WorldWideScience
 
 
1

Can sinogram-affirmed iterative (SAFIRE) reconstruction improve imaging quality on low-dose lung CT screening compared with traditional filtered back projection (FBP) reconstruction?  

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate the performance of sinogram-affirmed iterative (SAFIRE) reconstruction on image quality of low-dose lung computed tomographic (CT) screening compared with filtered back projection (FBP). METHODS: Three hundred four patients for annual low-dose lung CT screening were examined by a dual-source CT system at 120 kilovolt (peak) with reference tube current of 40 mA·s. Six image serials were reconstructed, including one data set of FBP and 5 data sets of SAFIRE with different reconstruction strengths from 1 to 5. Image noise was recorded; and subjective scores of image noise, images artifacts, and the overall image quality were also assessed by 2 radiologists. RESULTS: The mean ± SD weight for all patients was 66.3 ± 12.8 kg, and the body mass index was 23.4 ± 3.2. The mean ± SD dose-length product was 95.2 ± 30.6 mGy cm, and the mean ± SD effective dose was 1.6 ± 0.5 mSv. The observation agreements for image noise grade, artifact grade, and the overall image quality were 0.785, 0.595 and 0.512, respectively. Among the overall 6 data sets, both the measured mean objective image noise and the subjective image noise of FBP was the highest, and the image noise decreased with the increasing of SAFIRE reconstruction strength. The data sets of S3 obtained the best image quality scores. CONCLUSION: Sinogram-affirmed iterative reconstruction can significantly improve image quality of low-dose lung CT screening compared with FBP, and SAFIRE with reconstruction strength 3 was a pertinent choice for low-dose lung CT.

Yang WJ; Yan FH; Liu B; Pang LF; Hou L; Zhang H; Pan ZL; Chen KM

2013-03-01

2

Filtered back-projection algorithm for Compton telescopes  

Energy Technology Data Exchange (ETDEWEB)

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.

Gunter, Donald L. (Lisle, IL)

2008-03-18

3

Chest computed tomography using iterative reconstruction vs filtered back projection (Part 1): evaluation of image noise reduction in 32 patients  

International Nuclear Information System (INIS)

[en] To assess noise reduction achievable with an iterative reconstruction algorithm. 32 consecutive chest CT angiograms were reconstructed with regular filtered back projection (FBP) (Group 1) and an iterative reconstruction technique (IRIS) with 3 (Group 2a) and 5 (Group 2b) iterations. Objective image noise was significantly reduced in Group 2a and Group 2b compared with FBP (p

2011-01-01

4

CT coronary angiography: image quality with sinogram-affirmed iterative reconstruction compared with filtered back-projection.  

UK PubMed Central (United Kingdom)

AIM: To investigate image quality and potential for radiation dose reduction using sinogram-affirmed iterative reconstruction (SAFIRE) at computed tomography (CT) coronary angiography (CTCA) compared with filtered back-projection (FBP) reconstruction. MATERIALS AND METHODS: A water phantom and 49 consecutive patients were scanned using a retrospectively electrocardiography (ECG)-gated CTCA protocol on a dual-source CT system. Image reconstructions were performed with both conventional FBP and SAFIRE. The SAFIRE series were reconstructed image data from only one tube, simulating a 50% radiation dose reduction. Two blinded observers independently assessed the image quality of each coronary segment using a four-point scale and measured image noise (the standard deviation of Hounsfield values, SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Radiation dose estimates were calculated. RESULTS: In the water phantom, image noise decreased at the same ratio as the tube current increased for both reconstruction algorithms. Despite an estimated radiation dose reduction from 7.9 ± 2.8 to 4 ± 1.4 mSv, there was no significant difference in the SD and SNR within the aortic root and left ventricular chamber between the two reconstruction methods. There was also no significant difference in the image quality between the FBP and SAFIRE series. CONCLUSION: Compared with traditional FBP, there is potential for substantial radiation dose reduction at CTCA with use of SAFIRE, while maintaining similar diagnostic image quality.

Wang R; Schoepf UJ; Wu R; Gibbs KP; Yu W; Li M; Zhang Z

2013-03-01

5

Patient dose and image quality in low-dose abdominal CT: a comparison between iterative reconstruction and filtered back projection.  

Science.gov (United States)

BackgroundIn computed tomography (CT), there is increasing concern for potential CT radiation hazards. Several raw-data-based iterative reconstruction techniques attempt to facilitate low-dose imaging without compromising image quality, which raises the question whether these techniques may allow further dose reduction.PurposeTo compare image quality of iterative reconstruction and filtered back projection in low-dose abdominal CT and study the potential for further dose reduction.Material and MethodsForty-five patients underwent CT of the abdomen twice: with standard low-dose technique and with 30% reduced dose, using both iterative reconstruction and filtered back projection. Four radiologists made pair-wise image quality assessment using five visual criteria. Visual grading regression (VGR) and weighted kappa (?w) were used to analyze the data.ResultsThere were significant effects of log(mAs) (P <0.001) and reconstruction algorithm (P <0.01) on all image quality criteria with an estimated potential dose reduction of 5-9%. Inter-observer agreement ranged from 70% to 91% and ?w from -0.01 to 0.57.ConclusionAn iterative reconstruction algorithm improved image quality in abdominal CT, but the estimated dose reduction was rather small. The full potential of the algorithm remains unclear. PMID:23474768

Kataria, Bharti; Smedby, Orjan

2013-03-10

6

Ultrasonic computerized tomography (CT) for temperature measurements with limited projection data based on extrapolated filtered back projection (FBP) method  

Energy Technology Data Exchange (ETDEWEB)

This study uses ultrasound in combination with tomography to obtain three-dimensional temperature measurements using projection data obtained from limited projection angle. The main feature of the new computerized tomography (CT) reconstruction algorithm is to employ extrapolation scheme to make up for the incomplete projection data, it is based on the conventional filtered back projection (FBP) method while on top of that taking into account the correlation between the projection data and Fourier transform-based extrapolation. Computer simulation is conducted to verify the above algorithm. An experimental 3D temperature distribution measurement is also carried out to validate the proposed algorithm. The simulation and experimental results demonstrate that the extrapolated FBP CT algorithm is highly effective in dealing with projection data from limited projection angle.

Zhu Ning; Jiang Yong; Kato, Seizo

2005-03-01

7

Comparison of Maximum Entropy and Filtered Back-Projection Methods to Reconstruct Rapid-Scan EPR Images  

Science.gov (United States)

Reconstruction of two-dimensional images by filtered back-projection (FBP) and by the maximum entropy method (MEM) was compared for spectral-spatial EPR images with differing signal-to-noise ratios. Experimental projections were recorded using direct-detected rapid scans in the presence of a series of magnetic field gradients. The slow-scan absorption lineshapes were calculated by Fourier deconvolution. A Hamming filter was used in conjunction with FBP, but not for MEM. Imperfections in real experimental data, as well as random noise, contribute to discrepancies between the reconstructed image and experimental projections, which may make it impossible to achieve the customary MEM criterion for convergence. The Cambridge MEM algorithm, with allowance for imperfections in experimental data, produced images with more linear intensity scales and more accurate linewidths for weak signals than was obtained with other MEM methods. The more effective elimination of noise in baseline regions by MEM made it possible to detect weak trityl 13C trityl hyperfine lines that could not be distinguished from noise in images reconstructed by FBP. Another advantage of MEM is that projections do not need to be equally spaced. FBP has the advantages that computational time is less, the amplitude scale is linear, and there is less noise superimposed on peaks in images. It is useful to reconstruct images by both methods and compare results. Our observations indicate that FBP works well when the number of projections is large enough that the star effect is negligible. When there is a smaller number of projections, projections are unequally spaced, and/or signal-to-noise is lower MEM is advantageous.

Tseytlin, Mark; Dhami, Amarjot; Eaton, Sandra S.; Eaton, Gareth R.

2009-01-01

8

Systematic error in lung nodule volumetry: effect of iterative reconstruction versus filtered back projection at different CT parameters.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Iterative reconstruction potentially can reduce radiation dose compared with filtered back projection (FBP) for chest CT. This is especially important for repeated CT scanning, as is the case in patients with indeterminate lung nodules. It is currently unknown whether absolute nodule volumes measured with iterative reconstruction are comparable to those measured with FBP. We compared nodule volumes measured with iterative reconstruction and FBP at different CT parameters. MATERIALS AND METHODS: An anthropomorphic chest phantom was scanned using a 256-MDCT scanner at various tube voltages and tube current-time products. Raw data were reconstructed using FBP or a commercially available iterative reconstruction algorithm. Five inserted nodules with 100 HU radiodensity and different sizes (3, 5, 8, 10, and 12 mm) were measured by two observers using semiautomatic software. Volumetric nodule measurements were performed using thin-slice reconstructions. RESULTS: For very small nodules (volume, 14.1 mm(3); diameter, 3 mm), FBP and iterative reconstruction measurements exhibited large errors and overestimated the nodule size by up to 160%. For larger nodules (volume, ? 65.4 mm(3); diameter, ? 5 mm), CT underestimated the actual size, but errors were small (within 25%) and remained small when the tube voltage and tube current-time product were reduced, even without iterative reconstruction. CONCLUSION: In a phantom model, no clinically relevant differences beyond reported interscan variation levels between lung nodule volumes were measured in nodules 5 mm or larger at reduced tube voltage and tube current-time product, with radiation dose reductions up to 90.6% for both FBP and iterative reconstruction, suggesting that it is safe to convert FBP protocols to iterative reconstruction and reduce tube voltage and tube current-time product for lung nodule follow-up. CT appears to slightly underestimate actual nodule volume.

Willemink MJ; Leiner T; Budde RP; de Kort FP; Vliegenthart R; van Ooijen PM; Oudkerk M; de Jong PA

2012-12-01

9

CT of urolithiasis: comparison of image quality and diagnostic confidence using filtered back projection and iterative reconstruction techniques.  

UK PubMed Central (United Kingdom)

RATIONALE AND OBJECTIVES: To compare the image quality and diagnostic confidence of low-dose computed tomography (CT) of urololithiasis using filtered back projection (FBP) and iterative reconstruction techniques (IRT). MATERIALS AND METHODS: A 4.8 × 4.3 × 5.2 mm(3) uric acid ureteral stone was placed inside an anthropomorphic Alderson phantom at the pelvic level. Fifteen scans were performed on a 64-row dual-source CT system using different tube voltages (80, 100, and 120 kV) and current-time products (8, 15, 30, 70, and 100 mAs). Image reconstruction using FBP and IRT (iterative reconstruction in image space) resulted in 30 data sets. Objective image quality was evaluated by noise measurements. Effective doses were estimated for each data set with use of an established dosimetry program. Subjective image quality and confidence level were rated by two radiologists. RESULTS: Noise was systematically lower for images reconstructed with IRT compared to FBP (55 ± 30 vs 65 ± 26 Hounsfield units; P = .004) for volume CT dose index values above about 0.6 mGy (or an effective dose of about 0.4 mSv for both sexes). For the 14 scans rated to have diagnostic image quality, the estimated effective doses ranged from 0.3 to 2.5 mSv for males and from 0.4 to 3.1 mSv for females. Subjective image quality and diagnostic confidence for IRT was not significantly better than those for FBP. CONCLUSIONS: In a phantom study for CT of urolithiasis, IRT improves objective image quality compared to FBP above a certain dose threshold. However, this does not translate into improved subjective image quality or a higher degree of confidence for the diagnosis of high-contrast urinary stones.

Hansmann J; Schoenberg GM; Brix G; Henzler T; Meyer M; Attenberger UI; Schoenberg SO; Fink C

2013-09-01

10

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

UK PubMed Central (United Kingdom)

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_1a) and 80% tube current reduced low-dose (Group_1b). The low-dose raw data was additionally reconstructed using iterative raw data reconstruction (Group_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_2 was lowered by 22% on average when compared to group_1b (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_2 compared to group_1b (p<0.0001-0.0232). Subjective image quality of group_2 (1.88 ± 0.63) was also rated significantly higher when compared to group_1b (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.

Takx RA; Schoepf UJ; Moscariello A; Das M; Rowe G; Schoenberg SO; Fink C; Henzler T

2013-02-01

11

Computed tomography angiography for suspected pulmonary embolism: comparison of 2 adaptive statistical iterative reconstruction blends to filtered back-projection alone.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The objective of this study was to analyze pulmonary computed tomography angiography image quality and pulmonary embolism (PE) depiction comparing 2 blends of adaptive statistical iterative reconstruction (ASIR) to filtered back-projection alone. METHODS: Seventy-nine consecutive patients (49 women, 30 men; 52 ± 18 years) underwent pulmonary computed tomography angiography (120 kVp, 100-600 mA) reconstructed with filtered back-projection alone (ASIR0), 30% ASIR (ASIR30), and 50% ASIR (ASIR50) for this institutional review board-approved study. Two radiologists independently assessed PE depiction and vascular characterization, which was correlated with body mass index. RESULTS: Twelve patients (15%) had PE. No difference in PE depiction (P = 0.536), pulmonary arterial attenuation (P = 0.22-0.99), or subjective vascular characterization score (P = 0.58-.016) was observed for either blend. ASIR30 and ASIR50 achieved higher signal-to-noise ratio (P = 0.001-0.003). Body mass index inversely correlated with vascular characterization scores (P < 0.001). CONCLUSIONS: ASIR0, ASIR30, and ASIR50 accurately depict PE using the imaging parameters described. ASIR30 and ASIR50 improve objective image quality without altering subjective vascular characterization scores particularly when body mass index was less than 30 kg/m.

Ridge CA; Litmanovich D; Bukoye BA; Lin PJ; Wilcox C; Boiselle PM; Bankier AA

2013-09-01

12

Effect of number of of projections on inverse radon transform based image reconstruction by using filtered back-projection for parallel beam transmission tomography  

International Nuclear Information System (INIS)

This paper present the effect of number of projections on inverse Radon transform (IRT) estimation using filtered back-projection (FBP) technique for parallel beam transmission tomography. The head phantom and the lung phantom have been used in this work. Various filters used in this study include Ram-Lak, Shepp-Logan, Cosin, Hamming and Hanning filters. The slices have been reconstructed by increasing the number of projections through parallel beam transmission tomography keeping the projections uniformly distributed. The Euclidean and Mean Squared errors and peak signal-to-noise ratio (PSNR) have been analyzed for their sensitiveness as functions of number of projections. It has found that image quality improves with the number of projections but at the cost of the computer time. The error has been minimized to get the best approximation of inverse Radon transform (IRT) as the number of projections is enhanced. The value of PSNR has been found to increase from 8.20 to 24.53 dB as the number of projections is raised from 5 to 180 for head phantom. (author)

2007-01-01

13

Chest computed tomography using iterative reconstruction vs filtered back projection (Part 2): image quality of low-dose CT examinations in 80 patients.  

UK PubMed Central (United Kingdom)

PURPOSE: To evaluate the image quality of an iterative reconstruction algorithm (IRIS) in low-dose chest CT in comparison with standard-dose filtered back projection (FBP) CT. MATERIALS AND METHODS: Eighty consecutive patients referred for a follow-up chest CT examination of the chest, underwent a low-dose CT examination (Group 2) in similar technical conditions to those of the initial examination, (Group 1) except for the milliamperage selection and the replacement of regular FBP reconstruction by iterative reconstructions using three (Group 2a) and five iterations (Group 2b). RESULTS: Despite a mean decrease of 35.5% in the dose-length-product, there was no statistically significant difference between Group 2a and Group 1 in the objective noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios and distribution of the overall image quality scores. Compared to Group 1, objective image noise in Group 2b was significantly reduced with increased SNR and CNR and a trend towards improved image quality. CONCLUSION: Iterative reconstructions using three iterations provide similar image quality compared with the conventionally used FBP reconstruction at 35% less dose, thus enabling dose reduction without loss of diagnostic information. According to our preliminary results, even higher dose reductions than 35% may be feasible by using more than three iterations.

Pontana F; Duhamel A; Pagniez J; Flohr T; Faivre JB; Hachulla AL; Remy J; Remy-Jardin M

2011-03-01

14

Adaptive statistical iterative reconstruction versus filtered back projection in the same patient: 64 channel liver CT image quality and patient radiation dose.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To compare routine dose liver CT reconstructed with filtered back projection (FBP) versus low dose images reconstructed with FBP and adaptive statistical iterative reconstruction (ASIR). METHODS: In this retrospective study, patients had a routine dose protocol reconstructed with FBP, and again within 17 months (median 6.1 months), had a low dose protocol reconstructed twice, with FBP and ASIR. These reconstructions were compared for noise, image quality, and radiation dose. RESULTS: Nineteen patients were included. (12 male, mean age 58). Noise was significantly lower in low dose images reconstructed with ASIR compared to routine dose images reconstructed with FBP (liver: p?

Mitsumori LM; Shuman WP; Busey JM; Kolokythas O; Koprowicz KM

2012-01-01

15

Adaptive statistical iterative reconstruction versus filtered back projection in the same patient: 64 channel liver CT image quality and patient radiation dose  

Energy Technology Data Exchange (ETDEWEB)

To compare routine dose liver CT reconstructed with filtered back projection (FBP) versus low dose images reconstructed with FBP and adaptive statistical iterative reconstruction (ASIR). In this retrospective study, patients had a routine dose protocol reconstructed with FBP, and again within 17 months (median 6.1 months), had a low dose protocol reconstructed twice, with FBP and ASIR. These reconstructions were compared for noise, image quality, and radiation dose. Nineteen patients were included. (12 male, mean age 58). Noise was significantly lower in low dose images reconstructed with ASIR compared to routine dose images reconstructed with FBP (liver: p <.05, aorta: p < 0.001). Low dose FBP images were scored significantly lower for subjective image quality than low dose ASIR (2.1 {+-} 0.5, 3.2 {+-} 0.8, p < 0.001). There was no difference in subjective image quality scores between routine dose FBP images and low dose ASIR images (3.6 {+-} 0.5, 3.2 {+-} 0.8, NS).Radiation dose was 41% less for the low dose protocol (4.4 {+-} 2.4 mSv versus 7.5 {+-} 5.5 mSv, p < 0.05). Our initial results suggest low dose CT images reconstructed with ASIR may have lower measured noise, similar image quality, yet significantly less radiation dose compared with higher dose images reconstructed with FBP. (orig.)

Mitsumori, Lee M.; Shuman, William P.; Busey, Janet M.; Kolokythas, Orpheus; Koprowicz, Kent M. [University of Washington School of Medicine, Department of Radiology, Seattle, WA (United States)

2012-01-15

16

Low-dose chest computed tomography with sinogram-affirmed iterative reconstruction, iterative reconstruction in image space, and filtered back projection: studies on image quality.  

UK PubMed Central (United Kingdom)

OBJECTIVE: This study aimed to determine optimal strength of sinogram-affirmed iterative reconstruction (SAFIRE) and to evaluate image quality (IQ) of low-dose chest computed tomography (LDCT) using SAFIRE compared with iterative reconstruction in image space (IRIS) and filtered back projection (FBP). METHODS: Thirty patients underwent LDCT. Computed tomography (CT) was reconstructed using 5 strengths of SAFIRE (S1-S5), IRIS, and FBP. Objective noise of CT was measured. Two radiologists evaluated CT for subjective IQ, beam-hardening artifacts, and overall IQ. RESULTS: Measured noise was highest in FBP, followed by S1, S2, S3, IRIS, S4, and S5. S2 and S3 demonstrated significantly higher overall IQ scores than the other strengths (P < 0.05). Overall IQ and beam-hardening artifacts of S2 and S3 were significantly better than those in FBP and IRIS (P < 0.001). CONCLUSIONS: S2 or S3 strengths of SAFIRE can be used practically in clinical routines and may have more potential than IRIS and FBP for LDCT with improved IQ.

Hwang HJ; Seo JB; Lee HJ; Lee SM; Kim EY; Oh SY; Kim JE

2013-07-01

17

Comparison of image quality between filtered back-projection and the adaptive statistical and novel model-based iterative reconstruction techniques in abdominal CT for renal calculi.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To compare image quality on computed tomographic (CT) images acquired with filtered back-projection (FBP), adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) techniques in CT kidney/ureter/bladder (KUB) examination. METHODS: Eighteen patients underwent standard protocol CT KUB at our institution. The same raw data were reconstructed using FBP, ASIR and MBIR. Objective [mean image noise, contrast-to-noise ratio (CNR) for kidney and mean attenuation values of subcutaneous fat] and subjective image parameters (image noise, image contrast, overall visibility of kidneys/ureters/bladder, visibility of small structures, and overall diagnostic confidence) were assessed using a scoring system from 1 (best) to 5 (worst). RESULTS: Objective image measurements revealed significantly less image noise and higher CNR and the same fat attenuation values for the MBIR technique (P??0.05), while there was a significant difference between ASIR vs. MBIR (P?

Vardhanabhuti V; Ilyas S; Gutteridge C; Freeman SJ; Roobottom CA

2013-08-01

18

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 technique.

2000-01-01

19

Reduced-dose low-voltage chest CT angiography with Sinogram-affirmed iterative reconstruction versus standard-dose filtered back projection.  

UK PubMed Central (United Kingdom)

PURPOSE: To evaluate image quality of low-voltage chest computed tomographic (CT) angiography with raw data-based iterative reconstruction (sonogram-affirmed iterative reconstruction) in comparison with image quality of standard-dose standard-voltage filtered back projection (FBP) CT. MATERIALS AND METHODS: This prospective study was approved by the institutional review board, and the informed consent requirement was waived. Eighty consecutive patients who were referred for follow-up chest CT angiography underwent reduced-dose CT (hereafter, T2 examination) under technical conditions similar to those of the initial examination (hereafter, T1 examination), except the voltage selection was reduced by 20 kV with adaptation of the tube current to ensure a 50% reduction in CT dose index, and regular FBP was replaced by iterative reconstruction with sonogram-affirmed iterative reconstruction. The two techniques were compared by using paired tests (Student t test, Wilcoxon test, or McNemar test, according to the nature of variables). RESULTS: When compared with standard-dose T1 studies, reduced-dose T2 images showed: (a) significantly less objective noise at the level of the trachea on mediastinal and lung parenchymal images (P < .001) and no significant difference in objective noise at the level of the aorta on mediastinal images (P = .507); (b) significantly higher signal-to-noise and contrast-to-noise (P < .001) ratios; (c) similar visual perception of noise on mediastinal (P = .132) and lung (P = .366) images, mainly rated as moderate; and (d) similar overall subjective image quality (P = .405). CONCLUSION: Raw data-based iterative reconstruction yielded equivalent subjective and improved objective image quality of low-voltage half-dose CT angiograms compared with standard-dose FBP CT images for an average dose-length product of less than 80 mGy · cm in this population. Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120414/-/DC1.

Pontana F; Pagniez J; Duhamel A; Flohr T; Faivre JB; Murphy C; Remy J; Remy-Jardin M

2013-05-01

20

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

UK PubMed Central (United Kingdom)

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 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.

Matsuki M; Murakami T; Juri H; Yoshikawa S; Narumi Y

2013-10-01

 
 
 
 
21

Low-dose computed tomographic urography using adaptive iterative dose reduction 3-dimensional: comparison with routine-dose computed tomography with filtered back projection.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The aim of this study was to evaluate the image quality of low-dose computed tomographic (CT) urography using adaptive iterative dose reduction 3-dimensional (AIDR 3D) compared with routine-dose CT using filtered back projection (FBP). METHODS: Thirty patients underwent low- and routine-dose CT scans in the nephrographic and excretory phases of CT urography. Low-dose CT was reconstructed with AIDR 3D, and routine-dose CT was reconstructed with FBP. In quantitative analyses, image noises were measured on the renal cortex, aorta, retroperitoneal fat, and psoas muscle in both CT scans and compared. Qualitative analyses of the urinary system were performed in both CT scans and compared. These results were compared on the basis of the body mass index (BMI) of the patients. The CT dose index (CTDIvol) was measured, and the dose reduction was calculated. RESULTS: In quantitative analyses, image noises in all organs on low-dose CT were less than those on routine-dose CT in both phases independently of the patient's BMI. There were no statistical differences between low- and routine-dose CT for diagnostic acceptability on all urinary systems in both phases independently of the patient's BMI. The average CTDIvol on routine-dose CT was 14.5 mGy in the nephrographic phase and 9.2 mGy in the excretory phase. The average CTDIvol on low-dose CT was 4.2 mGy in the nephrographic phase and 2.7 mGy in the excretory phase. CONCLUSIONS: Low-dose CT urography using AIDR 3D can offer diagnostic acceptability comparable with routine-dose CT urography with FBP with approximately 70% dose reduction.

Juri H; Matsuki M; Inada Y; Tsuboyama T; Kumano S; Azuma H; Narumi Y

2013-05-01

22

Raw-data-based iterative reconstruction versus filtered back projection: image quality of low-dose chest computed tomography examinations in 87 patients.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The objective was to compare standard-dose chest computed tomography (CT) reconstructed with filtered back projection (FBP) versus low-dose images with FBP and raw-data-based iterative reconstruction. METHODS: Eighty-seven consecutive patients (46 male; mean age, 54.54±16.12; mean body mass index, 24.58±4.07) referred for initial chest CT with full-dose examinations [mean dose-length product (DLP), 183.37±44.13 mGy·cm] and follow-up chest CT with half-dose examinations (mean DLP, 91.08±23.81 mGy·cm) were included. The full-dose protocol was reconstructed with FBP; the half-dose protocol was reconstructed with FBP and sinogram-affirmed iterative reconstruction (SAFIRE). Noise and signal-to-noise ratio were compared using a paired Student's t test; subjective image quality and lesion conspicuity were compared using Wilcoxon signed ranks test. RESULTS: Actual radiation dose of follow-up CT was about 50% (49.26%±2.62%) of standard-dose protocol. Compared to full-dose images with FBP, there was no significant difference in half-dose images with SAFIRE in the objective noise (ascending aorta: P=.38, descending aorta: P=.70, trachea on mediastinal images: P=.37) and SNR (ascending aorta: P=.14, descending aorta: P=.72, trachea on mediastinal images: P=.06) on mediastinal images. Noise was significantly lower (P<.001) and SNR was significantly higher (P<.001) in half-dose images with SAFIRE on lung images. Noise was significantly higher (P<.001) and SNR was significantly lower (P<.001) in half-dose images with FBP. Subjective image quality was similar on both mediastinal images (P=.317) and lung images (P=.614) of half-dose SAFIRE images versus full-dose FBP images. Lesion conspicuity was also similar. Subjective image quality was significantly lower on both mediastinal images (P<.001) and lung images (P<.001) of half-dose FBP images versus full-dose FBP images. The conspicuity of some lesions was significantly lower (ground-glass opacity, P<.0001; ill-defined micronodule, P<.0001; lung cyst, P<.0001; emphysematous lesion, P=.003) on half-dose FBP versus full-dose FBP images. CONCLUSION: Compared to full-dose CT images reconstructed with the conventional FBP algorithm, SAFIRE with three iterations could provide similar or better image quality at 50% less dose.

Wang H; Tan B; Zhao B; Liang C; Xu Z

2013-08-01

23

Image quality of Adaptive Iterative Dose Reduction 3D of coronary CT angiography of 640-slice CT: comparison with filtered back-projection.  

UK PubMed Central (United Kingdom)

To assess the image quality of coronary CT angiography (CCTA) of 640-slice CT reconstructed by Adaptive Iterative Dose Reduction (AIDR) three-dimensional (3D) in comparison with the conventional filtered back-projection (FBP). CCTA images of 51 patients were scanned at the lowest tube voltage possible on condition that the built-in automatic exposure control system could suggest the optimal tube current. They were, then, reconstructed with FBP and AIDR 3D (standard). Objective measurements including CT density, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were performed. Subjective assessment was done by two radiologists, using a 5-point scale (0:nondiagnostic-4:excellent) based on the 15-coronary segment model which was grouped into three parts as the proximal, mid, and distal segmental classes. Radiation dose was also measured. AIDR images showed lower noise than FBP images (45.0 ± 9.4 vs. 73.4 ± 14.6 HU, p < 0.001) without any significant difference in CT density (665.5 ± 131.7 vs. 668 ± 136.3 HU, p = 0.8). Both SNR (15.0 ± 2.1 vs. 9.2 ± 1.7) and CNR (16.8 ± 2.3 vs. 10.4 ± 1.8) were significantly higher for AIDR than FBP (p < 0.001). Total subjective image quality score was also significantly improved in AIDR compared with FBP (3.1 ± 0.6 vs. 1.6 ± 0.4, p < 0.001), with better interpretability of the mid and distal segmental classes (100 vs. 95 % for the mid, p < 0.001; 100 vs. 90 % for the distal, p < 0.001). Mean effective radiation dose was 2.0 ± 1.0 mSv. The AIDR 3D reconstruction algorithm reduced image noise by 39 % compared with the FBP without affecting CT density, thus improving SNR and CNR for CCTA. Its advantages in interpretability were also confirmed by subjective evaluation by experts.

Yoo RE; Park EA; Lee W; Shim H; Kim YK; Chung JW; Park JH

2013-03-01

24

Evaluation of iterative reconstruction (OSEM) versus filtered back-projection for the assessment of myocardial glucose uptake and myocardial perfusion using dynamic PET  

Energy Technology Data Exchange (ETDEWEB)

Iterative reconstruction methods based on ordered-subset expectation maximisation (OSEM) has replaced filtered backprojection (FBP) in many clinical settings owing to the superior image quality. Whether OSEM is as accurate as FBP in quantitative positron emission tomography (PET) is uncertain. We compared the accuracy of OSEM and FBP for regional myocardial {sup 18}F-FDG uptake and {sup 13}NH{sub 3} perfusion measurements in cardiac PET. Ten healthy volunteers were studied. Five underwent dynamic {sup 18}F-FDG PET during hyperinsulinaemic-euglycaemic clamp, and five underwent {sup 13}NH{sub 3} perfusion measurement during rest and adenosine-induced hyperaemia. Images were reconstructed using FBP and OSEM {+-} an 8-mm Gaussian post-reconstruction filter. Filtered and unfiltered images showed agreement between the reconstruction methods within {+-}2SD in Bland-Altman plots of K{sub i} values. The use of a Gaussian filter resulted in a systematic underestimation of K{sub i} in the filtered images of 11%. The mean deviation between the reconstruction methods for both unfiltered and filtered images was 1.3%. Agreement within {+-}2SD between the methods was demonstrated for perfusion rate constants up to 2.5 min{sup -1}, corresponding to a perfusion of 3.4 ml g{sup -1} min{sup -1}. The mean deviation between the two methods for unfiltered data was 2.7%, and for filtered data, 5.3%. The {sup 18}F-FDG uptake rate constants showed excellent agreement between the two reconstruction methods. In the perfusion range up to 3.4 ml g{sup -1} min{sup -1}, agreement between {sup 13}NH{sub 3} perfusion obtained with OSEM and FBP was acceptable. The use of OSEM for measurement of perfusion values higher than 3.4 ml g{sup -1} min{sup -1} requires further evaluation. (orig.)

Soendergaard, Hanne M. [Aarhus University Hospital, Department of Cardiology B, Aarhus (Denmark); Aarhus University Hospital, Department of Clinical Pharmacology, Aarhus (Denmark); Madsen, Mette M.; Boisen, Karin; Boettcher, Morten; Nielsen, Torsten T.; Boetker, Hans E. [Aarhus University Hospital, Department of Cardiology B, Aarhus (Denmark); Schmitz, Ole [Aarhus University Hospital, Department of Clinical Pharmacology, Aarhus (Denmark); Aarhus University Hospital, Department of Endocrinology, Aarhus (Denmark); Hansen, Soeren B. [Aarhus University Hospital (NBG), The PET Centre, Aarhus (Denmark)

2007-03-15

25

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.  

UK PubMed Central (United Kingdom)

OBJECTIVE: 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). MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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 %.

