Detectors (LAD) in combination with a three-axis sample table were used to construct the CT system. The movement of the sample table in vertical, linear and rotary motion is controlled by a Lab View-based software, the x-ray transmission data is collected by using a commercial image grabber package, and the image reconstruction is performed by using the classical Linear Back Projection (LBP) algorithm. Sample of rear bracket engine mounting were scanned using this CT scanner with different type of filters. Some of the reconstructed images are presented in this paper. (author)

  3. Filtered cathodic arc source

    International Nuclear Information System (INIS)

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge is described. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45 degree to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles. 3 figures

  4. Simon nitinol filter

    International Nuclear Information System (INIS)

    The incidence of inferior vena cava (IVC) thrombosis associated with the Simon Nitinol filter was reviewed at two institutions in 20 patients with lower- extremity deep venous thrombosis within 12 months. Ten patients had underlying malignancy. Clinical findings were correlated with findings of color-flow US, spin-echo (SE) MR imaging, and gradient-echo (GE) MR imaging of the IVC. Four of the 20 patients developed symptoms of IVC thrombosis (bilateral leg edema) within 5 weeks. MR imaging in all four documented IVC thrombosis (absence of intracaval flow void on SE images, absence of increased signal on GE images), and each had underlying malignancy (three pelvic tumors, one renal cell carcinoma). The authors conclude that patients with tumors, especially genitourinary primary tumors, may be at increased risk of IVC thrombosis in the presence of this filter, possibly because of pelvic venous compression or reduced renal vein inflow with prior nephrectomy; MR imaging is very useful for following IVC patency

  5. Niobium filter on patient exposure and image quality

    International Nuclear Information System (INIS)

    The estimated annual dose to the population due to radiological examinations has reached by now the same level of the natural background. In order to reduce the probability of stochastic effects, it's necessary to minimize the medical exposure doses. In addition to the traditional techniques employed for dose reduction (intensifying screens, post-elaboration programs, beam filtration...), a niobium filter has been recently introduced with the property of having an X ray absorption peak between 19 and 30 keV, thus eliminating the portion of the spectrum that doesn't contribute to the radiological image but increases the patient dose. In this report, some of the image quality characteriztics are analyzed in order to compare the images obtained with and without filter in usual traditional radiology. (author)

  6. Convolution filters for triangles

    OpenAIRE

    Nicollier, Grégoire

    2014-01-01

    The construction of a new triangle by erecting similar ears on the sides of a given triangle (as in Napoleon's theorem) can be considered as the convolution of the initial triangle with another triangle. We use the discrete Fourier transformation and a shape function to give a complete and explicit description of such convolution filters and their iterates. Our method leads to many old and new results in a very direct way.

  7. Filter element in analysis apparatus

    International Nuclear Information System (INIS)

    This invention is concerned with the continuous-flow analysis of liquids, and more particularly, with the separation of mixtures of solid and liquid phases. The separator is comprised of a first conduit through which the mixture is passed and a lateral second conduit joined to the first conduit via a filter. Liquid is pumped from the first conduit through the filter into the second conduit, solid phase being retained by the filter. Means for backwashing the filter is provided. In continuous-flow analysis, the mixture in the first conduit is segmented by air or air and wash liquid, and the backflow washing is controlled to occur when an air or wash flow segment in the first conduit is in contact with the filter. The filter may be of sintered glass particles. The liquid phase is directed on to the filter via a special protuberance to facilitate and accelerate separation. (author)

  8. Carbon nanotube filters

    Science.gov (United States)

    Srivastava, A.; Srivastava, O. N.; Talapatra, S.; Vajtai, R.; Ajayan, P. M.

    2004-09-01

    Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as filters to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial step in post-distillation of crude oil-with a single-step filtering process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus (~25 nm) from water. These macro filters can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially.

  9. Implementational Aspects of the Contourlet Filter Bank and Application in Image Coding

    Directory of Open Access Journals (Sweden)

    Truong T. Nguyen

    2009-02-01

    Full Text Available This paper analyzed the implementational aspects of the contourlet filter bank (or the pyramidal directional filter bank (PDFB, and considered its application in image coding. First, details of the binary tree-structured directional filter bank (DFB are presented, including a modification to minimize the phase delay factor and necessary steps for handling rectangular images. The PDFB is viewed as an overcomplete filter bank, and the directional filters are expressed in terms of polyphase components of the pyramidal filter bank and the conventional DFB. The aliasing effect of the conventional DFB and the Laplacian pyramid to the directional filters is then considered, and the conditions for reducing this effect are presented. The new filters obtained by redesigning the PDFBs satisfying these requirements have much better frequency responses. A hybrid multiscale filter bank consisting of the PDFB at higher scales and the traditional maximally decimated wavelet filter bank at lower scales is constructed to provide a sparse image representation. A novel embedded image coding system based on the image decomposition and a morphological dilation algorithm is then presented. The coding algorithm efficiently clusters the significant coefficients using progressive morphological operations. Context models for arithmetic coding are designed to exploit the intraband dependency and the correlation existing among the neighboring directional subbands. Experimental results show that the proposed coding algorithm outperforms the current state-of-the-art wavelet-based coders, such as JPEG2000, for images with directional features.

  10. Traditional Music in the Gambia : the role of traditional musicians in a society of change

    OpenAIRE

    Öryd, Helena

    2008-01-01

    The aim of this research is to find out more about traditional music in Gambian society, to get a wider view of the tradition and what is happening to traditional music in a modern society. Furthermore, I want to find out if the informers consider that the traditional music is fading away from the society and if, in that case, any actions are being taken to preserve the tradition. The research question is: How do the traditional masters in the Gambia consider the role of traditional musicians...

  11. Market Risk Beta Estimation using Adaptive Kalman Filter

    Directory of Open Access Journals (Sweden)

    Atanu Das,

    2010-06-01

    Full Text Available Market risk of an asset or portfolio is recognized through beta in Capital Asset Pricing Model (CAPM. Traditional estimation techniques emerge poor results when beta in CAPM assumed to be dynamic and follows auto regressive model. Kalman Filter (KF can optimally estimate dynamic beta where measurement noise covariance and state noise covariance are assumed to be known in a state-space framework. This paper applied Adaptive Kalman Filter (AKF for beta estimation when the above covariances are not known and estimated dynamically. The technique is first characterized through simulation study and then applied to empirical data from Indian security market. A odification of the used AKF is also proposed to take care of the problems of AKF implementation onbeta estimation and simulations show that modified method improves the performance of the filter measured by RMSE.

  12. DCT based interpolation filter for motion compensation in HEVC

    Science.gov (United States)

    Alshin, Alexander; Alshina, Elena; Park, Jeong Hoon; Han, Woo-Jin

    2012-10-01

    High Efficiency Video Coding (HEVC) draft standard has a challenging goal to improve coding efficiency twice compare to H.264/AVC. Many aspects of the traditional hybrid coding framework were improved during new standard development. Motion compensated prediction, in particular the interpolation filter, is one area that was improved significantly over H.264/AVC. This paper presents the details of the interpolation filter design of the draft HEVC standard. The coding efficiency improvements over H.264/AVC interpolation filter is studied and experimental results are presented, which show a 4.0% average bitrate reduction for Luma component and 11.3% average bitrate reduction for Chroma component. The coding efficiency gains are significant for some video sequences and can reach up 21.7%.

  13. Filter-Trust-Region Methods for Nonlinear Optimization

    OpenAIRE

    Sainvitu, Caroline

    2007-01-01

    This work is concerned with the theoretical study and the implementation of algorithms for solving two particular types of nonlinear optimization problems, namely unconstrained and simple-bound constrained optimization problems. For unconstrained optimization, we develop a new algorithm which uses a filter technique and a trust-region method in order to enforce global convergence and to improve the efficiency of traditional approaches. We also analyze the effect of approximate first and secon...

  14. Efficient Feature Selection Methods in Chinese Spam Filtering

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2013-01-01

    Full Text Available This study, from the perspective of Chinese Spam Filtering, focuses on efficient feature selection methods. It expounds the traditional feature selection algorithms including Document Frequency (DF, Information Gain (IG, the Mutual Information (MI, Chi-square (CHI and Knowledge Gain (KG which is proposed in my previous study. Testing these methods on exposing Chinese spam data set, the results show that in Chinese spam corpus CHI and KG can efficiently extract valid features for spam classifications.

  15. Efficient Feature Selection Methods in Chinese Spam Filtering

    OpenAIRE

    Xu Yan

    2013-01-01

    This study, from the perspective of Chinese Spam Filtering, focuses on efficient feature selection methods. It expounds the traditional feature selection algorithms including Document Frequency (DF), Information Gain (IG), the Mutual Information (MI), Chi-square (CHI) and Knowledge Gain (KG) which is proposed in my previous study. Testing these methods on exposing Chinese spam data set, the results show that in Chinese spam corpus CHI and KG can efficiently extract valid features for spam cla...

  16. A collaborative filtering similarity measure based on singularities.

    OpenAIRE

    Bobadilla Sancho, Jesus; Ortega Requena, Fernando; Hernando Esteban, Antonio

    2012-01-01

    Recommender systems play an important role in reducing the negative impact of informa- tion overload on those websites where users have the possibility of voting for their prefer- ences on items. The most normal technique for dealing with the recommendation mechanism is to use collaborative filtering, in which it is essential to discover the most similar users to whom you desire to make recommendations. The hypothesis of this paper is that the results obtained by applying traditional similari...

  17. Folktale Narration: A Retreating Tradition

    Directory of Open Access Journals (Sweden)

    Tandin Dorji

    2002-01-01

    Full Text Available To talk of folktales in the Bhutanese context is to discuss ona literary genre popularly known as khaju1 or ‘oraltransmission’. It serves as an important tool ofcommunication between one generation and another. Amongothers, the folktales comprise an indispensable portion of oralliterature. In it is seen the manifestation of the popularimagination and creativity representing the Bhutanesepatrimony which has been passed down from mouth to earsince time immemorial. The role that it plays in thetransmission of moral values, philosophy, beliefs, humour,etiquette, and many other traits specific to the Bhutanesesociety holds an inescapably eminent place. Despite thisimportance, the documentation of folktales in Bhutan is stillin its infancy. Till the mid-twentieth century, education wasimparted through the monasteries and all the people did nothave access to it. Furthermore, the scarcity of writing andprinting facilities compounded the difficulty and consequentlythe larger section of the population remained illiterate. Evenafter schools were opened and facilities provided free of cost,the documentation of folktales took quite sometime to jumpfrom the springboard. It was only in 1984 that Dasho SherabThaye published his first volume of the collection of folktalesfollowed suite by another two in 1986. This was the debutand now we have authors like Kunzang Choden, Kinley Wangmo, Françoise Pommaret and a few others who hadfollowed the footsteps of Dasho Sherab Thaye. However, thecollections made until today is just a drop considering thevast reservoir of folktales that lies recorded in the memoriesof the Bhutanese. It requires the efforts of many Bhutaneseeven to document a part of this inexhaustible patrimony.This, however, is not to indicate that the Bhutanese folktalesare different form the rest. In fact, ‘…folktales are the same allover, for they tell of people. Not ordinary people like those wemeet on our journey through life, but the whole secret andexciting society of one eyed sorcerers, evil giants, handsomeprinces and dancing fairies….’ 2 All the same, what is specialabout the Bhutanese folktales is that, it still is a livingtradition in many pockets of rural Bhutan. In the villageswhich are far flung from motor roads, the narration offolktales in the pastures, and in the evenings are even todayvery much alive. However, the question is, how long will itcontinue to survive? Will the development process engulf thisbeautiful tradition? And, what could be done to keep thisheritage alive?

  18. Spatial filters for high average power lasers

    Science.gov (United States)

    Erlandson, Alvin C

    2012-11-27

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second slit filter positioned between the second pair of cylindrical lenses.

  19. DSP Control of Line Hybrid Active Filter

    DEFF Research Database (Denmark)

    Dan, Stan George; Benjamin, Doniga Daniel

    2005-01-01

    Active Power Filters have been intensively explored in the past decade. Hybrid active filters inherit the efficiency of passive filters and the improved performance of active filters, and thus constitute a viable improved approach for harmonic compensation. In this paper a parallel hybrid filter is studied for current harmonic compensation. The hybrid filter is formed by a single tuned Le filter and a small-rated power active filter, which are directly connected in series without any matching transformer. Thus the required rating of the active filter is much smaller than a conventional standalone active filter. Simulation and experimental results obtained in laboratory confirmed the validity and effectiveness of the control.

  20. A double-filter method for nitrocellulose-filter binding: application to protein-nucleic acid interactions.

    OpenAIRE

    Wong, I.; Lohman, T. M.

    1993-01-01

    Nitrocellulose-filter binding is a powerful technique commonly used to study protein-nucleic acid interactions; however, its utility in quantitative studies is often compromised by its lack of precision. To improve precision and accuracy, we have introduced two modifications to the traditional technique: the use of a 96-well dot-blot apparatus and the addition of a DEAE membrane beneath the nitrocellulose membrane. Using the dot-blot apparatus, an entire triplicate set of data spanning 20-24 ...

  1. Aboriginal Oral Traditions of Australian Impact Craters

    OpenAIRE

    Hamacher, Duane W.; Goldsmith, John

    2013-01-01

    We explore Aboriginal oral traditions that relate to Australian meteorite craters. Using the literature, first-hand ethnographic records, and fieldtrip data, we identify oral traditions and artworks associated with four impact sites: Gosses Bluff, Henbury, Liverpool, and Wolfe Creek. Oral traditions describe impact origins for Gosses Bluff, Henbury, and Wolfe Creek craters and non-impact origins of Liverpool crater, with Wolfe Creek and Henbury having both impact and non-imp...

  2. Traditional marketing vs. Internet marketing. A comparison

    OpenAIRE

    Varfan, Mona; Shima, Alfa

    2008-01-01

    Title: Traditional marketing vs. Internet marketing: A comparison Problem: Marketing is an important strategy for businesses and it contains numerous effective tools. Traditional marketing has been in use for many years and nowadays Internet has brought new ways of doing business for companies and that has affected marketing. What are the main differences between Internet marketing and traditional marketing? Which one of the two approaches contains the most used and effective marketing tools ...

  3. The Ecological Ideology in Traditional Chinese Culture

    OpenAIRE

    Liu, Jing-wei

    2006-01-01


    Traditional Chinese Culture includes many ecological ideas. This paper studies about some characteristics of them in three aspects. First, the feature that man is an integral part of nature in Traditional Chinese Culture provides potential foundation for harmonic coexistence of man and nature. Second, the concept of “the axes and bills enter the hills and forests only at the proper time” in Traditional Chinese Culture provides a rational basis for harmonic coex...

  4. The reformed tradition as public theology

    OpenAIRE

    Vellem, Vuyani S.

    2013-01-01

    This article is a South African perspective of a Black African reflection on the publicity of Reformed faith. Whilst the notion of public theology is fairly new, the article argues, it is important to define the ‘public’ of the type of public theology to which Reformed faith and tradition could be linked. As a confessional tradition, Reformed faith is intrinsically public, the article demonstrates. The publicity of this tradition is however ambivalent and tainted. I attempt to show this by di...

  5. Filtering Medical Images with a New Class of Digital Filters

    OpenAIRE

    Cohen, M. E.; Hudson, D. L.; Mallios, R. R.

    1987-01-01

    Digital filtering is an important technique in numerous medical applications. In the onedimensional domain, it is used on time series data such as electrocardiogram and electroencephalogram output. In the two-dimensional domain, digital filtering is used in all imaging modalities, including CT, MRI, and nuclear medicine scans, as well as computer analysis of x-rays. In this article, a new class of digital filters based on an orthogonal function developed by Cohen is presented. The resulting f...

  6. Grid filter design for a multi-megawatt medium-voltage voltage source inverter

    OpenAIRE

    Rockhill, A.A.; Liserre, M.; Teodorescu, Remus; Rodríguez Cortés, Pedro

    2010-01-01

    This paper describes the design procedure and performance of an LCL grid filter for a medium-voltage neutral point clamped (NPC) converter to be adopted for a multimegawatt wind turbine. The unique filter design challenges in this application are driven by a combination of the medium voltage converter, a limited allowable switching frequency, component physical size and weight concerns, and the stringent limits for allowable injected current harmonics. Traditional design ...

  7. Aboriginal Oral Traditions of Australian Impact Craters

    CERN Document Server

    Hamacher, Duane W

    2013-01-01

    We explore Aboriginal oral traditions that relate to Australian meteorite craters. Using the literature, first-hand ethnographic records, and fieldtrip data, we identify oral traditions and artworks associated with four impact sites: Gosses Bluff, Henbury, Liverpool, and Wolfe Creek. Oral traditions describe impact origins for Gosses Bluff and Wolfe Creek craters and non-impact origins of Liverpool and Henbury craters, with Wolfe Creek stories having both impact and non-impact origins. Three impact sites that are believed to have formed during human habitation of Australia - Dalgaranga, Veevers, and Boxhole - do not have associated oral traditions that are reported in the literature.

  8. Software Analysis Unifying Particle Filtering and Marginalized Particle Filtering.

    Czech Academy of Sciences Publication Activity Database

    Šmídl, Václav

    Edinburgh : IET, 2010, s. 1-7. ISBN 978-0-9824438-1-1. [13th International Conference on Information Fusion. Edinburgh (GB), 26.07.2010-29.07.2010] R&D Projects: GA MŠk 1M0572; GA ?R GP102/08/P250 Institutional research plan: CEZ:AV0Z10750506 Keywords : marginalized particle filter * software analysis * Bayesian filtering Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2010/AS/smidl-software analysis unifying particle filtering and marginalized particle filtering.pdf

  9. Filter and Filter Bank Design for Image Texture Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Randen, Trygve

    1997-12-31

    The relevance of this thesis to energy and environment lies in its application to remote sensing such as for instance sea floor mapping and seismic pattern recognition. The focus is on the design of two-dimensional filters for feature extraction, segmentation, and classification of digital images with textural content. The features are extracted by filtering with a linear filter and estimating the local energy in the filter response. The thesis gives a review covering broadly most previous approaches to texture feature extraction and continues with proposals of some new techniques. 143 refs., 59 figs., 7 tabs.

  10. Does median filtering truly preserve edges better than linear filtering?

    OpenAIRE

    Arias-castro, Ery; Donoho, David L.

    2006-01-01

    Image processing researchers commonly assert that "median filtering is better than linear filtering for removing noise in the presence of edges." Using a straightforward large-$n$ decision-theory framework, this folk-theorem is seen to be false in general. We show that median filtering and linear filtering have similar asymptotic worst-case mean-squared error (MSE) when the signal-to-noise ratio (SNR) is of order 1, which corresponds to the case of constant per-pixel noise l...

  11. New filter efficiency test for future nuclear grade HEPA filters

    International Nuclear Information System (INIS)

    We have developed a new test procedure for evaluating filter penetrations as low as 10/sup /minus/9/ at 0.1-?m particle diameter. In comparison, the present US nuclear filter certification test has a lower penetration limit of 10/sup /minus/5/. Our new test procedure is unique not only in its much higher sensitivity, but also in avoiding the undesirable effect of clogging the filter. Our new test procedure consists of a two-step process: (1) We challenge the test filter with a very high concentration of heterodisperse aerosol for a short time while passing all or a significant portion of the filtered exhaust into an inflatable bag; (2) We then measure the aerosol concentration in the bag using a new laser particle counter sensitive to 0.07-?m diameter. The ratio of particle concentration in the bag to the concentration challenging the filter gives the filter penetration as a function of particle diameter. The bad functions as a particle accumulator for subsequent analysis to minimize the filter exposure time. We have studied the particle losses in the bag over time and find that they are negligible when the measurements are taken within one hour. We also compared filter penetration measurements taken in the conventional direct-sampling method with the indirect bag-sampling method and found excellent agreement. 6 refs., 18 figs., 1 tab

  12. Converter and filter circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for converter and filter circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit sour

  13. Charcoal filter testing

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, J. [Nuclear Regulatory Commission, Washington, DC (United States)

    1997-08-01

    In this very brief, informal presentation, a representative of the US Nuclear Regulatory Commission outlines some problems with charcoal filter testing procedures and actions being taken to correct the problems. Two primary concerns are addressed: (1) the process to find the test method is confusing, and (2) the requirements of the reference test procedures result in condensation on the charcoal and causes the test to fail. To address these problems, emergency technical specifications were processed for three nuclear plants. A generic or an administrative letter is proposed as a more permanent solution. 1 fig.