Becce F; Ben Salah Y; Verdun FR; Vande Berg BC; Lecouvet FE; Meuli R; Omoumi P

2013-07-01

26

Reconstruction of CT images by the Bayes- back projection method  

CERN Multimedia

In the course of research on quantitative assay of non-destructive measurement of radioactive waste, the have developed a unique program based on the Bayesian theory for reconstruction of transmission computed tomography (TCT) image. The reconstruction of cross-section images in the CT technology usually employs the Filtered Back Projection method. The new imaging reconstruction program reported here is based on the Bayesian Back Projection method, and it has a function of iterative improvement images by every step of measurement. Namely, this method has the capability of prompt display of a cross-section image corresponding to each angled projection data from every measurement. Hence, it is possible to observe an improved cross-section view by reflecting each projection data in almost real time. From the basic theory of Baysian Back Projection method, it can be not only applied to CT types of 1st, 2nd, and 3rd generation. This reported deals with a reconstruction program of cross-section images in the CT of ...

Haruyama, M; Takase, M; Tobita, H

2002-01-01

27

UV Fluorescence Photography of Works of Art : Replacing the Traditional UV Cut Filters with Interference Filters  

Directory of Open Access Journals (Sweden)

Full Text Available For many years filters like the Kodak Wratten E series, or the equivalent Schneider B+W 415, were used as standard UV cut filters, necessary to obtain good quality on UV Fluorescence photography. The only problem with the use of these filters is that, when they receive the UV radiation that they should remove, they present themselves an internal fluorescence as side effect, that usually reduce contrast and quality on the final image. This article presents the results of our experiences on using some innovative filters, that appeared available on the market in recent years, projected to adsorb UV radiation even more efficiently than with the mentioned above pigment based standard filters: the interference filters for UV rejection (and, usually, for IR rejection too) manufactured using interference layers, that present better results than the pigment based filters. The only problem with interference filters type is that they are sensitive to the rays direction and, because of that, they are not adequate to wide-angle lenses. The internal fluorescence for three filters: the B+W 415 UV cut (equivalent to the Kodak Wratten 2E, pigment based), the B+W 486 UV IR cut (an interference type filter, used frequently on digital cameras to remove IR or UV) and the Baader UVIR rejection filter (two versions of this interference filter were used) had been tested and compared. The final quality of the UV fluorescence images seems to be of a superior quality when compared to the images obtained with classic filters.

Luís BRAVO PEREIRA

2010-01-01

28

Working Backs Project--implementing low back pain guidelines.  

UK PubMed Central (United Kingdom)

BACKGROUND: The St Vincent's Working Backs Project (WBP) represents a strategy for the implementation of the UK Faculty of Occupational Medicine guidelines for the management of low back pain (LBP) in the workplace (Carter J, Birrell L. Occupational Health Guidelines for the Management of Low Back Pain at Work-Principal Recommendations. London: Faculty of Occupational Medicine, 2000). AIM: To evaluate the efficacy of the St Vincent's WBP. METHODS: Questionnaire survey of staff and managers before and after the WBP intervention together with review of Occupational Health Department (OHD) data. The intervention included changes to LBP management pathways and protocols, combined with a guideline-based health promotion campaign. Outcomes included WBP awareness, LBP-related sickness absenteeism, staff back beliefs, intended management of LBP and manager attitudes towards LBP and it management. RESULTS: Following the WBP intervention, 85% (n=46) of managers and 57% (n=124) of staff reported having heard of the WBP. LBP-related sickness absenteeism in the previous year had not decreased significantly (95% confidence interval: -0.03 to 0.06). Among staff, a mean improvement of 1.8 had occurred on the Back Beliefs Questionnaire score. More staff (36%) reported that they would try to stay active (P<0.05) with LBP and would choose to attend the OHD if they required treatment. More managers demonstrated guideline-consistent attitudes. CONCLUSIONS: Following the WBP, staff and manager attitudes and beliefs towards LBP and its management were more consistent with the LBP guidelines although LBP-related sickness absenteeism did not decrease significantly. Future occupational guideline implementation strategy studies are required which should include a control worksite and rely on pre- and post-intervention organizational data.

Cunningham CG; Flynn TA; Toole CM; Ryan RG; Gueret PW; Bulfin S; Seale O; Blake C

2008-12-01

29

Modified Kalman Filter-based Approach in Comparison with Traditional Speech Enhancement Algorithms from Adverse Noisy Environments  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a new speech enhancement approach for a single channel speech enhancement in a noise environment. In this method speech is mixed with real-world noises from babble, car and street environments. In this paper we proposed modified Kalman method for effective speech enhancement. The proposed method is compared to the traditional Spectral Subtraction (SS), Wiener Filter (WF), Minimum Mean Square Error (MMSE) and Wavelet based Filter (WAVELET). Experiments showed that the modified algorithm can give better SNR improvement and Subjective evaluation tests demonstrate significant improvement results over classical algorithms, when tested withspeech signal corrupted a posterior by various noises at different signal to noise ratios.

G. Ramesh Babu,; Rameshwara Rao

2011-01-01

30

Filter  

UK PubMed Central (United Kingdom)

An epidural filter for connecting intermediate a syringe 70 and an epidural cannula 61 has a two part housing 1 formed with an inlet 3 and an outlet 4. Within the housing 1, a filter membrane 2 is supported, parallel with the direction of fluid flow through the filter, by struts 19 and 20 on opposite sides of the membrane, Fluid is supplied to the filter from the syringe via a female Luer-tapered bore 12 and distributed over the filter membrane 2 along a central channel and lateral passages between the struts 19. The filter has an outlet coupling 4 comprising a nose 42, having a bore 40, around which extends an internally screw-threaded collar 43. A clamping head 45 is screwed into the collar 43 and compresses a resilient sleeve 50 axially against the nose 42 so as to compress sleeve 50 about the cannula 61 which is received in bore 51 of sleeve 50 to form a fluid-tight seal between the cannula and the housing.

GILROY KEITH; JOHNSON MARK

31

Accurate two-dimensional IMRT verification using a back-projection EPID dosimetry method  

International Nuclear Information System (INIS)

[en] The use of electronic portal imaging devices (EPIDs) is a promising method for the dosimetric verification of external beam, megavoltage radiation therapy--both pretreatment and in vivo. In this study, a previously developed EPID back-projection algorithm was modified for IMRT techniques and applied to an amorphous silicon EPID. By using this back-projection algorithm, two-dimensional dose distributions inside a phantom or patient are reconstructed from portal images. The model requires the primary dose component at the position of the EPID. A parametrized description of the lateral scatter within the imager was obtained from measurements with an ionization chamber in a miniphantom. In addition to point dose measurements on the central axis of square fields of different size, we also used dose profiles of those fields as reference input data for our model. This yielded a better description of the lateral scatter within the EPID, which resulted in a higher accuracy in the back-projected, two-dimensional dose distributions. The accuracy of our approach was tested for pretreatment verification of a five-field IMRT plan for the treatment of prostate cancer. Each field had between six and eight segments and was evaluated by comparing the back-projected, two-dimensional EPID dose distribution with a film measurement inside a homogeneous slab phantom. For this purpose, the ?-evaluation method was used with a dose-difference criterion of 2% of dose maximum and a distance-to-agreement criterion of 2 mm. Excellent agreement was found between EPID and film measurements for each field, both in the central part of the beam and in the penumbra and low-dose regions. It can be concluded that our modified algorithm is able to accurately predict the dose in the midplane of a homogeneous slab phantom. For pretreatment IMRT plan verification, EPID dosimetry is a reliable and potentially fast tool to check the absolute dose in two dimensions inside a phantom for individual IMRT fields. Film measurements inside a phantom can therefore be replaced by EPID measurements

2006-01-01

32

Filter  

UK PubMed Central (United Kingdom)

A filter for removing solids and dissolved impurities, such as ammonia, from water being used in transporting live fish comprises a housing 1 with an inlet 10, an outlet 4 and an internal structure comprising an annular array of mesh bags closed at both ends and containing treating media such as zeolite (clinoptilolite), a quaternary ammonium based resin and active carbon, through which the water flows radially. The bags are individually located in outwardly open channels 10 secured to a central pipe 5, the pipe and channels being perforated. Pipe 5 may house an ultraviolet light to sterilize the water. Zeolite may be regenerated by circulating salt solution with pH raised to 9 to 12.5.

DRYDEN DR HOWARD THOMAS

33

Correction of computed tomography motion artifacts using pixel-specific back-projection  

International Nuclear Information System (INIS)

Cardiac and respiratory motion can cause artifacts in computed tomography scans of the chest. The authors describe a new method for reducing these artifacts called pixel-specific back-projection (PSBP). PSBP reduces artifacts caused by in-plane motion by reconstructing each pixel in a frame of reference that moves with the in-plane motion in the volume being scanned. The motion of the frame of reference is specified by constructing maps that describe the motion of each pixel in the image at the time each projection was measured; these maps are based on measurements of the in-plane motion. PSBP has been tested in computer simulations and with volunteer data. In computer simulations, PSBP removed the structured artifacts caused by motion. In scans of two volunteers, PSBP reduced doubling and streaking in chest scans to a level that made the images clinically useful. PSBP corrections of liver scans were less satisfactory because the motion of the liver is predominantly superior-inferior (S-I). PSBP uses a unique set of motion parameters to describe the motion at each point in the chest as opposed to requiring that the motion be described by a single set of parameters. Therefore, PSBP may be more useful in correcting clinical scans than are other correction techniques previously described.

1996-01-01

34

Parathyroid scintigraphy - benefit of early and late SPECT with iterative reconstruction (IR) versus filtered back projection (FBP)  

International Nuclear Information System (INIS)

[en] Full text: The published literature is conflicting on the benefit of Parathyroid SPECT. This study evaluates the incremental benefit of SPECT over planar imaging, comparing both the timing of SPECT and the processing technique used. Over 1 year, patients referred for parathyroid scintigraphy were studied with conventional dual tracer and dual phase planar imaging using 50 MBq of Tc-99m-pertechnetate and 800 MBq of Tc-99m MIBI. SPECT was performed both after the initial and 2 hour planars, and processed using both PBP and IR. All studies were randomised and read as planar, planar+FBP then planar+FBP+IR for both early and late SPECT by 2 blinded readers. Focal abnormalities were scored on a 5 point scale, with scores of 4 and 5 being called positive. In cases of observer disagreement a third blinded reader was used. Surgical follow up was available in 16 of 33 patients. 2 were surgically non curative and excluded (including one probable scintigraphic mediastinal adenoma not located at surgery). Sensitivity and ROC analyses were performed to evaluate incremental benefit of FBP and IR SPECT over planars. No significant difference was found between Early and Late SPECT. ROC analysis of individual readers showed improved accuracy of SPECT over planars for one of the two readers. IR SPECT improves sensitivity without loss of specificity compared to planar imaging. Late SPECT shows no additional benefit. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

2002-01-01

35

Importance of point-by-point back projection correction for isocentric motion in digital breast tomosynthesis: Relevance to morphology of structures such as microcalcifications  

International Nuclear Information System (INIS)

Digital breast tomosynthesis is a three-dimensional imaging technique that provides an arbitrary set of reconstruction planes in the breast from a limited-angle series of projection images acquired while the x-ray tube moves. Traditional shift-and-add (SAA) tomosynthesis reconstruction is a common mathematical method to line up each projection image based on its shifting amount to generate reconstruction slices. With parallel-path geometry of tube motion, the path of the tube lies in a plane parallel to the plane of the detector. The traditional SAA algorithm gives shift amounts for each projection image calculated only along the direction of x-ray tube movement. However, with the partial isocentric motion of the x-ray tube in breast tomosynthesis, small objects such as microcalcifications appear blurred (for instance, about 1-4 pixels in blur for a microcalcification in a human breast) in traditional SAA images in the direction perpendicular to the direction of tube motion. Some digital breast tomosynthesis algorithms reported in the literature utilize a traditional one-dimensional SAA method that is not wholly suitable for isocentric motion. In this paper, a point-by-point back projection (BP) method is described and compared with traditional SAA for the important clinical task of evaluating morphology of small objects such as microcalcifications. Impulse responses at different three-dimensional locations with five different combinations of imaging acquisition parameters were investigated. Reconstruction images of microcalcifications in a human subject were also evaluated. Results showed that with traditional SAA and 45 deg. view angle of tube movement with respect to the detector, at the same height above the detector, the in-plane blur artifacts were obvious for objects farther away from x-ray source. In a human subject, the appearance of calcifications was blurred in the direction orthogonal to the tube motion with traditional SAA. With point-by-point BP, the appearance of calcifications was sharper. The point-by-point BP method demonstrated improved rendition of microcalcifications in the direction perpendicular to the tube motion direction. With wide angles or for imaging of larger breasts, this point-by-point BP rather than the traditional SAA should also be considered as the basis of further deblurring algorithms that work in conjunction with the BP method.

2007-01-01

36

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

2011-07-01

37

[Comparative study on mathematical set-based drug release kinetics method and Kalman filter method applied in evaluating drug release of multi-component traditional Chinese medicine preparations].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To provide a mathematical set-based method for evaluating drug release kinetics of multi-component traditional Chinese medicine preparations. METHOD: With Fuzheng Huayu prescription as the study model, a mathematical set-based method for evaluating drug release kinetics was established to guide the preparation of drug release system of Fuzheng Huayu prescription, and a quantitative evaluation was made for its multi-component drug release characteristics. Its accuracy was verified by Kalman filtering method. RESULT: The comparison between the two showed that the sample No. 4 of Fuzheng Huayu drug release system showed synchronized drug release with its reference preparation Fuzheng Huayu capsules. CONCLUSION: The results verified the accuracy and rationality of the evaluation method based on mathematics set. Meanwhile, it displayed the release of target preparations according to asynchronous coefficient (k) and other parameters, and found the orientation of regulating and improving the unit drug release dosage from relevant error parameters of various characteristic peak information, in order to purposefully regulate relevant components, and enable target preparations to meet the synchronized drug release requirements of the reference preparation. Meanwhile, it provided an effective measure for evaluating the quantitative characterization and synchronized release behavior of multi-component traditional Chinese medicines.

Shen L; Zhai Y; Ma SY; Lin X; Feng Y; Ruan KF

2013-04-01

38

Helium-3 MR q-space imaging with radial acquisition and iterative highly constrained back-projection.  

Science.gov (United States)

An undersampled diffusion-weighted stack-of-stars acquisition is combined with iterative highly constrained back-projection to perform hyperpolarized helium-3 MR q-space imaging with combined regional correction of radiofrequency- 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-sec breath-hold. Measures of lung microstructure at three different lung volumes are evaluated using inhaled gas volumes of 500 mL, 1000 mL, and 1500 mL to demonstrate feasibility. Phantom results demonstrate that the proposed technique is in agreement with theoretical values, as well as with a fully sampled two-dimensional Cartesian acquisition. Results from the volunteer study demonstrate that the root mean squared diffusion distance increased significantly from the 500-mL volume to the 1000-mL volume. This technique represents the first demonstration of a spatially resolved hyperpolarized helium-3 q-space imaging technique and shows promise for microstructural evaluation of lung disease in three dimensions. PMID:19953515

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

2010-01-01

39

Helium-3 MR q-space imaging with radial acquisition and iterative highly constrained back-projection.  

UK PubMed Central (United Kingdom)

An undersampled diffusion-weighted stack-of-stars acquisition is combined with iterative highly constrained back-projection to perform hyperpolarized helium-3 MR q-space imaging with combined regional correction of radiofrequency- 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-sec breath-hold. Measures of lung microstructure at three different lung volumes are evaluated using inhaled gas volumes of 500 mL, 1000 mL, and 1500 mL to demonstrate feasibility. Phantom results demonstrate that the proposed technique is in agreement with theoretical values, as well as with a fully sampled two-dimensional Cartesian acquisition. Results from the volunteer study demonstrate that the root mean squared diffusion distance increased significantly from the 500-mL volume to the 1000-mL volume. This technique represents the first demonstration of a spatially resolved hyperpolarized helium-3 q-space imaging technique and shows promise for microstructural evaluation of lung disease in three dimensions.

O'Halloran RL; Holmes JH; Wu YC; Alexander A; Fain SB

2010-01-01

40

GPU-Accelerated Forward and Back-Projections with Spatially Varying Kernels for 3D DIRECT TOF PET Reconstruction.  

UK PubMed Central (United Kingdom)

We describe a GPU-accelerated framework that efficiently models spatially (shift) variant system response kernels and performs forward- and back-projection operations with these kernels for the DIRECT (Direct Image Reconstruction for TOF) iterative reconstruction approach. Inherent challenges arise from the poor memory cache performance at non-axis aligned TOF directions. Focusing on the GPU memory access patterns, we utilize different kinds of GPU memory according to these patterns in order to maximize the memory cache performance. We also exploit the GPU instruction-level parallelism to efficiently hide long latencies from the memory operations. Our experiments indicate that our GPU implementation of the projection operators has slightly faster or approximately comparable time performance than FFT-based approaches using state-of-the-art FFTW routines. However, most importantly, our GPU framework can also efficiently handle any generic system response kernels, such as spatially symmetric and shift-variant as well as spatially asymmetric and shift-variant, both of which an FFT-based approach cannot cope with.

Ha S; Matej S; Ispiryan M; Mueller K

2013-02-01

 
 
 
 
41

Rupture process of the 2011 off the Pacific coast of Tohoku Earthquake (Mw 9.0) as imaged with back-projection of teleseismic P-waves  

Science.gov (United States)

We use the back-projection method, with data recorded on the dense USArray network, to estimate the rupture propagation for the Mw 9.0 earthquake that occurred offshore of the Tohoku region, Japan. The results show a variable rupture propagation ranging from about 1.0 to 3.0 km/s for the high-frequency radiation. The rupture propagates over about 450 km in approximately 150 s. Based on the rupture speed and direction, the high-frequency source process can be divided into two parts. The first part has a relatively slow rupture speed of 1.0 to 1.5 km/s and propagates northwestward. In the second part, the rupture progresses southwestward starting with a slow speed of about 1.5 km/s and accelerating to about 3.0 km/s. We see three large pulses at 30 s, 80 s and 130 s. The first two, including the largest second pulse, were located 50 to 70 km northwest of the epicenter. The third occurred about 250 km southwest of the epicenter. The variability of rupture velocity may be associated with significant changes of physical properties along the fault plane. Areas of low/high rupture speed are associated with large/small energy releases on the fault plane. These variations may reflect the strength properties along the fault. Also, locations of the high-frequency radiation derived from the back-projection analysis are significantly different from the areas of very large slip for this earthquake.

Wang, D.; Mori, J.

2011-07-01

42

Air filters; Air filter  

Energy Technology Data Exchange (ETDEWEB)

Efforts for improving the collection efficiency of air filters began with the HEPA (high efficiency particulate air) filter for clean rooms in the semiconductor industry. Now, a ULPA (ultra low penetration air) filter has come into being, capable of dealing with 0.1{mu}m-large particulates, and studies are under way for a super ULPA or others capable of dust collection on the nanometer scale. The method generally used for enhancing filter material efficiency increases the number of fibers by making them finer in diameter, but this method also increases pressure loss. An improved method increases the amount of filter material without changing the diameter, which increases the handling capacity provided the rate remains the same of the fine dust travelling through the filter. Improvement on the folding of filter material or the use of materials lower in pressure loss should also be used jointly with the above-said measures. The latest filter is only 1/4 of the conventional ones in size and weight, which is attributed to the success in collection efficiency improvement and pressure loss reduction. Although the air filter aims primarily to collect fine dust, studies are under way to apply it for the control of chemical substances and for the cleaning of air at residential houses (against ticks and pollen). Used filters are buried as is or after incineration and compaction, or cleaned for reuse, but reconsideration needs be made about these methods of disposal. 6 refs., 4 figs., 4 tabs.

Takahashi, K. [Nippon Muki Co. Ltd., Tokyo (Japan)

1998-06-05

43

Implicit Kalman filtering.  

UK PubMed Central (United Kingdom)

For an implicitly defined discrete system, a new algorithm for Kalman filtering is developed and an efficient numerical implementation scheme is proposed. Unlike the traditional explicit approach, the implicit filter can be readily applied to ill-conditioned systems and allows for generalization to descriptor systems. The implementation of the implicit filter depends on the solution of the congruence matrix equation (A1)(Px)(AT1) = Py. We develop a general iterative method for the solution of this equation, and prove necessary and sufficient conditions for convergence. It is shown that when the system matrices of an implicit system are sparse, the implicit Kalman filter requires significantly less computer time and storage to implement as compared to the traditional explicit Kalman filter. Simulation results are presented to illustrate and substantiate the theoretical developments.

Skliar M; Ramirez WF

1997-01-01

44

Implicit Kalman filtering.  

Science.gov (United States)

For an implicitly defined discrete system, a new algorithm for Kalman filtering is developed and an efficient numerical implementation scheme is proposed. Unlike the traditional explicit approach, the implicit filter can be readily applied to ill-conditioned systems and allows for generalization to descriptor systems. The implementation of the implicit filter depends on the solution of the congruence matrix equation (A1)(Px)(AT1) = Py. We develop a general iterative method for the solution of this equation, and prove necessary and sufficient conditions for convergence. It is shown that when the system matrices of an implicit system are sparse, the implicit Kalman filter requires significantly less computer time and storage to implement as compared to the traditional explicit Kalman filter. Simulation results are presented to illustrate and substantiate the theoretical developments. PMID:11541942

Skliar, M; Ramirez, W F

1997-01-01

45

Traditional Chinese medicine lotion  

UK PubMed Central (United Kingdom)

The invention belongs to the field of traditional Chinese medicines, in particular relates to a traditional Chinese medicine lotion. The lotion comprises the following raw traditional Chinese medicinal materials by weight proportion: 30 to 40 of chrysanthemum indicum, 25 to 30 of folium fici microcarpae, 15 to 20 of rhubarb, 15 to 20 of artemisia capillaris, 15 to 20 of argy wormwood leaves, 10 to 15 of ordate houttuynia, 10 to 12 of gardenia, 10 to 12 of bupleurum, 10 to 12 of radix saposhnikoviae, 5 to 8 of Chinese prickly ash, 5 to 8 of salvia, 6 to 8 of notopterygium, 6 to 8 of phellodendron and 6 to 8 of lopseed and is prepared by the following steps: crushing the raw traditional Chinese medicinal materials into rough powder or directly adding water to decoct the raw traditional Chinese medicinal materials for 30 minutes to 40 minutes filtering residue and taking juice and diluting with warm water to soak or clean bodies or making paste by adopting a traditional technology, i.e. ethanol extraction or vacuum concentration or directly sterilizing in vacuum and packaging into bottled products. In addition, 3 to 5 parts of asparagus juice are added to the lotion before use. The product can achieve more than 94 percent of effective rate on eczema, pruritus, hypersensitivity, and the like and can achieve more than 90 percent of effective rate on icterus neonatorum, anemopyretic cold, measles, simple herpes, and the like.

QINGRONG WANG

46

Generalized Nonlinear Complementary Attitude Filter  

CERN Document Server

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.

Jensen, Kenneth

2011-01-01

47

Semicircular microstrip low pass filter  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents semicircular microstrip low pass filter with the sharp rejection and wide stop band. The proposed filter design is based on the calculation of filter parameters from traditional hi-lo impedance method and is available in the literature of microstrip filter. To further improve the design performance, high impedance lines are magnetically coupled, resulting an attenuation pole near -3dB cut off point of the filter. This design gives insight in designing a low pass filter with reduced size of an arbitrary geographical shape.

Kumud Ranjan Jha; Manish Rai

2008-01-01

48

GMTI processing using back projection.  

Energy Technology Data Exchange (ETDEWEB)

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.

Doerry, Armin Walter

2013-07-01

49

Qualitative Evaluation of Filter Function in Brain SPECT  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Filtering can greatly affect the quality of clinical images. Determining the best filter and the proper degree of smoothing can help to ensure the most accurate diagnosis. Methods: Forty five patient’s data aquired during brain phantom SPECT studies were reconstructed using filtered back-projection technique. The ramp, Shepp-Logan, Cosine, Hamming, Hanning, Butterworth, Metz and Wiener filters were examined to find the optimum condition for each filter. For each slice image, 6200 reconstruction options were considered. The corresponding planar image of each slice was used as the reference image. The quality of reconstructed images was determined using universal image quality index (UIQI). Four nuclear medicine physicians evaluated the images to choose the best of the filters. Results: Images with best resolution, contrast, smoothness and overall quality were selected by nuclear medicine physicians depending on filters used to generate the best image. A significant difference (p<0.05) between the filters regarding these parameters were observed. Conclusion: The results of this study revealed that maximum resolution and contrast could be obtained using both Metz and Wiener filters. However, the best quality images were generated by using Butterworth filter.

Elham Raeisi; Hossein Rajabi; Mahmoud Reza Aghamiri; Ebrahim Hajizadeh; Shahram Seifollahi-Asl; Nahid Yaghobi; Seyed Hassan Firozabadi; Ahmad Bitarafan Rajabi

2007-01-01

50

HIV incidence trends vary between jurisdictions in Australia: an extended back-projection analysis of men who have sex with men.  

UK PubMed Central (United Kingdom)

BACKGROUND: Trends in HIV diagnoses differ across Australia and are primarily driven by men who have sex with men (MSM). We use national population surveillance data to estimate the incidence of HIV infections among MSM by jurisdiction and infer the proportion of undiagnosed infections. METHODS: Annual surveillance data for AIDS diagnoses, HIV diagnoses and recently acquired HIV infections were obtained from 1980 to 2009. A modified statistical back-projection method was used to reconstruct HIV incidence by jurisdiction. RESULTS: HIV incidence among MSM peaked for all jurisdictions in the early 1980s and then declined into the early 1990s, after which incidence increased. Trends then differ between jurisdictions. In New South Wales (NSW) and South Australia, estimated HIV incidence peaked at 371 and 50 cases respectively in 2003, and has since decreased to 258 and 24 cases respectively in 2009. HIV infections in Queensland (Qld) have more than doubled over the past decade, from 84 cases in 2000 to 192 cases in 2009. Victoria and Western Australia have seen a rise in HIV incidence from 2000 to 2006 (to a peak of 250 and 38 incident cases respectively), followed by a plateau to 2009. HIV incidence in the Northern Territory, Tasmania and Australian Capital Territory have increased since 2000; however, case numbers remain small (<20 per year). The estimated proportion of HIV infections not yet diagnosed to 2009 ranges from 10% (NSW) to 18% (Qld), with an average of 12% across Australia. CONCLUSIONS: HIV diagnosis trends among MSM in Australia reflect changes in estimated incidence to 2009, and reveal the largest increase in the past 10 years in Qld.

Mallitt KA; Wilson DP; McDonald A; Wand H

2012-05-01

51

Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters  

Directory of Open Access Journals (Sweden)

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 α-stable and generalized-t. 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.

Gonzalo R. Arce; Juan G. Gonzalez

2002-01-01

52

Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters  

Directory of Open Access Journals (Sweden)

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.

Gonzalez Juan G; Arce Gonzalo R

2002-01-01

53

Intelligent Optimize Design of LCL Filter for Three-Phase Voltage-Source PWM Rectifier  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Compared to traditional L filter, a LCL filter is more effective on reducing harmonic distortion at switch frequency. So it is important to choose the LCL filter parameters to achieve good filtering effect. This paper introduces some traditional design methods. Design of a LCL filter by genetic algo...

Sun, Wei; Chen, Zhe; Wu, Xiaojie

54

FILTER TREATMENT  

Science.gov (United States)

A process is described for reconditioning fused alumina filters which have become clogged by the accretion of bismuth phosphate in the filter pores, The method consists in contacting such filters with faming sulfuric acid, and maintaining such contact for a substantial period of time.

Sutton, J.B.; Torrey, J.V.P.

1958-08-26

55

HVDC filter  

Science.gov (United States)

A filter for an HVDC system. The filter includes a capacitor and a reactor arranged in an indoor location having a first space for erecting filter components. The first space includes a high voltage area and a low voltage area defining a first electric potential direction.

2013-06-18

56

Filtering apparatus  

Energy Technology Data Exchange (ETDEWEB)

A vertical vessel having a lower inlet and an upper outlet enclosure separated by a main horizontal tube sheet. The inlet enclosure receives the flue gas from a boiler of a power system and the outlet enclosure supplies cleaned gas to the turbines. The inlet enclosure contains a plurality of particulate-removing clusters, each having a plurality of filter units. Each filter unit includes a filter clean-gas chamber defined by a plate and a perforated auxiliary tube sheet with filter tubes suspended from each tube sheet and a tube connected to each chamber for passing cleaned gas to the outlet enclosure. The clusters are suspended from the main tube sheet with their filter units extending vertically and the filter tubes passing through the tube sheet and opening in the outlet enclosure. The flue gas is circulated about the outside surfaces of the filter tubes and the particulate is absorbed in the pores of the filter tubes. Pulses to clean the filter tubes are passed through their inner holes through tubes free of bends which are aligned with the tubes that pass the clean gas.

Haldipur, Gaurang B. (Monroeville, PA); Dilmore, William J. (Murrysville, PA)

1992-01-01

57

Survey on Spam Filtering Techniques  

Directory of Open Access Journals (Sweden)

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.

Saadat Nazirova

2011-01-01

58

Well filter  

Energy Technology Data Exchange (ETDEWEB)

A well filter is proposed which consists of outer and inner perforated pipes arranged concentrically, and an above-filter pipe. It is distinguished by the fact that in order to improve its operating efficiency, the inner perforated pipe is installed with the possibility of axial and radial movement.

Kozhevnikov, A.A.; Antonov, Yu.I.; Davidenko, A.N.; Magala, V.A.; Stepanenko, P.G.

1982-01-01

59

A novel scheme to design the filter for CT reconstruction using FBP algorithm.  

UK PubMed Central (United Kingdom)

BACKGROUND: The Filtered Back-Projection (FBP) algorithm is the most important technique for computerized tomographic (CT) imaging, in which the ramp filter plays a key role. FBP algorithm had been derived using the continuous system model. However, it has to be discretized in practical applications, which necessarily produces distortion in the reconstructed images. METHODS: A novel scheme is proposed to design the filters to substitute the standard ramp filter to improve the reconstruction performance for parallel beam tomography. The design scheme is presented under the discrete image model and discrete projection environment. The designs are achieved by constrained optimization procedures. The designed filter can be regarded as the optimal filter for the corresponding parameters in some ways. RESULTS: Some filters under given parameters (such as image size and scanning angles) have been designed. The performance evaluation of CT reconstruction shows that the designed filters are better than the ramp filter in term of some general criteria. CONCLUSIONS: The 2-D or 3-D FBP algorithms for fan beam tomography used in most CT systems, are obtained by modifying the FBP algorithm for parallel beam tomography. Therefore, the designed filters can be used for fan beam tomography and have potential applications in practical CT systems.

Shi H; Luo S

2013-01-01

60

Cigarette filter  

UK PubMed Central (United Kingdom)

A cigarette filter for light cigarettes has the following features: a) a first section (2) with a filter core (3) of a conventional filter material, surrounded by an air-impermeable wrapper material (4), b) a second section (5) with an air-impermeable hollow body (6) which is surrounded by an air-permeable wrapper (7) to form a flow zone (10), c) a third section (11) with a filter core (12) which is surrounded by the air-impermeable wrapper material (4), d) the flow zone (10) being open towards the first section (2) and closed towards the third section (11), e) the volumetric air flow per unit time through the wrapper material (7) in the second section (5) being non-linearly dependent on the pressure drop, and f) the fibre material of the filter core (12) in the third section (11) having a count of at least 8 dpf, and the ratio of the puffing resistance in mm water gauge relative to the degree of retention of the filter core in %, relative to 1 cm length of the filter core, is greater than 1.5

SCHNEIDER WERNER DIPL PHYS DR; HENNING PAUL-GEORG DIPL CHEM D; SCHLUETER ADOLF DIPL ING DR; WIETHAUP WOLFGANG DIPL PHYS DR

 
 
 
 
61

Micromachined filters  

UK PubMed Central (United Kingdom)

The fluid filters are capable of accurately handling substantially continuous fluid flow rates as low as about 0.01 cc/day. The filters are so miniaturized, corrosion-resistant and non-toxic that they are suitable for being implanted in the human body; and are capable of being mass produced at costs so low, by using micromachining techniques, such as etching, that they may be considered to be disposable. The filters are passive devices which consume no electrical energy at all. The filters are reliable because they may have as few as only two parts, only one which is a moving part; and because they may handle fluids at very low pressures

Saaski Elric W.; Lawrence Dale M.

62

Filter for diesel fuel. Filter fuer Dieselkraftstoff  

Energy Technology Data Exchange (ETDEWEB)

Filter for diesel fuel, with a filter housing, with a fuel inlet and a fuel outlet, as well as with a filter element arranged between the inlet and outlet in the filter casing; the filter has media for heating the filter element electrically. (orig.).

Baumann, D.

1987-04-30

63

Survey on Spam Filtering Techniques  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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-base...

Saadat Nazirova

64

Filter cartridge for respirator filters  

UK PubMed Central (United Kingdom)

The invention relates to a filter cartridge for respirator filters (breathing apparatus filters) having adsorbents, separated by sieves, grid trays or perforated metal sheets, for gases and vapours of organic compounds having a boiling point below 65@C, so-called low-boilers. The filter cartridge has three layers. The first layer, situated remote from the mouth on use, comprises pure silica gel having a particle size of 2.5-4 mm in a bed height of approximately 20-30%. The second layer comprises a highly activated shaped charcoal having an effective surface area of 1200-1400 m< 2> g< -1> activated charcoal, a particle size of 0.8-1.0 mm grain diameter and 2.0-3.0 mm grain length, a moisture below 2%, in a bed height of approximately 60%. The third layer, like the first layer, comprises pure silica gel in a bed height of 10-20%.

BARTSCH GUENTER DIPL PHYS; BUFE HEIDI

65

Christiansen filter realized by an odd smooth cylindrical lens.  

Science.gov (United States)

The Christiansen filter that is realized by odd smooth cylindrical lenses is analyzed in detail. Several popular filtering functions are discussed. The corresponding lens profile functions are obtained by an inverse scattering theory, which enables the filter to synthesize a desired prescribed response function. This kind of Christiansen filter has a passband narrower than that of the traditional Christiansen filter. Three Christiansen filters centered at 545 nm with full width at half-maximum of 2 nm are synthesized, and the approach to a better suppression of halos from the main transmission peak of the filters is presented in a systematic way. PMID:20035309

Li, Jian; Goddard, N; Xie, Kang

2010-01-01

66

Christiansen filter realized by an odd smooth cylindrical lens.  

UK PubMed Central (United Kingdom)

The Christiansen filter that is realized by odd smooth cylindrical lenses is analyzed in detail. Several popular filtering functions are discussed. The corresponding lens profile functions are obtained by an inverse scattering theory, which enables the filter to synthesize a desired prescribed response function. This kind of Christiansen filter has a passband narrower than that of the traditional Christiansen filter. Three Christiansen filters centered at 545 nm with full width at half-maximum of 2 nm are synthesized, and the approach to a better suppression of halos from the main transmission peak of the filters is presented in a systematic way.

Li J; Goddard N; Xie K

2010-01-01

67

Air filter  

Energy Technology Data Exchange (ETDEWEB)

An air filter is described that has a counter rotating drum, i.e., the rotation of the drum is opposite the tangential intake of air. The intake air has about 1 lb of rock wool fibers per 107 cu. ft. of air sometimes at about 100% relative humidity. The fibers are doffed from the drum by suction nozzle which are adjacent to the drum at the bottom of the filter housing. The drum screen is cleaned by periodically jetting hot dry air at 120 psig through the screen into the suction nozzles.

Jackson, R.E.; Sparks, J.E.

1981-03-03

68

Ethernet filter  

Energy Technology Data Exchange (ETDEWEB)

This invention is comprised of an apparatus and method that prevents access to unauthorized data in a local area network, such as Ethernet, in which information is transmitted from a transceiver to at least one workstation. Encoded data packets transmitted from the transceiver are filtered by splitting the packet into two signals. One signal contains the data that was transmitted, while the other signal contains tainted data. The filter determines whether a workstation is authorized to access the data, and then delivers either the tainted data to unauthorized workstations, or the data that was transmitted to authorized workstations.

Charney, E.J.; Tanzella, A.J.; Wujcik, J.G.

1990-11-09

69

Filter apparatus  

Energy Technology Data Exchange (ETDEWEB)

A plurality of holding tubes are respectively mounted in apertures in a partition plate fixed in a housing receiving gas contaminated with particulate material. A filter cartridge is removably held in each holding tube, and the cartridges and holding tubes are arranged so that gas passes through apertures therein and across the partition plate while particulate material is collected in the cartridges. Replacement filter cartridges are respectively held in holding canisters mounted on a support plate which can be secured to the aforesaid housing, and screws mounted on said canisters are arranged to push replacement cartridges into the cartridge holding tubes and thereby eject used cartridges therefrom.

Kuban, Daniel P. (Oak Ridge, TN); Singletary, B. Huston (Oak Ridge, TN); Evans, John H. (Rockwood, TN)

1984-01-01

70

An audit of manufacturers' implementation of reconstruction filters in single-photon emission computed tomography.  

UK PubMed Central (United Kingdom)

AIM: The Nuclear Medicine Software Quality Group of the Institute of Physics and Engineering in Medicine has conducted an audit to compare the ways in which different manufacturers implement the filters used in single-photon emission computed tomography. The aim of the audit was to identify differences between manufacturers' implementations of the same filter and to find means for converting parameters between systems. METHODS: Computer-generated data representing projection images of an ideal test object were processed using seven different commercial nuclear medicine systems. Images were reconstructed using filtered back projection and a Butter worth filter with three different cutoff frequencies and three different orders. RESULTS: The audit found large variations between the frequency-response curves of what were ostensibly the same filters on different systems. The differences were greater than could be explained simply by different Butter worth formulae. Measured cutoff frequencies varied between 40 and 180% of that expected. There was also occasional confusion with respect to frequency units. CONCLUSION: The audit concluded that the practical implementation of filtering, such as the size of the kernel, has a profound effect on the results, producing large differences between systems. Nevertheless, this work shows how users can quantify the frequency response of their own systems so that it will be possible to compare two systems in order to find filter parameters on each that produce equivalent results. These findings will also make it easier for users to replicate filters similar to other published results, even if they are using a different computer system.

Lawson RS; White D; Cade SC; Hall DO; Kenny B; Knight A; Livieratos L; Nijran K

2013-08-01

71

Filtering apparatus  

Energy Technology Data Exchange (ETDEWEB)

A gas filtering bag house is disclosed that has having a stepped partition intermediate to the bags and the hopper with the gas inlet located in side wall below partition at maximum spacing of partition and hopper-the baghouse including walkway intermediate bay height and overlying other bags.

Peterson, H.G.

1981-04-14

72

Oil filter  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an oil filter cartridge having a central internally threaded receptacle for connection to a corresponding externally threaded conduit on an engine for return of filtered oil circulated through the filter and an annular gasket defining a pathway for oil from the engine to the filter. The improvement described here is whereby the central threaded receptacle has removeably threaded thereto an adaptor collar with external threads matched those of the receptacle and internal threads corresponding with the threads of the externally threaded conduit of the engine to which the cartridge is to be connected whereby varying the thickness of the collar allows the cartridge to be used in different engines. A decorative outer cylindrical cover is removeably secured to the outer walls of the cartridge by means of a magnetized generally cylindrically shaped sleeve, dimensioned to resiliently slide over the outer cartridge walls, the sleeve having upper walls of a larger diameter to match those of the decorative cover, and resilient spacer means between the lower walls of the sleeve and the walls of the decorative cover.

Hebert, A.M.

1987-02-10

73

Filter This  

Directory of Open Access Journals (Sweden)

Full Text Available In the Library with the Lead Pipe welcomes Audrey Barbakoff, a librarian at the Milwaukee Public Library, and Ahniwa Ferrari, Virtual Experience Manager at the Pierce County Library System in Washington, for a point-counterpoint piece on filtering in libraries. The opinions expressed here are those of the authors, and are not endorsed by their employers. [...

Audrey Barbakoff

2011-01-01

74

Properties of Multilayer Filters.  

Science.gov (United States)

New methods were investigated of using optical interference coatings to produce bandpass filters for the spectral region 110 nm to 200 nm. The types of filter are: triple cavity metal dielectric filters; all dielectric reflection filters; and all dielectr...

P. W. Baumeister

1973-01-01

75

Well filter  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the invention is to improve reliable operation of the filter by guaranteeing self-cleaning during operation. This goal is achieved because in the well filter which contains two metal concentrically arranged perforated pipes with openings of the same shape and dimensions and edges of the corresponding openings converged by the opposite sides and shifted in relation to each other with the formation of transitional channels, bottom in the lower part of the outer pipes and connecting element, the bottom of the outer pipes is equipped with an overflow valve, and the inner perforated pipe has a cap on its lower end forming a chamber with the bottom filled with gas. The gap between the perforated pipes is filled with a glue composition with electrical-insulating properties, while the connecting element is made of electrical-insulating material.

Aliverdizade, T.K.; Agayev, Sh,K.; Matveyenko, L.M.; Yelizarova, Z.Ye.

1984-01-01

76

Plasmonic filters.  

Energy Technology Data Exchange (ETDEWEB)

Metal films perforated with subwavelength hole arrays have been show to demonstrate an effect known as Extraordinary Transmission (EOT). In EOT devices, optical transmission passbands arise that can have up to 90% transmission and a bandwidth that is only a few percent of the designed center wavelength. By placing a tunable dielectric in proximity to the EOT mesh, one can tune the center frequency of the passband. We have demonstrated over 1 micron of passive tuning in structures designed for an 11 micron center wavelength. If a suitable midwave (3-5 micron) tunable dielectric (perhaps BaTiO{sub 3}) were integrated with an EOT mesh designed for midwave operation, it is possible that a fast, voltage tunable, low temperature filter solution could be demonstrated with a several hundred nanometer passband. Such an element could, for example, replace certain components in a filter wheel solution.

Passmore, Brandon Scott; Shaner, Eric Arthur; Barrick, Todd A.

2009-09-01

77

Analog filters using Matlab  

CERN Multimedia

Presents an introduction to analog filters for senior undergraduate and graduate students. This book covers the synthesis of analog filters as well as many other filter types including passive filters and filters with distributed elements. It also addresses the basic circuit elements for the filters.

Wanhammar, Lars

2009-01-01

78

Traditional Photographic Effects with Adobe Photoshop  

CERN Multimedia

Appropriate for both professional and amateur photographers, this guide approaches Adobe Photoshop from the technical and artistic standpoint of traditional photography. Rather than emphasizing how to distort or create unusual or outlandish digital effects, it explores the use of Photoshop to achieve very realistic photographic images. In-depth instruction illustrates how to duplicate traditional photography and darkroom effects and techniques and how to use alternative films, specialized filters, lenses, and camera accessories. Every technique is demonstrated step-by-step so that photographer

Perkins, Michelle

2003-01-01

79

Ceramic filters  

Energy Technology Data Exchange (ETDEWEB)

Filters were formed from ceramic fibers, organic fibers, and a ceramic bond phase using a papermaking technique. The distribution of particulate ceramic bond phase was determined using a model silicon carbide system. As the ceramic fiber increased in length and diameter the distance between particles decreased. The calculated number of particles per area showed good agreement with the observed value. After firing, the papers were characterized using a biaxial load test. The strength of papers was proportional to the amount of bond phase included in the paper. All samples exhibited strain-tolerant behavior.

Holmes, B.L.; Janney, M.A.

1995-12-31

80

Traditional Chinese medicine for treating infantile pneumonia  

UK PubMed Central (United Kingdom)

The invention discloses a traditional Chinese medicine for treating infantile pneumonia, which is characterized by comprising the following Chinese herbs as main components: 10g of lotus flower, 6g of herba ephedrae, 30g of plaster, 30g of radix isatidis, 10g of ordate houttuynia, 8g of almond, 3g of liquorice, 10g of bulbus fritilariae, 10g of radix sileris, 10g of balloon flower, 10g of uncaria, 6g of corn mint, 60g of rock candy, and the like. A preparation method of the traditional Chinese medicine for treating infantile pneumonia comprises the following steps: dipping the Chinese herbs into 500ml of water, frying the Chinese herbs till the water boils to be reduced to 250ml and then filtering the Chinese herbs decocting the 60g of rock candy to form rock candy water by 250ml of water adding the 250ml of rock candy water into the filtered 250ml of liquid medicine, and finally obtaining the traditional Chinese medicine which needs to be taken warm. The prescription is prepared from pure Chinese herbs by a traditional preparation method, remains the property of the Chinese herbs, has the efficacy of clearing away heat and toxic material and dispelling wind and arresting itching as well as freeing lung and relieving a cough, achieves the aim of treating and has no side effect.

SHILING ZONG

 
 
 
 
81

Filter systems for IGCC applications  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this program were to identify metallic filter medium to be utilized in the Integrated Gasification Combined Cycle process (IGCC). In IGCC processes utilizing high efficiency desulfurizing technology, the traditional corrosion attack, sulfidation, is minimized so that metallic filters are viable alternatives over ceramic filters. Tampa Electric Company`s Polk Power Station is being developed to demonstrate Integrated Gasification Combined Cycle technology. The Pall Gas Solid Separation (GSS) System is a self cleaning filtration system designed to remove virtually all particulate matter from gas streams. The heart of the system is the filter medium used to collect the particles on the filter surface. The medium`s filtration efficiency, uniformity, permeability, voids volume, and surface characteristics are all important to establishing a permeable permanent cake. In-house laboratory blowback tests, using representative full scale system particulate, were used to confirm the medium selection for this project. Test elements constructed from six alloys were supplied for exposure tests: PSS 310SC (modified 310S alloy); PSS 310SC heat treated; PSS 310SC-high Cr; PSS 310SC-high Cr heat treated; PSS Hastelloy X; and PSS Hastelloy X heat treated.

Bevan, S.; Gieger, R.; Sobel, N.; Johnson, D.

1995-11-01

82

Intelligent Optimize Design of LCL Filter for Three-Phase Voltage-Source PWM Rectifier  

DEFF Research Database (Denmark)

Compared to traditional L filter, a LCL filter is more effective on reducing harmonic distortion at switch frequency. So it is important to choose the LCL filter parameters to achieve good filtering effect. This paper introduces some traditional design methods. Design of a LCL filter by genetic algorithm (GA) and particle swam optimization (PSO) are presented in this paper and comparison of the two intelligent optimization. Simulation result and calculate data are provided to prove that intelligent optimization are more effective and simple than traditional methods.

Sun, Wei; Chen, Zhe

2009-01-01

83

Carbon Nanotube Filter.  

Science.gov (United States)

Monolithic, macroscopic, nanoporous nanotube filters are fabricated having radially aligned carbon nanotube walls. The freestanding filters have diameters and lengths up to several centimeters. A single-step filtering process was demonstrated in two impor...

A. Srivastava O. N. Srivastava P. M. Ajayan R. Vajtal S. Talapatra

2005-01-01

84

Review of Filter Techniques  

Directory of Open Access Journals (Sweden)

Full Text Available The paper focuses on filter fundamental along with different types of filter and its technology.Design of Filters, its analysis tools and its application has been discussed in detail.

Manidipa Nath

2012-01-01

85

Oral Tradition Journal  

Science.gov (United States)

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.

2008-01-01

86

Filter apparatus  

Energy Technology Data Exchange (ETDEWEB)

Electrified filter bed apparatus includes inner and outer cylindrical bed-retaining structures for confining a granular bed therebetween. The inner cylindrical structure may comprise a cage of superposed frusto-conical louvers and the outer structure may comprise a similar cage or a perforated cylindrical, liquid-drainage sheet. A cylindrical bed electrode for electrically charging the bed granules is suspended between the retaining structures. The tubular bed surrounds an internal gas passage from which polluted gas flows through the bed from the inside out. Gas enters the internal passage from above through an ionizer section of the apparatus. The ionizer section may include a disc-type ionizer assembly in an ionizer tube. The tube may form an extension of the inner louver cage. A corona discharge may be formed between the disc and the ionizer tube by providing electric current to the discs, whereby the corona discharge electrically charges particulate material within the gas stream. The discs may carry radially protruding needles defining circumferential corona discharge points. A blowdown system may be provided for cleaning the ionizer discs and the tube wall in the region of the discs. The apparatus may include means for avoiding blowout of bed granules from between the outer louvers, and a system for washing pollutant-coated bed granules.

Zahedi, K.; Alexander, J. C.; Zieve, P. B.

1985-03-19

87

Efficient Parallel Fir Filter Implementations Using Frequency Spectrum Characteristics  

UK PubMed Central (United Kingdom)

Parallel (or block) FIR digital filters can be used either forhigh-speed or low-power (with reduced supply voltage) applications.Traditional parallel filter implementations causelinear increase in the hardware cost with respect to theblock size. Recently, an efficient parallel FIR filter implementationtechnique requiring a less-than linear increase inthe hardware cost was proposed. This paper makes twocontributions. First the filter spectrum characteristics areexploited to select the best fast filter structures. Second, anovel block filter quantization algorithm is introduced. Usingfilter benchmarks, it is shown that the use of the appropriatefast FIR filter structures and the proposed quantizationscheme can result in reduction in the number of binaryadders ranging from 4% to 24% and an average reduction ofabout 10%. Furthermore, the power consumption of thesefilters is reduced by 14.8% on average and ranges from 10%to 20%.1 INTRODUCTIONLow complexity FIR filter impl...

Jin-gyun Chung; Yong-bae Kim; Hang-geun Jeong; Keshab K. Parhi; Zhongfeng Wang

88

Sensor Fusion with Square-Root Cubature Information Filtering  

Directory of Open Access Journals (Sweden)

Full Text Available This paper derives a square-root information-type filtering algorithm for nonlinear multi-sensor fusion problems using the cubature Kalman filter theory. The resulting filter is called the square-root cubature Information filter (SCIF). The SCIF propagates the square-root information matrices derived from numerically stable matrix operations and is therefore numerically robust. The SCIF is applied to a highly maneuvering target tracking problem in a distributed sensor network with feedback. The SCIF’s performance is finally compared with the regular cubature information filter and the traditional extended information filter. The results, presented herein, indicate that the SCIF is the most reliable of all three filters and yields a more accurate estimate than the extended information filter.

Ienkaran Arasaratnam

2013-01-01

89

Direct analysis of air filter samples for alpha emitting isotopes.  

Science.gov (United States)

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...

A. H. Mohagheghi F. Ghanbari S. B. Ebara M. E. Enghauser S. N. Bakhtiar

1997-01-01

90

Traditional Chinese medicine bactericide  

UK PubMed Central (United Kingdom)

The invention discloses a traditional Chinese medicine bactericide. The bactericide comprises the following Chinese medicinal herb raw materials according to the parts by weight: 90 parts of shrubalthea bark, 200 parts of quick lime, 300 parts of garlic, 150 parts of the tuber of stemona, 120 parts of polygonum cuspidatum, 100 parts of crowfoot, 100 parts of carpesium abrotanoides, 120 parts of calamus and 60 parts of white alum. The invention is a high effective traditional Chinese medicine bactericide with no toxity and residue. The traditional Chinese medicine bactericide can not pollute the crops such as fruit, vegetable and the like, has no residue and risk of damage and has the function of sterilizing, killing insects and preventing diseases effectively and fast.

JINWEI LI

91

Chinese traditional traditional medicine for SARS  

UK PubMed Central (United Kingdom)

The invention relates to a traditional Chinese medicine for treating atypical pneumonia, which is produced by the following medicinal materials: taking plant soot as the monarch drug, taking medical dogwood, gleditschia horrida and immature bitter orange as the adjuvant drug, taking the honey, pubescent angelica root and achyranthis bidentatae as the ministerial drug, taking the dahurian angelica root and Chinese angelica as the guiding drug, and all the medicinal materials are prepared in proportion as follows: 3 to 6 shares of plant soot, 6 to 12 shares of medical dogwood, 3 to 6 shares of gleditschia horrida, 6 to 12 shares of immature bitter orange, 12 to 24 thshares of honey, 6 to 9 shares of pubescent angelica root, 6 to 15 shares of achyranthis bidentatae, 6 to 9 shares of dahurian angelica root, 9 to 15 shares of Chinese angelica. The invention has the following advantages and effects that the invention with the cooperation of other medicines can motivate regeneration of the necrotic organize in the lung and nourish the lung, and the invention has remarkable effect for treating atypical pneumonia.

CUN LIANG; YIDE LIANG; YIHUA LIANG

92

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.

2011-01-01

93

Hepa filter dissolution process  

Energy Technology Data Exchange (ETDEWEB)

A process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

Brewer, Ken N. (Arco, ID); Murphy, James A. (Idaho Falls, ID)

1994-01-01

94

HEPA filter dissolution process  

Science.gov (United States)

A process is described for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal. 4 figures.

Brewer, K.N.; Murphy, J.A.

1994-02-22

95

HEPA filter dissolution process  

Science.gov (United States)

This invention is comprised of a process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

Brewer, K.N.; Murphy, J.A.

1992-12-31

96

Applied Kalman Filtering: An Overview.  

Science.gov (United States)

A brief resume of the evolution of Kalman filtering from classical filter theory is presented. The required format of the discrete filter model is discussed. The recursive equations for the discrete Kalman filter filter are then presented, but not derived...

R. G. Brown

1984-01-01

97

Filtering with a limiter  

Directory of Open Access Journals (Sweden)

Full Text Available We consider a filtering problem for a Gaussian diffusion process observed via discrete-time samples corrupted by a non-Gaussian white noise. Combining the Goggin's result [2] on weak convergence for conditional expectation with diffusion approximation when a sampling step goes to zero we construct an asymptotic optimal filter. Our filter uses centered observations passed through a limiter. Being asymptotically equivalent to a similar filter without centering, it yields a better filtering accuracy in a prelimit case.

R. Liptser; P. Muzhikanov

1998-01-01

98

Traditional Medicine in Zimbabwe  

Directory of Open Access Journals (Sweden)

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.

Takawira Kazembe

2007-01-01

99

Two-Channel IIR Filter Banks Utilizing the Frequency-Response Masking Technique  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a new approach for a twochannel IIR filter bank based on the frequency-response masking technique is presented. A model filter pair is a double complementary IIR filter pair implemented as a parallel connection of two all-pass filters. Masking filters are linear-phase FIR filters. The resulting overall filter pair is nearly power complementary, and simultaneously achieves high sub-channel selectivity. The approximately linear phase of channel filters is achieved with an IIR model filter pair of an approximately linear phase. Compared to the traditional solution based on FIR filters only, the proposed filter bank exhibits a smaller overall delay and requires a smaller number of multipliers for implementation.

L. D. Mili?; J. D. ?erti?

2009-01-01

100

Chinese traditional medicine for treating arthralgia syndrome and its preparation  

UK PubMed Central (United Kingdom)

The invention provides a Chinese traditional medicine for treating arthralgia syndrome and its preparation, which is prepared from fresh ginger and camphor through the steps of, squeezing fresh ginger, cold soaking the ginger dross with ethanol, merging steeping liquor and ginger ale, filtering and deslagging, charging camphor and right amount of glycerine.

XUE YONGXIN

 
 
 
 
101

IMPLEMENTATION OF DIGITAL FILTERS FOR HIGH THROUGHPUT APPLICATIONS ON FPGA  

Directory of Open Access Journals (Sweden)

Full Text Available The digital filter implementation in FPGA,utilising the dedicated hardware resources can effectively achieve ASIC-like performance while reducing development time cost and risks. Advantage of FPGA approach to digital filter implementation including sampling rates than are availablefrom traditional DSP chips. In this paper a low pass,band pass and highpass FIR filter is implemented on FPGA.This approach gives a better performance than the common filter structures in terms of speed of operation,cost and power consumption in real time.In this technique, codes for direct fixed point FIR filter have been realized. Modules such as multiplier, adder, ram and two’s complement were used. For an N order filter the filter the number of registers and adders required is N and the number of multipliers required is N+1.For high speed and high throughput applications,MAC is used and that consumes less power.

T.PUSHPA; M.VENKATLAKSHMI

2013-01-01

102

Robot Visual Servo with Fuzzy Particle Filter  

Directory of Open Access Journals (Sweden)

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.

Jie Ma; Qingjie Zhao

2012-01-01

103

Optimal Filter Systems for Photometric Redshift Estimation  

Science.gov (United States)

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.

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

104

The use of filtering methods to compensate for constant attenuation in single-photon emission computed tomography  

Energy Technology Data Exchange (ETDEWEB)

A back projection of filtered projection (BKFIL) reconstruction algorithm is presented that is applicable to single-photon emission computed tomography (ECT) in the presence of a constant attenuating medium such as the brain. The filters used in transmission computed tomography (TCT)-comprised of a ramp multiplied by window functions-are modified so that the single-photon ECT filter is a function of the constant attenuation coefficient. The filters give good reconstruction results with sufficient angular and lateral sampling. With continuous samples the BKFIL algorithm has a point spread function that is the Hankel transform of the window function. The resolution and statistical properties of the filters are demonstrated by various simulations which assume an ideal detector response. Statistical formulas for the reconstructed image show that the square of the percent-root-mean-square (percent-rms) uncertainty of the reconstruction is inversely proportional to the total measured counts. The results indicate that constant attenuation can be compensated for by using an attenuation-dependent filter that reconstructs the transverse section reliably. Computer time requirements are two times that of conventional TCT or positron ECT and there is no increase in memory requirements.

Gullberg, G.T.; Budinger, T.F.

1981-02-01

105

Rigid porous filter  

Energy Technology Data Exchange (ETDEWEB)

The present invention involves a porous rigid filter including a plurality of concentric filtration elements having internal flow passages and forming external flow passages there between. The present invention also involves a pressure vessel containing the filter for the removal of particulates from high pressure particulate containing gases, and further involves a method for using the filter to remove such particulates. The present filter has the advantage of requiring fewer filter elements due to the high surface area-to-volume ratio provided by the filter, requires a reduced pressure vessel size, and exhibits enhanced mechanical design properties, improved cleaning properties, configuration options, modularity and ease of fabrication.

Chiang, Ta-Kuan (Morgantown, WV); Straub, Douglas L. (Morgantown, WV); Dennis, Richard A. (Morgantown, WV)

2000-01-01

106

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 nonlinea...

S. Chouraqui; M. Benyettou

107

A New Glass of Nonlinear Filters: Microstatistic Volterra Filters  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper a new subset of the time-invariant microstatistic filters so-called microstatistic Volterra filters are proposed. This class of nonlinear filters is based on the idea of the conventional microstatistic filter generalization by substituting Wiener filters applied in the conventional microstatistic filter structure by Volterra filters. The advantage of the microstatistic Volterra filters in comparison with the Wiener filters, Volterra filters and conventional microstatistic filters is the fact that in the case of non-Gaussian signal processing the microstatistic Volterra filters can outperform Wiener filters, Volterra filters or conventional microstatistic filters. The validity of this basic property of the microstatistic Volterra filters is verified by a number of computer experiments. The disadvantage of the microstatistic Volterra filters is their relatively high computational complexity.

D. Kocur; M. Drutarovsky; S. Marchevsky

1996-01-01

108

Filter type gas sampler with filter consolidation  

Energy Technology Data Exchange (ETDEWEB)

Disclosed is an apparatus for automatically consolidating a filter or, more specifically, an apparatus for drawing a volume of gas through a plurality of sections of a filter, whereafter the sections are subsequently combined for the purpose of simultaneously interrogating the sections to detect the presence of a contaminant.

Miley, Harry S. (219 Rockwood Dr., Richland, WA 99352); Thompson, Robert C. (5313 Phoebe La., West Richland, WA 99352); Hubbard, Charles W. (1900 Stevens, Apt. 526, Richland, WA 99352); Perkins, Richard W. (1413 Sunset, Richland, WA 99352)

1997-01-01

109

Filter Bank Design for Subband Adaptive Filtering  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Adaptive filtering is an important subject in the field of signal processing and has numerous applications in fields such as speech processing and communications. Examples in speech processing include speech enhancement, echo- and interference- cancellation, and speech coding. Subband filter ban...

Haan, Jan

110

HEPA Filter Vulnerability Assessment  

Energy Technology Data Exchange (ETDEWEB)

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.

GUSTAVSON, R.D.

2000-05-11

111

SAW Filter Performance Improvement  

Directory of Open Access Journals (Sweden)

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.

Monali R. Dave

2012-01-01

112

Cordierite silicon nitride filters  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project was to develop a silicon nitride based crossflow filter. This report summarizes the findings and results of the project. The project was phased with Phase I consisting of filter material development and crossflow filter design. Phase II involved filter manufacturing, filter testing under simulated conditions and reporting the results. In Phase I, Cordierite Silicon Nitride (CSN) was developed and tested for permeability and strength. Target values for each of these parameters were established early in the program. The values were met by the material development effort in Phase I. The crossflow filter design effort proceeded by developing a macroscopic design based on required surface area and estimated stresses. Then the thermal and pressure stresses were estimated using finite element analysis. In Phase II of this program, the filter manufacturing technique was developed, and the manufactured filters were tested. The technique developed involved press-bonding extruded tiles to form a filter, producing a monolithic filter after sintering. Filters manufactured using this technique were tested at Acurex and at the Westinghouse Science and Technology Center. The filters did not delaminate during testing and operated and high collection efficiency and good cleanability. Further development in areas of sintering and filter design is recommended.

Sawyer, J.; Buchan, B. (Acurex Environmental Corp., Mountain View, CA (United States)); Duiven, R.; Berger, M. (Aerotherm Corp., Mountain View, CA (United States)); Cleveland, J.; Ferri, J. (GTE Products Corp., Towanda, PA (United States))

1992-02-01

113

Survey of Sparse Adaptive Filters for Acoustic Echo Cancellation  

Directory of Open Access Journals (Sweden)

Full Text Available This paper reviews the existing developments of adaptive methods of sparse adaptive filters for the identification of sparse impulse response in both network and acoustic echo cancellation from the last decade. A variety of different architectures and novel training algorithms have been proposed in literature. At present most of the work in echo cancellation on using more than one method. Sparse adaptive filters take the advantage of each method and showing good improvement in the sparseness measure performance. This survey gives an overview of existing sparse adaptive filters mechanisms and discusses their advantages over the traditional adaptive filters developed for echo cancellation.

Krishna Samalla; G.Mallikarjuna Rao; Ch.Stayanarayana

2013-01-01

114

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

115

FILTER DELIVERY SYSTEM  

UK PubMed Central (United Kingdom)

A filter delivery device for implanting a vessel filter within a blood vessel of a patient's body. The filter delivery device includes a mechanism for preventing hooks and/or legs on a vessel filter from entangling with each other while the vessel filter is loaded within the delivery device. In one variation, the filter delivery device includes a delivery catheter with grooves at the distal end lumen opening. When a vessel filter with radially expanding legs is compressed and inserted into the distal end of the delivery catheter, the hooks on the distal end of the legs are received and separated by the corresponding grooves on the delivery catheter. In another variation, a pusher rod, with a receptacle for receiving the hooks, is positioned within a delivery catheter to prevent the entanglement of the hooks and/or legs of a filter loaded within the delivery catheter.

TESSMER ALEXANDER W; SPILKA DAVID G; RAUCH DAVID W; CHANDUSZKO ANDRZEJ J; CARR JR ROBERT M

116

HEPA filter monitoring program  

Science.gov (United States)

The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

1986-07-01

117

South Africa: Traditional healers  

Science.gov (United States)

This two minute, nineteen second video from Howard Hughes Medical Institute highlights the role of traditional healers in South Africa. Doctors hope to encourage healers to direct their patients to clinics for TB and AIDS-related diseases. This video is available in QuickTime and Window Media formats. It is also featured on the 2007 Holiday Lecture Series DVD AIDS: Evolution of an Epidemic, available free from HHMI. This and other infectious disease videos can be found at: http://www.hhmi.org/biointeractive/disease/video.html

Howard Hughes Medical Institute (HHMI;)

2008-05-29

118

Integrated traditional Chinese medicine.  

UK PubMed Central (United Kingdom)

To experience the integration of traditional Chinese medicine (TCM) in China was 'the chance of a lifetime; thanks to the support of the Winston Churchill Memorial Trust. The scale and range of TCM available in terms of health care provision, education and research is unique in the world. This holistic integrative medicine is part of Chinese culture. Regulation and training of practitioners has similarities with current structures emerging in the UK in preparation for the statutory regulation for acupuncture and herbal medicine. China's research activity is a critical component of informing the debate on evidence-based practice and now real opportunities for collaboration and dissemination are beginning to emerge.

Robinson N

2006-05-01

119

Helical Vena Cava Filter  

UK PubMed Central (United Kingdom)

A vena cava filter is described, having at least one member arranged helically along a longitudinal axis of the filter. The filter may include a plurality of legs around which is arranged one or more filaments traveling in a helical path, or an elongated wire member arranged to define a first and second helecal path. The filter may include hooks and/or a retreival member.