  14. Adaptive projective filters

    International Nuclear Information System (INIS)

    The new approach to solving of the finding problem is proposed. The method is based on Discrete Projective Transformations (DPT), the List Square Fitting (LSF) and uses the information feedback in tracing for linear or quadratic track segments (TS). The fast and stable with respect to measurement errors and background points recurrent algorithm is suggested. The algorithm realizes the family of digital adaptive projective filters (APF) with known nonlinear weight functions-projective invariants. APF can be used in adequate control systems for collection, processing and compression of data, including tracking problems for the wide class of detectors. 10 refs.; 9 figs

  15. Advances in Collaborative Filtering

    Science.gov (United States)

    Koren, Yehuda; Bell, Robert

    The collaborative filtering (CF) approach to recommenders has recently enjoyed much interest and progress. The fact that it played a central role within the recently completed Netflix competition has contributed to its popularity. This chapter surveys the recent progress in the field. Matrix factorization techniques, which became a first choice for implementing CF, are described together with recent innovations. We also describe several extensions that bring competitive accuracy into neighborhood methods, which used to dominate the field. The chapter demonstrates how to utilize temporal models and implicit feedback to extend models accuracy. In passing, we include detailed descriptions of some the central methods developed for tackling the challenge of the Netflix Prize competition.

  16. A taxonomy fuzzy filtering approach

    Directory of Open Access Journals (Sweden)

    Vrettos S.

    2003-01-01

    Full Text Available Our work proposes the use of topic taxonomies as part of a filtering language. Given a taxonomy, a classifier is trained for each one of its topics. The user is able to formulate logical rules combining the available topics, e.g. (Topic1 AND Topic2 OR Topic3, in order to filter related documents in a stream. Using the trained classifiers, every document in the stream is assigned a belief value of belonging to the topics of the filter. These belief values are then aggregated using logical operators to yield the belief to the filter. In our study, Support Vector Machines and Naïve Bayes classifiers were used to provide topic probabilities. Aggregation of topic probabilities based on fuzzy logic operators was found to improve filtering performance on the Renters text corpus, as compared to the use of their Boolean counterparts. Finally, we deployed a filtering system on the web using a sample taxonomy of the Open Directory Project.

  17. Wavelength Filters in Fibre Optics

    CERN Document Server

    Venghaus, Herbert

    2006-01-01

    Wavelength filters constitute an essential element of fibre-optic networks. This book gives a comprehensive account of the principles and applications of such filters, including their technological realisation. After an introductory chapter on wavelength division multiplexing in current and future fibre optic networks follows a detailed treatment of the phase characteristics of wavelength filters, a factor frequently neglected but of significant importance at high bit rates. Subsequent chapters cover three-dimensional reflection of gratings, arrayed waveguide gratings, fibre Bragg gratings, Fabry-Perot filters, dielectric multilayer filters, ring filters, and interleavers. The book explains the relevant performance parameters, the particular advantages and shortcomings of the various concepts and components, and the preferred applications. It also includes in-depth information on the characteristics of both commercially available devices and those still at the R&D stage. All chapters are authored by inter...

  18. Performance evaluation of a Loeb-Eiber mass filter at 1 Torr.

    Science.gov (United States)

    Hoffmann, William D; Jin, Feng; Pedder, Randall E; Taormina, Christopher; Jackson, Glen P

    2015-02-01

    The Loeb-Eiber mass filter is best operated at relatively high pressures-such as 1 Torr-where collisional dampening of ions up to the mass filter thermalizes the ions' kinetic energy, which is a requirement for effective filtering. The inter-electrode gaps of ~8 ?m require rf amplitudes on the order of 0-5 V p-p at approximately 50 MHz to achieve mass filtering up to m/z 40. Mass filtering between the 25-?m diameter wires, therefore, takes place on time frames less than the collision frequency at ~1 Torr. The low power and high pressure capabilities of the Loeb-Eiber mass filter make it ideally suited for miniaturization, where power and space are a premium. In the present work, a Loeb-Eiber mass filter was constructed using commercial silicon-on-insulator (SOI) microfabrication techniques. Ions transmitting through the chip-based Loeb-Eiber mass filter were characterized in real time using a traditional linear quadrupole mass analyzer in series with the Loeb-Eiber mass filter. The new hybrid instrument has enabled us to verify several important claims regarding the operation of the Loeb-Eiber mass filter: (1) that ions can be effectively filtered at ~1 Torr, (2) that for ions of a fixed mass-to-charge ratio, the ion transmission current decreases linearly with increasing rf amplitude on the Loeb-Eiber mass filter, (3) that the cutoff voltage at which all ions of a particular m/z value are effectively blocked is linearly related to mass-to-charge, and (4) that square waveforms can filter ions more effectively than sinusoidal waveforms for a given peak-to-peak rf amplitude. PMID:25527329

  19. Performance Evaluation of a Loeb-Eiber Mass Filter at 1 Torr

    Science.gov (United States)

    Hoffmann, William D.; Jin, Feng; Pedder, Randall E.; Taormina, Christopher; Jackson, Glen P.

    2015-02-01

    The Loeb-Eiber mass filter is best operated at relatively high pressures—such as 1 Torr—where collisional dampening of ions up to the mass filter thermalizes the ions' kinetic energy, which is a requirement for effective filtering. The inter-electrode gaps of ~8 ?m require rf amplitudes on the order of 0-5 V p-p at approximately 50 MHz to achieve mass filtering up to m/z 40. Mass filtering between the 25-?m diameter wires, therefore, takes place on time frames less than the collision frequency at ~1 Torr. The low power and high pressure capabilities of the Loeb-Eiber mass filter make it ideally suited for miniaturization, where power and space are a premium. In the present work, a Loeb-Eiber mass filter was constructed using commercial silicon-on-insulator (SOI) microfabrication techniques. Ions transmitting through the chip-based Loeb-Eiber mass filter were characterized in real time using a traditional linear quadrupole mass analyzer in series with the Loeb-Eiber mass filter. The new hybrid instrument has enabled us to verify several important claims regarding the operation of the Loeb-Eiber mass filter: (1) that ions can be effectively filtered at ~1 Torr, (2) that for ions of a fixed mass-to-charge ratio, the ion transmission current decreases linearly with increasing rf amplitude on the Loeb-Eiber mass filter, (3) that the cutoff voltage at which all ions of a particular m/z value are effectively blocked is linearly related to mass-to-charge, and (4) that square waveforms can filter ions more effectively than sinusoidal waveforms for a given peak-to-peak rf amplitude.

  20. Central difference predictive filter for attitude determination with low precision sensors and model errors

    Science.gov (United States)

    Cao, Lu; Chen, Xiaoqian; Misra, Arun K.

    2014-12-01

    Attitude determination is one of the key technologies for Attitude Determination and Control System (ADCS) of a satellite. However, serious model errors may exist which will affect the estimation accuracy of ACDS, especially for a small satellite with low precision sensors. In this paper, a central difference predictive filter (CDPF) is proposed for attitude determination of small satellites with model errors and low precision sensors. The new filter is proposed by introducing the Stirling's polynomial interpolation formula to extend the traditional predictive filter (PF). It is shown that the proposed filter has higher accuracy for the estimation of system states than the traditional PF. It is known that the unscented Kalman filter (UKF) has also been used in the ADCS of small satellites with low precision sensors. In order to evaluate the performance of the proposed filter, the UKF is also employed to compare it with the CDPF. Numerical simulations show that the proposed CDPF is more effective and robust in dealing with model errors and low precision sensors compared with the UKF or traditional PF.

  1. CONSTITUTIONAL TRADITIONALISM IN THE ROBERTS COURT

    Directory of Open Access Journals (Sweden)

    Louis J Virelli III

    2011-05-01

    Full Text Available The debate over the role of traditionalism in constitutional interpretation has itself become a tradition. It remains a popular and controversial topic among constitutional scholars and presents normative questions that are as divisive, difficult, and important today as at the Founding. Missing from the discussion, however, is a comprehensive account of how the Supreme Court has employed traditionalism-an approach that looks for meaning in present manifestations of longstanding practices or beliefs-in its constitutional jurisprudence. This project is the first to fill this gap by providing an exhaustive and systematic analysis of the Court's use of constitutional traditionalism. This article focuses on the Roberts Court's first five terms to provide an empirical foundation that will not only offer previously unavailable insights into the Court's current traditionalist practices, but will also set forth a useful framework for the ongoing normative debate over traditionalism. This project uses content analysis of key terms to identify every instance in which the Roberts Court employed traditionalism to interpret the Constitution. More specifically, this project set out to answer the following three questions: First, how frequently does the Roberts Court employ traditionalism in its constitutional jurisprudence? Second, how robust is the Court's use of traditionalism (i.e., is it used to interpret a broad or narrow range of constitutional provisions? And finally, how often and in what contexts do individual Justices on the Roberts Court rely on traditionalism in their own constitutional opinions? The research provided here suggests answers to all three of these questions. First, the data indicate that traditionalism has been relied upon regularly by the Roberts Court, appearing in nearly half of the Court's constitutional cases. Second, traditionalism is frequently applied to a wide variety of constitutional provisions: Two-thirds of the constitutional provisions considered by the Roberts Court were subjected to a traditionalist analysis, ranging from provisions pertaining to government power and structure to individual rights. Finally, the data show that although traditionalism is used more frequently by conservative Justices, it is nevertheless employed by all members of the Court in a wide variety of contexts. Although there is more to learn about traditionalism's role in the Court's constitutional jurisprudence, this evidence makes clear that, notwithstanding the normative controversy surrounding traditionalism, any future study of the workings of this Court, its members, or of the future direction of constitutional law in general must take traditionalism into account.

  2. FILT - Filtering Indexed Lucene Triples

    OpenAIRE

    Stuhr, Magnus

    2012-01-01

    The Resource Description Framework (RDF) is the W3C recommended standard for data on the semantic web, while the SPARQL Protocol and RDF Query Language (SPARQL) is the query language that retrieves RDF triples by subject, predicate, or object. RDF data often contain valuable information that can only be queried through filter functions. The SPARQL query language for RDF can include filter clauses in order to define specific data criteria, such as full-text searches, numerical filtering, and c...

  3. Semi-Hausdorff Fuzzy Filters

    Directory of Open Access Journals (Sweden)

    Geetha Sivaraman

    2007-01-01

    Full Text Available The notion of fuzzy filters was studied by Vicente and Aranguren (1988, Lowen (1979, and Ramakrishnan and Nayagam (2002. The notion of fuzzily compactness was introduced and studied by Ramakrishnan and Nayagam (2002. In this paper, an equivalent condition of fuzzily compactness is studied and a new notion of semi-Hausdorffness on fuzzy filters, which cannot be defined in crisp theory of filters, is introduced and studied.

  4. Semi-Hausdorff Fuzzy Filters

    OpenAIRE

    Geetha Sivaraman; V. Lakshmana Gomathi Nayagam

    2007-01-01

    The notion of fuzzy filters was studied by Vicente and Aranguren (1988), Lowen (1979), and Ramakrishnan and Nayagam (2002). The notion of fuzzily compactness was introduced and studied by Ramakrishnan and Nayagam (2002). In this paper, an equivalent condition of fuzzily compactness is studied and a new notion of semi-Hausdorffness on fuzzy filters, which cannot be defined in crisp theory of filters, is introduced and studied.

  5. Derived category of filtered objects

    OpenAIRE

    Schapira, Pierre; Schneiders, Jean-Pierre

    2013-01-01

    For an abelian category C and a filtrant preordered set Lambda, we prove that the derived category of the quasi-abelian category of filtered objects in C indexed by Lambda is equivalent to the derived category of the abelian category of functors from Lambda to C. We apply this result to the study of the category of filtered modules over a filtered ring in a tensor category.

  6. Continuous RPD electron energy filter

    International Nuclear Information System (INIS)

    An electron energy filter based on the retarding potential difference method has been described. As opposed to the classical, pulsed RPD filter, the retarding potentials are applied at two spatially separated electrodes. The retarding potentials have continuous, i.e. constant in time values. As a result of that, the exit beam has continual in time characteristics. This geometry resulted in slightly superior resolution than in case of pulsed RPD filter. (author)

  7. Traditional Teacher/New Wave Student.

    Science.gov (United States)

    Norris, Dale

    What kind of meaningful learning goes on when an introverted and intuitive traditional professor imparts his knowledge to an extroverted student of the new wave generation? In a project exploring how teaching personalities influence student learning, a traditional professor of literature and a "new wave" (defined as characterized by improvisation…

  8. Adventures in Rhetoric: The Traditional Library

    Directory of Open Access Journals (Sweden)

    Kim Leeder

    2013-06-01

    Full Text Available In Brief: Librarians make frequent reference to “the traditional library” yet there is no accepted definition of the term. Responding to a debate that began at the 2013 ACRL National Conference, the author presents the results of a literature survey that explores the rhetorical usage and meaning of the phrase. Results indicate that the “traditional [...

  9. Job Search Methods: Internet versus Traditional.

    Science.gov (United States)

    Kuhn, Peter; Skuterud, Mikal

    2000-01-01

    In 1998, 15 percent of unemployed job seekers used the Internet to seek jobs, as did half of all job seekers with online access from home. Internet search rates exceeded those of traditional methods, but Internet job seekers were more likely to use traditional methods as well. Unemployed blacks and Hispanics used the Internet least in job…

  10. Alexis de Tocqueville and the liberal tradition

    Directory of Open Access Journals (Sweden)

    Constanza Mazzina

    2008-12-01

    Full Text Available The article tries to find inside Tocqueville´s thought his contributions to the liberal tradition, understanding that this tradition has been growing from time to time, thanks to the contribution of different persons, each one has contributed to give shape and to consolidate what now we call and know as “liberalism”.

  11. Vygotsky, Consciousness, and the German Psycholinguistic Tradition

    Science.gov (United States)

    Leitch, David G.

    2011-01-01

    This article argues that Vygotsky's choice of word meaning as the basic unit of analysis for cultural psychology connects him to a German psycholinguistic tradition--exemplified in the work of G. W. F. Hegel and J. G. Herder--distinct from the Marxist tradition. While later commentators criticize Vygotsky's reliance on word meaning, arguing that…

  12. Comet and Meteorite Traditions of Aboriginal Australians

    CERN Document Server

    Hamacher, Duane W

    2014-01-01

    Of the hundreds of distinct Aboriginal cultures of Australia, many have oral traditions rich in descriptions and explanations of comets, meteors, meteorites, airbursts, impact events, and impact craters. These views generally attribute these phenomena to spirits, death, and bad omens. There are also many traditions that describe the formation of meteorite craters as well as impact events that are not known to Western science.

  13. Application of isotopes in traditional Chinese medicine

    International Nuclear Information System (INIS)

    Modernization of traditional Chinese medicine necessitates many new or advanced methods. Among these methods, isotopes are considered to be a convenient, fast and feasible method. The recent advance of isotope's application to traditional Chinese medicine is reviewed. In addition, their present status, problems and prospect are discussed. (authors)

  14. Enhanced orbit determination filter sensitivity analysis: Error budget development

    Science.gov (United States)

    Estefan, J. A.; Burkhart, P. D.

    1994-02-01

    An error budget analysis is presented which quantifies the effects of different error sources in the orbit determination process when the enhanced orbit determination filter, recently developed, is used to reduce radio metric data. The enhanced filter strategy differs from more traditional filtering methods in that nearly all of the principal ground system calibration errors affecting the data are represented as filter parameters. Error budget computations were performed for a Mars Observer interplanetary cruise scenario for cases in which only X-band (8.4-GHz) Doppler data were used to determine the spacecraft's orbit, X-band ranging data were used exclusively, and a combined set in which the ranging data were used in addition to the Doppler data. In all three cases, the filter model was assumed to be a correct representation of the physical world. Random nongravitational accelerations were found to be the largest source of error contributing to the individual error budgets. Other significant contributors, depending on the data strategy used, were solar-radiation pressure coefficient uncertainty, random earth-orientation calibration errors, and Deep Space Network (DSN) station location uncertainty.

  15. Kalman Filtered Compressed Sensing

    CERN Document Server

    Vaswani, Namrata

    2008-01-01

    We consider the problem of reconstructing time sequences of spatially sparse signals (with unknown and time-varying sparsity patterns) from a limited number of linear "incoherent" measurements, in real-time. The signals are sparse in some transform domain referred to as the sparsity basis. For a single spatial signal, the solution is provided by Compressed Sensing (CS). The question that we address is, for a sequence of sparse signals, can we do better than CS, if (a) the sparsity pattern of the signal's transform coefficients' vector changes slowly over time, and (b) a simple prior model on the temporal dynamics of its current non-zero elements is available. The overall idea of our solution is to use CS to estimate the support set of the initial signal's transform vector. At future times, run a reduced order Kalman filter with the currently estimated support and estimate new additions to the support set by applying CS to the Kalman innovations or filtering error (whenever it is "large").

  16. Energy filtering in nanowires

    Science.gov (United States)

    Thewissen, Maarten; Sorée, Bart; Magnus, Wim; Imec Collaboration

    2015-03-01

    Nanowires present a viable geometry to allow for future semiconductor device scaling. When the dimensions of these nanowires become comparable to the wavelength of the carriers, quantum effects may have a profound impact on the transport properties of the wire. An example of such effect, theoretically investigated here, is the introduction of a periodic potential profile along the transport direction. This could be achieved by repeatedly varying the diameter of the wire, by including a superlattice perpendicular to the wire, by applying a periodic electric field etc. The consequent resonances will effectively block electrons at some energies, while allowing others to pass, and hence function as an energy filter. Such property might be beneficial for its use in a transistor. The transmission of electrons through the wire is examined here, by solving Schrödinger's equation in the effective mass approximation and Poisson's equation self-consistently. As for the contacts, quantum transmitting boundary conditions are used as suggested by Lent. The result shows that energy filtering as described can indeed occur in realistic device structures.

  17. Reduction of Data Sparsity in Collaborative Filtering based on Fuzzy Inference Rules

    Directory of Open Access Journals (Sweden)

    A tisha Sachan

    2013-06-01

    Full Text Available Collaborative filtering Recommender system plays avery demanding and significance role in this era ofinternet informationand of course e commerce age.Collaborative filtering predicts user preferencesfrom past user behaviouror user-item relationships.Though it has many advantages it also has somelimitations such as sparsity, scalability, accuracy,cold start problem etc.In this paper we proposed amethod that helps in reducing sparsity to enhancerecommendation accuracy. We developed fuzzyinference ruleswhich is easily to implement andalso gives better result. Acomparison experiment isalsoperformingwith two previous methods,Traditional Collaborative Filtering (TCF andHybrid User Model Technique (HUMCF.

  18. Are supernovae recorded in indigenous astronomical traditions?

    Science.gov (United States)

    Hamacher, Duane W.

    2014-07-01

    Novae and supernovae are rare astronomical events that would have had an influence on the skywatching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in indigenous oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral traditions and material culture, and claims from around the world are discussed to determine if they meet these criteria. Aboriginal Australian traditions are explored for possible descriptions of novae/supernovae. Although representations of supernovae may exist in Aboriginal traditions, there are currently no confirmed accounts of supernovae in Indigenous Australian oral or material traditions.

  19. Identifying seasonal stars in Kaurna astronomical traditions

    CERN Document Server

    Hamacher, Duane W

    2015-01-01

    Early ethnographers and missionaries recorded Aboriginal languages and oral traditions across Australia. Their general lack of astronomical training resulted in misidentifications, transcription errors, and omissions in these records. Additionally, many of these early records are fragmented. In western Victoria and southeast South Australia, many astronomical traditions were recorded, but curiously, some of the brightest stars in the sky were omitted. Scholars claimed these stars did not feature in Aboriginal traditions. This under-representation continues to be repeated in the literature, but current research shows that some of these stars may in fact feature in Aboriginal traditions and could be seasonal calendar markers. This paper uses established techniques in cultural astronomy to identify seasonal stars in the traditions of the Kaurna Aboriginal people of the Adelaide Plains, South Australia.

  20. Are Supernovae Recorded in Indigenous Astronomical Traditions?

    CERN Document Server

    Hamacher, Duane W

    2014-01-01

    Novae and supernovae are rare astronomical events that would have had an influence on the sky-watching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral and material culture, and claims from around the world are discussed to determine if they meet these criteria. Australian Aboriginal traditions are explored for possible descriptions of novae/supernovae. Although representations of supernovae may exist in Indigenous traditions, and an account of a nova in Aboriginal traditions has been confirmed, there are currently no confirmed accounts of supernovae in Indigenous oral or material traditions.

  1. Vietnamese traditional medicine from a pharmacist's perspective.

    Science.gov (United States)

    Woerdenbag, Herman J; Nguyen, Tuyen Manh; Vu, Dien Van; Tran, Hung; Nguyen, Dung Tuan; Tran, Thanh Van; De Smet, Peter A G M; Brouwers, Jacobus R B J

    2012-07-01

    Traditional medicine plays an important role in the healthcare system of Vietnam. Vietnamese traditional medicine (VTM) is underpinned by the oriental philosophy and theory of healing. VTM is largely influenced by traditional Chinese medicine, but differs to a certain extent. VTM is largely not evidence-based from a clinical perspective but subclinical research data from the past decades support the traditional use of many herbal VTM drugs. For safe use, knowledge of the occurrence of adverse reactions and herb-drug interactions is necessary. The Vietnamese government supports further development of VTM in a scientific way and integration of VTM with Western medicine. This article first gives an overview of the general aspects of VTM (historical perspective, regulatory aspects, comparison with traditional Chinese medicine, philosophical background, the Vietnamese market situation, quality assurance and formulations), and subsequently focuses on its safe and effective use in Vietnamese clinical pharmacy and medical practice. PMID:22943125

  2. Why Breast Cancer Patients Seek Traditional Healers

    International Nuclear Information System (INIS)

    Traditional healing is a common practice in low and middle income countries such as Malaysia. Eighty percent of Malaysians consult traditional healers or bomoh at some time in their life for health-related issues. The purpose of our study was to explore why breast cancer patients visit traditional healers. This is a qualitative study utilizing in-depth interviews with 11 cancer survivors who sought both traditional and Western medicine. The findings revealed the following reasons for which patients seek traditional healers: (1) recommendation from family and friends, (2) sanction from family, (3) perceived benefit and compatibility, (4) healer credibility, and (5) reservation with Western medicine and system delay. These factors work together and are strongly influenced by the Malaysian cultural context. The issue with the Western health system is common in a developing country with limited health facilities

  3. Position USBL/DVL Sensor-based Navigation Filter in the presence of Unknown Ocean Currents

    CERN Document Server

    Morgado, M; Oliveira, P; Silvestre, C

    2010-01-01

    This paper presents a novel approach to the design of globally asymptotically stable (GAS) position filters for Autonomous Underwater Vehicles (AUVs) based directly on the nonlinear sensor readings of an Ultra-short Baseline (USBL) and a Doppler Velocity Log (DVL). Central to the proposed solution is the derivation of a linear time-varying (LTV) system that fully captures the dynamics of the nonlinear system, allowing for the use of powerful linear system analysis and filtering design tools that yield GAS filter error dynamics. Simulation results reveal that the proposed filter is able to achieve the same level of performance of more traditional solutions, such as the Extended Kalman Filter (EKF), while providing, at the same time, GAS guarantees, which are absent for the EKF.

  4. Transport of nanoparticles with dispersant through biofilm coated drinking water sand filters.

    Science.gov (United States)

    Li, Zhen; Aly Hassan, Ashraf; Sahle-Demessie, Endalkachew; Sorial, George A

    2013-11-01

    This article characterizes, experimentally and theoretically, the transport and retention of engineered nanoparticles (NP) through sand filters at drinking water treatment plants (DWTPs) under realistic conditions. The transport of four commonly used NPs (ZnO, CeO2, TiO2, and Ag, with bare surfaces and coating agents) through filter beds filled with sands from either acid washed and calcined, freshly acquired filter media, and used filter media from active filter media, were investigated. The study was conducted using water obtained upstream of the sand filter at DWTP. The results have shown that capping agents have a determinant importance in the colloidal stability and transport of NPs through the different filter media. The presence of the biofilm in used filter media increased adsorption of NPs but its effects in retaining capped NPs was less significant. The data was used to build a mathematical model based on the advection-dispersion equation. The model was used to simulate the performance of a scale-up sand filter and the effects on filtration cycle of traditional sand filtration system used in DWTPs. PMID:24050685

  5. Application of Archimedes Filter for Reduction of Hanford HLW

    International Nuclear Information System (INIS)

    Archimedes Technology Group, Inc., is developing a plasma mass separator called the Archimedes Filter that separates waste oxide mixtures ion by ion into two mass groups: light and heavy. For the first time, it is feasible to separate large amounts of material atom by atom in a single pass device. Although vacuum ion based electromagnetic separations have been around for many decades, they have traditionally depended on ion beam manipulation. Neutral plasma devices, on the other hand, are much easier, less costly, and permit several orders of magnitude greater throughput. The Filter has many potential applications in areas where separation of species is otherwise difficult or expensive. In particular, radioactive waste sludges at Hanford have been a particularly difficult issue for pretreatment and immobilization. Over 75% of Hanford HLW oxide mass (excluding water, carbon, and nitrogen) has mass less than 59 g/mol. On the other hand, 99.9% of radionuclide activity has mass greater than 89 g/mol. Therefore, Filter mass separation tuned to this cutoff would have a dramatic effect on the amount of IHLW produced--in fact IHLW would be reduced by a factor of at least four. The Archimedes Filter is a brand new tool for the separations specialist's toolbox. In this paper, we show results that describe the extent to which the Filter separates ionized material. Such results provide estimates for the potential advantages of Filter tunability, both in cutoff mass (electric and bility, both in cutoff mass (electric and magnetic fields) and in degree of ionization (plasma power). Archimedes is now engaged in design and fabrication of its Demonstration Filter separator and intends on performing a full-scale treatment of Hanford high-level waste surrogates. The status of the Demo project will be described

  6. Traditional Halibut Hook Trials (Longline Bycatch Reduction Through the Use of Traditional Makah Halibut Hooks (Chiboods))

    National Oceanic and Atmospheric Administration, Department of Commerce — The Makah Tribe plans to build traditional Makah halibut hooks (cibuds) out of metal to determine if the traditional design is more selective for the size of...

  7. Particle Kalman Filtering: A Nonlinear Framework for Ensemble Kalman Filters

    KAUST Repository

    Hoteit, Ibrahim

    2010-09-19

    Optimal nonlinear filtering consists of sequentially determining the conditional probability distribution functions (pdf) of the system state, given the information of the dynamical and measurement processes and the previous measurements. Once the pdfs are obtained, one can determine different estimates, for instance, the minimum variance estimate, or the maximum a posteriori estimate, of the system state. It can be shown that, many filters, including the Kalman filter (KF) and the particle filter (PF), can be derived based on this sequential Bayesian estimation framework. In this contribution, we present a Gaussian mixture?based framework, called the particle Kalman filter (PKF), and discuss how the different EnKF methods can be derived as simplified variants of the PKF. We also discuss approaches to reducing the computational burden of the PKF in order to make it suitable for complex geosciences applications. We use the strongly nonlinear Lorenz?96 model to illustrate the performance of the PKF.

  8. Testing Dual Rotary Filters - 12373

    International Nuclear Information System (INIS)

    The Savannah River National Laboratory (SRNL) installed and tested two hydraulically connected SpinTekR Rotary Micro-filter units to determine the behavior of a multiple filter system and develop a multi-filter automated control scheme. Developing and testing the control of multiple filters was the next step in the development of the rotary filter for deployment. The test stand was assembled using as much of the hardware planned for use in the field including instrumentation and valving. The control scheme developed will serve as the basis for the scheme used in deployment. The multi filter setup was controlled via an Emerson DeltaV control system running version 10.3 software. Emerson model MD controllers were installed to run the control algorithms developed during this test. Savannah River Remediation (SRR) Process Control Engineering personnel developed the software used to operate the process test model. While a variety of control schemes were tested, two primary algorithms provided extremely stable control as well as significant resistance to process upsets that could lead to equipment interlock conditions. The control system was tuned to provide satisfactory response to changing conditions during the operation of the multi-filter system. Stability was maintained through the startup and shutdown of one of the filter units while the second was still in operation. The equipment selected for deployment, including the concentrate discharge control valve, the pressure transmitters, and flow meters, performed well. Automation of the valve control integrated well with the control scheme and when used in concert with the other control variables, allowed automated control of the dual rotary filter system. Experience acquired on a multi-filter system behavior and with the system layout during this test helped to identify areas where the current deployment rotary filter installation design could be improved. Completion of this testing provides the necessary information on the control and system behavior that will be used in deployment on actual waste. (authors)

  9. POLITICAL TRADITIONS: THE CONCEPT AND STRUCTURE

    Directory of Open Access Journals (Sweden)

    ??????? ?????????? ??????

    2013-05-01

    Full Text Available The article refers to the theoretical aspects of the study of the political traditions phenomenon. The influence of traditional components of the political culture on the current political process is recognized in contemporary literature, but political traditions rarely become the original subject of a scientific research, which explains the vagueness of their interpretation and the need of their system understanding.The author analyzes existing interpretations of the concept "tradition", on which formulates the definition of "political traditions" as (1 a form of fixation for meaningful content of the nation’s socio-political experience and as (2 a mechanism of political-cultural continuity.The author identifies mental, behavioral and institutional levels in the structure of political traditions. Mental level consists of political symbols, myths and stereotypes, which form the image of political reality and authority, and values and norms, which affect the motivation of political behavior. Behavioral level includes models of behavior and patterns of action, such as political habits and rituals. Institutional level reflects historical features of interaction between branches of power and relations between the state and society.The author pays attention to the influence of structural elements of political traditions on the political consciousness and behavior of individuals and social groups. DOI: http://dx.doi.org/10.12731/2218-7405-2013-4-25

  10. Mobile filters in nuclear engineering

    International Nuclear Information System (INIS)

    The need for filters with high efficiencies which may be used at any place originated in nuclear power plants. Filters of this type, called Filtermobil, have been developed by Sulzer. They have been used successfully in nuclear plants for several years. (orig.)

  11. Darut Tauhid: Modernizing a Pesantren Tradition

    Directory of Open Access Journals (Sweden)

    Zaki Nur'aeni

    2005-12-01

    Full Text Available This study presents a case study of the Daarut Tauhiid Pesantren in Bandung, West Java, which represents an emerging trend in recent years in Indonesia, that is, the growing popularity of what we refer to here as the 'virtual pesantren'. Employing such a term in relation to the pesantren tradition - a tradition that has existed in Indonesia for many centuries - palpably indicates the changing nature of the tradition.Copyright (c 2014 by SDI. All right reserved.DOI: 10.15408/sdi.v12i3.583

  12. Comet and meteorite traditions of Aboriginal Australians

    Science.gov (United States)

    Hamacher, Duane W.

    2014-06-01

    This research contributes to the disciplines of cultural astronomy (the academic study of how past and present cultures understand and utilise celestial objects and phenomena) and geomythology (the study of geological events and the formation of geological features described in oral traditions). Of the hundreds of distinct Aboriginal cultures of Australia, many have oral traditions rich in descriptions and explanations of comets, meteors, meteorites, airbursts, impact events, and impact craters. These views generally attribute these phenomena to spirits, death, and bad omens. There are also many traditions that describe the formation of meteorite craters as well as impact events that are not known to Western science.

  13. AER image filtering

    Science.gov (United States)

    Gómez-Rodríguez, F.; Linares-Barranco, A.; Paz, R.; Miró-Amarante, L.; Jiménez, G.; Civit, A.

    2007-05-01

    Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows real-time virtual massive connectivity among huge number of neurons located on different chips.[1] By exploiting high speed digital communication circuits (with nano-seconds timing), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Neurons generate "events" according to their activity levels. That is, more active neurons generate more events per unit time and access the interchip communication channel more frequently than neurons with low activity. In Neuromorphic system development, AER brings some advantages to develop real-time image processing system: (1) AER represents the information like time continuous stream not like a frame; (2) AER sends the most important information first (although this depends on the sender); (3) AER allows to process information as soon as it is received. When AER is used in artificial vision field, each pixel is considered like a neuron, so pixel's intensity is represented like a sequence of events; modifying the number and the frequency of these events, it is possible to make some image filtering. In this paper we present four image filters using AER: (a) Noise addition and suppression, (b) brightness modification, (c) single moving object tracking and (d) geometrical transformations (rotation, translation, reduction and magnification). For testing and debugging, we use USB-AER board developed by Robotic and Technology of Computers Applied to Rehabilitation (RTCAR) research group. This board is based on an FPGA, devoted to manage the AER functionality. This board also includes a micro-controlled for USB communication, 2 Mbytes RAM and 2 AER ports (one for input and one for output).

  14. Compressed sensing & sparse filtering

    CERN Document Server

    Carmi, Avishy Y; Godsill, Simon J

    2013-01-01

    This book is aimed at presenting concepts, methods and algorithms ableto cope with undersampled and limited data. One such trend that recently gained popularity and to some extent revolutionised signal processing is compressed sensing. Compressed sensing builds upon the observation that many signals in nature are nearly sparse (or compressible, as they are normally referred to) in some domain, and consequently they can be reconstructed to within high accuracy from far fewer observations than traditionally held to be necessary. Apart from compressed sensing this book contains other related app

  15. Sintered composite medium and filter

    Science.gov (United States)

    Bergman, Werner (Pleasanton, CA)

    1987-01-01

    A particulate filter medium is formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers. A preferred composition is about 40 vol. % quartz and about 60 vol. % stainless steel fibers. The media is sintered at about 1100.degree. C. to bond the stainless steel fibers into a cage network which holds the quartz fibers. High filter efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550.degree. C. The invention also includes methods to form the composite media and a HEPA filter utilizing the composite media. The filter media can be used to filter particles in both liquids and gases.

  16. Stochastic resonance with matched filtering

    CERN Document Server

    Li, Li-Fang

    2010-01-01

    Along with the development of interferometric gravitational wave detector, we enter into an epoch of gravitational wave astronomy, which will open a brand new window for astrophysics to observe our universe. Almost all of the data analysis methods in gravitational wave detection are based on matched filtering. Gravitational wave detection is a typical example of weak signal detection, and this weak signal is buried in strong instrument noise. So it seems attractable if we can take advantage of stochastic resonance. But unfortunately, almost all of the stochastic resonance theory is based on Fourier transformation and has no relation to matched filtering. In this paper we try to relate stochastic resonance to matched filtering. Our results show that stochastic resonance can indeed be combined with matched filtering for both periodic and non-periodic input signal. This encouraging result will be the first step to apply stochastic resonance to matched filtering in gravitational wave detection. In addition, based...

  17. Identification Filtering with fuzzy estimations

    Directory of Open Access Journals (Sweden)

    J.J Medel J

    2012-10-01

    Full Text Available A digital identification filter interacts with an output reference model signal known as a black-box output system. The identification technique commonly needs the transition and gain matrixes. Both estimation cases are based on mean square criterion obtaining of the minimum output error as the best estimation filtering. The evolution system represents adaptive properties that the identification mechanism includes considering the fuzzy logic strategies affecting in probability sense the evolution identification filter. The fuzzy estimation filter allows in two forms describing the transition and the gain matrixes applying actions that affect the identification structure. Basically, the adaptive criterion conforming the inference mechanisms set, the Knowledge and Rule bases, selecting the optimal coefficients in distribution form. This paper describes the fuzzy strategies applied to the Kalman filter transition function, and gain matrixes. The simulation results were developed using Matlab©.

  18. Shunt Active Filter in Damping Harmonics Propagation

    Directory of Open Access Journals (Sweden)

    BERBAOUI, B.

    2010-08-01

    Full Text Available This paper deals with a hybrid shunt active power filter applied on 500 kV HVDC, after a description of the causes and effects harmonic pollution which may damage equipments and interrupt electric power customers service; in this paper we present the deferent solutions of this problem among one has to study the two most recent types of filtering: passive and hybrid filter. The hybrid filter consists of active filter connected in shunt with passive filter. The hybrid shunt active filter proposed is based on three levels PWM inverter and characterized by detecting the harmonic current flowing into the passive filter and controlled by notch algorithm. This structure has been applied on a test HVDC power system, is presented as a technical solution makes it possible to eliminate the disadvantages from passive filtering, and also economic price of active filtering part. The simulation results justified the effectiveness of this type of filter face of the classic passive filter.

  19. Teaching Geography's Four Traditions with Poetry.

    Science.gov (United States)

    Donaldson, Daniel P.

    2001-01-01

    Uses four traditions of geography (spatial, area studies, human-environment interaction, and earth science) to show how poetry can be used to enhance the teaching of geography. Illustrates the explicitly spatial concepts present in selected poetry. (DAJ)

  20. A systems approach to traditional oriental medicine

    DEFF Research Database (Denmark)

    Kim, Hyun Uk; Ryu, Jae Yong

    2015-01-01

    Analyzing structural similarities between compounds derived from traditional oriental medicine and human metabolites is a systems-based approach that can help identify mechanisms of action and suggest approaches to reduce toxicity.

  1. Protecting traditional knowledge from the grassroots up

    Energy Technology Data Exchange (ETDEWEB)

    Arugomedo, Alejandro [ANDES Association (Peru); Pant, Ruchi [Ecoserve (India); Vedavathy, S. [Herbal Folklore Reseach Centre (India); Munyi, Peter [International Centre of Insect Physiology and Ecology (Kenya); Mutta, Doris [Kenya Forestry Research Institute (Kenya); Herrera, Heracilo [Dobbo Yala Foundation (Panama); Song, Yinching; Li, Jingsong [Centre of Chinese Agricultural Policy (China); Swiderska, Krystyna

    2009-06-15

    For indigenous peoples round the world, traditional knowledge based on natural resources such as medicinal herbs forms the core of culture and identity. But this wealth of knowledge is under pressure. Indigenous communities are increasingly vulnerable to eviction, environmental degradation and outside interests eager to monopolise control over their traditional resources. Intellectual property rights such as patents, however, sit uneasily with traditional knowledge. Their commercial focus wars with fundamental indigenous principles such as resource access and sharing. Local customary law offers a better fit, and findings in China, India, Kenya, Panama and Peru show how this pairing can work in practice. The research has identified common elements, and key differences, in customary law that should be informing policy on traditional knowledge and genetic resources.

  2. Intrusions of Modernity on a Traditional Culture.

    Science.gov (United States)

    Thomas, Anne Horsfall

    1991-01-01

    Presents a teacher's impressions of India, gathered during a Fulbright-sponsored study tour. Examines modernizing influences in the midst of traditional culture, religious cultural groups and potential religious conflict, women's status, and problems due to overpopulation. (CH)

  3. MARKETING OF TRADITIONAL PRODUCT IN TRANSYLVANIA

    Directory of Open Access Journals (Sweden)

    M. MATIUTI

    2013-07-01

    Full Text Available Transylvania and the Banat are two historical regions that gave birth to several domestic animal breeds. Over the last 15 years, number have sunken dramatically, because these local breeds have been greatly replaced by imported ones. Although very many so- called agrotouristic pensions are now on the market, only about 1% of them promote real traditional food products obtained from local animal breeds. Only few people, especially old people, know traditional recipes older than two or three hundred years and the youth totally ignore them. On the one hand, a large variety of names for different products have appeared on the market, but they are manufactured by big firms and do not have the quality of the traditional products. On the other hand, small producers often have hygiene problems. The reinforcement of traditional products can only occur if people know the quality and the value of the products obtained from the local animal breeds, many of them being endangered species.

  4. High frequency model of EMI filter

    OpenAIRE

    Szymon Pasko; Boguslaw Grzesik

    2012-01-01

    The EMI filters are usually used for suppression of electromagnetic conducted interference of range 9 kHz-30 MHz. The efficiency of electromagnetic interference filter is described by attenuation characteristics. The value of attenuation of EMI filter depends on main parameters of filter’s elements and its parasitic parameters. Therefore the high frequency model of electromagnetic interference filter is analyzed in this paper.

  5. Traditional foods of Black Sea Countries

    OpenAIRE

    Vasilopoulou, E.; Dilis, V.; Finglas, P.; Costa, H. S.; D’antuono, L. F.; Trichopoulou, A.; on behalf of the BaSeFood Black Sea area partners

    2011-01-01

    INTRODUCTION: Traditional dietary patterns, generally beneficial to health as judged over time, should be promoted beyond the native country’s borders. Scientific data is a prerequisite for the successful promotion of a sustainable diet. The Mediterranean diet is a distinguished example of such a dietary pattern. Accumulating scientific evidence has established it globally as a model diet. OBJECTIVES: A framework for the investigation of traditional foods, aiming primarily at t...