HARRIS KEITH S; LERDAHL ROBERT G; TA KHOI Q

120

Filter service system  

Energy Technology Data Exchange (ETDEWEB)

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.

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

 
 
 
 
121

HEPA filter encapsulation  

Energy Technology Data Exchange (ETDEWEB)

A low viscosity resin is delivered into a spent HEPA filter or other waste. The resin is introduced into the filter or other waste using a vacuum to assist in the mass transfer of the resin through the filter media or other waste.

Gates-Anderson, Dianne D. (Union City, CA); Kidd, Scott D. (Brentwood, CA); Bowers, John S. (Manteca, CA); Attebery, Ronald W. (San Lorenzo, CA)

2003-01-01

122

Replaceable filter respirator  

Energy Technology Data Exchange (ETDEWEB)

A respirator providing a dust mask includes a central exhalation valve and a concentric inhalation valve, the inhalation valve leading to a filter assembly comprising a perforate retaining member, a filter, a frame and an imperforate back wall, the filter and back wall being separated by buttresses of the frame which afford a passage for air to the inside of a face piece.

Montesi, E.N.

1988-03-09

123

Guided image filtering.  

Science.gov (United States)

In this paper, we propose a novel explicit image filter called guided filter. Derived from a local linear model, the guided filter computes the filtering output by considering the content of a guidance image, which can be the input image itself or another different image. The guided filter can be used as an edge-preserving smoothing operator like the popular bilateral filter [1], but it has better behaviors near edges. The guided filter is also a more generic concept beyond smoothing: It can transfer the structures of the guidance image to the filtering output, enabling new filtering applications like dehazing and guided feathering. Moreover, the guided filter naturally has a fast and nonapproximate linear time algorithm, regardless of the kernel size and the intensity range. Currently, it is one of the fastest edge-preserving filters. Experiments show that the guided filter is both effective and efficient in a great variety of computer vision and computer graphics applications, including edge-aware smoothing, detail enhancement, HDR compression, image matting/feathering, dehazing, joint upsampling, etc. PMID:23599054

He, Kaiming; Sun, Jian; Tang, Xiaoou

2013-06-01

124

Guided image filtering.  

UK PubMed Central (United Kingdom)

In this paper, we propose a novel explicit image filter called guided filter. Derived from a local linear model, the guided filter computes the filtering output by considering the content of a guidance image, which can be the input image itself or another different image. The guided filter can be used as an edge-preserving smoothing operator like the popular bilateral filter [1], but it has better behaviors near edges. The guided filter is also a more generic concept beyond smoothing: It can transfer the structures of the guidance image to the filtering output, enabling new filtering applications like dehazing and guided feathering. Moreover, the guided filter naturally has a fast and nonapproximate linear time algorithm, regardless of the kernel size and the intensity range. Currently, it is one of the fastest edge-preserving filters. Experiments show that the guided filter is both effective and efficient in a great variety of computer vision and computer graphics applications, including edge-aware smoothing, detail enhancement, HDR compression, image matting/feathering, dehazing, joint upsampling, etc.

He K; Sun J; Tang X

2013-06-01

125

FILTER FOR DEEP FRYER  

UK PubMed Central (United Kingdom)

Disclosed is a filter suitable for use with a deep fryer for filtering foreign particulates, such as solid particles, from cooking oil or shortening to minimize the carbonation of such particles and extend the useful life of the cooking oil. In particular, the filter does not use disposable paper filtration media.

PROFUGHI TERENCE; HERCIK GREGORY PAUL

126

Resampling the ensemble Kalman filter  

Science.gov (United States)

Ensemble Kalman filters (EnKF) based on a small ensemble tend to provide collapse of the ensemble over time. It is demonstrated that this collapse is caused by positive coupling of the ensemble members due to use of the estimated Kalman gain for the update of all ensemble members at each time step. This coupling can be avoided by resampling the Kalman gain from its sampling distribution in the conditioning step. In the analytically tractable Gauss-linear model finite sample distributions for all covariance matrix estimates involved in the Kalman gain estimate are known and hence exact Kalman gain resampling can be done. For the general nonlinear case we introduce the resampling ensemble Kalman filter (ResEnKF) algorithm. The resampling strategy in the algorithm is based on bootstrapping of the ensemble and Monte Carlo simulation of the likelihood model. We also define a semi-parametric and parametric version of the resampling ensemble Kalman filter algorithm. An empirical study demonstrates that ResEnKF provides more reliable prediction intervals than traditional EnKF, on the cost of somewhat less accuracy in the point predictions.

Myrseth, Inge; Sætrom, Jon; Omre, Henning

2013-06-01

127

Gene-gene interaction filtering with ensemble of filters  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Complex diseases are commonly caused by multiple genes and their interactions with each other. Genome-wide association (GWA) studies provide us the opportunity to capture those disease associated genes and gene-gene interactions through panels of SNP markers. However, a proper filtering procedure is critical to reduce the search space prior to the computationally intensive gene-gene interaction identification step. In this study, we show that two commonly used SNP-SNP interaction filtering algorithms, ReliefF and tuned ReliefF (TuRF), are sensitive to the order of the samples in the dataset, giving rise to unstable and suboptimal results. However, we observe that the ‘unstable’ results from multiple runs of these algorithms can provide valuable information about the dataset. We therefore hypothesize that aggregating results from multiple runs of the algorithm may improve the filtering performance. Results We propose a simple and effective ensemble approach in which the results from multiple runs of an unstable filter are aggregated based on the general theory of ensemble learning. The ensemble versions of the ReliefF and TuRF algorithms, referred to as ReliefF-E and TuRF-E, are robust to sample order dependency and enable a more informative investigation of data characteristics. Using simulated and real datasets, we demonstrate that both the ensemble of ReliefF and the ensemble of TuRF can generate a much more stable SNP ranking than the original algorithms. Furthermore, the ensemble of TuRF achieved the highest success rate in comparison to many state-of-the-art algorithms as well as traditional ?2-test and odds ratio methods in terms of retaining gene-gene interactions.

Yang Pengyi; Ho Joshua WK; Yang Yee; Zhou Bing B

2011-01-01

128

Analog Frequency Tracking Filter  

Directory of Open Access Journals (Sweden)

Full Text Available This paper propose a new type of analog adaptive filter derived as a generalization of the concept of matched filter. We conceive such a filter to track the instantaneous frequency of frequency modulated signals. Some properties of the proposed analog frequency tracking filter are established using the time-frequency representations theory. A constructive solution, based on common analog integrated circuits, is also proposed. The performance of the analog frequency tracking filter built is evaluated by measurements. Finally, some possible applications are highlighted.

ISAR, A.; ISAR, D.

2013-01-01

129

Filter disk rotator  

Science.gov (United States)

A filter disk rotator has been designed and developed in the electronics laboratory of Uttar Pradesh State Observatory (UPSO) for photometric observations. A stepper motor is used to rotate the filter disk in the forward as well as in the reverse directions. A start signal is required to drive the stepper motor to rotate the filter disk. As the filter comes in front of the diaphragm, its position is sensed by the photosensors and displayed on the observer panel and simultaneously a stop signal is generated to stop the motor. The observer can select the required filter at any time and may control the disk rotator remotely.

Gupta, S. K.; Nautiyal, S. L.; Negi, B. S.

1994-06-01

130

Screwable liquid filter  

Energy Technology Data Exchange (ETDEWEB)

A screwable filter for liquids, in particular a lubricant oil filter for internal combustion engines, has a filter housing subdivided into a pot-shaped top part and into a lid-shaped bottom part, as well as a bearing part which receives various individual elements, such as an exchangeable filtering element, seals, overflow valve and a return valve, and which may be separated from the filtering element. In order to allow the top and bottom parts of the housing to be mutually separated in the screwing area, the bottom part of the housing is detachably fixed to the bearing part. (author)

Haug, M.; Lenzen, D.

1994-07-07

131

Creating Filtered, Translated Newsfeeds  

Directory of Open Access Journals (Sweden)

Full Text Available 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 native language, aggregating and filtering newsfeeds progammatically, managing filter terms, and using Google Translate’s API.

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

2010-01-01

132

Air filter. Luftfilter  

Energy Technology Data Exchange (ETDEWEB)

The invention refers to an air filter, particularly for lawnmowers with internal combustion engines. Previously known air filters have the disadvantage that the length of sealing line is extremely large and any leaks of the housing can have adverse effects on the result of filtering and on the engine output. The purpose of the invention is to create an improved air filter in which these disadvantages can be avoided. This problem is solved by plugging a filter cartridge (3) inside a housing (1) directly into the suction opening (4) of the suction pipe (5) surrounded by the housing (1) and having a prefilter (9) in the housing.

Franz, A.

1991-04-11

133

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Bhavana Deshpande; H.K. Verma; Prachi Deshpande

2012-01-01

134

Performance of bacteria filters.  

UK PubMed Central (United Kingdom)

Several kinds and brands of bacteria filters are commercially available for use in anesthesia and respiratory therapy applications. Clinical experience of high airflow resistance, ruptured media, failure to retain visible dust particles, and lack of consistent performance statements or warranties by manufacturers about their bacteria filters prompted a study of the performance of 13 different filters. The filters were challenged by mineral oil droplets, Serratia marcescens and Excherichia coli bacteriophages T4 and T7, tobacco smoke, nebulized india ink, dioctylphthalate smoke (DOP), and water. Results showed that viable bacterial passed through some filters, many filters were unable to retain visible ink or tobacco smoke particles, and resistance to airflow was increased two-fold or more in many filters when the filters were laden with 10 ml of water. Conflicting data resulted from two different types of DOP testing machines. There was a wide variation in performance among the different brands of filters; variable results also were seen within a given brand. Five brands of filters met the federal DOP standards for HEPA filters, but the wide variation in DOP testing results with two different kinds of DOP machines indicates a need for better standards. The DOP 0.3-micron bubble test is the most readily available nontoxic test to rate filtration efficiency; however, the DOP efficiency rating cannot be used to equate equivalent performance against infectious organisms.

Dryden GE; Dryden SR; Brown DG; Schatzle KC; Godzeski C

1980-11-01

135

Performance of bacteria filters.  

Science.gov (United States)

Several kinds and brands of bacteria filters are commercially available for use in anesthesia and respiratory therapy applications. Clinical experience of high airflow resistance, ruptured media, failure to retain visible dust particles, and lack of consistent performance statements or warranties by manufacturers about their bacteria filters prompted a study of the performance of 13 different filters. The filters were challenged by mineral oil droplets, Serratia marcescens and Excherichia coli bacteriophages T4 and T7, tobacco smoke, nebulized india ink, dioctylphthalate smoke (DOP), and water. Results showed that viable bacterial passed through some filters, many filters were unable to retain visible ink or tobacco smoke particles, and resistance to airflow was increased two-fold or more in many filters when the filters were laden with 10 ml of water. Conflicting data resulted from two different types of DOP testing machines. There was a wide variation in performance among the different brands of filters; variable results also were seen within a given brand. Five brands of filters met the federal DOP standards for HEPA filters, but the wide variation in DOP testing results with two different kinds of DOP machines indicates a need for better standards. The DOP 0.3-micron bubble test is the most readily available nontoxic test to rate filtration efficiency; however, the DOP efficiency rating cannot be used to equate equivalent performance against infectious organisms. PMID:10315105

Dryden, G E; Dryden, S R; Brown, D G; Schatzle, K C; Godzeski, C

1980-11-01

136

Cigarette filter rod  

UK PubMed Central (United Kingdom)

The utility model discloses a cigarette filter rod which comprises a filtering element and a molding paper used for wrapping the filtering element, wherein the filtering element consists of at least two filtering element units which have the same cross-sectional area and made of different materials and the adjacent ends of the filtering element units made of different materials are in contact with each other. Since the filtering element of the filter rod is in a segmental design and made of different materials, not only the filter rod has beautiful and clean appearance but also the smoke concentration is effectively increased, the loss of the natural tobacco aroma is avoided, the contents of tar oil and nicotine in the smoke are greatly reduced, the loss of the moisture in the main stream smoke is reduced, and the waste tobacco particles produced during the expanded tobacco production are put to good use. The molding paper is preferably corrugated paper which forms flutes on the filter rod, thereby increasing the filtration efficiency of the filter rod and ensuring the cigarette smoke is mild and continuous and has sweet and pure mouth feel.

DONGQI WEN; GANHUI SHAO; GUOCONG XIA

137

ENDOVASCULAR GUIDEWIRE FILTER  

UK PubMed Central (United Kingdom)

A filter device for temporary placement of a filter in an artery or vein is disclosed. The devices include (1) an elongate tubular member having a single or double side-wire loop, (2) an elongate member having a filter bonded to a circular rim joined by a plurality of tethers and an independently moveable tether, and (3) an elongate member having a parachute filter joined by a plurality of flexible struts. The filter conforms to the interior of a vessel wall when expanded and contracts to a consistent diameter without bunching when stowed. The filter devices may act as guidewires for guiding a therapeutic catheter to a region of interest within a vessel. Methods of using the filter device to entrap and remove embolic material from a vessel during endovascular procedures are also disclosed.

BELEF W. Martin

138

Ceramic fiber filter technology  

Energy Technology Data Exchange (ETDEWEB)

Fibrous filters have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic filters were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, filters have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle filters has been a major obstacle in their development. The present work is focused on forming fibrous ceramic filters using a papermaking technique. These filters are highly porous and therefore very lightweight. The papermaking process consists of filtering a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.

Holmes, B.L.; Janney, M.A.

1996-06-01

139

FPGA Based Kalman Filter for Wireless Sensor Networks  

Directory of Open Access Journals (Sweden)

Full Text Available A Wireless Sensor Network (WSN) is a set of tiny and low-cost devices equipped with different kind of sensors, a small microcontroller and a radio transceiver, typically powered by batteries. Target tracking is one of the very important applications of such a network system. Traditionally, KF (Kalman filtering) and its derivatives are used for tracking of a random signal. Kalman filter is a linear optimal filtering approach, to address the problem when system dynamics become nonlinear, researchers developed sub-optimal extensions of Kalman filter, two popular versions are EKF (extended Kalman filter) and UKF (unscented Kalman filter).The rapidly increasing popularity of WSNs has placed increased computational demands upon these systemswhich can be met by FPGA based design. FPGAs offer increased performance compared to microprocessors and increased flexibility compared to ASICs , while maintaining low power consumption

Vikrant Vij; Rajesh Mehra

2011-01-01

140

Optimal filter systems for photometric redshift estimation  

CERN Multimedia

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...

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

 
 
 
 
141

Retrofitting fabric filters for clean stack emission  

International Nuclear Information System (INIS)

The fly ash generated from New South Wales coals, which are predominately low sulphur coals, has been difficult to collect in traditional electrostatic precipitators. During the early 1970's development work was undertaken on the use of fabric filters at some of the Commission's older power stations. The satisfactory performance of the plant at those power stations led to the selection of fabric filters for flue gas cleaning at the next two new power stations constructed by the Electricity Commission of New South Wales. On-going pilot plant testing has continued to indicate the satisfactory performance of enhanced designs of fabric filters of varying types and the Commission has recently retrofitted pulse cleaned fabric filters to 2 x 350 MW units at a further power station with plans to retrofit similar plant to the remaining 2 x 350 MW units at that station. A contract has also been let for the retrofitting of pulse cleaned fabric filters to 4 x 500 MW units at another power station in the Commission's system. The paper reviews the performance of the 6000 MW of plant operating with fabric filters. Fabric selection and fabric life forms an important aspect of this review.

1991-01-01

142

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

2009-01-01

143

Oil press filter device  

UK PubMed Central (United Kingdom)

Of the oil filter device of the oil mill, an oil pipe 21 connected with the oil pump 2 is arranged on the oil tank 1, the oil outlet of the pump 2 is communicated with the outlet of the first filer 3 by an oil pipe, the outlet of the first filter 3 is communicated with the inlet of the secondary filter, and the first filter and secondary filter are air-tight containers, inside which are arranged a filter cartridge 32 with a filter bag 31. With positive pressure, the foreign substances are filtered gradually and thus the oil filer speed and efficiency are improved. The whole set of oil filter device can be positioned on the frame of the oil mill to mill and filter the oil simultaneously so the energy is saved, the work efficiency is improved, the labor intensity is decreases and the quality of the oil is improved. The utility model has advantages of a small volume, easy operation and high oil treatment quantity. And it can be matched with different oil mills and be use for filtration or purification of industrial oil and other fluids.

HUANG DAOXI

144

Kalman filtering technique for reactivity measurement  

International Nuclear Information System (INIS)

Measurement of reactivity and its on-line display is of great help in calibration of reactivity control and safety devices and in the planning of suitable actions during the reactor operation. In traditional approaches the reactivity is estimated from reactor period or by solving the inverse point kinetic equation. In this paper, an entirely new approach based on the Kalman filtering technique has been presented. The theory and design of the reactivity measuring instrument based on the approach has been explained. Its performance has been compared with traditional approaches by estimation of transient reactivity from flux variation data recorded in a research reactor. It is demonstrated that the Kalman filtering approach is superior to other methods from the viewpoints of accuracy, noise suppression, and robustness against uncertainties in the reactor parameters. (author). 1 fig.

1997-01-01

145

Active Noise Control Using IIR Adaptive Filter  

Directory of Open Access Journals (Sweden)

Full Text Available Noise control is essential from the point of view ofhealth, conversation and communication. Traditionally reducednoise levels are achieved by means of passive absorbers like foam,perforated boards etc. But due to their size and weight, the passiveabsorbers are not suitable for mobile vehicles like aircrafts,helicopters and cars at low frequencies (50-500 Hz). This calls foran alternative technology, ACTIVE NOISE CONTROL (ANC).Generally, algorithms based on adaptive FIR structure withnumber of coefficients ranging up to hundreds are used in activenoise control and this increases the computational burden on theprocessor. Compared to FIR filters, in this project IIR filters areused that can model a physical system efficiently with less numberof coefficients due to its inherent pole-zero structure. The poles ofan IIR filter make it possible to obtain well-matched characteristicswith a lower-order structure, thus requiring fewer arithmeticoperations.

Rintu S Abraham; Veena S

2012-01-01

146

Sponge aquarium filter  

UK PubMed Central (United Kingdom)

A special, single-piece, absorbent sponge acts as the main filtering element for an aquarium filter. The present invention incorporates conventional air lines, bubble tubes and stem sockets in a unique arrangement in combination with a novel filter in the form of a contoured sponge. The surface of the sponge filter is contoured which creates large total surface area for facilitated absorption of dirt. Under magnification, the sponge filter is composed of thousands of tiny plastic rods joined together which exponentially increase total surface area. The tiny plastic rods within the expansive surface area create hundreds of thousands of "corners" which encourage habitation of microscopic protozoa. The present invention is designed for a multitude of applications including: filtration of waste products, creation of a balanced ecosystem essential for successful aquariums, establishment of filter beds, and utilization as hatcheries for brine shrimp and fry.

FINDELL CHRISTOPHER L

147

Complex Hilbert Transform Filter  

Directory of Open Access Journals (Sweden)

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.

Juuso T. Olkkonen; Hannu Olkkonen

2011-01-01

148

Finite Dimensional Filters  

UK PubMed Central (United Kingdom)

The class of optimal non-linear, finite dimensional, recursive filters found by Benesis extended to include cases in which the drift in the state propagation equation is ageneral linear function plus the gradient of a scalar potential.It is shown that if the state space is one dimensional, then the deterministic systemsunderlying the Benes filter fall into five classes, depending on the asymptotic behaviourof the state at large times. Only two of these classes can be obtained using the Kalmanfilter. It is shown that an arbitrary deterministic trajectory can be approximated atsmall times to an accuracy of O(t5) by a trajectory for which the Benes filter isappropriate.The Benes construction is the starting point for the development of new, finitedimensional, recursive approximations to the optimal filter. One of the new filters isapplied to a simple tracking problem taken from computer vision, and its performancecompared with that of the extended Kalman filter...

S. J. Maybank; Ox Pj

149

Decentralised Power Active Filters  

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with a decentralised power active filter control based on the separated computation of reference current for each active filter operating under determinated harmonic frequency. The basic principle of such controlled active filter is explained. It is shown how the nth hamonic component of the reference current can be calculated. Simulation results are shown on the end of the paper.

Marek Roch; Branislav Dobrucky; Wada M. Hosny

2004-01-01

150

Oriented Fiber Filter Media  

Directory of Open Access Journals (Sweden)

Full Text Available Coalescing filters are widely used throughout industry and improved performance will reduce droplet emissions and operating costs. Experimental observations show orientation of micro fibers in filter media effect the permeability and the separation efficiency of the filter media. In this work two methods are used to align the fibers to alter the filter structure. The results show that axially aligned fiber media improve quality factor on the order of 20% and cutting media on an angle from a thick layered media can improve performance by about 40%. The results also show the improved performance is not monotonically correlated to the average fiber angle of the medium.

R. Bharadwaj; A. Patel, S. Chokdeepanich, Ph.D.; G.G. Chase, Ph.D.

2008-01-01

151

Linear phase compressive filter  

Energy Technology Data Exchange (ETDEWEB)

A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.

McEwan, Thomas E. (Livermore, CA)

1995-01-01

152

Approximate Kalman filtering  

CERN Document Server

Kalman filtering algorithm gives optimal (linear, unbiased and minimum error-variance) estimates of the unknown state vectors of a linear dynamic-observation system, under the regular conditions such as perfect data information; complete noise statistics; exact linear modeling; ideal well-conditioned matrices in computation and strictly centralized filtering.In practice, however, one or more of the aforementioned conditions may not be satisfied, so that the standard Kalman filtering algorithm cannot be directly used, and hence "approximate Kalman filtering" becomes necessary. In the last decad

Chen, G

1993-01-01

153

FPGA BASED FIR FILTER  

Directory of Open Access Journals (Sweden)

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.

SUVARNA JOSHI,; BHARATI AINAPURE

2010-01-01

154

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

DEFF Research Database (Denmark)

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.

Wu, Weimin; He, Yuanbin

2012-01-01

155

Traditional Chinese medicine ointment for treating dermatophytosis  

UK PubMed Central (United Kingdom)

The invention provides a traditional Chinese medicine ointment for external administration, which cures tinea pedes (ringworm of feet), particularly an ointment for external administration and external treatment, which cures tinea pedes and has the effects of relieving itching, anti-septicizing, deswelling and recovering skin. The ointment comprises the following components by the weight ratio: 52 to 56 g of angelica root, 58 to 62 g of szechwan lovage rhizome, 58 to 62 g of coptis chinensis, 34 to 37 g of forsythia suspensa, 8 to 10 g of borneo camphor, 48 to 52 g of beeswax and 500 g of gingelly oil the ointment is prepared by the following steps: appropriately weighing angelica root, szechwan lovage rhizome, coptis chinensis and forsythia suspense, pulverizing, placing into the pot together with gingelly oil, frying to dry, removing slag, filtering, adding beeswax and borneo camphor to the filtered oil, melting, standing and stirring evenly. The ointment has the curative effects of relieving itching, anti-septicizing, alleviating pain, detoxifying and moistening skin, suits the external treatment of tinea pedes, and has the characteristics of rapid relieving itching effect, high cure rate, no toxic or side effect, no therapeutic environment restriction, convenient administration, easy cleaning, no contamination of clothes and socks, easy preparation, low cost, etc.

JIANLIANG ZHAO; XIAO WANG; BO YU

156

Cosine Modulated Non-Uniform Filter Banks  

Directory of Open Access Journals (Sweden)

Full Text Available Traditional designs for non-uniform filter bank (NUFB) are usually complex; involve complicated nonlinear optimization with a large number of parameters and lack of linear phase ([LP) property. In this paper, we describe a simple design method for multirate near perfect reconstruction (NPR) cosine modulated filter banks with non-uniform frequency spacing and linear phase property that involves optimization of only single parameter. It is derived from the uniform cosine modulated filter bank (CMFB) by merging some relevant band pass filters. The design procedure and the structure of the uniform CMFB are mostly preserved in the non-uniform implementation. Compared to other design methods our method provides very good design and converges very rapidly but the method is applicable, only if the upper band edge frequency of each non-uniform filter is an integral multiple of the bandwidth of the corresponding band. The design examples are presented to show the superiority of the proposed method over existing one.

Jyotsna Ogale; Samrat Ashok

2011-01-01

157

Air filter case. Luftfiltergehaeuse  

Energy Technology Data Exchange (ETDEWEB)

An air filter case for accommodating a dry filter cartridge for the air to be supplied to a carburettor is described. The main property of this case is that it has means of fixing accessible from the outside, by which the case can be fixed to the carburettor.

Mariani, L.

1982-04-29

158

Diesel particulate filter system  

Energy Technology Data Exchange (ETDEWEB)

During the last two decades a great deal of effort has gone into trying to eliminate particulate matter from diesel exhaust gases in order to overcome the one remaining issue concerning diesel engines - their 'dirty' image. Nowadays, many different diesel particulate filter (DPF) systems are available to filter the particulates from the exhaust gas effectively. The issue now is to develop appropriate regeneration strategies which clean the filter of the trapped particulates. In view of the extreme thermal conditions which could occur during this regeneration, the filter system needs to be adapted properly. Another remaining issue is the handling of the oil ashes which are trapped in the filter as well, by cleaning strategies or appropriate filter design. PSA is the first car manufacturer to develop and install a DPF system in passenger cars in Europe. This system uses a silicon carbide (SiC) filter and a fuel additive to support the regeneration. The aim of this study is to investigate alternative filter elements in view of their performance aspects such as brack pressure, regeneration performance, mechanical durability and ash accumulation behaviour using self-developed engine test-bench procedures that simulate realistically in-vehicle conditions as closely as possible. (orig.)

Michelin, J.; Terres, F.; Weltens, H. [Tenneco Automotive, Edenkoben (Germany)

2002-07-01

159

Filtering reprecipitated slurry  

Energy Technology Data Exchange (ETDEWEB)

As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

Morrissey, M.F.

1992-12-31

160

Filtering reprecipitated slurry  

Energy Technology Data Exchange (ETDEWEB)

As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

Morrissey, M.F.

1992-01-01

 
 
 
 
161

Robustifying Vector Median Filter  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes two methods for impulse noise reduction in colour images that outperform the vector median filter from the noise reduction capability point of view. Both methods work by determining first the vector median in a given filtering window. Then, the use of complimentary information from componentwise analysis allows to build robust outputs from more reliable components. The correlation among the colour channels is taken into account in the processing and, as a result, a more robust filter able to process colour images without introducing colour artifacts is obtained. Experimental results show that the images filtered with the proposed method contain less noisy pixels than those obtained through the vector median filter. Objective measures demonstrate the goodness of the achieved improvement.

Samuel Morillas; Valentín Gregori

2011-01-01

162

Composite oil filter  

Energy Technology Data Exchange (ETDEWEB)

An oil filter cartridge for an internal combustion engine is described comprising a container having an inlet connected to the oil circulating system of the engine to receive unfiltered engine oil under pressure from the engine, and an outlet connected back into the oil circulating system or the engine to discharge filtered and reconditioned engine oil back into the engine. The container having a filter material to remove contaminents from the engine oil circulating through the filter material. The filter material being impregnated with specific controlled amounts of certain of the essential additive chemicals that are initially supplied in engine oil by oil manufacturers, to replace a given proportion of those chemicals that are predictably lost in normal engine use over a given period of time, and under given conditions.

Moor, S.E.

1988-06-21

163

Filter cake breaker systems  

Energy Technology Data Exchange (ETDEWEB)

Drilling fluids filter cakes are based on a combination of properly graded dispersed particles and polysaccharide polymers. High efficiency filter cakes are formed by these combination , and their formation on wellbore walls during the drilling process has, among other roles, the task of protecting the formation from instantaneous or accumulative invasion of drilling fluid filtrate, granting stability to well and production zones. Filter cake minimizes contact between drilling fluid filtrate and water, hydrocarbons and clay existent in formations. The uniform removal of the filter cake from the entire interval is a critical factor of the completion process. The main methods used to breaking filter cake are classified into two groups, external or internal, according to their removal mechanism. The aim of this work is the presentation of these mechanisms as well their efficiency. (author)

Garcia, Marcelo H.F. [Poland Quimica Ltda., Duque de Caxias, RJ (Brazil)

2004-07-01

164

Vena cava filter; Vena-cava-Filter  

Energy Technology Data Exchange (ETDEWEB)

Fulminant pulmonary embolism is one of the major causes of death in the Western World. In most cases, deep leg and pelvic venous thrombosis are the cause. If an anticoagulant/thrombotic therapy is no longer possible or ineffective, a vena cava filter implant may be indicated if an embolism is threatening. Implantation of the filter is a simple and safe intervention. Nevertheless, it is necessary to take into consideration that the data base for determining the indications for this treatment are very limited. Currently, a reduction in the risk of thromboembolism with the use of filters of about 30%, of recurrences of almost 5% and fatal pulmonary embolism of 1% has been reported, with a risk of up to 20% of filter induced vena cava thrombosis. (orig.) [German] Die fulminante Lungenembolie zaehlt zu den Haupttodesursachen in der westlichen Welt. In der Mehrzahl der Faelle sind tiefe Bein- und Beckenvenenthrombosen ursaechlich verantwortlich. Ist eine antikoagulative/-thrombotische Therapie nicht (mehr) moeglich oder unwirksam, kann bei drohender Emboliegefahr die Vena-cava-Filterimplantation indiziert sein. Die Filterimplantation ist eine einfache und sehr sichere Intervention. Dennoch muss bei der Indikationsstellung beruecksichtigt werden, dass die Datenlage zur Wirksamkeit sehr limitiert ist. So wird aktuell ueber eine Reduktion des Thrombembolierisikos um 30% bei Embolierezidiven von knapp 5% und fatalen Lungenembolien von 1% unter Filterprophylaxe berichtet, bei einem Risiko von bis zu 20% fuer die filterinduzierte Vena-cava-Thrombose. (orig.)

Helmberger, T. [Klinikum Bogenhausen, Institut fuer Diagnostische und Interventionelle Radiologie und Nuklearmedizin, Muenchen (Germany)

2007-05-15

165

Filtered flash sterilization apparatus  

UK PubMed Central (United Kingdom)

A flash sterilization container (10) comprises a pan (12) forming the bottom of the container holding a tray (14), with a cover (16) forming the top of the container, and a filter element (20). The filter (20) covers an opening in the cover (16) so that the inside of the container (10) formed when the cover is removably sealed to the pan (12) can communicate with the atmosphere surrounding the sealed container allowing steam to enter and exit the container passing through the filter (20). Items to be sterilized are placed on the tray (14) and the cover (16) is attached and sealed to the pan (12). The sealed container in then placed in an autoclave or other source of pressurized steam. The filter (20) allows the steam to enter the interior of the container and sterilize any items contained therein. After sterilization, the container (10) is removed from the autoclave and any remaining steam escapes from the interior of the container through the filter (20). The filter is composed of a material which will allow the pressurized steam to pass through but which is relatively impervious to dust and microorganisms thereby maintaining the sterility of the interior of the container and it's contents. Examples of suitable filter materials are: paper; TEFLON TM ; hydrophobic material, such as GORE-TEX TM ; porous stainless steel and polysulfone. The filter (20) can be held in place with a filter retainer manufactured as a permanent part of the cover (16) or incorporated into a filter cartridge which is removably attached to the cover.

NALEPA DAVID; FRIEZE ALLAN S; FRIEZE MARCIA A

166

Research on E-mail Filtering Based On Improved Bayesian  

Directory of Open Access Journals (Sweden)

Full Text Available Naive Bayesian has been widely used in spam filter because it simply and it also could classify texts more correctly and quickly. However, in the process of classifying and filtering, the traditional method doesn't consider the different features between the spam mail and the legitimate mail, and it also doesn't take into account the loss of misclassifying legitimate mail as spam, so there are many limitations of e-mail filtering. An improved algorithm based on Naïve Bayesian and Boosting method is proposed in this paper. The experiment result shows that the improved algorithm has better performance.