  6. Transformation of traditional manufacturers towards servitized organisations

    OpenAIRE

    Vladimirova, Doroteya Kamenova

    2012-01-01

    In response to competitive and economic pressures, an increasing number of manufacturing firms are adding services to their traditional product offerings. However, companies are confronted with an arduous undertaking, and find it difficult to servitize successfully and profitably. This thesis investigates the transformation that traditional manufacturers undergo to become providers of integrated products and services, a phenomenon known as servitization. Servitization is considered a strategi...

  7. Teachers in Charter and Traditional Schools

    OpenAIRE

    Sally Bomotti; Rick Ginsberg; Brian Cobb

    1999-01-01

    Teachers from charter and traditional schools in Colorado were queried about their perceptions of their level of empowerment, school climate, and working conditions. Using a cluster sampling design, approximately 100 teachers from 16 charter schools and 100 teachers from seven traditional schools were surveyed by combining several well-established instruments to measure empowerment, school climate, and working conditions. Factor analyses yielded three composite variables each for the three co...

  8. Traditional local communities in international law

    OpenAIRE

    Bessa Da Costa Antunes Rodrigues, Adriana Aparecida

    2013-01-01

    One of the most important innovations of the 1992 Rio Summit was the consolidation of a synergetic approach between human rights and environmental conservation and the introduction of traditional local communities as new subjects of rights in international law. By proclaiming traditional local communities - together with indigenous peoples - as 'custodians of biodiversity', the documents adopted during the meeting called upon States to protect their cultures and lifestyles by, inter alia, enh...

  9. Cultural anthropology of traditional Chinese medicine

    OpenAIRE

    Wan, Xia; Liu, Jian-ping

    2008-01-01

    Abstract: Biological, psychological and sociological model of medicine substantializes the old model lacking the social humane attributes. The new medical model makes people take medical anthropology into research and highly evaluate traditional medical system. Cultural anthropology of traditional Chinese medicine (TCM) is part of medical anthropology with three major characteristics: wide research scope, specificity, and integration. It has developed its own research methods, such as field i...

  10. HAZARDS MANAGEMENT FOR TRADITIONAL FOOD PRODUCTS

    OpenAIRE

    Oana Brînzan; Eugenia ?igan

    2013-01-01

    Traditional food products is insufficient capitalized value of the Romanian rural space. Certification methodology of such a product existent documentation mentions the need to present the method of production and how is ensured the food safety. Here arises confusion between the notion of quality and safety. Safety is an explicit requirement of quality, is included in the quality assurance system, but does not overlap. Processor must find all resources needed to respect the traditionalism but...

  11. Mambila traditional religion : Sua in Somie

    OpenAIRE

    Zeitlyn, David

    1990-01-01

    This work is an analysis of Mambila religion based on fieldwork in Somie village, Cameroon. An ethnographic and historical introduction to the Mambila is followed by an account of their religious concepts. It is argued that, despite their adherence to Christianity (and to Islam), traditional practices continue to be of great importance in everyday life. In order to examine traditional practice descriptions are given of divination and oath-taking rites. Translated transcripts...

  12. Traditional Chinese Medicine for Senile Dementia

    OpenAIRE

    Zhihong Lin; Jie Gu; Jin Xiu; Tingyan Mi; Jie Dong; Jyoti Kumar Tiwari

    2012-01-01

    Traditional Chinese Medicine (TCM) has a 3000 years' history of human use. A literature survey addressing traditional evidence from human studies was done, with key result that top 10 TCM herb ingredients including Poria cocos, Radix polygalae, Radix glycyrrhizae, Radix angelica sinensis, and Radix rehmanniae were prioritized for highest potential benefit to dementia intervention, related to the highest frequency of use in 236 formulae collected from 29 ancient Pharmacopoeias, ancient formula...

  13. Milk-based traditional Turkish desserts

    OpenAIRE

    Tulay Ozcan; Lutfiye Yilmaz-Ersan; Arzu Akpinar-Bayizit

    2009-01-01

    Traditional foods are the reflection of cultural inheritance and affect the lifestyle habits. Culture can be viewed as a system of socially transmitted patterns of behaviour that characterises a particular group. Despite the fact of globalisation, these are key elements to accurately estimate a population’s dietary patterns and how these have been shaped through time. In Turkey, a meal with family or friends traditionally ends with a dessert, which is a testimony to the hosts’ hospitality...

  14. Portfolio choice beyond the traditional approach

    OpenAIRE

    Penaranda, Francisco

    2007-01-01

    This paper surveys asset allocation methods that extend the traditional approach. An important feature of the traditional approach is that measures the risk and return tradeoff in terms of mean and variance of final wealth. However, there are also other important features that are not always made explicit in terms of investor’s wealth, information, and horizon: The investor makes a single portfolio choice based only on the mean and variance of her final financial wealth and she knows the re...

  15. A personalized web page content filtering model based on segmentation

    CERN Document Server

    Kuppusamy, K S; 10.5121/ijist.2012.2104

    2012-01-01

    In the view of massive content explosion in World Wide Web through diverse sources, it has become mandatory to have content filtering tools. The filtering of contents of the web pages holds greater significance in cases of access by minor-age people. The traditional web page blocking systems goes by the Boolean methodology of either displaying the full page or blocking it completely. With the increased dynamism in the web pages, it has become a common phenomenon that different portions of the web page holds different types of content at different time instances. This paper proposes a model to block the contents at a fine-grained level i.e. instead of completely blocking the page it would be efficient to block only those segments which holds the contents to be blocked. The advantages of this method over the traditional methods are fine-graining level of blocking and automatic identification of portions of the page to be blocked. The experiments conducted on the proposed model indicate 88% of accuracy in filter...

  16. Nanophotonic filters for digital imaging

    Science.gov (United States)

    Walls, Kirsty

    There has been an increasing demand for low cost, portable CMOS image sensors because of increased integration, and new applications in the automotive, mobile communication and medical industries, amongst others. Colour reproduction remains imperfect in conventional digital image sensors, due to the limitations of the dye-based filters. Further improvement is required if the full potential of digital imaging is to be realised. In alternative systems, where accurate colour reproduction is a priority, existing equipment is too bulky for anything but specialist use. In this work both these issues are addressed by exploiting nanophotonic techniques to create enhanced trichromatic filters, and multispectral filters, all of which can be fabricated on-chip, i.e. integrated into a conventional digital image sensor, to create compact, low cost, mass produceable imaging systems with accurate colour reproduction. The trichromatic filters are based on plasmonic structures. They exploit the excitation of surface plasmon resonances in arrays of subwavelength holes in metal films to filter light. The currently-known analytical expressions are inadequate for optimising all relevant parameters of a plasmonic structure. In order to obtain arbitrary filter characteristics, an automated design procedure was developed that integrated a genetic algorithm and 3D finite-difference time-domain tool. The optimisation procedure's efficacy is demonstrated by designing a set of plasmonic filters that replicate the CIE (1931) colour matching functions, which themselves mimic the human eye's daytime colour response.

  17. Factors Influencing HEPA Filter Performance

    International Nuclear Information System (INIS)

    Properly functioning HEPA air filtration systems depend on a variety of factors that start with the use of fully characterized challenge conditions for system design and then process control during operation. This paper addresses factors that should be considered during the design phase as well as operating parameters that can be monitored to ensure filter function and lifetime. HEPA filters used in nuclear applications are expected to meet design, fabrication, and performance requirements set forth in the ASME AG-1 standard. The DOE publication Nuclear Air Cleaning Handbook (NACH) is an additional guidance document for design and operation HEPA filter systems in DOE facilities. These two guidelines establish basic maximum operating parameters for temperature, maximum aerosol particle size, maximum particulate matter mass concentration, acceptable differential pressure range, and filter media velocity. Each of these parameters is discussed along with data linking variability of each parameter with filter function and lifetime. Temporal uncertainty associated with gas composition, temperature, and absolute pressure of the air flow can have a direct impact on the volumetric flow rate of the system with a corresponding impact on filter media velocity. Correlations between standard units of flow rate (standard meters per minute or cubic feet per minute) versus actual units of volumetric flow rate are shown for variations in relative humidity for a 70 deg. C to 200 deg. C ve humidity for a 70 deg. C to 200 deg. C temperature range as an example of gas composition that, uncorrected, will influence media velocity. The AG-1 standard establishes a 2.5 cm/s (5 feet per minute) ceiling for media velocities of nuclear grade HEPA filters. Data are presented that show the impact of media velocities from 2.0 to 4.0 cm/s media velocities (4 to 8 fpm) on differential pressure, filter efficiency, and filter lifetime. Data will also be presented correlating media velocity effects with two different particle size distributions. (authors)

  18. Stability of sunscreens containing CePO4: proposal for a new inorganic UV filter.

    Science.gov (United States)

    Seixas, Vitor C; Serra, Osvaldo A

    2014-01-01

    Inorganic UV filters have become attractive because of their role in protecting the skin from the damage caused by continuous exposure to the sun. However, their large refractive index and high photocatalytic activity have led to the development of alternative inorganic materials such as CePO4 for application as UV filters. This compound leaves a low amount of white residue on the skin and is highly stable. The aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing ordinary organic UV filters combined with 5% CePO4, and, to compare it with other formulations containing the same vehicle with 5% TiO2 or ZnO as inorganic materials. The rheological behavior and chemical stability of the formulations containing these different UV filters were investigated. Results showed that the formulation containing CePO4 is a promising innovative UV filter due to its low interaction with organic filters, which culminates in longer shelf life when compared with traditional formulations containing ZnO or TiO2 filters. Moreover, the recognized ability of CePO4 to leave a low amount of white residue on the skin combined with great stability, suggests that CePO4 can be used as inorganic filter in high concentrations, affording formulations with high SPF values. PMID:25010465

  19. Stability of Sunscreens Containing CePO4: Proposal for a New Inorganic UV Filter

    Directory of Open Access Journals (Sweden)

    Vitor C. Seixas

    2014-07-01

    Full Text Available Inorganic UV filters have become attractive because of their role in protecting the skin from the damage caused by continuous exposure to the sun. However, their large refractive index and high photocatalytic activity have led to the development of alternative inorganic materials such as CePO4 for application as UV filters. This compound leaves a low amount of white residue on the skin and is highly stable. The aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing ordinary organic UV filters combined with 5% CePO4, and, to compare it with other formulations containing the same vehicle with 5% TiO2 or ZnO as inorganic materials. The rheological behavior and chemical stability of the formulations containing these different UV filters were investigated. Results showed that the formulation containing CePO4 is a promising innovative UV filter due to its low interaction with organic filters, which culminates in longer shelf life when compared with traditional formulations containing ZnO or TiO2 filters. Moreover, the recognized ability of CePO4 to leave a low amount of white residue on the skin combined with great stability, suggests that CePO4 can be used as inorganic filter in high concentrations, affording formulations with high SPF values.

  20. Development of Test Protocols for International Space Station Particulate Filters

    Science.gov (United States)

    Vijayakumar, R.; Green, Robert D.; Agui, Juan H.

    2015-01-01

    Air quality control on the International Space Station (ISS) is a vital requirement for maintaining a clean environment for the crew and the hardware. This becomes a serious challenge in pressurized space compartments since no outside air ventilation is possible, and a larger particulate load is imposed on the filtration system due to lack of gravitational settling. The ISS Environmental Control and Life Support System (ECLSS) uses a filtration system that has been in use for over 14 years and has proven to meet this challenge. The heart of this system is a traditional High-Efficiency Particulate Air (HEPA) filter configured to interface with the rest of the life support elements and provide effective cabin filtration. The filter element for this system has a non-standard cross-section with a length-to-width ratio (LW) of 6.6. A filter test setup was designed and built to meet industry testing standards. A CFD analysis was performed to initially determine the optimal duct geometry and flow configuration. Both a screen and flow straighter were added to the test duct design to improve flow uniformity and face velocity profiles were subsequently measured to confirm. Flow quality and aerosol mixing assessments show that the duct flow is satisfactory for the intended leak testing. Preliminary leak testing was performed on two different ISS filters, one with known perforations and one with limited use, and results confirmed that the testing methods and photometer instrument are sensitive enough to detect and locate compromised sections of an ISS BFE.Given the engineering constraints in designing spacecraft life support systems, it is anticipated that non-industry standard filters will be required in future designs. This work is focused on developing test protocols for testing the ISS BFE filters, but the methodology is general enough to be extended to other present and future spacecraft filters. These techniques for characterizing the test duct and perform leak testing can be applied to conducting acceptance testing and inventory testing for future manned exploration programs with air revitalization filtration needs, possibly even for in-situ filter element integrity testing for extensively long-duration missions. We plan to address the unique needs for test protocols for crewed spacecraft particulate filters by preparing the initial version of a standard, to be documented as a NASA Technical Memorandum (TM).

  1. Ensemble Kalman filtering without the intrinsic need for inflation

    Directory of Open Access Journals (Sweden)

    M. Bocquet

    2011-10-01

    Full Text Available The main intrinsic source of error in the ensemble Kalman filter (EnKF is sampling error. External sources of error, such as model error or deviations from Gaussianity, depend on the dynamical properties of the model. Sampling errors can lead to instability of the filter which, as a consequence, often requires inflation and localization. The goal of this article is to derive an ensemble Kalman filter which is less sensitive to sampling errors. A prior probability density function conditional on the forecast ensemble is derived using Bayesian principles. Even though this prior is built upon the assumption that the ensemble is Gaussian-distributed, it is different from the Gaussian probability density function defined by the empirical mean and the empirical error covariance matrix of the ensemble, which is implicitly used in traditional EnKFs. This new prior generates a new class of ensemble Kalman filters, called finite-size ensemble Kalman filter (EnKF-N. One deterministic variant, the finite-size ensemble transform Kalman filter (ETKF-N, is derived. It is tested on the Lorenz '63 and Lorenz '95 models. In this context, ETKF-N is shown to be stable without inflation for ensemble size greater than the model unstable subspace dimension, at the same numerical cost as the ensemble transform Kalman filter (ETKF. One variant of ETKF-N seems to systematically outperform the ETKF with optimally tuned inflation. However it is shown that ETKF-N does not account for all sampling errors, and necessitates localization like any EnKF, whenever the ensemble size is too small. In order to explore the need for inflation in this small ensemble size regime, a local version of the new class of filters is defined (LETKF-N and tested on the Lorenz '95 toy model. Whatever the size of the ensemble, the filter is stable. Its performance without inflation is slightly inferior to that of LETKF with optimally tuned inflation for small interval between updates, and superior to LETKF with optimally tuned inflation for large time interval between updates.

  2. Between tradition and renewal: Some considerations about the use of tradition in reformed theology

    Directory of Open Access Journals (Sweden)

    Willem van Vlastuin

    2013-08-01

    Full Text Available In the theology and practice of the Christian church a tension between tradition and renewal exists. This essay focuses on this tension to provide a first step of methodological reflection to deal with it. Firstly, this tension is illustrated from the reformed perspective of sola scripturathat led to criticism of the tradition on the one hand, whilst understanding the reformed movement as part of the tradition on the other hand. A danger of unqualified sola scriptura is subjectivity. Subsequently, the importance of tradition is elaborated from the perspective of the church as the body of Christ across all ages. This implies that Christians should study and love the traditional theology because of the fundamental unity of the church that transcends cultural diversity. Rejecting tradition will cut the church from its historical and spiritual roots. Thirdly, this raises the question whether the church is imprisoned by tradition, as well as the problem of the relation between tradition and renewal. In response, it is argued that the doctrine of incarnation guarantees openness to history. With the help of the philosophical and Christian view on structural contingency, the belief that tradition is principally open to renewal is defended. Some examples are given as illustrations of how classic theological concepts can be reframed in our postmodern context. The last part of this essay concludes with the insight of Cyprian that only the conveyed tradition can be renewed, implying that renewal is in essence not a new theology, but a new application of apostolic theology.

  3. Filtering ionosphere parameters to detect trends linked to anthropogenic effects

    Science.gov (United States)

    Elias, Ana G.

    2014-12-01

    The great concern about the global warming observed in the troposphere has generated a large interest in the study of long-term trends in the ionosphere since the early 1990s, which has now become a significant topic in global change investigations. Some research works link ionosphere trends to anthropogenic sources such as the increase in greenhouse gas concentration, and others to natural causes such as solar and geomagnetic activity long-term changes, and secular variations in the Earth's main magnetic field. In all the cases, in order to analyze ionospheric trends, solar activity effect must be filtered out first since around 90% of ionosphere parameter variance is due to solar variations. The filtering process can generate `spurious' trends in the filtered data series which may lead to erroneous conclusions. foF2 data series which include solar cycle 23 are analyzed in the present work in order to detect the effect of different filtering procedures on the determination of long-term trends. In particular, solar cycle 23 seems to have had an extreme ultraviolet (EUV) emission greater than that deduced from traditional solar EUV proxies during the maximum epoch and lower during the minimum epoch. When solar activity is filtered assessing the residuals of a linear regression between foF2 and Rz, or between foF2 and F10.7, this fact may bias trend values especially because it is at the end of the time series. The length of the period considered for trend assessment, the saturation and hysteresis effect of some ionosphere parameters, and the solar EUV proxy used are also considered in this study in order to quantify a possible spurious trend that may result as a by-product of a filtering process. Since trends expected as a consequence of anthropogenic effects are relatively small, these spurious effects may surely mask, or enhance, trends expected from anthropogenic origins.

  4. ADVANCED HOT GAS FILTER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    E.S. Connolly; G.D. Forsythe

    2000-09-30

    DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle filter manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any filters fabricated during this task would be used for product qualification tests being conducted by Westinghouse at Foster-Wheeler's Pressurized Circulating Fluidized Bed (PCFBC) test facility in Karhula, Finland. Task 5 was designed to demonstrate the improvements implemented in Task 4 by fabricating fifty 1.5-meter hot gas filters. These filters were to be made available for DOE-sponsored field trials at the Power Systems Development Facility (PSDF), operated by Southern Company Services in Wilsonville, Alabama.

  5. Independently tunable multichannel terahertz filters

    International Nuclear Information System (INIS)

    We numerically demonstrate terahertz multichannel filters with independently tunable defect modes based on fractal photonic crystals. Single defect and multiple defects models are proposed to fabricate the multichannel terahertz filters. The facts that the wave functions of the defect states do not overlap and their bases are orthogonal lead to the independency among the defect modes. The simulated results theoretically provide the principle for fabricating independently tunable multichannel terahertz filters by utilizing one-dimensional photonic crystals with defects. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  6. Face Recognition using Gabor Filters

    Directory of Open Access Journals (Sweden)

    Sajjad MOHSIN

    2011-01-01

    Full Text Available An Elastic Bunch Graph Map (EBGM algorithm is being proposed in this research paper that successfully implements face recognition using Gabor filters. The proposed system applies 40 different Gabor filters on an image. As aresult of which 40 images with different angles and orientation are received. Next, maximum intensity points in each filtered image are calculated and mark them as Fiducial points. The system reduces these points in accordance to distance between them. The next step is calculating the distances between the reduced points using distance formula. At last, the distances are compared with database. If match occurs, it means that the image is recognized.

  7. Determination of 'dynamic filter factor'

    International Nuclear Information System (INIS)

    The aim of this work was to experimentally determine the 'dynamic filter factor' in symmetrical fields for energies of 6 MV and 15 MV and to compare these results with values obtained by treatment planning system (Cad Plan) under the same conditions. So that, is possible to attribute, for treatment calculation with fields of irradiation that use dynamic filter, the same depth dose percentage used for opened field, without filter. In this way, is validated the system of planning CAD PLAN calculation used in this Institution

  8. Simplified design of filter circuits

    CERN Document Server

    Lenk, John

    1999-01-01

    Simplified Design of Filter Circuits, the eighth book in this popular series, is a step-by-step guide to designing filters using off-the-shelf ICs. The book starts with the basic operating principles of filters and common applications, then moves on to describe how to design circuits by using and modifying chips available on the market today. Lenk's emphasis is on practical, simplified approaches to solving design problems.Contains practical designs using off-the-shelf ICsStraightforward, no-nonsense approachHighly illustrated with manufacturer's data sheets

  9. Properties of ceramic candle filters

    Energy Technology Data Exchange (ETDEWEB)

    Pontius, D.H.

    1995-06-01

    The mechanical integrity of ceramic filter elements is a key issue for hot gas cleanup systems. To meet the demands of the advanced power systems, the filter components must sustain the thermal stresses of normal operations (pulse cleaning), of start-up and shut-down conditions, and of unanticipated process upsets such as excessive ash accumulation without catastrophic failure. They must also survive the various mechanical loads associated with handling and assembly, normal operation, and process upsets. For near-term filter systems, these elements must survive at operating temperatures of 1650{degrees}F for three years.