Pei-yu Liu; Li-wei Zhang; Zhen-fang Zhu

2009-01-01

167

LCL Interface Filter Design for Shunt Active Power Filters  

Directory of Open Access Journals (Sweden)

Full Text Available This paper is focused on finding the parameters of a second order interface filter connected between the power system and the shunt active filter based on switching frequency of the active filter. Many publications on power active filters include various design methods for the interface inductive filter which take into account the injected current and its dynamic. Compared to these ones, the approach presented in this paper is oriented toward the design of the interface filter starting from filter transfer functions by imposing the performances of the filter.

BITOLEANU, A.; POPESCU, M.; MARIN, D.; DOBRICEANU, M.

2010-01-01

168

An Amplitude Spectral Capon Estimator with a Variable Filter Length  

DEFF Research Database (Denmark)

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.

Nielsen, Jesper Kjær; Smaragdis, Paris

2012-01-01

169

Ceramic filters for bulk inoculation of nickel alloy castings  

Directory of Open Access Journals (Sweden)

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.

F. Binczyk; J. ?leziona; P. Grado?

2011-01-01

170

Filter Paper: Solution to High Self-Attenuation Corrections in HEPA Filter Measurements  

Energy Technology Data Exchange (ETDEWEB)

An 8 by 8 by 6 inch High Efficiency Particulate Air (HEPA) filter was measured as part of a uranium holdup survey in June of 2005 as it has been routinely measured every two months since 1998. Although the survey relies on gross gamma count measurements, this was one of a few measurements that had been converted to a quantitative measurement in 1998. The measurement was analyzed using the traditional Generalized Geometry Holdup (GGH) approach, using HMS3 software, with an area calibration and self-attenuation corrected with an empirical correction factor of 1.06. A result of 172 grams of {sup 235}U was reported. The actual quantity of {sup 235}U in the filter was approximately 1700g. Because of this unusually large discrepancy, the measurement of HEPA filters will be discussed. Various techniques for measuring HEPA filters will be described using the measurement of a 24 by 24 by 12 inch HEPA filter as an example. A new method to correct for self attenuation will be proposed for this measurement Following the discussion of the 24 by 24 by 12 inch HEPA filter, the measurement of the 8 by 8 by 6 inch will be discussed in detail.

Oberer, R.B.; Harold, N.B.; Gunn, C.A.; Brummett, M.; Chaing, L.G.

2005-10-01

171

Filter Paper: Solution to High Self-Attenuation Corrections in HEPA Filter Measurements  

International Nuclear Information System (INIS)

[en] An 8 by 8 by 6 inch High Efficiency Particulate Air (HEPA) filter was measured as part of a uranium holdup survey in June of 2005 as it has been routinely measured every two months since 1998. Although the survey relies on gross gamma count measurements, this was one of a few measurements that had been converted to a quantitative measurement in 1998. The measurement was analyzed using the traditional Generalized Geometry Holdup (GGH) approach, using HMS3 software, with an area calibration and self-attenuation corrected with an empirical correction factor of 1.06. A result of 172 grams of 235U was reported. The actual quantity of 235U in the filter was approximately 1700g. Because of this unusually large discrepancy, the measurement of HEPA filters will be discussed. Various techniques for measuring HEPA filters will be described using the measurement of a 24 by 24 by 12 inch HEPA filter as an example. A new method to correct for self attenuation will be proposed for this measurement Following the discussion of the 24 by 24 by 12 inch HEPA filter, the measurement of the 8 by 8 by 6 inch will be discussed in detail

2005-01-01

172

Derivative free filtering using Kalmtool  

DEFF Research Database (Denmark)

In this paper we present a toolbox enabling easy evaluation and comparison of different filtering algorithms. The toolbox is called Kalmtool 4 and is a set of MATLAB tools for state estimation of nonlinear systems. The toolbox contains functions for extended Kalman filtering as well as for DD1 filter and the DD2 filter. It also contains functions for Unscented Kalman filters as well as several versions of particle filters. The toolbox requires MATLAB version 7, but no additional toolboxes are required.

Bayramoglu, Enis Technical University of Denmark,

2010-01-01

173

Air-powered filter arrangement  

UK PubMed Central (United Kingdom)

A filter including a filter housing having a spillway and a pneumatic intake assembly that draws water from an aquarium into the filter housing. The filter housing being configured to internally mount to the aquarium. The filter housing having first and second chamber oriented in a side-by-side arrangement such that water flows in a generally horizontal direction through a filter cartridge positioned between the first and second chambers.

CARLEY JOSEPH C; AGRESTA MARK G

174

Traditional healers in Casamance, Senegal.  

UK PubMed Central (United Kingdom)

As part of a long-standing effort to foster collaboration between Western and traditional health workers, the writers talked with six animist healers and marabouts about their work. They begin with some general information about traditional healing in Casamance, a region in southern Senegal.

Baldé S; Sterck C

1994-01-01

175

Traditional healers in Casamance, Senegal.  

Science.gov (United States)

As part of a long-standing effort to foster collaboration between Western and traditional health workers, the writers talked with six animist healers and marabouts about their work. They begin with some general information about traditional healing in Casamance, a region in southern Senegal. PMID:7999235

Baldé, S; Sterck, C

1994-01-01

176

Ceramic fiber reinforced filter  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1991-01-01

177

Defueling filter test  

International Nuclear Information System (INIS)

The Three Mile Island Unit 2 Reactor (TMI-2) has sustained core damage creating a significant quantity of fine debris, which can become suspended during the planned defueling operations, and will have to be constantly removed to maintain water clarity and minimize radiation exposure. To accomplish these objectives, a Defueling Water Cleanup System (DWCS) has been designed. One of the primary components in the DWCS is a custom designed filter canister using an all stainless steel filter medium. The full scale filter canister is designed to remove suspended solids from 800 microns to 0.5 microns in size. Filter cartridges are fabricated into an element cluster to provide for a flowrate of greater than 100 gals/min. Babcock and Wilcox (B and W) under contract to GPU Nuclear Corporation has evaluated two candidate DWCS filter concepts in a 1/100 scale proof-of-principle test program at BandW's Lynchburg Research Center. The filters were challenged with simulated solids suspensions of 1400 and 140 ppm in borated water (5000 ppm boron). Test data collected includes solids loading, effluent turbidity, and differential pressure trends versus time. From the proof-of-principle test results, a full-scale filter canister was generated.

1985-05-03

178

Static Filtered Skin Detection  

Directory of Open Access Journals (Sweden)

Full Text Available A static skin filter defines explicitly (using a number of rules) the boundaries the skin cluster has in a color space. Single or multiple ranges of threshold values for each color space component are created and the image pixel values falling within these range(s) for all the chosen color components are defined as skin pixels. In this paper, we investigate and evaluate static skin filters for skin segmentation. As a contribution, two new static skin filters for the IHLS and CIELAB color spaces are developed. The two new static filters and four state-of-the-art static filters in YCbCr, HSI, RGB and normalized RGB color spaces are evaluated on the two datasets DS1 and DS2, on the basis of F-measure. Experimental results reveal the feasibility of the developed static skin filters. We also found that since the static filters use static boundaries, any shift of skin color ranges from the static boundaries will result in varying performance. Therefore, the F-measure rankings of the color spaces are different for the datasets DS1 and DS2.

Rehanullah Khan; Zeeshan Khan; Muhammad Aamir

2012-01-01

179

Frequency Spectrum Based Low-Area Low-Power Parallel FIR Filter Design  

Directory of Open Access Journals (Sweden)

Full Text Available Parallel (or block) FIR digital filters can be used either for high-speed or low-power (with reduced supply voltage) applications. Traditional parallel filter implementations cause linear increase in the hardware cost with respect to the block size. Recently, an efficient parallel FIR filter implementation technique requiring a less-than linear increase in the hardware cost was proposed. This paper makes two contributions. First, the filter spectrum characteristics are exploited to select the best fast filter structures. Second, a novel block filter quantization algorithm is introduced. Using filter benchmarks, it is shown that the use of the appropriate fast FIR filter structures and the proposed quantization scheme can result in reduction in the number of binary adders up to 20%.

Chung Jin-Gyun; Parhi Keshab K

2002-01-01

180

EMI filter design  

CERN Document Server

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

Ozenbaugh, Richard Lee

2011-01-01

 
 
 
 
181

HEPA filter jointer  

Energy Technology Data Exchange (ETDEWEB)

A HEPA filter jointer system was created to remove nitrate contaminated wood from the wooden frames of HEPA filters that are stored at the Rocky Flats Plant. A commercial jointer was chosen to remove the nitrated wood. The chips from the wood removal process are in the right form for caustic washing. The jointer was automated for safety and ease of operation. The HEPA filters are prepared for jointing by countersinking the nails with a modified air hammer. The equipment, computer program, and tests are described in this report.

Hill, D.; Martinez, H.E.

1998-02-01

182

Preparation method of traditional Chinese medicine for treating endometritis  

UK PubMed Central (United Kingdom)

The invention relates to a preparation method of a traditional Chinese medicine for treating endometritis, belonging to the technical field of preparation methods of traditional Chinese medicines. Atpresent, endometritis is usually treated with antibiotics, such as ampicillin, but the application of ampicillin can cause discomfort of the gastrointestinal tract, and the intramuscular injection results in pain in parts of the body. Both oral administration and injection can cause allergic response. The traditional Chinese medicine has the technical scheme as follows: immersing honeysuckle, weeping forsythia, neat philippine violet, dandelion, isatis leaf, radix isatidis, herba patriniae, houttuyinia cordata, sargentgloryvine stem, winterchery fruit or calyx, pariphyllin, potentilla discolor, barberry root, sticktight, Japanese cayratia, Japanese raspberry root, coix seed, tuckahoe, rhizoma alismatis, peach kernel, herba leonuri, boneset, red peony root, rhizoma corydalis, nutgrass galingale rhizome, costus root and licorice in 1200 millilitres of water, decocting the mixture with gentle fire, and filtering the decoction to remove slag. The obtained liquid medicine is the traditionalChinese medicine for treating endometritis. The traditional Chinese medicine liquid has the advantages of simple preparation technology, light toxic and side effect of the prepared traditional Chinese medicine liquid, short course of treatment, and high cure rate.

PING LU; KUIQUAN LIU; LU LI; DERONG SUN; YAN LIU; ZHENGJUN KONG

183

Vena cava filter  

International Nuclear Information System (INIS)

Fulminant pulmonary embolism is one of the major causes of death in the Western World. In most cases, deep leg and pelvic venous thrombosis are the cause. If an anticoagulant/thrombotic therapy is no longer possible or ineffective, a vena cava filter implant may be indicated if an embolism is threatening. Implantation of the filter is a simple and safe intervention. Nevertheless, it is necessary to take into consideration that the data base for determining the indications for this treatment are very limited. Currently, a reduction in the risk of thromboembolism with the use of filters of about 30%, of recurrences of almost 5% and fatal pulmonary embolism of 1% has been reported, with a risk of up to 20% of filter induced vena cava thrombosis. (orig.)

2007-01-01

184

Cryogenic coaxial microwave filters  

CERN Multimedia

At millikelvin temperatures the careful filtering of electromagnetic radiation, especially in the microwave regime, is critical for controlling the electromagnetic environment for experiments in fields such as solid-state quantum information processing and quantum metrology. We present a design for a filter consisting of small diameter dissipative coaxial cables that is straightforward to construct and provides a quantitatively predictable attenuation spectrum. We describe the fabrication process and demonstrate that the performance of the filters is in good agreement with theoretical modelling. We further perform an indicative test of the performance of the filters by making current-voltage measurements of small, underdamped Josephson Junctions at 15 mK and we present the results.

Tancredi, G; Meeson, P J

2013-01-01

185

Generalized linear correlation filters  

Science.gov (United States)

We present two generalized linear correlation filters (CFs) that encompass most of the state-of-the-art linear CFs. The common criteria that arc used in linear CF design are the mean squared error (MSE), output noise variance (ONV), and average similarity measure (ASM). We present a simple formulation that uses an optimal tradeoff among these criteria both constraining and not constraining the correlation peak value, and refer to them as generalized Constrained Correlation Filter (CCF) and Unconstrained Couelation Filter (UCF). We show that most state-of-the-art linear CFs arc subsets of these filters. We present a technique for efficient UCF computation. We also introduce the modified CCF (mCCF) that chooses a unique correlation peak value for each training image, and show that mCCF usually outperforms both UCF and CCF.

Rodriguez, Andres; Vijaya Kumar, B. V. K.

2013-05-01

186

Locomotive oil filter  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a locomotive lube oil filter comprised of means for filtering lube oil sufficient for locomotive engine use without filter swelling or plugging due to water in the lube oil. It includes a filter medium having a substantial portion of lignin-containing fiber pulp derived from the disc refining of wood chips having a ligning content of at least about 10 percent under steam pressures in the range of about 90 psig to about 120 psig, at temperatures in the range of from about 330/sup 0/F to about 350/sup 0/F, and using energy levels in the range of from about 8 to about 35 HPD/ADT.

Moser, D.

1987-04-07

187

A gas purification filter  

Energy Technology Data Exchange (ETDEWEB)

A filter is proposed, which contains a body with an input and an output gas branch pipe, filtering cartridges with a granular material (whose size is reduced along the travel of the gas being purified) a hopper for collecting dust, and a vibrator. To increase the effectiveness of filtering and to ensure the continuous regeneration of the filtering material through changing the speed of the gas, the cross section of the cartridge with the coarse granulated material is reduced, while that with the fine granular material is increased along the travel of the gas being purified. One of the lateral walls is made perforated and is located opposite the hopper for collecting the dust and is connected with the vibrator.

Shikhov, V.N.; Lipetskaya, F.E.

1981-01-01

188

Westinghouse filter update  

Energy Technology Data Exchange (ETDEWEB)

Hot gas filters have been implemented and operated in four different test facilities: Subpilot scale entrained gasifier, located at the Texaco Montebello Research facilities in California, Foster Wheeler Advanced Pressurized Fluidized Bed Combustion pilot plant facilities, located in Livingston, New Jersey, Slipstream of the American Electric Power (AEP) 70 MW (electric) Tidd-PFBC, located in Brilliant, Ohio, and in the Ahlstrom 10 MW (thermal) Circulating PFBC facility, located in Karhula, Finland. Candle filter testing has occurred at all four facilities; cross flow filter testing has occurred at the Texaco and Foster Wheeler facilities. Table 1 identifies and summarizes the key operating characteristics of these facilities and the type and scale of filter unit tested. A brief description of each project is given.

Lippert, T.E.; Bruck, G.J.; Smeltzer, E.E.; Newby, R.A.; Bachovchin, D.M. [Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center

1993-09-01

189

Traditional soyfoods: processing and products.  

UK PubMed Central (United Kingdom)

Although soyfoods have been consumed for more than 1000 years, only for the past 15 years have they made an inroad into Western cultures and diets. Soyfoods are typically divided into two categories: nonfermented and fermented. Traditional nonfermented soyfoods include fresh green soybeans, whole dry soybeans, soy nuts, soy sprouts, whole-fat soy flour, soymilk and soymilk products, tofu, okara and yuba. Traditional fermented soyfoods include tempeh, miso, soy sauces, natto and fermented tofu and soymilk products. This paper presents a brief overview of processing techniques used in the manufacture of traditional soyfoods.

Golbitz P

1995-03-01

190

Traditional soyfoods: processing and products.  

Science.gov (United States)

Although soyfoods have been consumed for more than 1000 years, only for the past 15 years have they made an inroad into Western cultures and diets. Soyfoods are typically divided into two categories: nonfermented and fermented. Traditional nonfermented soyfoods include fresh green soybeans, whole dry soybeans, soy nuts, soy sprouts, whole-fat soy flour, soymilk and soymilk products, tofu, okara and yuba. Traditional fermented soyfoods include tempeh, miso, soy sauces, natto and fermented tofu and soymilk products. This paper presents a brief overview of processing techniques used in the manufacture of traditional soyfoods. PMID:7884535

Golbitz, P

1995-03-01

191

Aurorae in Australian Aboriginal Traditions  

CERN Multimedia

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.

Hamacher, Duane W

2013-01-01

192

A Filter for Visual Tracking Based on a Stochastic Model for Driver Behaviour  

UK PubMed Central (United Kingdom)

A driver controls a car by turning the steering wheel or bypressing on the accelerator or the brake. These actions are modelled byGaussian processes, leading to a stochastic model for the motion of thecar. The stochastic model is the basis of a new filter for tracking andpredicting the motion of the car, using measurements obtained by fittinga rigid 3D model to a monocular sequence of video images. Experimentsshow that the filter easily outperforms traditional filters.1 IntroductionThe abilities to track and to predict car motion are important in any visionsystem for road traffic monitoring. Accurate tracking is required to simplify themeasurement process. Tracking and prediction rely on filters which contain amodel for the vehicle motion. Traditional filters such as the extended Kalmanfilter (EKF) [4] or the ff Gamma fi filter [1] have very poor models for the car motion.For this reason they perform badly whenever the car carries out a complicatedmanoeuvre, for examp...

Stephen J. Maybank; Anthony D. Worrall; Geoffrey D. Sullivan

193

Staging with spatial filters  

International Nuclear Information System (INIS)

[en] It is known that small scale beam instabilities limit the focusable energy that can be achieved from a terawatt laser chain. Spatial filters are currently being used on CYCLOPS to ameliorate this problem. Realizing the full advantage of such a filter, however, may require certain staging modifications. A staging methodology is discussed that should be applicable to the CYCLOPS, 381, and SHIVA systems. Experiments are in progress on CYCLOPS that will address directly the utility of the proposed approach

1974-01-01

194

Filter drying tools  

Energy Technology Data Exchange (ETDEWEB)

Drying tools have been developed to speed up processing of spent purification filters from fuel handling and gland seal systems. Results to date have been mixed; in one case, the drying time was reduced significantly while in a second case, drying time does not appear to be any faster. Further measurements and testing are planned. If successful, the concept will be expanded to include other filters and flasks. (author)

Mersereau, M.; McIntyre, K. [Point Lepreau Generating Station, Lepreau, New Brunswick (Canada)]. E-mail: MMersereau@nbpower.com; KMcIntyre@nbpower.com

2006-07-01

195

Kalman Filtering in R  

Directory of Open Access Journals (Sweden)

Full Text Available Support in R for state space estimation via Kalman filtering was limited to one package, until fairly recently. In the last five years, the situation has changed with no less than four additional packages offering general implementations of the Kalman filter, including in some cases smoothing, simulation smoothing and other functionality. This paper reviews some of the offerings in R to help the prospective user to make an informed choice.

Fernando Tusell

2011-01-01

196

Oil filter restriction sensor  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an oil filter sensor device for insertion between the oil filter mounting bracket mounted on an internal combustion engine and an oil filter cartridge having a filter element therein. The sensor device provides a warning to an operator of the engine if a restricted oil filter condition occurs, the sensor device includes: a. a disk-shaped body means having a first generally flat surface and an opposite second generally flat surface; b. the body means having a first longitudinal passageway centrally positioned through the body means to carry filtered oil between the oil filter element and the engine bracket interconnecting through the first and second surfaces. A second longitudinal passageway is separately formed in the body means to carry incoming unfiltered oil between the engine bracket and the oil filter cartridge and arranged to interconnect through the first and second surfaces; c. a closed internal cylindrical bore formed in the body means having a first end opening through the outer surface of the body means, a slidable piston mounted within the cylindrical bore and sized to closely fit the diameter of the bore, a removable plug suitably mounted within the open end of the bore to close and seal the bore and to restrict the movement of the piston; and d. a biasing means positioned within the bore between the plug and the piston to bias the piston in a first position away from the plug. The plug has an insulated electrical connector mounted therein which extends into the bore so that the piston when it moves to a second position against the biasing means makes electrical contact with the connector.

Fick, V.L.; Fick, K.W.

1986-12-02

197

Fabric filters; Filtermedia  

Energy Technology Data Exchange (ETDEWEB)

In this article are described fabric filters for dust and hot gas filtration. A fabric filter is one in which dust bearing gas is passed unidirectionally through a fabric in such a manner that the dust particles are retained on the dirty gas side of the fabric, while the clear gas passes through the fabric to the clean gas side. The fabric may be of any fibrous material - either natural or manmade and woven or impacted to a felt.

Andersson, L. (Nordifa, Halmstad (SE))

1987-01-01

198

Dust collection with bag filters and envelope filters  

International Nuclear Information System (INIS)

The state of the art in the field of bag filters is reviewed in great detail, with special regard to the practical aspects of planning, constructing, selecting and operating filter systems. The book contains three main chapters. Chapter 1 reviews the theoretical and experimental basic research on separation and pressure loss phenomena. Chapter 2 discusses the central part of the filter, i.e. the filter medium, and presents a detailed introduction to the problems of filter media development and production. Chapter 3 discusses filter systems: After a classification of filter systems, constructional details and problems of application are discussed. With 203 figs.

1988-01-01

199

Contactor/filter improvements  

Energy Technology Data Exchange (ETDEWEB)

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.

Stelman, David (West Hills, CA)

1989-01-01

200

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

UK PubMed Central (United Kingdom)

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 quality of brain CT.

Buhk JH; Laqmani A; von Schultzendorff HC; Hammerle D; Sehner S; Adam G; Fiehler J; Nagel HD; Regier M

2013-08-01

 
 
 
 
201

Application of Unscented Kalman Filter for Sonar Signal Processing  

Directory of Open Access Journals (Sweden)

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.

Leela Kumari. B , Padma Raju.K

2012-01-01

202

The Effectiveness of Irlen Filters for Improving Reading Performance: A Pilot Study.  

Science.gov (United States)

The study compared the effectiveness of Irlen filters and traditional optometric intervention with 30 volunteers (ages 9-51). Pre- and posttesting revealed that subjects in both treatment groups were more comfortable after treatment, that only the vision therapy group showed improved visual functioning, and that the Irlen filter group did not show…

Blaskey, Penni; And Others

1990-01-01

203

AN ALTERNATIVE ELUENT TO BEEF EXTRACT FOR ELUTING POLIOVIRUS FROM ELECTROPOSITIVE FILTERS  

Science.gov (United States)

Traditional methods for enteric virus removal from waters involve filtering the water through a positively charged filter followed by elution with beef extract, second step concentration by flocculation, and assay in cell culture. Two of the problems associated with this method ...

204

Forceps retrieval of a tip-embedded superior vena cava filter.  

UK PubMed Central (United Kingdom)

The use of rigid endobronchial forceps has been described for the percutaneous retrieval of tip-embedded retrievable inferior vena cava filters, especially when retrieval with the use of traditional devices has failed. The present report describes retrieval of a tip-embedded retrievable filter from the superior vena cava with the use of this technique.

Yan Y; Galfione M; William Stavropoulos S; Trerotola SO

2013-04-01

205

Preaching in the Lutheran Tradition  

DEFF Research Database (Denmark)

  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

Lorensen, Marlene Ringgaard

2010-01-01

206

Fully optimal filter for ALLEGRO  

Science.gov (United States)

The FAST and SLOW filters are compared when applied to data from one-mode and two-mode resonant gravitational wave detectors. There is no substantial difference between the performance of two filters in the case of the one-mode detector. Notable reduction of the noise temperature is achieved for a two-mode detector when filtering the data with the FAST filter. We explain the principal reason for the better performance of the FAST filter with respect to the SLOW filter. We also observed that the performance of the FAST filter depends on the ratio ? between the thermal narrow band noise and the SQUID amplifier white noise.

Santostasi, Giovanni

2004-03-01

207

Fully optimal filter for ALLEGRO  

International Nuclear Information System (INIS)

The FAST and SLOW filters are compared when applied to data from one-mode and two-mode resonant gravitational wave detectors. There is no substantial difference between the performance of two filters in the case of the one-mode detector. Notable reduction of the noise temperature is achieved for a two-mode detector when filtering the data with the FAST filter. We explain the principal reason for the better performance of the FAST filter with respect to the SLOW filter. We also observed that the performance of the FAST filter depends on the ratio ? between the thermal narrow band noise and the SQUID amplifier white noise.

2004-03-07

208

Fully optimal filter for ALLEGRO  

Energy Technology Data Exchange (ETDEWEB)

The FAST and SLOW filters are compared when applied to data from one-mode and two-mode resonant gravitational wave detectors. There is no substantial difference between the performance of two filters in the case of the one-mode detector. Notable reduction of the noise temperature is achieved for a two-mode detector when filtering the data with the FAST filter. We explain the principal reason for the better performance of the FAST filter with respect to the SLOW filter. We also observed that the performance of the FAST filter depends on the ratio {gamma} between the thermal narrow band noise and the SQUID amplifier white noise.

Santostasi, Giovanni [Physics and Astronomy Department, Louisiana State University, Baton Rouge, LA 70803-4001 (United States)

2004-03-07

209

Analog filters in nanometer CMOS  

CERN Multimedia

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

Uhrmann, Heimo; Zimmermann, Horst

2013-01-01

210

The impact of metallic filter media on HEPA filtration  

International Nuclear Information System (INIS)

[en] Traditional HEPA filter systems have limitations that often prevent them from solving many of the filtration problems in the nuclear industry; particularly in applications where long service or storage life, high levels of radioactivity, dangerous decomposition products, chemical aggression, organic solvents, elevated operating temperatures, fire resistance and resistance to moisture are issues. This paper addresses several of these matters of concern by considering the use of metallic filter media to solve HEPA filtration problems ranging from the long term storage of transuranic waste at the WIPP site, spent and damaged fuel assemblies, in glove box ventilation and tank venting to the venting of fumes at elevated temperatures from incinerators, vitrification processes and conversion and sintering furnaces as well as downstream of iodine absorbers in gas cooled reactors in the UK. The paper reviews the basic technology, development, performance characteristics and filtration efficiency, flow versus differential pressure, cleanability and costs of sintered metal fiber in comparison with traditional resin bonded glass fiber filter media and sintered metal powder filter media. Examples of typical filter element and system configurations and applications will be presented The paper will also address the economic case for installing self cleaning pre-filtration, using metallic media, to recover the small volumes of dust that would otherwise blind large volumes of final disposable HEPA filters, thus presenting a route to reduce ultimate disposal volumes and secondary waste streams. (authors)

2006-01-01

211

NOTCH FILTER USING SIMULATED INDUCTOR  

Directory of Open Access Journals (Sweden)

Full Text Available The design of analog filters at low frequencies is not possible because the size of inductors becomes very large. In such cases, the simulated inductors using operational amplifiers are used. This paper deals with the implementation of notch filter using band pass filter which uses simulated inductor where the direct implementation of notch filter using simulated inductor is not possible because of floating inductor. The design of notch filter and the simulation done in PSPICE is presented.

D.SUSAN,; Dr.S.JAYALALITHA

2011-01-01

212

DOE HEPA filter test program  

International Nuclear Information System (INIS)

This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL)

1998-01-01

213

Boolean filters of distributive lattices  

Directory of Open Access Journals (Sweden)

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.

M. Sambasiva Rao; K.P. Shum

2013-01-01

214

DOE HEPA filter test program  

Energy Technology Data Exchange (ETDEWEB)

This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL).

NONE

1998-05-01

215

State space second order filter estimation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 properties 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 (more) 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.

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

2013-06-01

216

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

International Nuclear Information System (INIS)

[en] 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)

2004-09-03

217

Spatial filters for focusing ultrasound images  

DEFF Research Database (Denmark)

Traditionally focusing is done by taking out one sample in the received signal from each transducer element and then sum these signals. This method does not take into account the temporal or spatial spread of the received signal from a point scatterer and does not make an optimal focus of the data. A new method for making spatial matched filter focusing of RF ultrasound data is proposed based on the spatial impulse response description of the imaging. The response from a scatterer at any given point in space relative to the transducer can be calculated, and this gives the spatial matched filter for beamforming the received RF signals from the individual transducer elements. The matched filter is applied on RF signals from individual transducer elements, thus properly taking into account the spatial spread of the received signal. The method can be applied to any transducer and can also be used for synthetic aperture imaging for single element transducers. It is evaluated using the Field II program. Data from asingle 3 MHz transducer focused at a distance of 80 mm is processed. Far from the transducer focal region, the processing greatly improves the image resolution: the lateral slice of the autocovariance function of the image shows a -6 dB width reduction by a factor of 3.3 at 20 mm and by a factor of 1.8 at 30 mm. Other simulations use a 64 elements, 3 MHz, linear array. Different receiving conditions are compared and this shows that the effect of the filter is progressively lower, but the approach always yields point spread functions better or equal to a traditional dynamically focused image. Finally, the process was applied to in-vivo clinical images of the liver and right kidney from a 28 years old male. The data was obtained with a single element transducer focused at 100 mm. The improvement in resolution was in this case less evident and further optimization is needed.

Jensen, JØrgen Arendt; Gori, Paola

2001-01-01

218

Filter component assessment  

Energy Technology Data Exchange (ETDEWEB)

The objectives of this program are to provide a more ruggedized filter system that utilizes porous ceramic filters which have improved resistance to damage resulting from crack propagation, thermal fatigue and/or thermal excursions during plant or process transient conditions, and/or mechanical ash bridging events within the candle filter array. As part of the current Phase 1, Task 1, effort of this program, Westinghouse is evaluating the filtration characteristics, mechanical integrity, and corrosion resistance of the following advanced or second generation candle filters for use in advanced coal-fired process applications: 3M CVI-SiC composite--chemical vapor infiltration of silicon carbide into an aluminosilicate Nextel{trademark} 312 fiber preform; DuPont PRD-66--filament wound candle filter structure containing corundum, cordierite, cristobalite, and mullite; DuPont SiC-SiC--chemical infiltration of silicon carbide into a silicon carbide Nicalon{trademark} fiber mat or felt preform; and IF and P Fibrosic{trademark}--vacuum infiltrated oxide-based chopped fibrous matrix. Results to date are presented.

Alvin, M.A.; Lippert, T.E.; Diaz, E.S.; Smeltzer, E.W. [Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center

1995-11-01

219

Multilevel Mixture Kalman Filter  

Directory of Open Access Journals (Sweden)

Full Text Available The mixture Kalman filter is a general sequential Monte Carlo technique for conditional linear dynamic systems. It generates samples of some indicator variables recursively based on sequential importance sampling (SIS) and integrates out the linear and Gaussian state variables conditioned on these indicators. Due to the marginalization process, the complexity of the mixture Kalman filter is quite high if the dimension of the indicator sampling space is high. In this paper, we address this difficulty by developing a new Monte Carlo sampling scheme, namely, the multilevel mixture Kalman filter. The basic idea is to make use of the multilevel or hierarchical structure of the space from which the indicator variables take values. That is, we draw samples in a multilevel fashion, beginning with sampling from the highest-level sampling space and then draw samples from the associate subspace of the newly drawn samples in a lower-level sampling space, until reaching the desired sampling space. Such a multilevel sampling scheme can be used in conjunction with the delayed estimation method, such as the delayed-sample method, resulting in delayed multilevel mixture Kalman filter. Examples in wireless communication, specifically the coherent and noncoherent 16-QAM over flat-fading channels, are provided to demonstrate the performance of the proposed multilevel mixture Kalman filter.

Guo Dong; Wang Xiaodong; Chen Rong

2004-01-01

220

Ceramic filter material issues  

Energy Technology Data Exchange (ETDEWEB)

The development of advanced power production processes such as pressurized fluid bed combustion (PFBC) or integrated gasification combined cycle (IGCC) is important to assure the energy future of the United States. These power producing processes can potentially produce electric power at competitive prices in an environmentally benign manner. The use of high temperature filters is required in these processes to assure high operating efficiency. However, high temperature filters have not proven to be durable in these applications. The objective of the effort is to identify and investigate the filter material degradation mechanisms. The filter materials examined under this project are silicon carbide based ceramic candle filters from two manufactures: Schumacher and Refractron. Specifically, the Schumacher Diaschumalith F40 and the Refractron 70/3 with 442-T binder were subjected to a series of tests which examined their ability to withstand thermal fatigue and chemical corrosion from steam and alkali. Both these candles are composed to silicon carbide grains in an alumina/silica based binder. There are differences in binder formulation between the two candles and each manufacturer has a different approach to forming the filtration membrane on the candle surface.

Sawyer, J.W. [Acurex Environmental Corp., Mountian View, CA (United States); Brown, J.J.; Brown, N.R. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

1993-06-01

 
 
 
 
221

Systolic Filter Design Using Multi-Filtering Techniques  

Directory of Open Access Journals (Sweden)

Full Text Available To improve the performance of system in terms of processing power, a new architecture and clocking technique is to be realized in this paper. To process the signal in Embedded Parallel Systolic Filters (EPSF) and to eliminate the noise present in the signal using flag-bit and flicker clock condition. Kalman filter and extended kalman filter are the filtering techniques used by systolic arrays that can simultaneously triggered on all data elements with different clock cycles. Kalman filter and extended kalman filter to work in two conditions namely with and without flag-bit, flicker clock are to be synthesized and compared.