  10. Fuel Efficient Diesel Particulate Filter (DPF) Modeling and Development

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Mark L.; Gallant, Thomas R.; Kim, Do Heui; Maupin, Gary D.; Zelenyuk, Alla

    2010-08-01

    The project described in this report seeks to promote effective diesel particulate filter technology with minimum fuel penalty by enhancing fundamental understanding of filtration mechanisms through targeted experiments and computer simulations. The overall backpressure of a filtration system depends upon complex interactions of particulate matter and ash with the microscopic pores in filter media. Better characterization of these phenomena is essential for exhaust system optimization. The acicular mullite (ACM) diesel particulate filter substrate is under continuing development by Dow Automotive. ACM is made up of long mullite crystals which intersect to form filter wall framework and protrude from the wall surface into the DPF channels. ACM filters have been demonstrated to effectively remove diesel exhaust particles while maintaining relatively low backpressure. Modeling approaches developed for more conventional ceramic filter materials, such as silicon carbide and cordierite, have been difficult to apply to ACM because of properties arising from its unique microstructure. Penetration of soot into the high-porosity region of projecting crystal structures leads to a somewhat extended depth filtration mode, but with less dramatic increases in pressure drop than are normally observed during depth filtration in cordierite or silicon carbide filters. Another consequence is greater contact between the soot and solid surfaces, which may enhance the action of some catalyst coatings in filter regeneration. The projecting crystals appear to provide a two-fold benefit for maintaining low backpressures during filter loading: they help prevent soot from being forced into the throats of pores in the lower porosity region of the filter wall, and they also tend to support the forming filter cake, resulting in lower average cake density and higher permeability. Other simulations suggest that soot deposits may also tend to form at the tips of projecting crystals due to the axial velocity component of exhaust moving down the filter inlet channel. Soot mass collected in this way would have a smaller impact on backpressure than soot forced into the flow restrictions deeper in the porous wall structure. This project has focused on the development of computational, analytical, and experimental techniques that are generally applicable to a wide variety of exhaust aftertreatment technologies. By helping to develop improved fundamental understanding pore-scale phenomena affecting filtration, soot oxidation, and NOX abatement, this cooperative research and development agreement (CRADA) has also assisted Dow Automotive in continuing development and commercialization of the ACM filter substrate. Over the course of this research project, ACM filters were successfully deployed on the Audi R10 TDI racecar which won the 24 Hours of LeMans endurance race in 2006, 2007, and 2008; and the 12 Hours of Sebring endurance race in 2006 and 2007. It would not have been possible for the R10 to compete in these traditionally gasoline-dominated events without reliable and effective exhaust particulate filtration. These successes demonstrated not only the performance of automotive diesel engines, but the efficacy of DPF technology as it was being deployed around the world to meet new emissions standards on consumer vehicles. During the course of this CRADA project, Dow Automotive commercialized their ACM DPF technology under the AERIFYTM DPF brand.

  11. On-line filtering

    International Nuclear Information System (INIS)

    Present day electronic detectors used in high energy physics make it possible to obtain high event rates and it is likely that future experiments will face even higher data rates than at present. The complexity of the apparatus increases very rapidly with time and also the criteria for selecting desired events become more and more complex. So complex in fact that the fast trigger system cannot be designed to fully cope with it. The interesting events become thus contaminated with multitudes of uninteresting ones. To distinguish the 'good' events from the often overwhelming background of other events one has to resort to computing techniques. Normally this selection is made in the first part of the analysis of the events, analysis normally performed on a powerful scientific computer. This implies however that many uninteresting or background events have to be recorded during the experiment for subsequent analysis. A number of undesired consequences result; and these constitute a sufficient reason for trying to perform the selection at an earlier stage, in fact ideally before the events are recorded on magnetic tape. This early selection is called 'on-line filtering' and it is the topic of the present lectures. (Auth.)

  12. Collaborative Filtering Recommender Systems

    Directory of Open Access Journals (Sweden)

    Mehrbakhsh Nilashi

    2013-04-01

    Full Text Available Recommender Systems are software tools and techniques for suggesting items to users by considering their preferences in an automated fashion. The suggestions provided are aimed at support users in various decision-making processes. Technically, recommender system has their origins in different fields such as Information Retrieval (IR, text classification, machine learning and Decision Support Systems (DSS. Recommender systems are used to address the Information Overload (IO problem by recommending potentially interesting or useful items to users. They have proven to be worthy tools for online users to deal with the IO and have become one of the most popular and powerful tools in E-commerce. Many existing recommender systems rely on the Collaborative Filtering (CF and have been extensively used in E-commerce .They have proven to be very effective with powerful techniques in many famous E-commerce companies. This study presents an overview of the field of recommender systems with current generation of recommendation methods and examines comprehensively CF systems with its algorithms.

  13. Tunable HTS Filters

    Science.gov (United States)

    Mancusi, Joseph E.; Roberson, Mark

    2002-06-01

    The tunable HTS program goals are to develop a process, method, or device to tune high-temperature superconductor (HTS) resonant circuits. The process for tuning should preserve the low-loss nature of the s preconducting resonant circuits and be compatible with the operating environment of packaged HTS RF circuitry. Although we were originally developing three technologies to perform this tuning, we have down selected to the two that offer the greatest potential for high 0 operation, the half-HTS MEMS variable capacitor and the continuously variable inductor. The target application is for this technology is SIGINT applications in the 400 MHz to 3000 MHz frequency band, with potential applications in areas from 20 MHz to 20 GHz. We reached a significant milestone with the demonstration of the continuously variable inductors. In this demonstration we achieved a 23% tuning range, with better than 1 pan in 10,000 resettability, and a 0 of over 1.0,000. These are significant achievements in the area of tunable filters.

  14. Digital notch filter based active damping for LCL filters

    DEFF Research Database (Denmark)

    Yao, Wenli; Yang, Yongheng

    2015-01-01

    LCL filters are widely used in Pulse Width Modulation (PWM) inverters. However, it also introduces a pair of unstable resonant poles that may challenge the controller stability. The passive damping is a convenient possibility to tackle the resonance problem at the cost of system overall efficiency. In contrast, the active damping does not require any dissipation elements, and thus has become of increasing interest. As a result, a vast of active damping solutions have been reported, among which multi-loop control systems and additional sensors are necessary, leading to increased cost and complexity. In this paper, a notch filter based active damping without the requirement of additional sensors is proposed, where the inverter current is employed as the feedback variable. Firstly, a design method of the notch filter for active damping is presented. The entire system stability has then been investigated, which has revealed that negative variations of the resonant frequency can seriously affect the system stability. In order to make the controller more robust against grid impedance variations, the notch filter frequency is thus designed smaller than the LCL filter resonant frequency, which is done in the z-domain. Simulations and experiments are carried out to verify the proposed active damping method. Both results have confirmed that the notch filter based active damping can ensure the entire system stability in the case of resonances with a good system performance.

  15. Experience with three percutaneous vena cava filters

    International Nuclear Information System (INIS)

    Twenty-one Kimray-Greenfield, 33 bird's nest, and 19 Amplatz vena cava filters were placed percutaneously. The Kimray-Greenfield filter was the most difficult to insert. The major problem was the insertion site, which required venipuncture with a 24-F catheter. Minor hemorrhage was frequent, and femoral vein thrombosis occurred in four patients. No migration, caval thrombosis, or pulmonary emboli were seen after Kimray-Greenfield filter placement. The bird's nest filter was relatively easy to insert, although in two cases the filter prongs could not be adequately seated in the wall of the inferior vena cava. Three patients with bird's nest filters had thrombosis below the filter, and three filters migrated to the heart. One migrated filter could not be removed. One patient had multiple small pulmonary emboli at autopsy. No other pulmonary emboli after filter placement were noted. The Amplatz filter was the easiest of the three filters to insert. Only one patient with an Amplatz filter had thrombosis of the vena cava below the filter. No filter migrations were documented, and no recurrent pulmonary emboli were found on clinical or radiologic follow-up. The Amplatz vena cava filter is easier to place than percutaneous Kimray-Greenfield or bird's nest filters, has a low complication rate, and has proven to be clinically effective in preventing pulmonary emboli

  16. Mechanical comparison of a polymer nanocomposite to a ceramic thin-film anti-reflective filter

    International Nuclear Information System (INIS)

    Thin-film filters on optical components have been in use for decades and, for those industries utilizing a polymer substrate, the mismatch in mechanical behaviour has caused problems. Surface damage including scratches and cracks induces haze on the optical filter, reducing the transmission of the optical article. An in-mold anti-reflective (AR) filter incorporating 1/4-wavelength thin films based on a polymer nanocomposite is outlined here and compared with a traditional vacuum deposition AR coating. Nanoindentation and nanoscratch techniques are used to evaluate the mechanical properties of the thin films. Scanning electron microscopy (SEM) images of the resulting indentations and scratches are then compared to the force deflection curves to further explain the phenomena. The traditional coatings fractured by brittle mechanisms during testing, increasing the area of failure, whereas the polymer nanocomposite gave ductile failure with less surface damage

  17. Sensory pollution from bag-type fiberglass ventilation filters: Conventional filter compared with filters containing various amounts of activated carbon

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Fadeyi, M.O.

    2009-01-01

    As ventilation filters accumulate particles removed from the airstream, they become emitters of sensory pollutants that degrade indoor air quality. Previously we demonstrated that an F7 bag-type filter that incorporates activated carbon (a "combination filter") reduces this adverse effect compared to an equivalent filter without carbon. The aim of the present study was to examine how the amount of activated carbon (AC) used in combination filters affects their ability to remove both sensory offending pollutants and ozone. A panel evaluated the air downstream of four different filters after each had continuously filtered outdoor suburban air over a period of 6 months. Interim assessments (mid-term evaluation) were performed after 3 months. During both assessments, four unused filters, identical in type to the loaded filters, were also evaluated. The evaluated filters included a conventional F7 fiberglass filter and three modifications of a bag-type fiberglass combination filter: the "Heavy" corresponded to a commercially available filter containing 400 g of carbon per square meter of filter area, the "Medium" contained half as much carbon (200 g/m(2)), and the "Light" contained a quarter as much carbon (100 g/m(2)). Each filter was weighed at the beginning of the soiling period and after 3 and 6 months of service. Additionally, up- and down-stream ozone concentrations and filter pressure drops were measured monthly. Following 6 months of service, the air downstream of each of the combination filters was judged to be significantly better than the air downstream of the 6-month-old F7 filter, and was comparable to that from an unused F7 filter. Additionally, the combination filters removed more ozone from the air than the F7 filter, with their respective fractional removal efficiencies roughly scaling with their carbon content.

  18. Fluid-filled dynamic bowtie filter: a feasibility study

    Science.gov (United States)

    Shunhavanich, Picha; Hsieh, Scott S.; Pelc, Norbert J.

    2015-03-01

    By varying its thickness to compensate for the different path length through the patient as a function of fan angle, a pre-patient bowtie filter modulates flux distribution to reduce patient dose, scatter, and detector dynamic range, and to improve image quality. A dynamic bowtie filter is superior to its traditional, static counterpart in its ability to adjust its thickness along different fan and view angles to suit a specific patient and task. Among the proposed dynamic bowtie designs, the piecewise-linear and the digital beam attenuators offer more flexibility than conventional filters, but rely on analog positioning of a limited number of wedges. In this work, we introduce a new approach with digital control, called the fluid-filled dynamic bowtie filter. It is a two-dimensional array of small binary elements (channels filled or unfilled with attenuating liquid) in which the cumulative thickness along the x-ray path contributes to the bowtie's total attenuation. Using simulated data from a pelvic scan, the performance is compared with the piecewise-linear attenuator. The fluid-filled design better matches the desired target attenuation profile and delivers a 4.2x reduction in dynamic range. The variance of the reconstruction (or noise map) can also be more homogeneous. In minimizing peak variance, the fluid-filled attenuator shows a 3% improvement. From the initial simulation results, the proposed design has more control over the flux distribution as a function of both fan and view angles.

  19. Local geometry variable conductance diffusion for post-reconstruction filtering

    International Nuclear Information System (INIS)

    Variable conductance diffusion (VCD) filtering can preserve edges while smoothing noise in an image. The threshold of the conductance function determines the degree to which a part of the image is smoothed. Traditionally, a constant threshold has been used. The use of a global threshold does not allow for adaptation to local variations within the image. The approach presented in this paper exploits the local geometry of the image and derives the threshold from the variations that are more likely caused by noise than by structural changes. The authors apply it to simulated noisy reconstructed single-photon emission computed tomographic (SPECT) image sets. For a particular voxel, if a consistent gradient direction is found within its neighborhood, then the variations on the plane perpendicular to the gradient direction are considered as noise and used to derive the threshold. The results show that, for the same average noise level in the liver, the image contrast from both local geometry and constant threshold VCD filters are higher than those from Butterworth filtering. The local geometry VCD filtering provides images with smoother boundaries than the constant threshold method. Moreover, the contrast loss is less sensitive to the tumor size for the local geometry method

  20. Pansharpening of multispectral images using filtering in Fourier domain

    Science.gov (United States)

    Akoguz, Alper; Kurt, Burak; Pinar, Sedef K.

    2014-10-01

    In this study, there is examined filtering based pansharpening methods which means of using several 2D FIR filters in Fourier domain which implies that the filters are applied after taking 2D Discrete Fourier Transform of both multispectral and panchromatic image and after the pansharpening process in Fourier domain, the resulting pansharpened image is obtained with an inverse 2D DFT. In addition, these methods are compared with commonly used fusion methods which are combined as modulation based and component substitution based methods. The algorithms are applied to SPOT 6 co-registered image couples that were acquired simultaneously. Couples are chosen for three different regions which are a city image (Gebze/Turkey), a forest image (Istanbul/Turkey) and an agriculture field image (Sanliurfa/Turkey) in order to analyse the methods in different regional characteristics. These methods are compared by the fusion quality assessments that have common acceptance in community. The results of these quality assessments shows the filtering based methods had the best scores among the traditional methods.

  1. Traditional Chinese food technology and cuisine.

    Science.gov (United States)

    Li, Jian-rong; Hsieh, Yun-Hwa P

    2004-01-01

    From ancient wisdom to modern science and technology, Chinese cuisine has been established from a long history of the country and gained a global reputation of its sophistication. Traditional Chinese foods and cuisine that exhibit Chinese culture, art and reality play an essential role in Chinese people's everyday lives. Recently, traditional Chinese foods have drawn a great degree of attention from food scientists and technologists, the food industry, and health promotion institutions worldwide due to the extensive values they offer beyond being merely another ethnic food. These traditional foods comprise a wide variety of products, such as pickled vegetables, salted fish and jellyfish, tofu and tofu derived products, rice and rice snack foods, fermented sauces, fish balls and thousand-year-old eggs. An overview of selected popular traditional Chinese foods and their processing techniques are included in this paper. Further development of the traditional techniques for formulation and production of these foods is expected to produce economic, social and health benefits. PMID:15228981

  2. Image Enhancement using Filtering Techniques

    OpenAIRE

    Krishan Kant Lavania; Shivali; Rajiv Kumar

    2012-01-01

    Image enhancement is used to improve the quality of an image. In this paper, two novel algorithms CB (Center-to-Boundary) and BB (Boundary-to-Boundary) filters have proposed. These algorithms have implemented for

  3. Biometric verification with correlation filters

    Science.gov (United States)

    Vijaya Kumar, B. V. K.; Savvides, Marios; Xie, Chunyan; Venkataramani, Krithika; Thornton, Jason; Mahalanobis, Abhijit

    2004-01-01

    Using biometrics for subject verification can significantly improve security over that of approaches based on passwords and personal identification numbers, both of which people tend to lose or forget. In biometric verification the system tries to match an input biometric (such as a fingerprint, face image, or iris image) to a stored biometric template. Thus correlation filter techniques are attractive candidates for the matching precision needed in biometric verification. In particular, advanced correlation filters, such as synthetic discriminant function filters, can offer very good matching performance in the presence of variability in these biometric images (e.g., facial expressions, illumination changes, etc.). We investigate the performance of advanced correlation filters for face, fingerprint, and iris biometric verification.

  4. Variable-Basis Fuzzy Filters

    CERN Document Server

    Luna-Torres, Joaquin

    2010-01-01

    U. H{\\"o}hle and A. {\\v{S}}ostak have developed in \\cite{HS} the category of complete quasi-monoidal lattices; S. E. Rodabaugh in \\cite{RO} proposed its opposite category and with a subcategory $\\mathbf{C}$ of the latter, he define grounds of the form $\\mathbf{SET\\times C}$. In this paper, for each ground category of the form $\\mathbf{SET\\times C}$, we study categorical frameworks for variable-basis fuzzy filters, particularly the category $\\mathbf{C-FFIL}$ of variable-basis fuzzy filters, as a natural generalization of the category of fixed-basis fuzzy filters which was introduced in \\cite{LO}. In addition, we get some relations between the category of variable-basis fuzzy filters and the category of variable-basis fuzzy topological spaces.

  5. Dimensional reduction in nonlinear filtering

    International Nuclear Information System (INIS)

    The theory of nonlinear filtering forms the framework of many data assimilation problems. When the rates of change of different variables differ by orders of magnitude, efficient data assimilation can be accomplished by constructing nonlinear filtering equations for the coarse-grained signal. We consider the conditional law of a signal given the observations in a multi-scale context. In particular, we study how scaling interacts with filtering via stochastic averaging. This is an extension of our previous work (Park et al 2008 Stoch. Dyn. 8 543–60) where the observation process depended only on the fast variable, so the filter became independent of the observation in the limit. Here, we investigate a more realistic setting in which the observation depends on both the slow and the fast variables

  6. Wiener Chaos and Nonlinear Filtering

    International Nuclear Information System (INIS)

    The paper discusses two algorithms for solving the Zakai equation in the time-homogeneous diffusion filtering model with possible correlation between the state process and the observation noise. Both algorithms rely on the Cameron-Martin version of the Wiener chaos expansion, so that the approximate filter is a finite linear combination of the chaos elements generated by the observation process. The coefficients in the expansion depend only on the deterministic dynamics of the state and observation processes. For real-time applications, computing the coefficients in advance improves the performance of the algorithms in comparison with most other existing methods of nonlinear filtering. The paper summarizes the main existing results about these Wiener chaos algorithms and resolves some open questions concerning the convergence of the algorithms in the noise-correlated setting. The presentation includes the necessary background on the Wiener chaos and optimal nonlinear filtering

  7. Deconstructing Tradition in Japanese Music : A Study of Shakuhachi, Historical Authenticity and Transmission of Tradition

    OpenAIRE

    Linder, Gunnar Jinmei

    2012-01-01

    In the present study I examine the vertical bamboo flute shakuhachi, as an example of how a tradition can be constructed. There are two main issues: the historical authenticity of the believed origins and development of the shakuhachi tradition, and how the transmission of this tradition is conducted. The first main issue is concerned with how a legendary origin, probably constructed in the late seventeenth century, was disproved in early twentieth-century studies. According to this legendary...

  8. Between tradition and renewal: Some considerations about the use of tradition in reformed theology

    OpenAIRE

    Willem van Vlastuin

    2013-01-01

    In the theology and practice of the Christian church a tension between tradition and renewal exists. This essay focuses on this tension to provide a first step of methodological reflection to deal with it. Firstly, this tension is illustrated from the reformed perspective of sola scripturathat led to criticism of the tradition on the one hand, whilst understanding the reformed movement as part of the tradition on the other hand. A danger of unqualified sola scriptura is subjectivity. Subseque...

  9. An epistemological reflection on the relevance of monastic traditions for retreat in the Dutch Reformed tradition

    OpenAIRE

    Schutte, C. H.; Yolanda Dreyer

    2006-01-01

    The article focuses on retreat as a relatively new phenomenon in the Dutch Reformed tradition. Retreat is viewed as "communicative action". The aim of the article is firstly to explore epistemological theories in the postmodern paradigm. These theories provide a mental framework for the identification of a research model and a related methodology by means of which the relevance of monastic traditions for retreat in the Reformed tradition can be discovered. The identification o...