DEEPAN RAJ.B; T.V.P.SUNDARARAJAN; K.SHOUKATH ALI

2013-01-01

222

Stack filter classifiers  

Energy Technology Data Exchange (ETDEWEB)

Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

2009-01-01

223

Morphing Ensemble Kalman Filters  

CERN Document Server

A new type of ensemble filter is proposed, which combines an ensemble Kalman filter (EnKF) with the ideas of morphing and registration from image processing. This results in filters suitable for nonlinear problems whose solutions exhibit moving coherent features, such as thin interfaces in wildfire modeling. The ensemble members are represented as the composition of one common state with a spatial transformation, called registration mapping, plus a residual. A fully automatic registration method is used that requires only gridded data, so the features in the model state do not need to be identified by the user. The morphing EnKF operates on a transformed state consisting of the registration mapping and the residual. Essentially, the morphing EnKF uses intermediate states obtained by morphing instead of linear combinations of the states.

Beezley, Jonathan D

2007-01-01

224

A Simple Framework For Filtering Queued Smtp Mail (cyberwar Countermeasures)  

UK PubMed Central (United Kingdom)

Pre-information age military battlefields are based on the traditional land, sea, air, and space paradigm. Global internetworking is causal to the creation of a dangerously real 5th Dimension of Warfare - Cyberspace. This paper describes an Internet based assault, commonly referred to as e-mail spam, on the Langley AFB internetworking infrastructure. We discuss the cyber-attack, a framework for defending against the attack, and the results of the campaign. The countermeasure was accomplished by running the MTA in a mode which accepts and queues SMTP mail; processes the messages with a rules-based filter; and then forwards mail after filtering. The filtering framework is simple and effective for a large subset of email bombs. The prototype filter scripts may be obtained from the authors. INTRODUCTION E-mail is extensively used for the exchange of numerous types of messages in the military environment. From low value questions and staff summaries to messages bordering on command and co...

Tim Bass; Lt. Col; Glenn Watt

225

Filtered containment venting  

International Nuclear Information System (INIS)

After the TMI accident in the USA, the Swedish Government in 1981 decided that all Swedish nuclear power plants must be upgraded to mitigate the consequences of severe accidents. Mitigating measures were required to be in place by 1985 for the Barsebaeck plants and by 1988 for the remaining plants. The technical solution selected for accident mitigation was filtered venting of the reactor containment. The filtering requirement was that the release of radioactivity should be less than 0.1% of the core inventory. In Barsebaeck the filter consists of a gravel bed with a volume of 10,000 cubic metres. For the other Swedish plants (7 BWRs and 3 PWRs) a wet scrubber system of significantly smaller volume (300-400 cubic metres) has been selected. This filter system which is called FILTRA-MVSS (Multi Venturi Scrubber System) has been jointly developed by ASEA-ATOM and FLAEKT Industri, two companies belonging to the ASEA BROWN BOVERI Group of Companies. The FILTRA-MVSS which can accomodate a wide range of flow rates based on an automatic passive technique consists of a number of venturi nozzles submerged in a pool of water. The venturi separation technique has been employed in the field of industrial air pollution control for several decades. The technique has now been further developed and adapted for the cleaning of contaminated radioactive off-gases that might be the consequence of a severe reactor accident. After the Chernobyl accident the discussion on filtered containment venting intensified also in other European countries, and several countries, for example France, the Federal Republic of Germany and Finland are now planning for filtered venting systems. The FILTRA-MVSS system can be designed to meet a wide range of hypothetic design basis events for both BWR and PWR plants. The system can be optimized with respect to its size depending on various pressure requirements and it can be optimized for specified decontamination factors. (author). Poster presentation. 3 figs

1988-01-01

226

Groundspeed filtering for CTAS  

Science.gov (United States)

Ground speed is one of the radar observables which is obtained along with position and heading from NASA Ames Center radar. Within the Center TRACON Automation System (CTAS), groundspeed is converted into airspeed using the wind speeds which CTAS obtains from the NOAA weather grid. This airspeed is then used in the trajectory synthesis logic which computes the trajectory for each individual aircraft. The time history of the typical radar groundspeed data is generally quite noisy, with high frequency variations on the order of five knots, and occasional 'outliers' which can be significantly different from the probable true speed. To try to smooth out these speeds and make the ETA estimate less erratic, filtering of the ground speed is done within CTAS. In its base form, the CTAS filter is a 'moving average' filter which averages the last ten radar values. In addition, there is separate logic to detect and correct for 'outliers', and acceleration logic which limits the groundspeed change in adjacent time samples. As will be shown, these additional modifications do cause significant changes in the actual groundspeed filter output. The conclusion is that the current ground speed filter logic is unable to track accurately the speed variations observed on many aircraft. The Kalman filter logic however, appears to be an improvement to the current algorithm used to smooth ground speed variations, while being simpler and more efficient to implement. Additional logic which can test for true 'outliers' can easily be added by looking at the difference in the a priori and post priori Kalman estimates, and not updating if the difference in these quantities is too large.

Slater, Gary L.

1994-11-01

227

Time-variant filters  

International Nuclear Information System (INIS)

Various types of time-variant filters are considered and compared with time-invariant ones. Some conditions to achieve the better signal-to-noise ratio are considered when one uses the gated integrator. It is shown that: 1) at high counting rates the gated integrator is preferable for a peak detector, as far as noise is concerned; 2)at low counting rates the noise whitening filter-double integrator structure is prederable, it can be realized using monolithic technology. 9 refs.; 5 figs.

1990-01-01

228

Firewall: Packet Filters  

Science.gov (United States)

This brief interactive activity, by Electromechanical Digital Library and Wisconsin Technical College System faculty members Joseph Wetzel and Douglas Tabbutt, provides an interactive lesson on packet filters to demonstrate their use. After a brief explanation, there is a very useful activity that allows the user to control theoretical settings to try to block a certain port from transferring information â itâÂÂs a good test to verify if the concept is understood. This should prove a useful resource for students or teachers looking to introduce the concept of packet filters.

Tabbutt, Douglas; Wetzel, Joseph

2009-04-15

229

Efficient Iterated Filtering  

DEFF Research Database (Denmark)

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.

Lindstro?m, Erik; Ionides, Edward

2012-01-01

230

Filtering aviation fuels  

Energy Technology Data Exchange (ETDEWEB)

An industry-wide review is currently taking place on existing standards for aviation fuel filters, used for handling at airports where speed of operation and safety criteria must be met to exacting quality standards. This article reports on an American Petroleum Industry conference which addressed the importance of fuel cleanliness and dryness to the aviation industry and the need for appropriate standards for fuel filtration. The changes in standards which are needed to keep pace with changes in aviation are outlined and recent research into jet fuel, surfactants and fuel filters is examined. Other papers focused on developments in hydrant leak detection and containment measures. (UK)

Jackson, Kim

1996-01-01

231

Shifted Linear Interpolation Filter  

Directory of Open Access Journals (Sweden)

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.

Hannu Olkkonen; Juuso T. Olkkonen

2010-01-01

232

Progressive Gaussian Filtering  

CERN Document Server

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.

Hanebeck, Uwe D

2012-01-01

233

Optimal radiation filter for angiography  

Energy Technology Data Exchange (ETDEWEB)

The material and thickness of an additional filter have been investigated for angiography. The result is that the copper filter reduce effectively, the patient dosage with little increase in tube loading. The 0.15-mm copper filter reduce skin exposure 35 % using the 1.0-mm aluminum filter for abdominal angiography. The 0.15-mm copper filter achieves an exposure reduction as much as the 0.12-mm gadolinium filter with about 30 % less tube loading under the same iodine contrast.

Oda, Nobuhiro; Terada, Kunihiro; Tanaka, Sachie

1988-12-01

234

Filter assembly for metallic and intermetallic tube filters  

Energy Technology Data Exchange (ETDEWEB)

A filter assembly (60) for holding a filter element (28) within a hot gas cleanup system pressure vessel is provided, containing: a filter housing (62), said filter housing having a certain axial length and having a peripheral sidewall, said sidewall defining an interior chamber (66); a one piece, all metal, fail-safe/regenerator device (68) within the interior chamber (66) of the filter housing (62) and/or extending beyond the axial length of the filter housing, said device containing an outward extending radial flange (71) within the filter housing for seating an essential seal (70), the device also having heat transfer media (72) disposed inside and screens (80) for particulate removal; one compliant gasket (70) positioned next to and above the outward extending radial flange of the fail-safe/regenerator device; and a porous metallic corrosion resistant superalloy type filter element body welded at the bottom of the metal fail-safe/regenerator device.

Alvin, Mary Anne (113 Lehr Ave., Pittsburgh, PA 15223); Lippert, Thomas E. (3205 Cambridge Rd., Murrysville, PA 15668); Bruck, Gerald J. (4469 Sardis Rd., Murrysville, PA 15668); Smeltzer, Eugene E. (R.D. 7, Box 267-I, Italy Rd., Export, PA 15632-9621)

2001-01-01

235

Positive implicative ordered filters of implicative semigroups  

Directory of Open Access Journals (Sweden)

Full Text Available We introduce the notion of positive implicative ordered filters in implicative semigroups. We show that every positive implicative ordered filter is both an ordered filter and an implicative ordered filter. We give examples that an ordered filter (an implicative ordered filter) may not be a positive implicative ordered filter. We also give equivalent conditions of positive implicative ordered filters. Finally we establish the extension property for positive implicative ordered filters.

Young Bae Jun; Kyung Ho Kim

2000-01-01

236

Static Filtered Skin Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A static skin filter defines explicitly (using a number of rules) the boundaries the skin cluster has in a color space. Single or multiple ranges of threshold values for each color space component are created and the image pixel values falling within these range(s) for all the chosen color componen...

Rehanullah Khan; Zeeshan Khan; Muhammad Aamir

237

Ozone decomposing filter  

Energy Technology Data Exchange (ETDEWEB)

In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

Simandl, Ronald F. (Farragut, TN); Brown, John D. (Harriman, TN); Whinnery, Jr., LeRoy L. (Dublin, CA)

1999-01-01

238

Multilevel Mixture Kalman Filter  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The mixture Kalman filter is a general sequential Monte Carlo technique for conditional linear dynamic systems. It generates samples of some indicator variables recursively based on sequential importance sampling (SIS) and integrates out the linear and Gaussian state variables conditioned on these i...

Rong Chen; Xiaodong Wang; Dong Guo

239

Novel efficient oil filter  

UK PubMed Central (United Kingdom)

The utility model discloses a novel efficient oil filter, which comprises an oil storage tank and an oil filtration tank, wherein a feed inlet of the oil storage tank is provided with a feed inlet valve, the oil storage tank is also provided with a gas inlet with a gas inlet valve and a gas outlet with a gas outlet valve, a filter bag is installed in the oil filtration tank, an oil inlet is arranged on the tank cover of the oil storage tank, the oil inlet is opposite to a bag port of the filter bag, a packing washer is arranged between the tank cover of the oil storage tank and the tank body for sealing, and an oil outlet is arranged on the tank bottom of the oil storage tank and is communicated with the oil inlet of the oil filtration tank through a pipeline with a valve. The oil filter has high filtration efficiency, adopts the oil storage tank to store oil, can realize intermittent production, and is in particular suitable for production in families and small-sized vegetable oil enterprises.

GUOPING LIU; HEMING CAO; YUNSHUI GONG; YOUTANG JI

240

Disposable bacteria filter  

UK PubMed Central (United Kingdom)

An interchangeable set of wide orifice respiratory filter elements can be built into either a low resistance, high dead space embodiment for forced vital capacity testing or high resistance, low dead space embodiment for diffusion and residual air tests. A disposable 3M Filtrete TM pad is at the heart of all embodiments thus allowing extremely high levels of filtration efficiencies.

LEHMAN ARLIN D

 
 
 
 
241

VENTILATED FILTER CIGARETTE  

UK PubMed Central (United Kingdom)

A ventilated filter cigarette has a multiple filter with a higher global retention provided in different sections with ventilation perforations. The ventilated filter cigarette contains a tobacco mixture of expanded tobacco having a high nicotine content. The tobacco mixture contains as constitutive element expanded tobacco lamina with a nicotine content from 1.0 % to 8 % and/or tobacco foil with a nicotine content from 5 % to 10 %, to which fruit acid is incorporated. The tobacco mixture has a nicotine content from 2.5 % to 5 %. The resistance to draw of the multiple filter is higher at the tow side than at the mouth side, and the degree of ventilation lies in a range from 50 % to 95 % added air. The main smoke flow preferably has an "American blend" taste with an approximately constant taste per puff. The pH value of the smoke lies in a range from 6.0 to 7.5. While giving good sensory results, the cigarettes have condensate and nicotine values respectively of less than 1 mg/cigarette and 0.1 mg/cigarette and in special cases of less than 3 mg/cigarette and less than 0.6 mg/cigarette.

PETERS Gunther; WILDENAU Wolfgang; SEIDEL Henning; ZIEHN Klaus-Dieter; BETTELS Erika; WILLNER Joachim

242

Savitsky-Golay Filters  

Science.gov (United States)

This paper describes how to create Savitsky-Golay filters for smoothing and determining derivatives from raw data taken at points equally spaced in time based on a polynomial fitting model. For example, they can be used to evaluate velocity and acceleration from ultrasonic motion sensor data and angular velocity and acceleration from rotary encoder data.

Deserio, Robert

2008-06-25

243

The ATLAS event filter  

CERN Document Server

An overview of the studies for the ATLAS Event Filter is given. The architecture and the high level design of the DAQ-1 prototype is presented. The current status if the prototypes is briefly given. Finally, future plans and milestones are given. (11 refs).

Beck, H P; Boissat, C; Davis, R; Duval, P Y; Etienne, F; Fede, E; Francis, D; Green, P; Hemmer, F; Jones, R; MacKinnon, J; Mapelli, Livio P; Meessen, C; Mommsen, R K; Mornacchi, Giuseppe; Nacasch, R; Negri, A; Pinfold, James L; Polesello, G; Qian, Z; Rafflin, C; Scannicchio, D A; Stanescu, C; Touchard, F; Vercesi, V

1999-01-01

244

Structural notch filter optimization  

Energy Technology Data Exchange (ETDEWEB)

A modified algorithm for nonlinear constrained optimization of structural mode filters for an aeroelastic aircraft model is presented. The optimizer set-up and control is implemented in a MATLAB{trademark} graphical user interface environment. It is shown that the modified algorithm gives improved performance over existing nonlinear constrained optimization methods.

Felton, R.; Burge, S.; Bradshaw, A. [Lancaster Univ. (United Kingdom). Dept. of Engineering

1995-09-01

245

Property Rights And Traditional Knowledge  

Directory of Open Access Journals (Sweden)

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 practical. 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.

JT Cross

2010-01-01

246

Property rights and traditional knowledge  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 practical. However, underlying these practical concerns is a core philosophical concern. A system of traditional knowledge rights, this argument suggests, simply does not satisfy the b (more) asic 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.

Cross, JT

2010-01-01

247

Statistically-Efficient Filtering in Impulsive Environments: Weighted Myriad Filters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 pr...

Gonzalo R. Arce; Juan G. Gonzalez

248

Filter-radiometer-based realization of candela and establishment of photometric scale at UME  

Science.gov (United States)

The luminous intensity unit of candela was realized based on filter-radiometer, which is traceable to detector-based primary standard electrical substitution cryogenic radiometer (ESCR). In that realization the traditional Osram Wi41/G-type incandescent lamp and filter-radiometer consisting of an aperture, a V(?) filter and a silicon photodiode based trap detector were used as light source and detection element, respectively. Measurement techniques of effective aperture area, spectral transmittance of V(?) filter and absolute responsivity of trap detector are also presented.

Samedov, Farhad; Durak, Murat; Bazk?r, Özcan

2005-11-01

249

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

Directory of Open Access Journals (Sweden)

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.

S. Chouraqui; M. Benyettou

2009-01-01

250

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

DEFF Research Database (Denmark)

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.

Larsen, Thomas Dall; Andersen, Nils Axel

1999-01-01

251

Prestack mid-value filtering  

Energy Technology Data Exchange (ETDEWEB)

This paper describes mid-value filtering, a specific nonlinear smoothing filtering, and widely used in graphic processing, etc. Mid-value filtering before stack of seismic data can remove wild value (inconceivable particular big value) and improve signal-noise ratio. In view of big data volume before stack, computation efficiency of mid-value filtering is critical to its feasibility. The algorithm used here is sufficiently based on the properties of mid-value filtering, so that the computation efficiency is greatly improved. It is experimentally shown that prestack mid-value filtering can quite well eliminate wild value, abnormal traces as well as surface waves, and raise signal-noise ratio. After lateral low frequency noises are removed by high pass filtering, mid-value filtering works better.

Changlian, X. (Geophysical Research Inst., Bureau of Oil Geophysical Prospecting, Zhuozhou City, Hebei Province (CN))

1992-01-01

252

Filters used in scoliosis radiography  

Energy Technology Data Exchange (ETDEWEB)

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.

Lyons, J.M. (Royal Perth Hospital (Australia))

1984-03-01

253

USE OF TANNINS IN FILTERS  

UK PubMed Central (United Kingdom)

The invention relates to the use of a tannin in or on filters, in particular consisting of natural or synthetic woven fibres or foams, for preventing infections, said filters forming in particular part of respirator masks or respirator equipment.

HUEFFER STEPHAN; REESE OLIVER; SCHERR GUENTER; GARNIER SEBASTIEN

254

Narrowband Planar Microwave Active Filter.  

Science.gov (United States)

A new circuit design for narrowband microwave active filters is presented in the letter. By increasing the tank circuit unloaded Q-value an ideal one-section bandpass filter is realized. Reprints. (rrh)

C. Y. Chang T. Itoh

1989-01-01

255

Active filter of symmetrical components  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a filter which provides frequency symmetry between electrical components. In order to improve its accuracy when the frequency deviates, the filter includes two bridge phase shifters and a transformer. A diagram is provided.

Benin, V.L.; Saydov, A.S.

1982-01-01

256

Kalman filtering implementation with Matlab  

Digital Repository Infrastructure Vision for European Research (DRIVER)

1960 und 1961 veröffentlichte Rudolf Emil Kalmen seine Arbeiten über einen rekursiven prädiktiven Filter, der auf dem Gebrauch von rekursiven Algorithmen basiert. Damit revolutionierte er das Feld der Schätzverfahren. Seitdem ist der sogenannte Kalman Filter Gegenstand ausführlicher Forschung und fi...

Kleinbauer, Rachel

257

The Magnetic Centrifugal Mass Filter  

Energy Technology Data Exchange (ETDEWEB)

Mass filters using rotating plasmas have been considered for separating nuclear waste and spent nuclear fuel. We propose a new mass filter that utilizes centrifugal and magnetic confinement of ions in a way similar to the asymmetric centrifugal trap. This magnetic centrifugal mass filter is shown to be more proliferation resistant than present technology. This filter is collisional and produces well confined output streams, among other advantages. __________________________________________________

Abraham J. Fetterman and Nathaniel J. Fisch

2011-08-04

258

The magnetic centrifugal mass filter  

Energy Technology Data Exchange (ETDEWEB)

Mass filters using rotating plasmas have been considered for separating nuclear waste and spent nuclear fuel. We propose a new mass filter that utilizes centrifugal and magnetic confinement of ions in a way similar to the asymmetric centrifugal trap. This magnetic centrifugal mass filter is shown to be more proliferation resistant than present technology. This filter is collisional and produces well confined output streams, among other advantages.

Fetterman, Abraham J.; Fisch, Nathaniel J. [Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08540 (United States)

2011-09-15

259

The magnetic centrifugal mass filter  

Science.gov (United States)

Mass filters using rotating plasmas have been considered for separating nuclear waste and spent nuclear fuel. We propose a new mass filter that utilizes centrifugal and magnetic confinement of ions in a way similar to the asymmetric centrifugal trap. This magnetic centrifugal mass filter is shown to be more proliferation resistant than present technology. This filter is collisional and produces well confined output streams, among other advantages.

Fetterman, Abraham J.; Fisch, Nathaniel J.

2011-09-01

260

The magnetic centrifugal mass filter  

International Nuclear Information System (INIS)

Mass filters using rotating plasmas have been considered for separating nuclear waste and spent nuclear fuel. We propose a new mass filter that utilizes centrifugal and magnetic confinement of ions in a way similar to the asymmetric centrifugal trap. This magnetic centrifugal mass filter is shown to be more proliferation resistant than present technology. This filter is collisional and produces well confined output streams, among other advantages.

2011-01-01

 
 
 
 
261

Research of Collaborative Filtering Recommendation Algorithm based on Network Structure  

Directory of Open Access Journals (Sweden)

Full Text Available 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 processes and obtain extended multi-dimensional semi-Markov processes which are combined with social network analysis theory, and then we get social network information flow model. The model describes the flow of information between the members of the social network. So, we propose collaborative filtering algorithm based on social network information flow model. The algorithm uses social network information and combines user trust with user interest and find nearest neighbors of the target user and then forms a project recommended to improve the accuracy of recommended. Compared with the traditional collaborative filtering algorithm, the algorithm can effectively alleviate the sparsity and malicious behavior problem, and significantly improve the quality of the recommendation system recommended.

Hui PENG

2013-01-01

262

The Rao-Blackwellized Particle Filter: A Filter Bank Implementation  

Directory of Open Access Journals (Sweden)

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.

Hendeby Gustaf; Karlsson Rickard; Gustafsson Fredrik

2010-01-01

263

Resonant grating filters for microsystems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the present work we report on the design and characterization of a tunable optical filter for use in a compact add-drop multiplexer. The optical filter is a resonant grating filter (RGF) consisting of a planar waveguide and a grating parallel to the surface. A resonance occurs when the incoming l...

Niederer, Guido; Herzig, Hans-Peter

264

Volterra Filtering with Spectral Constraints.  

Science.gov (United States)

One of the major drawbacks of Volterra filters is the large number of parameters associated with such structures. In this paper, it is shown how the Volterra filter can be constrained to yield parsimonious filter structures that are adequately flexible fo...

R. D. Nowak B. D. VanVeen

1994-01-01

265

Inorganic UV filters  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese 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 podem ser filtros orgânicos e inorgânicos. Filtros inorgânicos apresentam muitas vantagens em relação aos orgânicos, tais como fotoestabilidade, ausência de irri (more) tabilidade 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, ino (more) rganic 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.

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

2013-06-01

266

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).

1981-01-01

267

Editorial: Between Tradition and Modernity  

Directory of Open Access Journals (Sweden)

Full Text Available 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. 

Editor Al-Jami'ah: Journal of Islamic Studies

2011-01-01

268

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)

1979-01-01

269

Chinese traditional medicine for curing diarrhea and preparation method thereof  

UK PubMed Central (United Kingdom)

The invention discloses a Chinese traditional medicine for curing diarrhea and a preparation method thereof. The Chinese traditional medicine comprises the following medicinal materials by weight parts: 3-5 parts of Sichuan pepper, 1-3 parts of artemisia leaves, 1-3 parts of dried ginger, 2-4 parts of red halloysite, 5-9 parts of ebony, 3-5 parts of coptis, 4-8 parts of scutellaria and 5-9 parts of areca. The preparation method for the Chinese traditional medicine comprises the following steps of: (1.1) soaking the red halloysite in water with 20 times of the weight of the red halloysite for 20-30 minutes and boiling for 30-60 minutes subsequently adding other medicinal materials and water (the weight ratio of water and all medicinal materials is 10:1) and boiling for 30-60 minutes subsequently adding water and boiling for 30-60 minutes again with the weight of the water being 8 times of that of the total medicinal materials and (1. 2) filtering the hot decocted solution and concentrating the solution to obtain the concentrated solution, thus preparing different orally taken dosages. The Chinese traditional medicine has extremely obvious clinical efficacy on diarrhea, has no side effects, and is simple and feasible and easy to be accepted by patients.

BAIXIANG LIU

270

Retinal vascular boundary extraction based on direction filtering  

Science.gov (United States)

Blood vessel images have strongly morphological characteristic as well as complicated backgrounds. However, traditional boundary extraction algorithms rarely utilize the local uniform direction of the pixels in the vascular margin and often incur discontinuities of edges due to background noises. In this paper a new vascular boundary extraction algorithm based on direction filtering is presented, in which some algorithms, such as chaotic filtering, direction and distance matrix, as well as edge tracing, are put forward. The experimental results indicate that the algorithm has achieved better effects in noise depression and vascular extraction.

Wang, Haishun; Wang, Rong; Chen, Limin

2007-11-01

271

Demonstration of polarization-independent resonant subwavelength grating filter arrays.  

UK PubMed Central (United Kingdom)

We demonstrate a two-dimensional (2D) polarization-independent resonant subwavelength grating (RSG) in a filter array. RSGs, also called guided mode resonant filters, are traditionally one-dimensional gratings; however, this leads to TE and TM resonances at different wavelengths and with different spectral shape. A 2D grating can remove the polarization dependence at normal incidence, while maintaining the desirable RSG properties of high reflectivity, narrow passband, and low sidebands without ripple. We designed and fabricated 2D gratings with near-identical responses for both polarizations at normal incidence in the telecommunication band. Ninety percent reflectivity is achieved at the resonant wavelengths.

Peters DW; Boye RR; Wendt JR; Kellogg RA; Kemme SA; Carter TR; Samora S

2010-10-01

272

Demonstration of polarization-independent resonant subwavelength grating filter arrays.  

Science.gov (United States)

We demonstrate a two-dimensional (2D) polarization-independent resonant subwavelength grating (RSG) in a filter array. RSGs, also called guided mode resonant filters, are traditionally one-dimensional gratings; however, this leads to TE and TM resonances at different wavelengths and with different spectral shape. A 2D grating can remove the polarization dependence at normal incidence, while maintaining the desirable RSG properties of high reflectivity, narrow passband, and low sidebands without ripple. We designed and fabricated 2D gratings with near-identical responses for both polarizations at normal incidence in the telecommunication band. Ninety percent reflectivity is achieved at the resonant wavelengths. PMID:20890333

Peters, D W; Boye, R R; Wendt, J R; Kellogg, R A; Kemme, S A; Carter, T R; Samora, S

2010-10-01

273

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.

1997-01-01

274

Direct analysis of air filter samples for alpha emitting isotopes  

Energy Technology Data Exchange (ETDEWEB)

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.

Mohagheghi, A.H.; Ghanbari, F.; Ebara, S.B.; Enghauser, M.E. [Sandia National Labs., Albuquerque, NM (United States); Bakhtiar, S.N. [Westinghouse WIPP, Carlsbad, NM (United States)

1997-04-01

275

Theory and Applications of Kalman Filtering.  

Science.gov (United States)

Contents: Linear estimation theory; Further comments on the derivation of Kalman filters; Computational techniques in Kalman filtering; Modeling errors in Kalman filters; Suboptimal Kalman filter techniques; Comparison of Kalman, Bayesian and maximum like...

C. T. Leondes

1970-01-01

276

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.

1992-12-04

277

Tensor Product Basis Approximations for Volterra Filters.  

Science.gov (United States)

This paper studies approximations for a class of nonlinear filters known as Volterra filters. Although the Volterra filter provides a relatively simple and general representation for nonlinear filtering, it is often highly overparameterized. Due to the la...

R. D. Nowak B. D. VanVeen

1996-01-01

278

Condensate filtering device  

Energy Technology Data Exchange (ETDEWEB)

In a condensate filtering device of a nuclear power plant, a water collecting pipe is disposed over the entire length, an end of a hollow thread is in communication with the water collecting pipe and secured. If the length of the water collecting pipe is extended, a filtering device of an optional length can be obtained irrespective of the length of the hollow thread. Therefore, since there is no need to connect units upon constituting a module, flow of cleaning gases is not restricted at connection portions. Accordingly, even if the volume of the device is increased by the extension of the module, the working life of the module is not degraded. (T.M.)

Takii, Taichi; Suzuki, Hiroaki; Murase, Michio

1997-04-22

279

Metamaterial Tunable Filter Design  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a new concept to implement a tunable filter metamaterial with dual negative refraction composed of ferrite slabs and metallic resonators, including split-ring resonators (SRR), and short wire pairs. The ferrite slabs under an applied magnetics bias provide one magnetic resonance frequency band and the metallic resonators provide another one. The continuous wires within the metamaterials provide the negative permittivity in a wide frequency band covering the two magnetic resonance bands. This type of metamaterialis analyzed in detail, and tunable stop band filters are successfully designed. The effective electromagnetic parameters obtained from the simulation of the S-parameters indicate that metamaterial exhibit negative refraction bands, which can be shifted by changing the magnetic bias.

Naima Benmostefa; M. Meliani; H. Ouslimani

2013-01-01

280

Stochastic stacking without filters  

Energy Technology Data Exchange (ETDEWEB)

The rate of accumulation of antiprotons is a critical factor in the design of p anti p colliders. A design of a system to accumulate higher anti p fluxes is presented here which is an alternative to the schemes used at the CERN AA and in the Fermilab Tevatron I design. Contrary to these stacking schemes, which use a system of notch filters to protect the dense core of antiprotons from the high power of the stack tail stochastic cooling, an eddy current shutter is used to protect the core in the region of the stack tail cooling kicker. Without filters one can have larger cooling bandwidths, better mixing for stochastic cooling, and easier operational criteria for the power amplifiers. In the case considered here a flux of 1.4 x 10/sup 8/ per sec is achieved with a 4 to 8 GHz bandwidth.

Johnson, R.P.; Marriner, J.

1982-12-01

 
 
 
 
281

Widely Linear Kalman Filtering  

CERN Document Server

For a zero mean, proper, complex random vector x, the Hermitian covariance ExxH is a complete second-order characterization. However, if the vector x is improper, it is correlated with its complex conjugate, meaning ExxT = 0. This improper or complementary covariance must be accounted for in a complete second-order characterization. The improper covariance has been exploited for widely linear (WL) Wiener filters and WL minimum mean squared error (MMSE) estimators, and the improvement in performance of the WLMMSE estimator over the LMMSE estimator has been quantified. In this paper we consider the design of the widely linear Kalman filter (WLKF). We analyze the WLKF, extended WLKF, and unscented WLKF. The key idea of this paper is to modify the error covariance matrices and the construction of effective sigma points in the WLKF in a systematic way that exploits the Hermitian and complementary covariance of improper states and noises.

Dang, Wenbing

2011-01-01

282

Privacy Preserving Spam Filtering  

CERN Multimedia

We present an approach to training a binary logistic regression classifier in the setting where the training data needs to be kept private. We provide a theoretical analysis of the security of this procedure and experimental results for the problem of large scale spam detection. High performance spam filters often use character n-grams as features which result in large sparse vectors to which applying our protocol directly is not feasible. We explore various dimensionality reduction and parallelization approaches and provide a detailed analysis of the speed and accuracy trade-off. Our results show that we can achieve the accuracy of state of the art spam filters at comparable training and testing time of non-private version of logistic regression.

Pathak, Manas A; Raj, Bhiksha

2011-01-01

283

Regenerable particulate filter  

Energy Technology Data Exchange (ETDEWEB)

A method of making a three-dimensional lattice structure, such as a filter used to remove particulates from a gas stream, where the physical lattice structure is designed utilizing software simulation from pre-defined mass transfer and flow characteristics and the designed lattice structure is fabricated using a free-form fabrication manufacturing technique, where the periodic lattice structure is comprised of individual geometric elements.