  10. Data-mining of potential antitubercular activities from molecular ingredients of traditional Chinese medicines

    Directory of Open Access Journals (Sweden)

    Salma Jamal

    2014-07-01

    Full Text Available Background. Traditional Chinese medicine encompasses a well established alternate system of medicine based on a broad range of herbal formulations and is practiced extensively in the region for the treatment of a wide variety of diseases. In recent years, several reports describe in depth studies of the molecular ingredients of traditional Chinese medicines on the biological activities including anti-bacterial activities. The availability of a well-curated dataset of molecular ingredients of traditional Chinese medicines and accurate in-silico cheminformatics models for data mining for antitubercular agents and computational filters to prioritize molecules has prompted us to search for potential hits from these datasets. Results. We used a consensus approach to predict molecules with potential antitubercular activities from a large dataset of molecular ingredients of traditional Chinese medicines available in the public domain. We further prioritized 160 molecules based on five computational filters (SMARTSfilter so as to avoid potentially undesirable molecules. We further examined the molecules for permeability across Mycobacterial cell wall and for potential activities against non-replicating and drug tolerant Mycobacteria. Additional in-depth literature surveys for the reported antitubercular activities of the molecular ingredients and their sources were considered for drawing support to prioritization. Conclusions. Our analysis suggests that datasets of molecular ingredients of traditional Chinese medicines offer a new opportunity to mine for potential biological activities. In this report, we suggest a proof-of-concept methodology to prioritize molecules for further experimental assays using a variety of computational tools. We also additionally suggest that a subset of prioritized molecules could be used for evaluation for tuberculosis due to their additional effect against non-replicating tuberculosis as well as the additional hepato-protection offered by the source of these ingredients.

  11. Identification Filtering with fuzzy estimations

    OpenAIRE

    J. J. Medel J.; J. C: Garcia I; J. C. Sanchez G

    2012-01-01

    A digital identification filter interacts with an output reference model signal known as a black-box output system. The identification technique commonly needs the transition and gain matrixes. Both estimation cases are based on mean square criterion obtaining of the minimum output error as the best estimation filtering. The evolution system represents adaptive properties that the identification mechanism includes considering the fuzzy logic strategies affecting in probability sense the evolu...

  12. Multi-Domain Collaborative Filtering

    OpenAIRE

    ZHANG, YU; CAO, BIN; Yeung, Dit-Yan

    2012-01-01

    Collaborative filtering is an effective recommendation approach in which the preference of a user on an item is predicted based on the preferences of other users with similar interests. A big challenge in using collaborative filtering methods is the data sparsity problem which often arises because each user typically only rates very few items and hence the rating matrix is extremely sparse. In this paper, we address this problem by considering multiple collaborative filterin...

  13. Stochastic processes and filtering theory

    CERN Document Server

    Jazwinski, Andrew H

    2007-01-01

    This unified treatment of linear and nonlinear filtering theory presents material previously available only in journals, and in terms accessible to engineering students. Its sole prerequisites are advanced calculus, the theory of ordinary differential equations, and matrix analysis. Although theory is emphasized, the text discusses numerous practical applications as well.Taking the state-space approach to filtering, this text models dynamical systems by finite-dimensional Markov processes, outputs of stochastic difference, and differential equations. Starting with background material on probab

  14. F-boxes for filtering

    OpenAIRE

    Strauss, Olivier; Destercke, Sebastien

    2011-01-01

    Selecting a particular summative kernel (i.e., formally equivalent to a probability distribution) when filtering a digital signal can be a difficult task. An obvious solution to this problem is to filter with multiple kernels rather than with a single one, but the computing cost of such a solution can quickly become prohibitive (especially in real-time applications). Another alternative, the one studied in this paper, is to consider kernels modeled by imprecise probabilistic representations. ...

  15. Optimization of the filter technique

    International Nuclear Information System (INIS)

    A technique of the resonant filtering is used in the Moessbauer spectroscopy for receiving polarized radiation. Two main contributions suppress the filter quality: unwanted small absorption line located at the resonance energy and large unwanted absorption line located far from the resonance energy. Both contributions can be parametrized by a single small parameter r. The optimal effective thickness is proportional to 1 / r2, while the departure of the maximum polarization degree from the unity is proportional to r.

  16. Aquatic Plants Aid Sewage Filter

    Science.gov (United States)

    Wolverton, B. C.

    1985-01-01

    Method of wastewater treatment combines micro-organisms and aquatic plant roots in filter bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of filter, act in several steps to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.

  17. New constructions of antilaser filters

    Science.gov (United States)

    Mierczyk, Zygmunt; Kwasny, Miroslaw; Ciosek, Jerzy

    1995-03-01

    In this paper some solutions of anti-laser absorption-interference filters are presented, satisfying demands of increased transmission in the visible range, enlarged resistance, and improved work comfort at longer usage. In order to increase the total transmission the anti- reflecting coatings were used on the glass surface. Besides the contrast increase the work comfort is improved. The anti-reflecting layers are necessary in case of using the large power lasers due to the possibility of reflection of large intensity radiation from the filter surface. A selective reflection of light by thin-layer interference pile was used in construction of anti-laser filters for several wavelengths. The absorption-interference filter was elaborated for I and II YAG:Nd laser harmonics. By depositing the cut-off type thin-layer filter onto the infrared and NIR filters virtually brightened image, very apparent rising of contrast, and a final green color well accepted by the eye were obtained.

  18. The traditional knowledge and the intellectual property

    International Nuclear Information System (INIS)

    This article seeks to describe the state of the art in the international context of the traditional knowledge, its content, its recognition, and its valuation. The prosperous results of the biotechnical industry in the scientific and commercial field, has had a great impact in the valuation of the intellectual property, in the context of the globalization of the market. Traditionally the ancestral knowledge of the ethnic communities in the relative thing to the appropriation of the nature for their survival, it has not been considered neither valued in the same terms that the scientific knowledge and therefore, neither it has been analyzed as intellectual property, just as the western right it has structured this special form of property. The convention of the biodiversity, put in undoubtedly the traditional knowledge should be protected and valued, for this reason starting from 1992, the commercial agreements consecrate and they recognize this theme

  19. Commission on Traditional Leadership: Disputes and Claims

    Scientific Electronic Library Online (English)

    Jeff, Peires.

    2014-09-01

    Full Text Available This article examines the practices of the Commission on Traditional Leadership: Disputes and Claims, set up under the Framework Act of 2003 to 'cleanse' the institution of traditional leadership by ridding it of the illegitimate traditional leaders installed during the colonial and homeland eras. C [...] lose analysis of the Commission's hearings and determinations with regard to kingship claims by the Western Mpondo and Mpumalanga Ndebele shows that the Commission violated not only the historical past but even the limited constraints of binding legislation, in order to impose its own preferences in the name of custom. The experience of the Commission therefore highlights one of the most fundamental deficiencies in the Framework Act, namely insisting on the guiding role of 'custom' while failing to define the meaning of the term and its implications.

  20. Elliptical microwave cavity filters for satellites

    Science.gov (United States)

    Deschamps, P.; Sombrin, J.

    1980-02-01

    Dual-mode waveguide bandpass filters have been realized for communication-satellite transponders. The filter designs permit the reduction of weight and volume as well as the efficient use of allocated frequency bands. Some theoretical calculations of filter properties are presented and some designs of transponder filters at 4 GHz are considered.

  1. Filters and Components With Inductance Cancellation

    OpenAIRE

    Neugebauer, Timothy C.; Phinney, Joshua W.; Perreault, David J.

    2003-01-01

    Electrical filters are important for attenuating electrical ripple, eliminating electromagnetic interference (EMI) and susceptibility, improving power quality, and minimizing electromagnetic signature. Capacitors are critical elements in such filters, and filter performance is strongly influenced by the capacitor parasitics. This paper introduces a new design technique that overcomes the capacitor parasitic inductance that limits filter performance at high frequencies. Coupled magnetic windin...

  2. The ?Guslar?: Individual identity and tradition

    Directory of Open Access Journals (Sweden)

    Laji?-Mihajlovi? Danka

    2007-01-01

    Full Text Available The subject of this paper is the relation between individual and collective identity within the folk-music tradition, from the perspective of ethnomusicology. Solo folk musicians have more latitude than those who perform in ensembles. They are more independent in developing their own style. As an example of this intermingling of individual and traditional styles, we have chosen Branko Perovi?, ?guslar? (a singer of epic songs who accompanies himself on the ?gusle? - currently one of the very best. Both his extraordinary vocal qualities and his unique combination of temperament and emotions have enabled Perovi? to develop an original performing style. By comparing the regional, Montenegrin style of gusle-playing (of which Perovi? is a representative with his personal style, we have established certain corresponding structures regarding a few basic analytical parameters: musical form at the macro-level, tonal structure, and harmonic structure. Individual characteristics are to be found in melodic patterns, dynamics, agogics and ornaments, and to a certain extent, in rhythm. Although Perovi? is considered to be an ?innovator? among folk musicians, taking a dynamic approach to tradition, he is, however, well received and highly rated in folk music circles, which is proof of his successful communication with his audience. His reputation and influence on other gusle-players makes him a worthy link in the chain of epic tradition. His performance underlines the importance of the connection between traditional music and society, within which he develops his own style according to his capacities and inclinations, although constantly referring to the functional and aesthetic criteria of his cultural environment in which he performs. This is how adopted models are being reshaped by both individual artistic style and the current cultural pattern of a given community. The individual identity (of the musician is in constant interaction with those of his/her ancestors and contemporaries. The extraordinary, charismatic personalities of a guslar such as Perovi?, secure the continuation of the tradition into the future.

  3. Religious Tradition and the Archaic Man

    Directory of Open Access Journals (Sweden)

    Veress Károly

    2005-04-01

    Full Text Available My article as a first step in a comprehensive research program attempts to verify the hypothesis according to which M. Eliade's morphological and historical investigations of archaic religiousness reveal the outlines of an archaic ontology. For this purpose, the article focuses upon Eliade's conception of religious tradition as the carrier of the indivisible unity of sacred existence and religious experience. The ontological difference found in religious existence and revealed by religious experience is rooted in the essentially hermeneutic nature of religious tradition. Therefore the perspective of philosophical hermeneutics proves very productive in the investigation of this problem.

  4. Confucianism and the Asian Martial Traditions

    Directory of Open Access Journals (Sweden)

    C. Alexander Simpkins

    2012-07-01

    Full Text Available Confucianism has been foundational in the political and social life of many Asian countries. Its influence pervades institutions and practices at every level of human activity. Martial arts have also benefited from this philosophy, as the traditional Confucian legacy continues to influence modern practices. This article briefly highlights some key figures and events, describes relevant core concepts of Confucian philosophy, and then shows exemplary applications to martial arts today. Modern martial artists can gain understanding of the traditional Confucian insights that deepen the significance of contemporary martial arts.

  5. Historical tradition in Serbian genre literature

    Directory of Open Access Journals (Sweden)

    ?or?evi? Ivan

    2008-01-01

    Full Text Available This paper discusses two Serbian science-fiction stories with a special emphasis on the motives in their narrative structure; the motive analysis is focused on those motives that represent a transposition of 'historical tradition' elements. The key words connecting images appearing in this context are: fear of losing (national identity and a strategy of resistance towards those, who presumably, want to 'take over' the identity. In this sense, a return to 'the historical tradition', in the analyzed texts, aims to reassess certain past models indicating at the same time those that have successfully served and endured as historical models in this discourse.

  6. Spatial filters for high power lasers

    Science.gov (United States)

    Erlandson, Alvin Charles; Bayramian, Andrew James

    2014-12-02

    A spatial filter includes a first filter element and a second filter element overlapping with the first filter element. The first filter element includes a first pair of cylindrical lenses separated by a first distance. Each of the first pair of cylindrical lenses has a first focal length. The first filter element also includes a first longitudinal slit filter positioned between the first pair of cylindrical lenses. The second filter element includes a second pair of cylindrical lenses separated by a second distance. Each of the second pair of cylindrical lenses has a second focal length. The second filter element also includes a second longitudinal slit filter positioned between the second pair of cylindrical lenses.

  7. Large margin filtering for signal sequence labeling

    OpenAIRE

    Flamary, Rémi; Labbé, Benjamin; Rakotomamonjy, Alain

    2010-01-01

    Signal Sequence Labeling consists in predicting a sequence of labels given an observed sequence of samples. A naive way is to filter the signal in order to reduce the noise and to apply a classification algorithm on the filtered samples. We propose in this paper to jointly learn the filter with the classifier leading to a large margin filtering for classification. This method allows to learn the optimal cutoff frequency and phase of the filter that may be different from zero...

  8. Implementing Kalman Filter in GPS Navigation

    OpenAIRE

    Prof. Kanika Gupta,; Ms. Apurva,; Ms. Priya Jindal,; Ms. Vishakha Snehi,

    2013-01-01

    This paper describes about the increase in efficiency of the GPS Navigation System when conventional tracking loops are replaced by the Kalman Filter. The Kalman Filter is a recursive algorithm that helps in reducing the square root of the error in the non-linear and noisy dynamic systems. The approach is also called Digital Filtering, more precisely - Adaptive Filtering. The paper highlights various errors in the GPS Systems and describes how Kalman Filter can effectively reduce them. The va...

  9. A simple way for Šolc filter synthesis.

    Science.gov (United States)

    Kucherov, V. A.

    1996-01-01

    Mathematical conditions are proposed for explaining a sidelobe-free Šolc filter structure. The author developed filter designs in which the outer phase plates are rejected in systems with a large number of elements and a binomial distribution of component orientation angles. Spectral properties of filters with a truncated binomial distribution compare well with other optimum solutions for Šolc filters, while the filter synthesis follows the simplest procedure.

  10. Analytic Moment-based Gaussian Process Filtering

    OpenAIRE

    Deisenroth, MP; Huber, MF; Hanebeck, UD

    2009-01-01

    We propose an analytic moment-based filter for nonlinear stochastic dynamic systems modeled by Gaussian processes. Exact expressions for the expected value and the covariance matrix are provided for both the prediction step and the filter step, where an additional Gaussian assumption is exploited in the latter case. Our filter does not require further approximations. In particular, it avoids finite-sample approximations. We compare the filter to a variety of Gaussian filters, that is, the EKF...

  11. Multiplier-free filters for wideband SAR

    DEFF Research Database (Denmark)

    Dall, JØrgen; Christensen, Erik Lintz

    2001-01-01

    This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results are presented in terms of filter complexity and performance. One filter has been coded in VHDL and preliminary results indicate that the filter can meet a 2 GHz input sample rate.

  12. Digital Image Filtering Techniques- A survey

    Directory of Open Access Journals (Sweden)

    Sakshi Mahajan

    2013-08-01

    Full Text Available This paper presents a review on digital image filtering techniques. The main emphasis is on median filtering and its extended versions like hybrid median filtering, relaxed median filtering etc. It is found that still median filtering demands some sort of enhancements as it is best for salt and pepper noise only. By conducting a survey suitable gaps are found in existing literature. In the end comparison table is also drawn among the existing techniques.

  13. A Framework for Nonlinear Filtering in MATLAB

    OpenAIRE

    Rosén, Jakob

    2005-01-01

    The object of this thesis is to provide a MATLAB framework for nonlinear filtering in general, and particle filtering in particular. This is done by using the object-oriented programming paradigm, resulting in truly expandable code. Three types of discrete and nonlinear state-space models are supported by default, as well as three filter algorithms: the Extended Kalman Filter and the SIS and SIR particle filters. Symbolic expressions are differentiated automatically, which allows for comforta...

  14. Image Enhancement Algorithm based on Improved Fuzzy Filter

    Directory of Open Access Journals (Sweden)

    Shaosheng Sun

    2014-01-01

    Full Text Available Due to dynamic range compression and contrast enhancement realized simultaneously in traditional image enhancement algorithm based on frequency domain, which cause the low contrast degree, an improved image enhancement algorithm based on fuzzy filter is proposed in this paper. According to subjective feeling of the human visual system to light luminance, the image is processed with the global brightness transform. And the image with the global low contrast degree and the poor effect of edge parts has sound reinforcing effect. Furthermore, the edge contrast is enhanced, even the brightness contrast and information can also effectively improve. Experimental results demonstrate that the algorithm has got good enhancement effect.

  15. Improving Recommendation Quality by Merging Collaborative Filtering and Social Relationships

    CERN Document Server

    De Meo, Pasquale; Fiumara, Giacomo; Provetti, Alessandro

    2011-01-01

    Matrix Factorization techniques have been successfully applied to raise the quality of suggestions generated by Collaborative Filtering Systems (CFSs). Traditional CFSs based on Matrix Factorization operate on the ratings provided by users and have been recently extended to incorporate demographic aspects such as age and gender. In this paper we propose to merge CFS based on Matrix Factorization and information regarding social friendships in order to provide users with more accurate suggestions and rankings on items of their interest. The proposed approach has been evaluated on a real-life online social network; the experimental results show an improvement against existing CFSs. A detailed comparison with related literature is also present.

  16. Traditional Arts Knowledge, Traditional Ecological Lore: The Intersection of Art Education and Environmental Education

    Science.gov (United States)

    Bequette, James W.

    2007-01-01

    Teaching about Native artworks as part of school arts curriculum can serve to pass on traditional ecological knowledge while also contextualizing colonialism's influence on traditional and contemporary Native arts practices. This article explores how schools can actively engage in community arts partnerships with American Indians who have…

  17. An Occupational Analysis Comparing 4-H Youth Development Agents Serving Traditional and Non-Traditional Clientele.

    Science.gov (United States)

    Borden, Lynne M.; Harris, William

    1998-01-01

    Six 4-H agents working with traditional clients and six with nontraditional clients participated in a DACUM (Developing a Curriculum) analysis of job tasks. They performed similar duties but the nontraditional group spent more time assessing individual members; the traditional group focused more on program management. (SK)

  18. A Novel Super Resolution Reconstruction of Low Reoslution Images Progressively Using DCT and Zonal Filter Based Denoising

    Directory of Open Access Journals (Sweden)

    Liyakathunisa

    2011-02-01

    Full Text Available Due to the factors like processing power limitations and channel capabilities images are often down sampled and transmitted at low bit rates resulting in a low resolution compressed image. High resolutionimages can be reconstructed from several blurred, noisy and down sampled low resolution images using a computational process know as super resolution reconstruction. Super-resolution is the process ofcombining multiple aliased low-quality images to produce a high resolution, high-quality image. The problem of recovering a high resolution image progressively from a sequence of low resolutioncompressed images is considered. In this paper we propose a novel DCT based progressive image display algorithm by stressing on the encoding and decoding process. At the encoder we consider a set of lowresolution images which are corrupted by additive white Gaussian noise and motion blur. The low resolution images are compressed using 8 by 8 blocks DCT and noise is filtered using our proposed novelzonal filter. Multiframe fusion is performed in order to obtain a single noise free image. At the decoder the image is reconstructed progressively by transmitting the coarser image first followed by the detail image. And finally a super resolution image is reconstructed by applying our proposed novel adaptive interpolation technique. We have performed both objective and subjective analysis of the reconstructed image, and the resultant image has better super resolution factor, and a higher ISNR and PSNR. A comparative study done with Iterative Back Projection (IBP and Projection on to Convex Sets (POCS,Papoulis Grechberg, FFT based Super resolution Reconstruction shows that our method has out performed the previous contributions.

  19. Filter-adsorber aging assessment

    International Nuclear Information System (INIS)

    An aging assessment of high-efficiency particulate (HEPA) air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the U.S. Nuclear Regulatory Commission's (USNRC) Nuclear Plant Aging Research (NPAR) Program. This evaluation of the general process in which characteristics of these two components gradually change with time or use included the compilation of information concerning failure experience, stressors, aging mechanisms and effects, and inspection, surveillance, and monitoring methods (ISMM). Stressors, the agents or stimuli that can produce aging degradation, include heat, radiation, volatile contaminants, and even normal concentrations of aerosol particles and gasses. In an experimental evaluation of degradation in terms of the tensile breaking strength of aged filter media specimens, over forty percent of the samples did not meet specifications for new material. Chemical and physical reactions can gradually embrittle sealants and gaskets as well as filter media. Mechanisms that can lead to impaired adsorber performance are associated with the loss of potentially available active sites as a result of the exposure of the carbon to airborne moisture or volatile organic compounds. Inspection, surveillance, and monitoring methods have been established to observe filter pressure drop buildup, check HEPA filters and adsorbers for bypass, and determine the retention effectiveness of aged carbon. These evaluatifectiveness of aged carbon. These evaluations of installed filters do not reveal degradation in terms of reduced media strength but that under normal conditions aged media can continue to effectively retain particles. However, this degradation may be important when considering the likelihood of moisture, steam, and higher particle loadings during severe accidents and the fact it is probable that the filters have been in use for an extended period

  20. Industrial redesign of traditional valencian tiles

    Directory of Open Access Journals (Sweden)

    Lucas, F.

    2000-02-01

    Full Text Available The idea behind this project was to recover a type of Traditional Valencian Ceramics, by adapting its own particular production technology to present-day systems, installations and materials.