Stuecker, John N. (Albuquerque, NM); Cesarano, III, Joseph (Albuquerque, NM); Miller, James E. (Albuquerque, NM)

2009-05-05

284

Toxin elimination and clot absorbing traditional Chinese medicine and preparation method thereof  

UK PubMed Central (United Kingdom)

The invention discloses a traditional Chinese medicine used for expelling toxin and removing blood stasis and a preparation method thereof, and the traditional Chinese medicine can be made into traditional Chinese medicine pulvis and traditional Chinese medicine pill which are used for expelling toxin and removing blood stasis the formula of the traditional Chinese medicine is herba scutellariae barbatae, realgar, dried body of ground beetle, frankincense, myrrh, ginseng, radix astragali, rhizoma pleionis, oldenlandia diffusa, pangolin, common burreed rhizome, rhizoma zedoariae, peach seed, safflower, Sanchi, tortoise plastron, turtle shell, leech, magnolia officinalis, tulipa gesneriana, radix bupleuri, angelica, scorpion, scolopendra, black-striped snake, varech, radix linderae, rhizoma corydalis, gleditschia xylocarpa hance, rhizoma arisaematis and dandelion. The method for preparing the traditional Chinese medicine pulvis is that the raw materials are filtered and sterilized at high temperature, and then are dried and ground into powder, finally the obtained product is packed. The method for preparing the traditional Chinese medicine pill is that the raw materials are filtered and sterilized at high temperature, then are dried and ground into powder which is made into pills, and granular pills are obtained, polished and packed.

ZHEN WANG

285

Time variant filters. Pt. 1  

International Nuclear Information System (INIS)

The noise analysis for an ideal voltage amplifier with time-variant filters has been performed. The filter studied has an F1-switch-F2 structure. Two types of F1 are considered - an ideal differentiator D and a noise-whitening filter W. The F2 pulse response was varied. It is shown that: (1) in all cases the equivalent noise charge (ENC) is not better than for the optimum time-invariant filter (cusp); (2) in the case of the W-switch-double integrator the ENC is about 1.6% worse than for the optimum filter. (orig.).

1990-01-01

286

Time variant filters. Pt. 1  

Energy Technology Data Exchange (ETDEWEB)

The noise analysis for an ideal voltage amplifier with time-variant filters has been performed. The filter studied has an F1-switch-F2 structure. Two types of F1 are considered - an ideal differentiator D and a noise-whitening filter W. The F2 pulse response was varied. It is shown that: (1) in all cases the equivalent noise charge (ENC) is not better than for the optimum time-invariant filter (cusp); (2) in the case of the W-switch-double integrator the ENC is about 1.6% worse than for the optimum filter. (orig.).

Fedyakin, N.N.; Krasnokutsky, R.N.; Kurchaninov, L.L.; Shuvalov, R.S.; Tikhonov, V.V. (Institut Fiziki Vysokikh Ehnergij, Serpukhov (USSR))

1990-07-01

287

Kaon Filtering For CLAS Data  

International Nuclear Information System (INIS)

[en] The analysis of data from CLAS is a multi-step process. After the detectors for a given running period have been calibrated, the data is processed in the so called pass-1 cooking. During the pass-1 cooking each event is reconstructed by the program a1c which finds particle tracks and computes momenta from the raw data. The results are then passed on to several data monitoring and filtering utilities. In CLAS software, a filter is a parameterless function which returns an integer indicating whether an event should be kept by that filter or not. There is a main filter program called g1-filter which controls several specific filters and outputs several files, one for each filter. These files may then be analyzed separately, allowing individuals interested in one reaction channel to work from smaller files than using the whole data set would require. There are several constraints on what the filter functions should do. Obviously, the filtered files should be as small as possible, however the filter should also not reject any events that might be used in the later analysis for which the filter was intended

2001-01-01

288

In-service filter testing  

Energy Technology Data Exchange (ETDEWEB)

This report contains the observations, test results, and conclusions of three separate in-service tests beginning in November 1979 and concluding in September 1983. The in-service tests described in this report produced encouraging results on filters constructed with fiberglass medium containing 5% Nomex and separators of aluminum foil coated with a thin film of vinyl-epoxy polymer. Filters containing medium with Kevlar fiber additives demonstrated they merited further evaluation. Other types of filters tested include separatorless filters (Flanders SuperFlow) and one filter with fiberglass separators. Asbestos-containing filters were used for comparison until their supply was exhausted. All filters tested were judged to have performed satisfactorily under the test conditions.

Terada, K.; Woodard, R.W.; Jensen, R.T.

1985-04-29

289

Fuzzy Digital Filtering: Signal Interpretation  

Directory of Open Access Journals (Sweden)

Full Text Available 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, in order to actualize the best correct new conditions updating a process dynamically. The interpretation of the input signal level describes the operation of the reference model, to update the filter weights giving the answers approximation in accordance with the reference signal in natural form. Finally the paper shows the simulations results of the fuzzy filter into the Kalman structure using the Matlab© tool.

Juan C. García Infante; J. Jesús Medel Juárez; Juan C. Sánchez García

2011-01-01

290

Modernism and tradition and the traditions of modernism  

Directory of Open Access Journals (Sweden)

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.

Kros Džonatan

2006-01-01

291

Fantastic filters of lattice implication algebras  

Directory of Open Access Journals (Sweden)

Full Text Available The notion of a fantastic filter in a lattice implication algebra is introduced, and the relations among filter, positive implicative filter, and fantastic filter are given. We investigate an equivalent condition for a filter to be fantastic, and state an extension property for fantastic filter.

Young Bae Jun

2000-01-01

292

OPTIMIZATION OF ADVANCED FILTER SYSTEMS  

Energy Technology Data Exchange (ETDEWEB)

Reliable, maintainable and cost effective hot gas particulate filter technology is critical to the successful commercialization of advanced, coal-fired power generation technologies, such as IGCC and PFBC. In pilot plant testing, the operating reliability of hot gas particulate filters have been periodically compromised by process issues, such as process upsets and difficult ash cake behavior (ash bridging and sintering), and by design issues, such as cantilevered filter elements damaged by ash bridging, or excessively close packing of filtering surfaces resulting in unacceptable pressure drop or filtering surface plugging. This test experience has focused the issues and has helped to define advanced hot gas filter design concepts that offer higher reliability. Westinghouse has identified two advanced ceramic barrier filter concepts that are configured to minimize the possibility of ash bridge formation and to be robust against ash bridges should they occur. The ''inverted candle filter system'' uses arrays of thin-walled, ceramic candle-type filter elements with inside-surface filtering, and contains the filter elements in metal enclosures for complete separation from ash bridges. The ''sheet filter system'' uses ceramic, flat plate filter elements supported from vertical pipe-header arrays that provide geometry that avoids the buildup of ash bridges and allows free fall of the back-pulse released filter cake. The Optimization of Advanced Filter Systems program is being conducted to evaluate these two advanced designs and to ultimately demonstrate one of the concepts in pilot scale. In the Base Contract program, the subject of this report, Westinghouse has developed conceptual designs of the two advanced ceramic barrier filter systems to assess their performance, availability and cost potential, and to identify technical issues that may hinder the commercialization of the technologies. A plan for the Option I, bench-scale test program has also been developed based on the issues identified. The two advanced barrier filter systems have been found to have the potential to be significantly more reliable and less expensive to operate than standard ceramic candle filter system designs. Their key development requirements are the assessment of the design and manufacturing feasibility of the ceramic filter elements, and the small-scale demonstration of their conceptual reliability and availability merits.

R.A. Newby; G.J. Bruck; M.A. Alvin; T.E. Lippert

1998-04-30

293

Adapting agriculture with traditional knowledge  

Energy Technology Data Exchange (ETDEWEB)

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.

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

294

[Traditional Chinese medicine in urology.  

Science.gov (United States)

Traditional Chinese medicine (TCM) is an ancient holistic medicine based on the doctrine of Tao and Qi. Tao represents an alteration from which the polarity of Yin and Yang arises and Qi is the vitality which circulates through the body. Therapeutic concepts of TCM include acupuncture, herbal therapy, nutrition and Tuina, a form of manual therapy. TCM is now gaining increased acceptance in the Western society as a complementary therapy. Acupuncture and herbal therapy are the main forms of implementation of TCM in urology. PMID:23754610

Hüsch, T; Tsaur, I; Reiter, M; Mager, R; Haferkamp, A

2013-06-12

295

Latin American traditions and perspectives  

Science.gov (United States)

Educational and related non-pedagogical issues are generally described and discussed. Implicitly or explicitly, the theology of liberation, educación popular and traditional education tend to perpetuate male/female roles and very often incite violence. Peace education in Latin America should concentrate more on the pathology of the violent man. The so-called `weaknesses' associated with women and their `powerlessness' in Western civilization are precisely those which are absolutely essential to our survival. It is important for women to reject Western patterns of violence and participate actively in finding a viable alternative.

Garcia, Celina

1983-09-01

296

Christian Belief and Religious Traditions  

Directory of Open Access Journals (Sweden)

Full Text Available This section of the Osica de Sus commune monograph - Puterea r?d?cinilor - The Roots Power, authors: Constantin Ro?ca - university profesor (coordinator), Ion Sîrbu - preuniversitary teacher, and Ion Paul Popescu - sociologist et al., Craiova, Editura Universitaria, 2009, emphasizes the main elements which characterize Christian belief, religious spirit and the religious feelings of the people in the commune. It underlines the religious traditions, the Christian customs and festivities and presents the worship places (churches and distinct religious communities, such as the Adventist community) in the commune.

CONSTANTIN RO?CA

2010-01-01

297

RESEARCH ON SPATIAL FILTERS AND HOMOMORPHIC FILTERING METHODS  

Directory of Open Access Journals (Sweden)

Full Text Available In image processing, denoising is one of the important tasks. Despite the significant research conducted on this topic, the development of efficient denoising methods is still a compelling challenge. In this paper, comparison of Spatial Filters methods with the Homomorphic Filters Methods. The spatial filter methods like Median Filter and Wiener Filter are based on the simple formulas that are proposed by different authors. In Homomorphic Filters Method NormalShrink and BayesShrink are used. The basic idea of homomorphic methods is to denoise the image by applying wavelet transform to the noisy image, then thresholding the detailed wavelet coefficient and inverse transforming the set of thresholded coefficient to obtain the denoised image. In this soft thresholding technique is applied.

Kanwaljeet Kaur; Gurjant Singh; Abhinash Singla

2012-01-01

298

Traditional and Modern Morphometrics: Review  

Directory of Open Access Journals (Sweden)

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.

Gökhan OCAKO?LU; ?lker ERCAN

2013-01-01

299

Radiopasteurization of traditional herbal medicine  

Energy Technology Data Exchange (ETDEWEB)

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 10/sup 4/ and 10/sup 8/ per gram, and mould and yeast counts varied between 0 and 10/sup 5/ 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 10/sup 3/ 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.

Hilmy, N.; Suryasaputra, C. (National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre)

1981-04-01

300

TRADITIONAL FERMENTED FOODS OF LESOTHO  

Directory of Open Access Journals (Sweden)

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.

Tendekayi H. Gadaga; Molupe Lehohla; Victor Ntuli

2013-01-01

 
 
 
 
301

Liquid filter for liquids containing radioactive materials  

International Nuclear Information System (INIS)

A filter insert consisting of several filter plates is suspended in a filter case. The radioactive liquid containing solids flows into the filter case from above and is distributed from its centre via a central duct into intermediate spaces between the filter plates. A filter cake is formed on the filters. The filtrate flows through the centre of the filter and is taken radially outwards. The filtrate is collected in a lower collector space. The filter insert can be removed from the filter case by remote operation when it is used up. (DG)

1985-05-24

302

A cloud filtering method for microwave upper tropospheric humidity measurements  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a cloud filtering method for upper tropospheric humidity (UTH) measurements at 183.31±1.00 GHz. The method uses two criteria: The difference between the brightness temperatures at 183.31±7.00 and 183.31±1.00 GHz, and a threshold for the brightness temperature at 183.31±1.00 GHz. The robustness of this cloud filter is demonstrated by a mid-latitudes winter case-study. The paper then studies different biases on UTH climatologies. Clouds are associated with high humidity, therefore the dry bias introduced by cloud filtering is discussed and compared to the wet biases introduced by the clouds radiative effect if no filtering is done. This is done by means of a case study, and by means of a stochastic cloud database with representative statistics for midlatitude conditions. The consistent result is that both cloud wet bias (0.8% RH) and cloud filtering dry bias (–2.4% RH) are modest for microwave data, where the numbers given are for the stochastic cloud dataset. This indicates that for microwave data cloud-filtered UTH and unfiltered UTH can be taken as error bounds for errors due to clouds. This is not possible for the more traditional infrared data, since the radiative effect of clouds is much stronger there. The focus of the paper is on midlatitude data, since atmospheric data to test the filter for that case were readily available. The filter is expected to be applicable also to subtropical and tropical data, but should be further validated with case studies similar to the one presented here for those cases.

S. A. Buehler; M. Kuvatov; T. R. Sreerekha; V. O. John; B. Rydberg; P. Eriksson; J. Notholt

2007-01-01

303

Filter and Filter Bank Design for Image Texture Recognition  

Energy Technology Data Exchange (ETDEWEB)

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.

Randen, Trygve

1997-12-31

304

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

1988-01-01

305

Applied Filtered Density Function  

Directory of Open Access Journals (Sweden)

Full Text Available An overview is presented of recent advances in the filtered density function (FDF) modeling and simulation of turbulent combustion. The review is focused on the developments that have facilitated the FDF to be broadly applied in large eddy simulation (LES) of practical flows. These are primarily the development of a new Lagrangian Monte Carlo solver for the FDF, and the implementation of this solver on Eulerian domains portrayed by unstructured grids. With these developments, it is now much easier to apply FDF for predictions of reacting flows in complex geometrical configurations.

S.Levent Yilmaz; N. Ansari; P.H Pisciuneri; M.B. Nik; C.C. Otis; P. Givi

2013-01-01

306

Filtered Kernel Density Estimation  

UK PubMed Central (United Kingdom)

this paper for the construction ofthe filtering functions for two reasons: we have some experience in finite mixtureestimation, and it is a convenient arena in which to do some comparisons with thestandard kernel estimator. There are a number of methods for choosing the numberof components to be used, either subjectively or using automated methods such asin Priebe 1994, Solka et al 1995 or Rogers et al 1995. In this paper, we will eitherassume knowledge of the true mixture (for comparison with the standard kernelestimator) or use subjective methods

David J. Marchette; Carey E. Priebe; George W. Rogers; Jeffrey L. Solka

307

Filtered Kernel Density Estimation  

UK PubMed Central (United Kingdom)

this paper for the construction ofthe filtering functions for two reasons: we have some experience in finite mixtureestimation, and it is a convenient arena in which to do some comparisons with thestandard kernel estimator. There are a number of methods for choosing the numberof components to be used, either subjectively or using automated methods such asin Priebe 1994, Solka et al 1995 or Rogers et al 1995. In this paper, we will eitherassume knowledge of the true mixture (for comparison with the standard kernelestimator) or use subjective methods.

David J. Marchette; Carey E. Priebe; George W. Rogers; Jeffrey L. Solka

308

Comparison of several Kalman filter models for establishing MUF  

International Nuclear Information System (INIS)

Detection of MUF in a material balance area is a problem in nuclear material control. It has been shown that the Kalman filter can detect a MUF in situations which could not be detected by the traditional control chart approach using LEMUF. The Kalman filter is extended in this paper to cover two additional scenarios: (1) the case where a random quantity with a mean of M(t) is removed per period, and (2) the case where MUF is a fraction of the on-hand inventory each period. The Kalman filter is robust, sensitive, produces estimates of the error covariance matrix, and is an iterative technique which is suited for on-line-direct-input information systems

1976-06-13

309

Kalman Filter Based Tracking in an Video Surveillance System  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we have developed a Matlab/Simulink based model for monitoring a contact in a video surveillance sequence. For the segmentation process and corect identification of a contact in a surveillance video, we have used the Horn-Schunk optical flow algorithm. The position and the behavior of the correctly detected contact were monitored with the help of the traditional Kalman filter. After that we have compared the results obtained from the optical flow method with the ones obtained from the Kalman filter, and we show the correct functionality of the Kalman filter based tracking. The tests were performed using video data taken with the help of a fix camera. The tested algorithm has shown promising results.

SULIMAN, C.; CRUCERU, C.; MOLDOVEANU, F.

2010-01-01

310

Market Risk Beta Estimation using Adaptive Kalman Filter  

Directory of Open Access Journals (Sweden)

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.

Atanu Das,; Tapan Kumar Ghoshal

2010-01-01

311

DCT based interpolation filter for motion compensation in HEVC  

Science.gov (United States)

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%.

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

2012-10-01

312

Impregnation of filters for sampling of atmospheric gases. The vacuum drying technique  

Energy Technology Data Exchange (ETDEWEB)

Impregnation of filters for sampling of atmospheric gases has traditionally been done by addition of the dissolved absorbing media through either dipping the filter into the absorbing solution or pouring it over the filter. To minimize blank values, to obtain a good reproducibility of the capacity of the impregnated filters, and to ensure a uniform distribution of the absorbing media on the filter, a new impregnation technique is suggested. The technique involves minimum manual handling and exposes the filters to a minimum of laboratory air. The technique is based on the principles of vacuum drying. It is applicable to any absorbing media solvable in a volative solvent. Filters are impregnated by addition of a quantitative amount of a solution of the absorbing media to each filter by a micropipette. The filters are placed on shelves inside a vacuum-tight chamber and the vacuum chamber is connected to a freeze trap. Air is removed from the chamber by a vacuum pump so the pressure in the chamber is about 1 mm Hg. The drying time of the described equipment will be 30 min. for the impregnation of 48 Whatman 41 filters of 50 mm dia., each added 350 myl of impregnation solution. No heating of the vacuum chamber is necessary to compensate the heat loss due to evaporation. (EG).

Fuglsang, K.

1986-02-01

313

Vessel filtering of photoacoustic images  

Science.gov (United States)

This paper investigates the application of the vessel filter proposed by Frangi et al., [MICCAI, LNCS vol. 1496, pp. 130-137, 1998] to photoacoustic images of the vasculature. The filter works by classifying the eigenvalue decomposition of the local Hessian matrix at each image voxel to find tubular structures in the image. A detailed analysis of the algorithm is provided, and the effect of the filters on photoacoustic images is studied using numerical and experimental phantoms. In particular, the impact of the filter on image resolution, feature preservation, and noise is discussed. The vessel filter is then applied to photoacoustic images of the vasculature in mice. The classical Hessian filter is shown to be highly effective at removing noise and highlighting vessels, at the expense of reducing the sharpness of vessel edges.

Oruganti, Tanmayi; Laufer, Jan G.; Treeby, Bradley E.

2013-03-01

314

Improvement of filtering properties of dust filters. Dust filter roka seino no kojo  

Energy Technology Data Exchange (ETDEWEB)

The preventive measures of dust filter blinding with diatomaceous earth were reported of the waste water treatment facility for a desulfurizer in a power plant. After dust concentration in exhaust gas at the inlet of a dust collecting column, dust particle size in waste water, and unburnt carbon concentration in waste water were checked, a dust coagulant, filter cloth and filtering assistant were selected to be examined. As the results of laboratory tests and model apparatus tests, the improvement of the dust coagulant and filter cloth were ineffective in preventing the blinding, however, diatomaceous earth used for the filtering assistant was considerably effective in preventing the binding because of bridges formed on a filter cloth surface, and in reducing the filtering resistance of dust cake. As the results of trial operation tests, the filtering cycle of 120 times or more was attained, and the cost reduction was estimated to reach 77%, because of the reduction of filter cloth and filtering assistant costs. 23 figs., 9 tabs.

Betsumori, K. (The Hokuriku Electric Power Co. Ltd., Toyama (Japan))

1989-12-25

315

Hydrated lime tobacco smoke filter  

UK PubMed Central (United Kingdom)

A multi-sectioned filter section for reducing the content of toxic constituents contained in a stream of tobacco smoke. The multi-sectioned filter section is composed of at least one non-fibrous section and at least one fibrous plug section. The multi-sectioned filter section is adaptable for use in tobacco products such as cigarettes, cigars, cigarillos and smoking articles such as tobacco pipes and cigarette and cigar holders.

WRIGHT MILTON F

316

[Erythrocyte filterability of angina patients].  

Science.gov (United States)

Erythrocyte filterability and its relation to erythrocyte volume, hemoglobin level and cholesterol/phospholipid ratio were studied in anginal patients. A 25% decrease in filterability and elevated erythrocyte cholesterol/phospholipid ratios were found in anginal patients, as compared to normal subjects. A close inverse correlation (r = -0.623) was demonstrated between erythrocyte filterability and cholesterol/phospholipid ratio. Mean erythrocyte volume and Hb levels were similar in anginal patients to those of normal subjects. PMID:3586485

Razumov, V B; Redchits, E G; Vinogradova, I V; Deev, A I; Khrennikov, V P

1987-03-01

317

Mode filters and energy conservation.  

UK PubMed Central (United Kingdom)

The discrete form of the mode filtering problem is considered. The relevant equations constitute a linear inverse problem. Solutions to problems of this type are subject to a well-known trade-off between resolution and precision. But unlike the typical linear inverse problem, the correctly formulated mode filtering problem is subject to an energy conservation constraint. This letter focuses on the importance of satisfying, approximately at least, the energy conservation constraint when mode filtering is performed.

Udovydchenkov IA; Rypina II; Brown MG

2010-05-01

318

Mode filters and energy conservation.  

Science.gov (United States)

The discrete form of the mode filtering problem is considered. The relevant equations constitute a linear inverse problem. Solutions to problems of this type are subject to a well-known trade-off between resolution and precision. But unlike the typical linear inverse problem, the correctly formulated mode filtering problem is subject to an energy conservation constraint. This letter focuses on the importance of satisfying, approximately at least, the energy conservation constraint when mode filtering is performed. PMID:21117712

Udovydchenkov, Ilya A; Rypina, Irina I; Brown, Michael G

2010-05-01

319

HEPA filter performance comparative study  

International Nuclear Information System (INIS)

[en] Current products such as HEPA filters made without separators, with tapered separators and with mini separators have raised many questions for the Nuclear Ventilation System Design Engineer and/or the end user. The principal objective of this investigation is to report HEPA filter performance data and to compare the effectiveness of the various type HEPA filters for use in Nuclear Ventilation Systems with all tests run on the same equipment and under the same controlled conditions

1976-08-04

320

The Promise of Traditional Medicines  

Directory of Open Access Journals (Sweden)

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.

J.A. Ansari; N.N. Inamdar

2010-01-01

 
 
 
 
321

Traditional Procurement is too Slow  

Directory of Open Access Journals (Sweden)

Full Text Available This paper reports on an exploratory interview survey of construction project participants aimed at identifying the reasons for the decrease in use of the traditional, lump-sum, procurement system in Malaysia. The results show that most people believe it is too slow. This appears to be in part due to the contiguous nature of the various phase and stages of the process and especially the separation of the design and construction phases. The delays caused by disputes between the various parties are also seen as a contributory factor - the most prominent cause being the frequency of variations, with design and scope changes being a particular source of discontent. It is concluded that an up scaling of the whole of the time related reward/penalty system may be the most appropriate measure for the practice in future.

Ann Kong; Jason Gray

2012-01-01

322

Adaptive filtering and change detection  

CERN Multimedia

Adaptive filtering is a branch of digital signal processing which enables the selective enhancement of desired elements of a signal and the reduction of undesired elements. Change detection is another kind of adaptive filtering for non-stationary signals, and is the basic tool in fault detection and diagnosis.This text takes the unique approach that change detection is a natural extension of adaptive filtering, and the broad coverage encompasses both the mathematical tools needed for adaptive filtering and change detection and the applications of the technology. Real engineering applicatio

Gustafsson, Fredrik

2003-01-01

323

Specific filter designs for PFBC  

Energy Technology Data Exchange (ETDEWEB)

Pressurized Fluidized Bed Combustion (PFBC) technologies (bubbling bed, circulating bed, second generation) are currently being developed and demonstrated for commercial scale application. Hot gas particulate filters are key components for the successful application of PFBC in power generation gas turbine cycles. The objective of this work is to develop practical hot gas filter designs that meet the performance and operational requirements of PFBC. The design basis for the filter is verified by operating filter test units in subpilot and pilot scale facilities. Key features of the commercial design are incorporated into the test modules.

Bruck, G.J.; Newby, R.A.; Smeltzer, E.E. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

1993-06-01

324

Filter media for dust collectors  

Energy Technology Data Exchange (ETDEWEB)

Fabric filters have increased their market share considerably due to a number of important factors which are described in the paper. Low ratio and high ratio filters and their application in the cement industry are described. The relevant qualities of filter media for the different types of dust collectors are recommended. Special consideration is given to fabric selection and fabric treatment in the Cement Industry with respect to the prevailing physical and chemical attacks. New experience with bag filters after coal grinding and coal drying plants is provided.

Dietrich, H.

1981-10-01

325

Cryptographically Secure Bloom-Filters  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we propose a privacy-preserving variant of Bloom-filters. The Bloom-filter has many applications such as hash-based IP-traceback systems and Web cache sharing. In some of those applications, equipping the Bloom-filter with the privacy-preserving mechanism is crucial for the deployment. In this paper, we propose a cryptographically secure privacy-preserving Bloom-filter protocol. We propose such two protocols based on blind signatures and oblivious pseudorandom functions, respectively. To show that the proposed protocols are secure, we provide a reasonable security definition and prove the security.

Ryo Nojima; Youki Kadobayashi

2009-01-01

326

WIRELESS ACOUSTIC OIL FILTER SENSOR  

UK PubMed Central (United Kingdom)

A wireless oil filter sensing system includes an oil filter and a sensing mechanismthat is connectable to the oil filter. The sensing mechanism includes one or moreacoustic wave sensing elements and at least one antenna that communicate withthe acoustic wave sensing element(s). An external interrogation system couldexcite the acoustic wave sensing element(s) wireless and passively. When theacoustic wave sensing elements are in contact with oil contained in the oil filter,the acoustic wave sensing elements detect acoustic waves associated with theoil in response to an excitation of the acoustic wave sensing elements, therebygenerating data indicative of the quality of the oil for wireless transmissionthrough the antenna(s).

LIU James ZT; RAHMAN Azia; RHODES Michael L.

327

Specific filter designs for PFBC  

Energy Technology Data Exchange (ETDEWEB)

Bubbling bed PFBC technology is currently being demonstrated at commercial scale. Economic and performance improvements in these first generation type PFBC plants can be realized with the application of hot gas particulate filters. Both the secondary cyclone(s) and stack gas ESP(s) could be eliminated saving costs and providing lower system pressure losses. The cleaner gas (basically ash free) provided with the hot gas filter, also permits a wider selection of gas turbines with potentially higher performance. For these bubbling bed PFBC applications, the hot gas filter must operate at temperatures of 1580{degree}F and system pressures of 175 psia (conditions typical of the Tidd PFBC plant). Inlet dust loadings to the filter are estimated to be about 500 to 1000 ppm with mass mean particle diameters ranging from 1.5 to 3 {mu}m. For commercial applications typical of the 70 MW{sub e} Tidd PFBC demonstration unit, the filter must treat up to 56,600 acfm of gas flow. Scaleup of this design to about 320 MW{sub e} would require filtering over 160,000 acfm gas flow. For these commercial scale systems, multiple filter vessels are required. Thus, the filter design should be modular for scaling. An alternative to the bubbling bed PFBC is the circulating bed concept. In this process the hot gas filter will in general be exposed to higher operating temperatures (1650{degree}F) and significantly higher (factor of 10 or more) particle loading.

Lippert, T.E.; Bruck, G.J.; Newby, R.A.; Smeltzer, E.E.

1993-09-01

328

Traditional Chinese medicine for treating hernia for children  

UK PubMed Central (United Kingdom)

The invention relates to a traditional Chinese medicine for treating hernia for children, which is prepared by the following main components: 6g of radix bupleuri, 15g of white peony root, 12g of immature bitter orange, 10g of cordate houttuynia, 5g of pinellia tuberifera, 6g of liquorice, 12g of radix astragali, 6g of fructus schisandrae, 12g of lychee seed, 10g of radix scutellariae, 15g of hemerocallis root, 15g of clematis recta and other Chinese medical herbs. The traditional Chinese medicine for treating hernia for children is prepared according to the following steps: all the Chinese medical herbs are put in a container to be steeped for 30 min the steeped Chinese medical herbs are decocted on slow fire for 30 min, and dregs of a decoction are filtered to obtain the decoction of 100 ml. One dose of the decoction is taken after the supper every day for three days in one course of treatment. The preparation is prepared by the Chinese medical herbs with a traditional method, thereby preserving the medicine property of tonifying middle-Jiao and Qi, sending down abnormally ascended Qi, achieving the purpose of protecting health and treating hernia in children and having no side effect.

YANGFA PENG

329

Bridging the ensemble Kalman filter and particle filters  

Energy Technology Data Exchange (ETDEWEB)

The nonlinear filtering problem occurs in many scientific areas. Sequential Monte Carlo solutions with the correct asymptotic behavior such as particle filters exist but they are computationally too expensive when working with high-dimensional systems. The ensemble Kalman filter is a more robust method that has shown promising results with a small sample size but the samples are not guaranteed to come from the true posterior distribution. By approximating the model error with Gaussian kernels we get the advantage of both a Kalman correction and a weighting step. The resulting Gaussian mixture filter has the advantage of both a local Kalman type correction and the weighting/re sampling step of a particle filter. The Gaussian mixture approximation relies on a tunable bandwidth parameter which often has to be kept quite large in order to avoid weight collapse in high dimensions. As a result, the Kalman correction is too large to capture highly non-Gaussian posterior distributions. In this paper we have extended the Gaussian mixture filter (Hoteit et al., 2008b) and also made the connection to particle filters more transparent. In particular we introduce a tuning parameter for the importance weights. In the last part of the paper we have performed a simulation experiment with the Lorenz40 model where our method has been compared to the EnKF and a full implementation of a particle filter. The results clearly indicate that the new method has advantages compared to the standard EnKF. (Author)

Stordal, Andreas Stoerksen; Karlsen, Hans A.; Naevdal, Geir; Skaug, Hans J.; Valles, Brice

2009-12-15

330

Glove-box filters  

International Nuclear Information System (INIS)

[en] Description is given of a device for simply and rapidly assembling and dissassembling the filters used inside sealed enclosures, such as glove-boxes and shielded cells equipped with nippers or manipulators, said filters being of the type comprising a cylindrical casing containing a filtering member, the upper portion of said casing being open so as to allow the gases to be cleaned to flow in, whereas the casing bottom is centrally provided with a hole extended outwardly by a threaded collar on which is screwed a connecting-sleeve to be fixed to the mouth of a gas outlet pipe. To a yoke transverse bar is welded a pin which can be likened to a bent spring-blade, one arm of which welded to said transverse bar, is rectilinear whereas its other arm is provided with a boss cooperating with a cavity made in a protrusion of said pipe, right under the mouth thereof[fr] On decrit un dispositif permettant le montage et le demontage simples et rapides des filtres que l'on utilise a l'interieur d'enceintes etanches, telles que les boites a gants et les cellules blindees equipees de pinces ou de telemanipulateurs filtres du type constitue d'un boitier cylindrique contenant un organe filtrant, boitier dont le sommet est ouvert pour assurer l'entree des gaz a epurer, alors que le fond represente centralement un trou prolonge exterieurement au boitier par un collier filete exterieurement autour duquel est visse un manchon de raccordement que l'on fixe sur l'embouchure d'une canalisation de sortie de gaz. Sur la barre transversale de l'etrier, est soudee une epingle que l'on peut assimiler a une lame de ressort repliee en deux branches dont l'une, qui est soudee sur la barre transversale, est rectiligne alors que l'autre presente une bosse qui coopere avec une cavite d'une saillie prevue sur la canalisation a l'aplomb de l'embouchure

1974-01-01

331

Large array VLSI filter  

Energy Technology Data Exchange (ETDEWEB)

A 35-by-35-element pipelined convolutional kernel is being fabricated using VLSI chips, each containing a 5-by-1 segment of the kernel. Three levels of printed circuitry are used: the first is used for the VLSI chips; the second connects seven chips on one platform; and the third connects seven platforms with associated delay lines fitting on one board. Therefore, on each board there are seven rows of the kernel containing 245 multipliers and adders, and five such boards complete the kernel array. Each multiplier accepts an 8-bit picture element which is multiplied by a 16-bit weight. A truncated 22-bit product is added to a previously stored product sum and the results are shifted to the following multiplier as the next picture element is read. The multiplier uses a modified booth algorithm to reduce the number of shift add operations nearly in half. The filter box can be connected to any CPU. 3 references.

Nathan, R.