    Se ha pretendido recuperar una tipología de Cerámica tradicional Valenciana, adaptando su tecnología productiva a los sistemas , instalaciones y materiales actuales.

  1. Alternative Approaches to Traditional Topics in Algebra

    Science.gov (United States)

    Coburn, John W.

    2010-01-01

    Students who otherwise seem unreachable through traditional approaches to algebra require some alternative teaching methods. So do teachers who seek to add elements of freshness and innovation to their classrooms or who simply appreciate variety. This article offers some unconventional techniques for teaching a few conventional algebra topics.…

  2. The Danish Free School Tradition under Pressure

    Science.gov (United States)

    Olsen, Tore Vincents

    2015-01-01

    The Danish free school tradition has entailed a large degree of associational freedom for non-governmental schools, religious as well as non-religious. Until the late 1990s, the non-governmental schools were under no strict ideological or pedagogical limitations; they could recruit teachers and students according to their own value base, and were…

  3. Loss and mourning in the Jewish tradition.

    Science.gov (United States)

    Rubin, Simon Shimshon

    Robert Kastenbaum was a man who helped reintroduce issues related to death, dying, and bereavement to academic, clinical, and general discourse. This article, devoted to an encounter with the observance of mourning custom and ritual in the Jewish tradition, continues the dialogue in this journal that Bob founded. The article utilizes the Two-Track Model of Bereavement to address the Jewish tradition's structuring of the loss experience. After a brief introduction, I present a schematic presentation of some of the issues operant in grief and mourning for the believer. This is followed by two responses to loss that portray the pain of loss in the tradition. The article goes on to consider the Jewish time cycle of response to loss-from preburial Aninut, to Shiva, the first week, to Shloshim, the first month, to Shanah, the first year, to the expectations for encounters across the life cycle. The Yizkor and Kaddish are also considered. In the Jewish tradition, alongside attention to what level of functioning to require of the bereaved, there are lifelong opportunities to re-work and maintain connection to the memories, associations, narratives, and experiences that comprise the psychological organization of the continuing bond and relationship to the deceased. PMID:25351592

  4. An Alternative to the Traditional Grading System.

    Science.gov (United States)

    Galvez, Ferdinand V.

    The purpose of this practicum was to change the grading policy in the San Juan Unified School District (California) through a two-state process. The first stage was to change the traditional ABCDF grading system to a three-scale grading system in one high school, one intermediate school, and six elementary schools serving the same attendance area.…

  5. Expressing the Tradition in an Educational Context

    Science.gov (United States)

    Jones, Robert

    2005-01-01

    Being born into a religious tradition, remaining within it and making one's life an expression of it as a chaplain in a faith-based college is not necessarily an unimaginative choice. A culture has some enduring characteristics but to survive meaningfully it has to be relevant to contemporary life. Thus, there is a necessity to question what is to…

  6. Akan Traditional Arbitration: Its Structure and Language

    Science.gov (United States)

    Agyekum, Kofi

    2006-01-01

    This paper examines the basic components of the process of settlement, types of offences and language of Akan traditional arbitration. The paper also considers arbitration and Akan sociocultural norms and values. The paper finally discusses the status of Akan arbitration within the context of contemporary forms of adjudication, democracy,…

  7. A MISCELLANY ON INDIAN TRADITIONAL MUSIC

    Directory of Open Access Journals (Sweden)

    Rauf Kerimov

    2013-06-01

    Full Text Available Indian music has a very long, unbroken tradition and is an accumulated heritage of centuries. Music in India was popular among all the sections of society and intertwined in life and culture from birth to death. Indian music was formed with the evolution of ancient religious and secular music. The Indian culture absorbed all the best that was brought by other nations in the process of historical development. The Indian music is quite diverse: there are classical instrumental and vocal works and traditional singing of sacred hymns, folk songs and music of different nations. In contrast to the music scholarship, where typically image is a certain regularity, discipline and harmony, beauty of the traditional Indian music in the free improvisation, which is used by the performer. Listening carefully of this music, the man in a new world, a different sounds and explore a different idea of music for himself. The aim of the Indian music, unlike European musical culture define, explore, create and move depths to people's moods. And the Indian instruments is a miracle, that could reflect all these philosophical and aesthetic views. Along with the vocal art, this musical tradition has rich variety of melodic and rhythmic instruments.

  8. Traditions of Moral Education in Iraq

    Science.gov (United States)

    Al-Khaizaran, Huda

    2007-01-01

    This article suggests three ideas. First, under the pressures of the Ottoman and Iraqi state modernity projects, two types of cultural traditions in Iraq, namely Islam and Arab tribal values, were negotiated and re-negotiated. Second, the concepts of merit based on these values changed over time and were institutionalised in education. Third,…

  9. Contract Grading - Traditional Grading: A Comparison.

    Science.gov (United States)

    Eddy, James M.; Zimmerli, William H.

    The study compared the relationship of the contract plan of student evaluation and a traditional type of evaluation, for changes in knowledge and attitudes during a college course in ecological relationships. The Syracuse Environmental Awareness Test was used to measure both cognitive and affective changes. In the experimental group the contract…

  10. The 80's--Return to Traditions.

    Science.gov (United States)

    Deloria, Vine, Jr.

    Indians should be the ones to determine Indian education policy. Local control and freedom from outside interference would be the best thing for Indian education all around. Policymakers must first realize that education, if it is to be relevant to American Indians, must return in both content and substance to Indian traditions. Rather than…

  11. The Internet: The Demise of Traditional Online.

    Science.gov (United States)

    Ochsner, Heinz; Thomas, Karen

    The Internet has brought about a revolution in the concept of information provision for end-users, and opened up a diverse new market. The Internet has challenged the need for and role of traditional online services. Despite the benefits of the Internet, users face a number of dilemmas: finding needed information in a vast sea of information; time…

  12. Pedagogic Discourse and Transformation: A Selective Tradition

    Science.gov (United States)

    Liu, Yongbing

    2011-01-01

    This is the second of four essays discussing Wu's "Interpretation, autonomy, and transformation: Chinese pedagogic discourse in a cross-cultural perspective" (JCS, 43(5), 569-590). The essay is interesting against the background of recent debates, both inside and outside China, about the relationship between the Chinese and Western traditions of…

  13. Traditional festivities in Bohemia: Continuity and Revitalisation.

    Czech Academy of Sciences Publication Activity Database

    Stav?lová, Daniela

    Limerick : The Irish World Academy of Music and Dance, University of Limerick, 2014 - (Dunin, E.; Foley, C.), s. 278-286 ISBN 9781905952533. [Symposium of the Internacional Council for Traditional Music (ICTM) /27./. Limerick (IE), 22.07.2012-29.07.2012] Institutional support: RVO:68378076 Keywords : shrovetide * carnival * archetype * identity * collective memory Subject RIV: AC - Archeology, Anthropology, Ethnology

  14. Teaching Cultural Traditions: Art of Laos

    Science.gov (United States)

    Henderson, Lynette

    2005-01-01

    In the fall of 2003 the Children's Art Workshop, the Program for Southeast Asian Studies and Hayden Library at Arizona State University (ASU), in cooperation with the Arizona Lao Association, had both the fascinating and occasionally difficult experience of teaching Lao art traditions to a group of 25 students from diverse communities in the…

  15. Roman domestic art and early Christian traditions

    OpenAIRE

    Henten, Jan W.

    2010-01-01

    How to cite this book review: Van Henten, J.W., 2010, ‘Roman domestic art and early Christian traditions’, HTS Teologiese Studies/Theological Studies 66(1), Art. #999, 1 page. DOI: 10.4102/hts.v66i1.999

  16. Corporate Web Sites in Traditional Print Advertisements.

    Science.gov (United States)

    Pardun, Carol J.; Lamb, Larry

    1999-01-01

    Describes the Web presence in print advertisements to determine how marketers are creating bridges between traditional advertising and the Internet. Content analysis showed Web addresses in print ads; categories of advertisers most likely to link print ads with Web sites; and whether the Web site attempts to develop a database of potential…

  17. Sex Role Traditions and Retirement from Academe.

    Science.gov (United States)

    Kaye, Lenard W.; Monk, Abraham

    1984-01-01

    Examines gender-specific differences both prior and subsequent to retirement among 373 retired faculty and administrators. Findings indicated traditional sex roles influenced both retirement preparation and activities. Males were more likely to continue work-oriented pursuits while females participated in more social or recreational activities.…

  18. Milk-based traditional Turkish desserts

    Directory of Open Access Journals (Sweden)

    Tulay Ozcan

    2009-12-01

    Full Text Available Traditional foods are the reflection of cultural inheritance and affect the lifestyle habits. Culture can be viewed as a system of socially transmitted patterns of behaviour that characterises a particular group. Despite the fact of globalisation, these are key elements to accurately estimate a population’s dietary patterns and how these have been shaped through time. In Turkey, a meal with family or friends traditionally ends with a dessert, which is a testimony to the hosts’ hospitality or to the housewife’s love and affection for her husband and children, since sweets and desserts are important elements of Turkish cuisine. However, the consciousnesses of nutrition and healthy eating, due to rapid change in popular life style and dietary patterns, has contributed to the increased interest in traditional foods with potential health benefits, with increased uncertainty for dessert consumption. Dairy desserts are extensively consumed due to their nutritive and sensoric characteristics. Some of traditional dairy desserts are Mustafakemalpasa, Gullac, Kazandibi, Hosmerim and Tavukgogsu, which are mainly made from milk or fresh cheese, and the current paper discusses their manufacturing processes and composition.

  19. Traditional breeding and cultivar development (potato)

    Science.gov (United States)

    Traditional breeding allows for the genetic ‘reshuffling’ of genes and their recombination into new genotypes that may carry the desired assemblage of resistance and agronomic traits necessary for release as a new cultivar. While molecular biology techniques can be useful for improving upon a weakne...

  20. Alternatives to traditional transportation fuels 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    Interest in alternative transportation fuels (ATF`s) has increased in recent years due to the drives for cleaner air and less dependence upon foreign oil. This report, Alternatives to Traditional Transportation Fuels 1996, provides information on ATFs, as well as the vehicles that consume them.

  1. Integration of GPS Precise Point Positioning and MEMS-Based INS Using Unscented Particle Filter

    Science.gov (United States)

    Abd Rabbou, Mahmoud; El-Rabbany, Ahmed

    2015-01-01

    Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) integrated system involves nonlinear motion state and measurement models. However, the extended Kalman filter (EKF) is commonly used as the estimation filter, which might lead to solution divergence. This is usually encountered during GPS outages, when low-cost micro-electro-mechanical sensors (MEMS) inertial sensors are used. To enhance the navigation system performance, alternatives to the standard EKF should be considered. Particle filtering (PF) is commonly considered as a nonlinear estimation technique to accommodate severe MEMS inertial sensor biases and noise behavior. However, the computation burden of PF limits its use. In this study, an improved version of PF, the unscented particle filter (UPF), is utilized, which combines the unscented Kalman filter (UKF) and PF for the integration of GPS precise point positioning and MEMS-based inertial systems. The proposed filter is examined and compared with traditional estimation filters, namely EKF, UKF and PF. Tightly coupled mechanization is adopted, which is developed in the raw GPS and INS measurement domain. Un-differenced ionosphere-free linear combinations of pseudorange and carrier-phase measurements are used for PPP. The performance of the UPF is analyzed using a real test scenario in downtown Kingston, Ontario. It is shown that the use of UPF reduces the number of samples needed to produce an accurate solution, in comparison with the traditional PF, which in turn reduces the processing time. In addition, UPF enhances the positioning accuracy by up to 15% during GPS outages, in comparison with EKF. However, all filters produce comparable results when the GPS measurement updates are available. PMID:25815446

  2. Integration of GPS precise point positioning and MEMS-based INS using unscented particle filter.

    Science.gov (United States)

    Abd Rabbou, Mahmoud; El-Rabbany, Ahmed

    2015-01-01

    Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) integrated system involves nonlinear motion state and measurement models. However, the extended Kalman filter (EKF) is commonly used as the estimation filter, which might lead to solution divergence. This is usually encountered during GPS outages, when low-cost micro-electro-mechanical sensors (MEMS) inertial sensors are used. To enhance the navigation system performance, alternatives to the standard EKF should be considered. Particle filtering (PF) is commonly considered as a nonlinear estimation technique to accommodate severe MEMS inertial sensor biases and noise behavior. However, the computation burden of PF limits its use. In this study, an improved version of PF, the unscented particle filter (UPF), is utilized, which combines the unscented Kalman filter (UKF) and PF for the integration of GPS precise point positioning and MEMS-based inertial systems. The proposed filter is examined and compared with traditional estimation filters, namely EKF, UKF and PF. Tightly coupled mechanization is adopted, which is developed in the raw GPS and INS measurement domain. Un-differenced ionosphere-free linear combinations of pseudorange and carrier-phase measurements are used for PPP. The performance of the UPF is analyzed using a real test scenario in downtown Kingston, Ontario. It is shown that the use of UPF reduces the number of samples needed to produce an accurate solution, in comparison with the traditional PF, which in turn reduces the processing time. In addition, UPF enhances the positioning accuracy by up to 15% during GPS outages, in comparison with EKF. However, all filters produce comparable results when the GPS measurement updates are available. PMID:25815446

  3. A Sensor Fusion Algorithm for Filtering Pyrometer Measurement Noise in the Czochralski Crystallization Process

    Directory of Open Access Journals (Sweden)

    M. Komperød

    2011-01-01

    Full Text Available The Czochralski (CZ crystallization process is used to produce monocrystalline silicon for solar cell wafers and electronics. Tight temperature control of the molten silicon is most important for achieving high crystal quality. SINTEF Materials and Chemistry operates a CZ process. During one CZ batch, two pyrometers were used for temperature measurement. The silicon pyrometer measures the temperature of the molten silicon. This pyrometer is assumed to be accurate, but has much high-frequency measurement noise. The graphite pyrometer measures the temperature of a graphite material. This pyrometer has little measurement noise. There is quite a good correlation between the two pyrometer measurements. This paper presents a sensor fusion algorithm that merges the two pyrometer signals for producing a temperature estimate with little measurement noise, while having significantly less phase lag than traditional lowpass- filtering of the silicon pyrometer. The algorithm consists of two sub-algorithms: (i A dynamic model is used to estimate the silicon temperature based on the graphite pyrometer, and (ii a lowpass filter and a highpass filter designed as complementary filters. The complementary filters are used to lowpass-filter the silicon pyrometer, highpass-filter the dynamic model output, and merge these filtered signals. Hence, the lowpass filter attenuates noise from the silicon pyrometer, while the graphite pyrometer and the dynamic model estimate those frequency components of the silicon temperature that are lost when lowpass-filtering the silicon pyrometer. The algorithm works well within a limited temperature range. To handle a larger temperature range, more research must be done to understand the process' nonlinear dynamics, and build this into the dynamic model.

  4. A biological oil adsorption filter

    International Nuclear Information System (INIS)

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. (author)

  5. Iodine filters in nuclear installations

    International Nuclear Information System (INIS)

    The present report discusses the significance for environmental exposure of the iodine released with the gaseous effluents of nuclear power stations and reprocessing plants in relation to releases of other airborne radionuclides. Iodine filtration processes are described. The release pathways and the composition of airborne fission product iodine mixtures and their bearing on environmental exposure are discussed on the basis of measured fission product iodine emissions. The sorbents which can be used for iodine filtration, their removal efficiencies and range of applications are dealt with in detail. The particular conditions governing iodine removal, which are determined by the various gaseous iodine species, are illustrated on the basis of experimentally determined retention profiles. Particular attention is given to the limitations imposed by temperature, humidity, radiation and filter poisoning. The types of filter normally used are described, their advantages and drawbacks discussed, the principles underlying their design are outlined and the sources of error indicated. The methods normally applied to test the efficiency of various iodine sorbents are described and assessed. Operating experience with iodine filters, gathered from surveillance periods of many years, is supplemented by a large number of test results and the findings of extensive experiments. Possible ways of prolonging the permissible service lives of iodine filters are discussed and information is given on protective measures. The various iodine removal processes applied in reprocessing plants are described and compared with reference to efficiency and cost. The latest developments in filter technology in reprocessing plants are briefly outlined

  6. A biological oil adsorption filter

    Energy Technology Data Exchange (ETDEWEB)

    Pasila, A. [University of Helsinki (Finland). Dept. of Agricultural Engineering and Household Technology

    2005-12-01

    A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore. (author)

  7. Inferior vena cava filters in cancer patients: to filter or not to filter

    Directory of Open Access Journals (Sweden)

    Hikmat Abdel-Razeq

    2011-03-01

    Full Text Available Hikmat Abdel-Razeq1, Asem Mansour2, Yousef Ismael1, Hazem Abdulelah11Department of Internal Medicine, 2Department of Radiology, King Hussein Cancer Center, Amman, JordanPurpose: Cancer and its treatment are recognized risk factors for venous thromboembolism (VTE; active cancer accounts for almost 20% of all newly diagnosed VTE. Inferior vena cava (IVC filters are utilized to provide mechanical thromboprophylaxis to prevent pulmonary embolism (PE or to avoid bleeding from systemic anticoagulation in high-risk situations. In this report, and utilizing a case study, we will address the appropriate utilization of such filters in cancer patients.Methods: The case of a 43-year-old female patient with rectal cancer, who developed deep vein thrombosis following a complicated medical course, will be presented. The patient was anticoagulated with a low molecular weight heparin, but a few months later and following an episode of bleeding, an IVC filter was planned. Using the PubMed database, articles published in English language addressing issues related to IVC filters in cancer patients were accessed and will be presented.Results: Many recent studies questioned the need to insert IVC filters in advanced-stage cancer patients, particularly those whose anticipated survival is short and prevention of PE may be of little clinical benefit and could be a poor utilization of resources.Conclusion: Systemic anticoagulation can be safely offered for the majority of cancer patients. When the risk of bleeding or pulmonary embolism is high, IVC filters can be utilized. However, placement of such filters should take into consideration the stage of disease and life expectancy of such patients.Keywords: anticoagulation, bleeding, chemotherapy

  8. A combined series active filter and passive filters for harmonics, unbalances and flicker compensation

    OpenAIRE

    Pinto, J. G.; Pregitzer, Ricardo G.; Monteiro, Luís F. C.; Couto, Carlos, ed. lit.; João L Afonso

    2007-01-01

    This paper describes a combined operation involving a series active filter and shunt passive filters for three-phase three-wire systems. The series active filter is able to minimize Power Quality problems like unbalances, harmonics and flicker observed at the system voltages. Another task for the series active filter is to damp possible resonances involving the passive filters and the system impedance. The shunt passive filters are designed to drain harmonic current-components generated by th...

  9. Traditional and Non-traditional Collective Bargaining: Strategies to Improve the Patient Care Environment

    Directory of Open Access Journals (Sweden)

    Budd, K., Warino, L., Patton, M.,

    2004-01-01

    Full Text Available Acquiring organizational autonomy and control over nursing practice, through a combination of traditional and non-traditional collective bargaining (CB strategies, is emerging as an important solution to the nursing shortage crisis. For the past 60 years, nurses have improved their economic and general welfare by organizing through traditional CB, particularly during periods of nursing shortages. During the past decade, however, the downsizing of nursing staffs, systems redesign, and oppressive management practices have created such poor nursing practice environments that improvement in wages no longer is viewed as the primary purpose of CB. Much more essential to nurses is assuring they have a safe practice environment free of mandatory overtime and other work issues, and a voice in the resource allocation decisions that affect their ability to achieve quality health outcomes for patients. The thesis presented in this article is that traditional and non-traditional CB strategies empower nurses to find such a voice and gain control over nursing practice. This article describes the current shortage; discusses how CB can be used to help nurses find a voice to effect change; reviews the American Nurses Association’s (ANA's history of collective action activities; explains differences between traditional and non-traditional CB strategies; and presents a case study in which both strategies were used to improve the present patient care environment.

  10. On some fuzzy filters in pseudo-BCI algebras.

    Science.gov (United States)

    Zhang, Xiaohong

    2014-01-01

    Some new properties of fuzzy associative filters (also known as fuzzy associative pseudo-filters), fuzzy p-filter (also known as fuzzy pseudo-p-filters), and fuzzy a-filter (also known as fuzzy pseudo-a-filters) in pseudo-BCI algebras are investigated. By these properties, the following important results are proved: (1) a fuzzy filter (also known as fuzzy pseudo-filters) of a pseudo-BCI algebra is a fuzzy associative filter if and only if it is a fuzzy a-filter; (2) a filter (also known as pseudo-filter) of a pseudo-BCI algebra is associative if and only if it is an a-filter (also call it pseudo-a filter); (3) a fuzzy filter of a pseudo-BCI algebra is fuzzy a-filter if and only if it is both a fuzzy p-filter and a fuzzy q-filter. PMID:24977218

  11. An Efficient and Optimal Filter for Identifying Point Sources in Millimeter/Sub-Millimeter Wavelength Sky Maps

    CERN Document Server

    Perera, T A; Scott, K S; Austermann, J E; Schaar, J R; Mancera, A

    2013-01-01

    A new technique for reliably identifying point sources in millimeter/sub-millimeter wavelength maps is presented. This method accounts for the frequency dependence of noise in the Fourier domain as well as non-uniformities in the coverage of a field. This optimal filter is an improvement over commonly-used matched filters that ignore coverage gradients. Treating noise variations in the Fourier domain as well as map space is traditionally viewed as a computationally intensive problem. We show that the penalty incurred in terms of computing time is quite small due to casting many of the calculations in terms of FFTs and exploiting the absence of sharp features in the noise spectra of observations. Practical aspects of implementing the optimal filter are presented in the context of data from the AzTEC bolometer camera. The advantages of using the new filter over the standard matched filter are also addressed in terms of a typical AzTEC map.

  12. Optimal Filter for Radiation Detection

    International Nuclear Information System (INIS)

    Many Radiological Detection Systems detect Poison distributed data from a sensor. These systems process and analyze the data in order to detect intensity changes of the monitored radiation field. In some cases, when the changes are lower than the noise level, a Low Pass Filter (LPF) is applied to the noisy data. The filter smoothes the signal and enables the system to detect small changes of the field. Applying such a filter increases the response time, causing a delay between the event and the response. In some safety systems this delay can cause a small fault to become a serious accident. For example, in case of an increasing radiation field in an emergency shut-down system that detects neutron flux in a nuclear reactor [1], every passing second is crucial in deciding whether the increased power is real or just noise when the emergency shut-down must be operated immediately in order to prevent a serious accident

  13. Filtered containment venting in Sweden

    International Nuclear Information System (INIS)

    After the TMI accident, Swedish authorities decided that all Swedish nuclear power plants should be upgraded with respect to mitigation of the consequences of severe accidents. One contribution to meet these ends is filtered containment venting, i.e. means to relieve containment overpressure and to clean the relief gas from radioactive components. The first system in operation was built at the Barsebaeck site (2 BWR's) where a gravel bed filter was installed. For the remaining Swedish units (7 BWR's and 3 PWR's) a passive, self-controlling wet scrubber system, FILTRA-MVSS, is now under installation. The principle of the FILTRA-MVSS is a self-controlling, self-pumping venturi collector submerged in a pool, and it is used to filter out emissions of solid and gaseous radioactive components

  14. Sample-whitened matched filters

    DEFF Research Database (Denmark)

    Andersen, Ib

    1973-01-01

    A sample-whitened matched filter (SWMF) for a channel with intersymbol interference and additive white Gaussian noise is defined as a linear filter with the properties that its output samples are a sufficient statistic for the MAP estimation of the transmitted sequence and have uncorrelated noise components. These filters are shown to exist for ali realistic channels and the complete set of SWMF's for any channel is determined. It is shown that for nonpathological channels there is a unique SWMF which minimizes the amount of intersymbol interference defined as the discrete-time analog to the rms duration of a continuous-time signal. Finally, the theory is extended to more general modulation systems including pulse position modulation and frequency position modulation.

  15. Neural Filters for Jet Analysis

    CERN Document Server

    Dong, D W; Dong, Dawei W; Gyulassy, Miklos

    1992-01-01

    We study the efficiency of a neural-net filter and deconvolution method for estimating jet energies and spectra in high-background reactions such as nuclear collisions at the relativistic heavy-ion collider and the large hadron collider. The optimal network is shown to be surprisingly close but not identical to a linear high-pass filter. A suitably constrained deconvolution method is shown to uncover accurately the underlying jet distribution in spite of the broad network response. Finally, we show that possible changes of the jet spectrum in nuclear collisions can be analyzed quantitatively, in terms of an effective energy loss with the proposed method. {} {Dong D W and Gyulassy M 1993}{Neural filters for jet analysis} {(LBL-31560) Physical Review E Vol~47(4) pp~2913-2922}

  16. Traditional Ecological Knowledge Prior Art Database

    Science.gov (United States)

    The Traditional Ecological Knowledge Prior Art Database (TEK*PAD) "is an index and search engine of existing Internet-based, public domain documentation concerning indigenous knowledge and plant species uses." TEK*PAD, a multi-organization collaboration offered through the American Association for the Advancement of Science, provides links to taxonomic data, ethnobotanical information, academic abstracts and articles, and other resources intended to facilitate research on traditional ecological knowledge. The database itself may be searched easily by keywords, plant names, medicinal application, geographical region, or cultural/ ethnic group. The Web site also includes recent news articles and other features, such as the Biopiracy Hot List. Even those not actively involved in ethnobotanical research should find the TEK*PAD Web site worth exploring.

  17. Alternative, complementary and traditional medicine in Malaysia.

    Science.gov (United States)

    Talib, N

    2006-09-01

    This paper sets out the practice of traditional, alternative and/or complementary medicine in Malaysia. It gives an overview of the types of alternative medicine available, and the legal regulation, or lack of it within the current setting. The relevant policies and governmental action in this area are highlighted. Relevant case law decisions in this area are also included. The practice of spiritual healing as one form of traditional medicine, and its role within the spectrum of alternative medicine is dealt with briefly. The significant question of integration of alternative medicine within the existing allopathic system is addressed. The paper concludes that as interest in, and usage of alternative medicine is not likely to decrease, certain measures must be taken by the relevant authorities to ensure among others, the safety and efficacy of these medicines. PMID:17078519

  18. The Danish free school tradition under pressure

    DEFF Research Database (Denmark)

    Olsen, Tore Vincents

    2015-01-01

    The Danish free school tradition has entailed a large degree of associational freedom for non-governmental schools, religious as well as non-religious. Until the late 1990s, the non-governmental schools were under no strict ideological or pedagogical limitations, they could recruit teachers and students according to their own value base, and were given a large state subsidy. From the late 1990s a number of legislative changes were introduced demanding that non-governmental schools provide civic education and document the academic value of their teaching programs. The rules concerning the monitoring of schools were also changed. This article analyses the political justification for these changes and asks to what extent the changes have altered the Danish free school tradition.

  19. Traditionally-used antimalarials from the Meliaceae.

    Science.gov (United States)

    Omar, S; Zhang, J; MacKinnon, S; Leaman, D; Durst, T; Philogene, B J R; Arnason, J T; Sanchez-Vindas, P E; Poveda, L; Tamez, P A; Pezzuto, J M

    2003-01-01

    A quantitative ethnobotanical approach to antimalarial drug discovery led to the identification of Lansium domesticum Corr. Ser. (Meliaceae) as an important antimalarial used by Kenyah Dyak healers in Indonesian Borneo. Triterpenoid lansiolides with antimalarial activity were isolated from the bark and shown to have activity in both in vitro bioassays with Plasmodium falciparum, and in mice infected with P. berghei. A survey of African and tropical American Meliaceae led to further development of the limonoid gedunin from the traditionally used medicinal plants, tropical cedar, Cedrela odorata L., and neem, Azadirachta indica A. Juss. Gedunin has significant in vitro activity but initially showed poor in vivo activity. In vivo activity was improved by (1) incorporation into an easy to absorb suspension, (2) preparation of a more stable compound, 7-methoxygedunin; and (3) synergism with dillapiol, a cytochrome P450 3A4 inhibitor. The results show the potential for both antimalarial drug and phytomedicine development from traditionally used plants. PMID:12570769

  20. Culture, Tradition, Custom, Law and Gender Equality

    Directory of Open Access Journals (Sweden)

    MJ Maluleke

    2012-03-01

    Full Text Available In August 2011 Advocate Joyce Maluleke, Director in the Gender Directorate of the South African Department of Justice and Constitutional Development addressed the Annual General Conference of the South African Chapter of the International Association of Women Judges held in Potchefstroom on the dangers of harmful traditional practices such as early and forced marriages, virginity testing, widow's rituals, levirate and sororate unions, female genital mutilation, breast sweeping/ironing, the primogeniture rule, practices such as 'cleansing' after male circumcision, and witch-hunting. Although she considers respect for tradition, culture and customs to be part of the South African identity, she argues that cultural practices should be rooted in respect for human rights, democracy and equality. We publish her paper here as an oratio.

  1. Une acadie litéraire entre tradition et modernité

    Directory of Open Access Journals (Sweden)

    Gwénael Lamarque

    2008-01-01

    Full Text Available In the great family of francophone literatures, Acadian literature occupies a singular position. Long dominated by the ‘ Maillet phenomenon’ of Antonine Maillet, the only Acadian to have received the Priz Goncourt, which she received for her novel Pélagie-la-Charette in 1979, a deeper analysis shows the complexities of this literature, hesitating constantly between a respect for a certain historical tradition and the necessity to go beyond this. More than ever, Acadianité (Acadianness and Américanité (Americanness meet before being subtly intermingled. The case of the writers who are members of the Association Acadienne des Artistes Professionel(les du Nouveau Brunswick appears, from this point of view, to provide an excellent case study and a good reflection of a literary Acadia lost more than ever between tradition and modernism at the beginning of the twenty-first century.

  2. Quantized, piecewise linear filter network

    DEFF Research Database (Denmark)

    SØrensen, John Aasted

    1993-01-01

    A quantization based piecewise linear filter network is defined. A method for the training of this network based on local approximation in the input space is devised. The training is carried out by repeatedly alternating between vector quantization of the training set into quantization classes and equalization of the quantization classes linear filter mean square training errors. The equalization of the mean square training errors is carried out by adapting the boundaries between neighbor quantization classes such that the differences in mean square training errors are reduced

  3. ATTITUDE FILTERING ON SO(3)

    Science.gov (United States)

    Markley, F. Landis

    2005-01-01

    A new method is presented for the simultaneous estimation of the attitude of a spacecraft and an N-vector of bias parameters. This method uses a probability distribution function defined on the Cartesian product of SO(3), the group of rotation matrices, and the Euclidean space W N .The Fokker-Planck equation propagates the probability distribution function between measurements, and Bayes s formula incorporates measurement update information. This approach avoids all the issues of singular attitude representations or singular covariance matrices encountered in extended Kalman filters. In addition, the filter has a consistent initialization for a completely unknown initial attitude, owing to the fact that SO(3) is a compact space.

  4. Adaptive filtering prediction and control

    CERN Document Server

    Goodwin, Graham C

    2014-01-01

    Preface1. Introduction to Adaptive TechniquesPart 1. Deterministic Systems2. Models for Deterministic Dynamical Systems3. Parameter Estimation for Deterministic Systems4. Deterministic Adaptive Prediction5. Control of Linear Deterministic Systems6. Adaptive Control of Linear Deterministic SystemsPart 2. Stochastic Systems7. Optimal Filtering and Prediction8. Parameter Estimation for Stochastic Dynamic Systems9. Adaptive Filtering and Prediction10. Control of Stochastic Systems11. Adaptive Control of Stochastic SystemsAppendicesA. A Brief Review of Some Results from Systems TheoryB. A Summary o

  5. Performance comparison of various time variant filters

    Energy Technology Data Exchange (ETDEWEB)

    Kuwata, M. [JEOL Engineering Co. Ltd., Akishima, Tokyo (Japan); Husimi, K.

    1996-07-01

    This paper describes the advantage of the trapezoidal filter used in semiconductor detector system comparing with the other time variant filters. The trapezoidal filter is the compose of a rectangular pre-filter and a gated integrator. We indicate that the best performance is obtained by the differential-integral summing type rectangular pre-filter. This filter is not only superior in performance, but also has the useful feature that the rising edge of the output waveform is linear. We introduce an example of this feature used in a high-energy experiment. (author)

  6. PSpice for filters and transmission lines

    CERN Document Server

    Tobin, Paul

    2007-01-01

    In this book, PSpice for Filters and Transmission Lines, we examine a range of active and passive filters where each design is simulated using the latest Cadence Orcad V10.5 PSpice capture software. These filters cannot match the very high order digital signal processing (DSP) filters considered in PSpice for Digital Signal Processing, but nevertheless these filters have many uses. The active filters considered were designed using Butterworth and Chebychev approximation loss functions rather than using the 'cookbook approach' so that the final design will meet a given specification in an exact

  7. Capillary-based x-ray filters

    International Nuclear Information System (INIS)

    The results of computer simulation and experimental investigation of different capillary-based filters are presented. Filters with multiple reflections in polycapillaries, filters with single reflections, combinations of capillary structures with crystals and conventional x-ray absorption filters are considered. Capillary-based x-ray filters effectively suppress the high-energy part of radiation while the supplementary elements suppress the soft part of spectrum. The possibility of application of such filters in laboratory set-up and in synchrotron beam line is discussed

  8. Bottom loaded filter for radioactive liquids

    International Nuclear Information System (INIS)

    This invention relates to equipment for filtering liquids and more particularly to filter assemblies for use with radioactive by-products of nuclear power plants. The invention provides a compact, bottom-loaded filter assembly that can be quickly and safely loaded and unloaded without the use of complex remote equipment. The assembly is integrally shielded and does not require external shielding. The closure hatch may be automatically aligned to facilitate quick sealing attachment after replacement of the filter cartridge, and the filter cartridge may be automatically positioned within the filter housing during the replacement operation

  9. Indirect Kalman Filter in Mobile Robot Application

    Directory of Open Access Journals (Sweden)

    Surachai Panich

    2010-01-01

    Full Text Available Problem statement: The most successful applications of Kalman filtering are to linearize about some nominal trajectory in state space that does not depend on the measurement data. The resulting filter is usually referred to as simply a linearized Kalman filter. Approach: This study introduced mainly indirect Kalman filter to estimate robot?s position. A developed differential encoder system integrated accelerometer is experimental tested in square shape. Results: Experimental results confirmed that indirect Kalman filter improves the accuracy and confidence of position estimation. Conclusion: In summary, we concluded that indirect Kalman filter has good potential to reduce error of measurement data.

  10. Review Of Parameter Estimation Using Adaptive Filtering

    Directory of Open Access Journals (Sweden)

    LALITA RANI, SHALOO KIKAN

    2013-07-01

    Full Text Available In this paper, a comparative study of different adaptive filter algorithm for channel parameter estimation is described. We presented different parameter estimation approaches of adaptive filtering. An extended Kalman filter is then applied as a near-optimal solution to the adaptive channel parameter estimation problem. Kalman filtering is applied for motion parameters resulting in optimal pose estimation. A parallel Kalman filter is applied for joint estimation of code delay, multipath gains and Doppler shift. In this paper, a complete review of parameter estimation using adaptive filtering is explained.

  11. Design and construction of electronic filters

    International Nuclear Information System (INIS)

    The design and construction of very low frequencies electronic filters which will be used for carrying out analysis of pile noise at Mexico's Nuclear Center Triga Mark III Reactor, in order to realize measurements of its parameters is presented. NIM norms and active filters with lineal integrated circuits were used: a. Band pass filter from 10 to 500 hertz, band width 50. b. Low pass filter from 0.001 to 10 hertz in 3 steps. c. Kalman Bucy filter, an analogical simulation of this filter was undertaken, obtained from a mathematical model of a Zero power experimental reactor, with the purpose to establish a control searching. (author)

  12. Use of morphological filters for SAR data filtering

    Science.gov (United States)

    Mouchot, Marie-Catherine; Pelet, Eric; Alfoldi, Thomas

    1994-12-01

    The identification and classification of targets in synthetic aperture radar images has been difficult due to the presence of multiplicative noise from the coherent energy source. This manifests itself in the image as the familiar `speckle.' A variety of solutions to this problem have been proposed by others, all with different degrees of success. In many cases, users have resorted to the simple and partly effective solution of using a median filter. Mathematical morphology is a technique which is finding some selective uses in the realm of remote sensing image analysis especially outside of France (where it was first introduced by Matheron). We have investigated in the past its applicability to define/detect target `shapes' in satellites images. Our current work evaluates the success of using various morphological filters to reduce/remove speckle-based noise on SAR images. A number of target types on land (forested area) and water (open ocean and ice pack) were tested. They all present specific features that have to be preserved after filtering. In this work, we report on the results as compared to more conventional filtering approaches, evaluated with respect to the criteria of noise reduction and feature preservation.

  13. Cyber bullying, traditional bullying and depression

    OpenAIRE

    Guðrún Inga Baldursdóttir 1987

    2013-01-01

    With increased technological evolution and availability of the Internet, a new form of bullying has developed called cyber bullying. The hypothesis is that victims of cyber bullying show more symptoms of depression than victims of traditional bullying. Participants in this research were from a random sample of 2000 children drawn from a population study carried out by The Icelandic Centre for Social Research (ICSRA). The participants were in grades five through seven in primary school in ...

  14. Traditional Carving Art and Modern Advertising Design

    Directory of Open Access Journals (Sweden)

    Jianwen LI

    2014-04-01

    Full Text Available This paper studies carving art and modern advertising design, teases out the origin and features of form of carving art, explores the cultural spirit and artistic value of carving art, elaborates carving art’s linguistic characteristics, forms and aesthetic similarities between modern advertising combined with examples, analyze innovation and integration of traditional carving art and modern advertising design, in order to develop and enrich the form of local design language.

  15. The Physicochemical Quality of Traditional Burduf Cheese

    OpenAIRE

    Carmen Pop; Cristina Anamaria Semeniuc; Sorin Apostu; Ancu?a Mihaela Rotar

    2013-01-01

    The aim of this study is the assessmentof the quality control of raw milk and traditional burduf cheese obtained fromcow milk mixed with 10% sheep milk. Appreciation of the integrity and freshness assessmentof milk (cow and sheep) was tested by physico-chemical analysis.On theshelf-live were determined the physico-chemical parameters in cheese samples. Theantibiotics residues were tested of the milk samples with portable analyser,model Rosa Charm Reader. Theresults of physico-chemical determi...

  16. Landscape science: a Russian geographical tradition

    OpenAIRE

    Shaw, D. J. B.; Oldfield, J.

    2007-01-01

    The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia'...

  17. Are Supernovae Recorded in Indigenous Astronomical Traditions?

    OpenAIRE

    Hamacher, Duane W.

    2014-01-01

    Novae and supernovae are rare astronomical events that would have had an influence on the sky-watching peoples who witnessed them. Although several bright novae/supernovae have been visible during recorded human history, there are many proposed but no confirmed accounts of supernovae in oral traditions or material culture. Criteria are established for confirming novae/supernovae in oral and material culture, and claims from around the world are discussed to determine if they...

  18. QUALITY CONTROL OF SOME TRADITIONAL MEAT PRODUCTS

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    S. DOBRINAS; A. SOCEANU; Popescu, V.; G. STANCIU; Suliman, S

    2014-01-01

    In this paper, we present the characterization of six traditional meat products: smoked file, smoked bacon, pork sausages, sausage prepared from swine’s entrails, pork pastrami, sheep sausages. Organoleptic tests (the aspect and shape, the aspect of freshly cut in the section, smell, taste and consistency), physico-chemical and microbiological determinations (NTG, Salmonella, Listeria monocytogenes and Escherichia coli) were performed. These analyzes are a part of quality control that must be...

  19. SIKH APPROACH TOWARDS YOGA TRADITION IN INDIA

    Directory of Open Access Journals (Sweden)

    Arvinder Singh

    2015-05-01

    Full Text Available In fifteenth century, Guru Nanak laid the foundation of new, dynamic and revolutionary way of life in form of Sikhism. He took the due notice of religious practises, actual behaviour and general attitude of the followers of Yog tradition of his time. He denounced the asceticism and all those religious beliefs, which motivated the masses to renounce the world and to run away from the performance of social responsibilities. Sikh Gurus criticised the outward religiosity of yogis.

  20. Kurban (sacrifice) tradition in Western Thracian Turks

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    Füsun A?kar

    2011-01-01

    This article is prepared within 04-DPT-007 the Project of Preparing Museum and Archive on Folk Music Instruments, Folk Dances, Traditional Clothes and Folk Music in Anatolia and the Balkans started with the research of Ege University State Turkish Music Conservatory, Turkish Folk Dance Department in Macedonia on 18 April 2004.In the Greece trip within the project, on-site monitoring works have been conducted in the villages where Western Thracian Turks that are taken under research live in Ko...