1983-10-01

332

Magnetic oil filter  

Energy Technology Data Exchange (ETDEWEB)

A filter is described for removing particulate matter from lubricating oil, comprising: an outer container, the container having a top plate member having at least one oil inlet aperture passing therethrough, and a bottom plate member having at least one oil outlet aperture passing therethrough; an inner container having an inner top plate member having at least one oil inlet aperture passing therethrough, and an inner bottom plate member having at least one oil outlet aperture passing therethrough; a highly magnetized magnetic plate means having apertures passing therethrough; the inner top plate member further having flexible sealing means for contacting an inner surface of the outer container; the inner container further comprising inner side walls having an upper portion and a lower portion thereof; an upper chamber being defined by the inner top plate member having the oil inlet aperture passing therethrough; and a lower chamber being defined by the highly magnetized magnetic plate means.

Shoemaker, F.N.

1986-09-23

333

Profile - A Proactive Information Filter  

UK PubMed Central (United Kingdom)

Contents1 Introduction 32 Project structure 43 The information filtering process 43.1 User modeling: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :53.1.1 Profiles : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 53.1.2 Collaborative filtering: : : : : : : : : : : : : : : : : : : : : : : : : : : : :63.1.3 Learning : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 63.2 Parsing: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :63.2.1 Linguistic variation : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 63.2.2 Nounphrases: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :73.3 Retrieval: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :73.4 Interaction and rendering : : :

E. Hoenkamp; L. Schomaker; P. Van Bommel; C. H. A. Koster; Th. P. Van Der Weide

334

Solid colloidal optical wavelength filter  

Energy Technology Data Exchange (ETDEWEB)

A solid colloidal optical wavelength filter includes a suspension of spheal particles dispersed in a coagulable medium such as a setting plastic. The filter is formed by suspending spherical particles in a coagulable medium; agitating the particles and coagulable medium to produce an emulsion of particles suspended in the coagulable medium; and allowing the coagulable medium and suspended emulsion of particles to cool.

Alvarez, Joseph L. (Boulder, CO)

1992-01-01

335

Chopped filter for nuclear spectroscopy  

International Nuclear Information System (INIS)

Some of the theoretical and practical factors affecting the energy resolution of a spectrometry system are considered, specially those related to t he signal-to-noise ratio, and a time-variant filter with the transfer function of the theoretical optimum filter, during its active time, is proposed. A prototype has been tested and experimental results are presented. (Author).

1980-01-01

336

GPU Accelerated Vector Median Filter.  

Science.gov (United States)

Noise reduction is an important step for most image processing tasks. For three channel color images, a widely used technique is vector median filter in which color values of pixels are treated as 3-component vectors. Vector median filters are computation...

R. Aras Y. Shen

2011-01-01

337

Properties of auxiliary filtering materials  

Energy Technology Data Exchange (ETDEWEB)

The authors have studied the physicochemical and filtering properties of the perlites FP-1 and FP-2, kieselguhr, diatomite, asbestos, wood pulp, and the diatomite powders Spidplace and Saperaid. They propose a classification for filtering materials according to their properties when mechanical impurities are being removed from the additives.

Rudenko, L.I.; Sklyar, V.T.

1981-01-01

338

DOE HEPA filter test program.  

Science.gov (United States)

This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a...

1998-01-01

339

USE OF TANNINS IN FILTERS  

UK PubMed Central (United Kingdom)

The present invention relates to the use of a tanning agent in or on filters, in particular natural or synthetic fibrous fabric or foams, for the avoidance of infections, these filters in particular being part of respiratory protection masks or respiratory protection apparatuses.

HUEFFER STEPHAN; REESE OLIVER; SCHERR GUENTER; GARNIER SEBASTIEN

340

BMP FILTERS: UPFLOW VS. DOWNFLOW  

Science.gov (United States)

Filtration methods have been found to be effective in reducing pollutant levels in stormwater. The main drawback of these methods is that the filters get clogged frequently and require periodical maintenance. In stormwater treatment, because of the cost of pumping, the filters ar...

 
 
 
 
341

Human Rights and American Traditions  

Directory of Open Access Journals (Sweden)

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.

Alexandru Boboc-Cojocaru

2013-01-01

342

Application of Archimedes Filter for Reduction of Hanford HLW  

Energy Technology Data Exchange (ETDEWEB)

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 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.

Gilleland, J.; Agnew, S.; Cluggish, B.; Freeman, R.; Miller, R.; Putvinski, S.; Sevier, L.; Umstadter, K.

2002-02-26

343

Precision filters. Seimitsu roka sochi  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the precision filration is to separate suspended particles or colloidal particles which cannot be separated by conventional sedimentation or sand filtration. Recently, filters for super precision filteration which are located between the ultrafiltration and the precision filtration are used to manufacture highly refined pure water for semiconductors, medicines and nuclear services. The superprecision filters are classified to direct type and precoated type and further the former are divided into the solid type and the packed layer type, and the latter into the cylinder type and the leaflike type. New materials like ion exchange fibers, ceramic filter and hollow fiber membrane are used. Future superfine filters may be developed and wudely used, and especially the hollow fiber membrane is thought to be applied extensively compared with the precoated type because the stability after treatment, simple handling and operation, and capacity enlarging can be obtained. 2 refs., 6 figs.

Okugawa, Katsumi (Japan Organo Co., Ltd., Tokyo, (Japan))

1990-03-01

344

Sintered composite medium and filter  

Energy Technology Data Exchange (ETDEWEB)

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.

Bergman, Werner (Pleasanton, CA)

1987-01-01

345

ITP Filter Particulate Decontamination Measurement  

Energy Technology Data Exchange (ETDEWEB)

A new test method was developed which showed the installed In- Tank Precipitation Filter Unit {number_sign}3 provided at least 40, 000 x decontamination of the precipitated potassium tetraphenylborate (KTPB) during the cold chemical runs.This filter is expected to meet the needed 40,000 x hot cesium decontamination requirements, assuming that the cesium precipitate, CsTPB, behaves the same as KTPB. The new method permits cold chemicals field testing of installed filters to quantify particulate decontamination and verify filter integrity before going hot. The method involves a 1000 x concentration of fine particulate KTPB in the filtrate to allow direct analysis by counting for naturally radioactive isotope K-40 using the underground SRTC gamma spectroscopy facility. The particulate concentration was accomplished by ultra filtration at Rhone-Poulenc, NJ, using a small cross-flow bench facility, followed by collection of all suspended solids on a small filter disc for K analysis.

Dworjanyn, L.O. [Westinghouse Savannah River Company, Aiken, SC (United States)

1993-05-21

346

Application of an improved adaptive Kalman filter to transfer alignment of airborne missile INS  

Science.gov (United States)

Transfer alignment is an initialization of the missile INS prior to launch using data provided by master INS or GPS/INS system in aircraft. Generally, Kalman filter is applied to estimate misalignment attitude. Unfortunately, the Kalman filter provides optimal estimates only if the system model is accurate and filter noise is white and accurately obtained. Considering the complicated vibrated air environment, these demands can not be satisfied all the time. Therefore, after establishing a 12-state velocity matching transfer alignment model, an improved adaptive method is derived on the basis of the study on traditional adaptive Kalman filter such as Sage-Husa and intense adaptive filter. The improved adaptive filter is aimed at modifying the model and noise matrix with the process of filtering according to the practical measurement data. Numerical simulations show that with this improved adaptive filter under a "s" turn maneuver, transfer alignment Kalman filter keeps good working condition under large range of P, Q and R, and reaches good performance on estimating precise and convergent speed.

Xie, Chun-ming; Zhao, Yan; Wang, Ji-nan

2008-11-01

347

Comparative Study of Target Function Definition in Linear Phase FIR Filter Design  

Directory of Open Access Journals (Sweden)

Full Text Available The Weighted Least Squares (WLS) principle is popular in filter design due to its flexibility, where it can output equiripple filters with appropriate target function and weighted function. Therefore, this research studies the influence of the target function in linear phase Finite-Impulse-Response (FIR) filter design by comparing different target functions in WLS iterations. Compared with the traditional one, simulations show that the proposed target function can obtain more accurate stopband start frequencies which will be useful if the stopband start frequency must be precise in applications.

Jingyu Hua; Zheng Gao; Wankun Kuang; Zhijiang Xu; Chengfeng Ruan

2012-01-01

348

Shunt Active Filter in Damping Harmonics Propagation  

Directory of Open Access Journals (Sweden)

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.

TEDJINI, H.; MESLEM, Y.; RAHLI, M.; BERBAOUI, B.

2010-01-01

349

A Gaussian mixture ensemble transform filter  

CERN Document Server

We generalize the popular ensemble Kalman filter to an ensemble transform filter where the prior distribution can take the form of a Gaussian mixture. The design of the filter is based on a continuous formulation of the Bayesian filter analysis step. We call the new filter algorithm the ensemble Gaussian mixture filter (EGMF). The EGMF is implemented for two simple test problems (Brownian dynamics in one dimension and a modified Lorenz-96 model).

Reich, Sebastian

2011-01-01

350

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 s...

Öryd, Helena

351

Recent applications of bandpass filtering  

Energy Technology Data Exchange (ETDEWEB)

Bandpass filtering has been applied recently in two widely different seismic applications: S.R. Taylor and A.A. Velasco in their source-path amplitude-correction (SPAC) algorithm and N.K. Yacoub in his maximum spectral energy algorithm for picking teleseismic P-wave arrival times. Though the displacement spectrum is the intermediate product in both cases, the filters and scaling corrections used to estimate it are entirely different. They tested both and found that the scaling used by Taylor and Velasco worked in all cases tested whereas Yacoub's did not. They also found that bandpass filtering as implemented by Taylor and Velasco does not work satisfactorily; however, the Gaussian filter used by Yacoub does work. The bandpass filter of Taylor and Velasco works satisfactorily when the results are centered in the band; however, a comb filter with the same number of poles and zeros as the bandpass used by Taylor and Velasco works better than the bandpass filter.

Denny, M D

1999-03-15

352

Factors Influencing HEPA Filter Performance  

International Nuclear Information System (INIS)

[en] 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 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)

2009-01-01

353

PTFE media for ULPA filter; ULPA filter yo PTFE rozai  

Energy Technology Data Exchange (ETDEWEB)

Outlined herein are polytetrafluoroethylene (PTFE) media for ULPA filters. PTFE is a tetrafluoroethylene resin more stable than any other fluorine resins. Water repellency, resistance to chemicals and purity are important characteristics of PTFE as a medium for ULPA filters. For production of a membrane, a mixture of finely powdered PTFE and a lubricating agent is extruded into a sheet, which is treated to remove the agent into a porous structure. A PTFE medium is completed by compositing the PTFE membrane with a non-woven fabric, to keep the membrane shape intact by protecting it from damages during the filter production process. The ULPA filters with a PTFE membrane fall into two general types; high collection efficiency and low pressure drop types. Their major advantages include high collection efficiency, low pressure drop, small quantities of impurities (boron-free) and high resistance to chemicals. 8 refs., 4 figs., 5 tabs.

Ichiyasu, S. [Japan Gore-Tex Inc., Tokyo (Japan)

1998-09-30

354

Color Filter Array Interpolation for Edge Strength Filters  

Directory of Open Access Journals (Sweden)

Full Text Available Basically we use beam splitters to capture data or image. Using beam splitters is very expensive, so inorder to overcome this we go for an alternative technique called color filters arrays. As a result of this, only one of the required three color samples becomes available at each pixel location and the other two need to be interpolated. This process is called Color Filter Array (CFA) interpolation or demosaicing. Many demosaicing algorithms have been introduced over the years to improve subjective and objective interpolation quality. Wepropose an orientation-free edge strength filter and apply it to the demosaicing problem. Edge strength filter output is utilized both to improve the initial green channel interpolation and to apply the constant color difference rule adaptively. This simple edge directed method yields visually pleasing results with high CPSNR.

L.Naveen#1, B.Shobanbabu*2, M.Tech (Ph????. ?d?)

2013-01-01

355

Air filter systems - series 7000; Air Filter Systeme - Serie 7000  

Energy Technology Data Exchange (ETDEWEB)

The new generation of light-design Knecht air filters has been specially developed for tractors, light commercial vehicles, construction machines and compressors. Four filter sizes with rated air flows of 4.5 to 12 m{sup 3}/min air cover a combustion engine output range from approx. 50 to 130 kW. Consistent value-oriented design of the basic air filters has resulted in cost reductions of 30% compared to earlier models. (orig.) [Deutsch] Die neue Generation der Knecht Luftfilter leichter Bauart wurde fuer den Einbau in Traktoren, leichten Nutzfahrzeugen, Baumaschinen und Kompressoren entwickelt. Vier Filter-Baugroessen mit Nenn-Luftdurchsaetzen von 4,5 bis 12 m{sup 3}/min Luft decken den Leistungsbereich von Verbrennungsmotoren von etwa 50 bis 130 kW Leistung ab. Durch konsequente Wertgestaltung der Basis-Luftfilter wurde im Vergleich zu frueheren Baureihen eine Kostenreduzierung von 30% realisiert. (orig.)

Frueh, W. [Bereich Erstausruestung, Knecht Filterwerke GmbH, Stuttgart (Germany)

1997-08-01

356

Tobacco-smoke filters  

UK PubMed Central (United Kingdom)

According to the invention, a material for the filtration of tobacco smoke by reduction of vapor-phase constituents without adverse effect on the taste of the smoke comprises carbon particles of a size substantially within the range of 300 to 1700 micron, coated over their surfaces, individually and without being bonded together, with a barrier layer which has a thickness within the range of 5 x 10-4 to 0.5 micron and which is discontinuous in that it has a porosity within the range of 7,000 to 200,000 cm3/min/10 cm2 per 10 cm water gauge and a permeability for organic vapors contained in tobacco smoke such that it permits the passage of molecules within the size range 5 x 10-4 to 2 micron, the said layer being composed substantially of an organic non-nitrogen-containing polymeric material which is non-volatile, substantially non-water-soluble and non-toxic. The invention is further concerned with tobacco smoke filters comprising such coated carbon particles.

CRELLIN ROBIN ARTHUR; JENKINS CHRISTOPHER ROBERT; PHELPSTEAD JAMES WILLIAM PERCY

357

Positive pressure filter respirator  

UK PubMed Central (United Kingdom)

The flow of air into a positive pressure filter respirator during exhalation is reduced without having to provide an inhalation valve by using an exhale valve which is a flap valve having a high cracking resistance but a low resistance to flow. The exhale valve has a pressure/flow characteristic (C, Fig. 1) in which the pressure resistance increases with flow from a cracking pressure greater than 10 mm water gauge at 30 litres per minute flow until at a flow rate in the region of 70 - 80 litres per minute, the pressure resistance across the valve falls such that the pressure across the exhale valve at a rate of flow of 85 litres per minute through the valve is less than 12.5 mm water gauge. This effect is achieved by using an exhale valve which is a flap valve having a flexible flap (2) connected to a circular stem (3) by a resilient fold (1) which permits the flexible flap (2) to move axially relative to the circular stem (3) as the rate of flow through the valve increases past 70 litres per minute.

SIMPSON KEITH

358

Simplified design of filter circuits  

CERN Multimedia

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

Lenk, John

1999-01-01

359

Distortion tolerant correlation filter design.  

UK PubMed Central (United Kingdom)

This paper introduces a computationally efficient algorithm for synthesis of a distortion tolerant correlation filter and associated threshold, denoted collectively as the enhanced matched filter (EMF). Application areas of EMF include imagery based automatic target detection and recognition and biometrics. The EMF is synthesized from a set of training images characterizing the target of interest within the expected distortion range. A distinguishing feature of EMF is the ascribed threshold, which is a byproduct of the filter computation process and does not rely on nontarget trainers. The EMF performance is compared to that of the synthetic discriminant function using realistic test scenarios.

Heidary K

2013-04-01

360

Distortion tolerant correlation filter design.  

Science.gov (United States)

This paper introduces a computationally efficient algorithm for synthesis of a distortion tolerant correlation filter and associated threshold, denoted collectively as the enhanced matched filter (EMF). Application areas of EMF include imagery based automatic target detection and recognition and biometrics. The EMF is synthesized from a set of training images characterizing the target of interest within the expected distortion range. A distinguishing feature of EMF is the ascribed threshold, which is a byproduct of the filter computation process and does not rely on nontarget trainers. The EMF performance is compared to that of the synthetic discriminant function using realistic test scenarios. PMID:23669663

Heidary, Kaveh

2013-04-20

 
 
 
 
361

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

2004-01-01

362

Designing or specifying harmonic filters  

Energy Technology Data Exchange (ETDEWEB)

Interest in electric power system harmonics has produced many technical magazine articles and conference papers over the past several years. Most writing, however, has been devoted to detailed discussion on the effects of harmonics and the equipment that produces it. Much less has been presented about filtering as a means of coping with harmonic problems. This article focuses on factors to consider in applying filters as solutions to harmonic problems. The paper discusses the causes of harmonics, major effects of harmonics, types of harmonic filters, and component selection, and considers changes to power systems.

St. Pierre, C.R. [Power Technologies, Inc., Schenectady, NY (United States). Industrial Power Systems

1995-03-06

363

Properties of ceramic candle filters  

Energy Technology Data Exchange (ETDEWEB)

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.

Pontius, D.H.

1995-06-01

364

Narrowband tunable photonic notch filter.  

UK PubMed Central (United Kingdom)

We propose a technique for realization of a high-contrast, tunable, low-insertion-loss notch filter using polarization selectivity of whispering-gallery-mode resonators. We demonstrate a 10 MHz filter with 5.5 dB insertion loss and 45.5 dB of in-band rejection. The measured rejection value is limited by the finite (3 kHz) linewidth of our laser. We show that the filter can potentially have tunable bandwidth without significant rejection modification.

Savchenkov AA; Liang W; Matsko AB; Ilchenko VS; Seidel D; Maleki L

2009-05-01

365

Pragmatic circuits signals and filters  

CERN Multimedia

Pragmatic Circuits: Signals and Filters is built around the processing of signals. Topics include spectra, a short introduction to the Fourier series, design of filters, and the properties of the Fourier transform. The focus is on signals rather than power. But the treatment is still pragmatic. For example, the author accepts the work of Butterworth and uses his results to design filters in a fairly methodical fashion. This third of three volumes finishes with a look at spectra by showing how to get a spectrum even if a signal is not periodic. The Fourier transform provides a way of dealing wi

Eccles, William

2006-01-01

366

Face Recognition using Gabor Filters  

Directory of Open Access Journals (Sweden)

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.

Muhammad SHARIF; Adeel KHALID; Mudassar RAZA; Sajjad MOHSIN

2011-01-01

367

ADVANCED HOT GAS FILTER DEVELOPMENT  

Energy Technology Data Exchange (ETDEWEB)

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.

E.S. Connolly; G.D. Forsythe

2000-09-30

368

Traditional Chinese medicine for treating infant cough caused by external factor  

UK PubMed Central (United Kingdom)

The invention relates to a traditional Chinese medicine for treating infant cough caused by external factor, which is characterized in that the traditional Chinese medicine is mainly prepared from the following Chinese medical herbs: 6g of mulberry leaf, 3g of toasted almond, 3g of peppermint, 3g of radix isatidis, 3g of tuber pinellia, 4g of balloon flower, 3g of bitter orange, 4g of dried orange peel, 4g of white peony root, 3g of aster, 3g of liquorice, and the like. The preparation method of the traditional Chinese medicine comprises the following steps: putting the Chinese medical herbs in a container soaking the Chinese medical herbs with water for 30 minutes decocting the Chinese medical herbs with soft fire for 30 minutes and then, filtering residues and extracting 100ml of extraction liquid. One dose of the traditional Chinese medicine is taken after supper every day. The traditional Chinese medicine is prepared from pure Chinese medical herbs by a traditional preparation method. Thus, the traditional Chinese medicine for treating infant cough caused by external factor keeps the medicinal properties, has the efficacies of reducing fever, freeing lung, regulating qi and eliminating phlegm to achieve the purpose of treatment, and has no side effects.

MIN OU

369

Traditional Chinese medicine for treating encephalitis  

UK PubMed Central (United Kingdom)

The invention belongs to the technical field of traditional Chinese medicines, and particularly discloses a traditional Chinese medicine for treating encephalitis. The traditional Chinese medicine isprepared from raw materials containing dandelion, salvia miltiorrhiza, honey-fried licorice root, tuber of dwarf lilyturf, radix picrorrhizae, bamboo leaves, caulis bambusae in taenian, atractylis ovata, radix isatidis, aster, polygala, dried orange peel, soap pod, selfheal, euphorbia kansui, pittosporum illicioides, earthworm and reed root in certain proportion by weight. The traditional Chinesemedicine has simple preparation, good absorption effect, remarkable curative effect, no side effect and high security and is beneficial to alleviating symptoms of patients in time.

BING LIU

370

Experience with three percutaneous vena cava filters  

International Nuclear Information System (INIS)

[en] 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

1987-12-04

371

Tracheotomy filter for tracheotomy patients  

UK PubMed Central (United Kingdom)

PCT No. PCT/FR92/00999 Sec. 371 Date Apr. 28, 1994 Sec. 102(e) Date Apr. 28, 1994 PCT Filed Oct. 26, 1992 PCT Pub. No. WO93/08860 PCT Pub. Date May 13, 1993.An artificial nose (1) comprising a housing (20) mounted around the surgical opening (3) by a base ring (10) with a two-sided adhesive (15) containing a hydrophilic filtering disc (40) which forms an alternate heat and moisture exchanger between the exhaled and inhaled air. A grid (30) is arranged between the filter (40) and the surgical opening (3) and has a plane front surface (32) contacting the filter, and a convex rear surface (31) with calibrated through-passages. The distance between the front surface (32) and the rear surface (31) ensures, together with the calibre of the through-passages, that mucus ejected from the trachea is essentially unable to reach the filter.

BEZICOT ROBERT

372

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

DEFF Research Database (Denmark)

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.

Bekö, Gabriel; Fadeyi, M.O.

2009-01-01

373

Space-time correlation filters for human action detection  

Science.gov (United States)

To automate video surveillance systems, algorithms must be developed to automatically detect and classify basic human actions. Many traditional approaches focus on the classification of actions, which usually assumes prior detection, tracking, and segmentation of the human figure from the original video. On the other hand, action detection is a more desirable paradigm, as it is capable of simultaneous localization and classification of the action. This means that no prior segmentation or tracking is required, and multiple action instances may be detected in the same video. Correlation filters have been traditionally applied for object detection in images. In this paper, we report the results of our investigation using correlation filters for human action detection in videos. Correlation filters have previously been explored for action classification, but this is the first time they are evaluated for the more difficult task of action detection. In addition, we investigate several practical implementation issues, including parameter selection, reducing computational time, and exploring the effects of preprocessing and temporal occlusion (i.e., loss of video frames) on performance.

Fernandez, Joseph A.; Vijaya Kumar, B. V. K.

2013-03-01

374

Narrow-Band Microwave Filters  

Directory of Open Access Journals (Sweden)

Full Text Available Original design of the narrow-band compact filters based on the high-quality waveguide-dielectric resonator with anisotropic materials has been presented in this work. Designed filters satisfy the contradictory requirements: they provide the narrow frequency band (0.05 ÷ 0.1 % of the main frequency f0) and the low initial losses ?0 ? 1 dB).

A.V. Strizhachenko; A.A. Zvyagintsev; S.N. Shul’ga; V.V. Chizhov

2010-01-01

375

Greenfield filters in pulmonary embolism  

International Nuclear Information System (INIS)

Pulmonary embolism remains one of the most important causes of sudden hospital deaths. From January 1982 to December 1985 24 Greenfield filters were inserted for the treatment of recurrent pulmonary embolism. Only 1 patient had a possible recurrent pulmonary embolus and 1 patient had angulation and penetration of the vein wall. Radionuclide venography demonstrated that all inferior venae cavae were patent. The mortality rate of 38% was not related to the Greenfield filter

1986-01-01

376

Protein transfer to nitrocellulose filters  

International Nuclear Information System (INIS)

The authors report that under their conditions the transfer efficiency of a given protein from a SDS-polyacrylamide gel to nitrocellulose filters depends on its Msub(r)-value. After immunodetection with specific antisera and 125I-labelled protein A, the amount of label bound to each antigen increases linearly with the amount of protein applied to the gel. The 125I-labelled protein A bound to the filter is not removed during successive incubations with different antisera. (Auth.)

1981-02-23

377

Filter indexing for spectrophotometer system  

International Nuclear Information System (INIS)

A spectrophotometer system has an optical system for transmitting a beam from a source at select wavelengths onto a detector. A plurality of filters are positioned in a tray. A stepper mechanism indexes the tray along a path. A microcomputer controls the stepper mechanism and the optical system. The wavelength is successively changed over a range, the tray is indexed to move a select filter into the beam at a predetermined wavelength and the changing is discontinued during indexing.

1982-01-01

378

Filter indexing for spectrophotometer system  

Energy Technology Data Exchange (ETDEWEB)

A spectrophotometer system has an optical system for transmitting a beam from a source at select wavelengths onto a detector. A plurality of filters are positioned in a tray. A stepper mechanism indexes the tray along a path. A microcomputer controls the stepper mechanism and the optical system. The wavelength is successively changed over a range, the tray is indexed to move a select filter into the beam at a predetermined wavelength and the changing is discontinued during indexing.

Chamran, M.M.; Scott, L.B.; Williams, P.B.

1982-08-03

379

OXYGENATOR WITH INTEGRATED ARTERIAL FILTER  

UK PubMed Central (United Kingdom)

An oxygenator combines, in a single structure, a heat exchanger, a gas exchanger and an arterial filter. Such an oxygenator permits fewer fluid connections and thus may simplify an extracorporeal blood circuit, including a heart-lung machine and a blood reservoir, in which it is used. In some cases, the oxygenator may be configured to include multiple purge ports for purging bubbles both before and after filtering the blood.

REGGIANI STEFANO; SILVESTRI CLAUDIO; GIRI ALBERTO

380

Ensemble Kalman filtering without the intrinsic need for inflation  

Directory of Open Access Journals (Sweden)

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.

M. Bocquet

2011-01-01

 
 
 
 
381

High efficiency particulate air filter  

Energy Technology Data Exchange (ETDEWEB)

A high efficiency particulate air filter is described which is characterized by being lightweight and readily disposable after use, and comprising a sheet of high efficiency particulate air filtering medium folded upon itself in accordion fashion to form a generally rectangular filter pack which includes opposite side edges defined by the edges of the folded sheet and opposite end edges defined by the ends of the sheet, a relatively thin and lightweight four sided peripheral frame surrounding and supporting the filter pack, with the four sides of the frame being separately molded and overlying and covering respective ones of the opposite side edges and opposite end edges of the pack, the frame being composed of a relatively thin, hard, air impermeable material which is self-bonded and sealed to the filter medium over substantially the entire interface between the medium and the frame to effectively preclude the leakage of air therebetween, and with adjacent edges of adjacent sides of the frame being self-bonded to each other, the frame further having an exterior surface which includes a peripheral shoulder formed in the exterior surface adjacent at least one end of the filter to define a peripheral ledge thereabout, and at least one separate header surrounding and sealably secured to the external periphery of the frame, with the one header being mounted upon the ledge in abutting relation with the associated shoulder.

Allan, T.T.; Cramer, R.V.

1987-08-11

382

The Kalman-Levy filter  

CERN Multimedia

The Kalman filter combines forecasts and new observations to obtain an estimation which is optimal in the sense of a minimum average quadratic error. The Kalman filter has two main restrictions: (i) the dynamical system is assumed linear and (ii) forecasting errors and observational noises are taken Gaussian. Here, we offer an important generalization to the case where errors and noises have heavy tail distributions such as power laws and L\\'evy laws. The main tool needed to solve this ``Kalman-L\\'evy'' filter is the ``tail-covariance'' matrix which generalizes the covariance matrix in the case where it is mathematically ill-defined (i.e. for power law tail exponents $\\mu \\leq 2$). We present the general solution and discuss its properties on pedagogical examples. The standard Kalman-Gaussian filter is recovered for the case $\\mu = 2$. The optimal Kalman-L\\'evy filter is found to deviate substantially fro the standard Kalman-Gaussian filter as $\\mu$ deviates from 2. As $\\mu$ decreases, novel observations are ...

Sornette, D

2001-01-01

383

Particle Filter Improved by Genetic Algorithm and Particle Swarm Optimization Algorithm  

Directory of Open Access Journals (Sweden)

Full Text Available Particle filter algorithm is a filtering method which uses Monte Carlo idea within the framework of Bayesian estimation theory. It approximates the probability distribution by using particles and discrete random measure which is consisted of their weights, it updates new discrete random measure recursively according to the algorithm. When the sample is large enough, the discrete random measure approximates the true posteriori probability density function of the state variable. The particle filter algorithm is applicable to any non-linear non-Gaussian system. But the standard particle filter does not consider the current measured value, which will lead to particles with non-zero weights become less after some iterations, this results in particle degradation; re-sampling technique was used to inhibit degradation, but this will reduce the particle diversity, and results in particle impoverishment. To overcome the problems, this paper proposed a new particle filter which introduced genetic algorithm and particle swarm optimization algorithm. The new algorithm is called intelligent particle filter (IPF). Driving particles move to the optimal position by using particle swarm optimization algorithm, thus the numbers of effective particles was increased, the particle diversity was improved, and the particle degradation was inhibited. Replace the re-sampling method in traditional particle filter by using the choice, crossover and mutation operation of the genetic algorithm, avoiding the phenomenon of impoverishment. Simulation results show that the new algorithm improved the estimation accuracy significantly compare with the standard particle filter.

Ming Li; Bo Pang; Yongfeng He; Fuzhong Nian

2013-01-01

384

Study on Soft Phase Locked Method to Solving the Synchronization Problem of Active Power Filter in Stand-alone Power Grid  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Traditional LC filters can't work stably in small rating stand-alone power grid. So active power filter (APF) is becoming an important tool to solve the power quality problem in small rating stand-alone power grid. In most current detection algorithm of APF, it needs a synchronizing signal. Firstly,...

Zhuo, Fang; Wu, Longhui; Chen, Zhe; Wang, Xianwei; Wang, Zhaoan

385

A bulk filter for separating suspensions  

Energy Technology Data Exchange (ETDEWEB)

The bulk filter, consisting of a frame, a nozzle for feeding the suspension, a filter material feeder, a drainage device and mobile scrapers differs in that the scrapers are mounted on tractive elements, forming cells for filling the filtering material with the walls of the frame and the drainage device. An improvement in the productivity of the filter is attained.

Kurbatov, V.P.; Kazakov, V.N.; Kontorovich, V.E.; Kukolev, Y.B.; Ulybin, B.I.; Veretennikov, A.F.

1980-04-30

386

Diesel Hydrocarbon Measurement - Series Filter Test.  

Science.gov (United States)

Filters were loaded by driving various cycles (FTP, LA-4 and 50 mph SS) and collecting the particulate materials. Wet filters are those on which particulate was collected and no drying steps were taken. Dry filters were prepared by baking wet filters at 3...

E. Danielson

1978-01-01

387

CPHD filter derivation for extended targets  

CERN Document Server

This document derives the CPHD filter for extended targets. Only the update step is derived here. Target generated measurements, false alarms and prior are all assumed to be independent identically distributed cluster processes. We also prove here that the derived CPHD filter for extended targets reduce to PHD filter for extended targets and CPHD filter for standard targets under suitable assumptions.

Orguner, Umut

2010-01-01

388

Water washable stainless steel HEPA filter  

Science.gov (United States)

The invention is a high efficiency particulate (HEPA) filter apparatus and system, and method for assaying particulates. The HEPA filter provides for capture of 99.99% or greater of particulates from a gas stream, with collection of particulates on the surface of the filter media. The invention provides a filter system that can be cleaned and regenerated in situ.

Phillips, Terrance D. (617 Chestnut Ct., Aiken, SC 29803)

2001-01-01

389

Ethnobotany of pru, a traditional Cuban refreshment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Gouania polygama (Jacq.) Urban, Smilax domingensis Willd., and Pimenta dioica Merr., are three species widely used within Cuban ethnobotanical traditions and practices. Pru is a traditional refreshment and medicinal drink produced by their decoction and fermentation with sugar. It is claimed to have...

Volpato, G.; Godínez, D.

390

New Testament prophecy and the Gospel tradition  

Digital Repository Infrastructure Vision for European Research (DRIVER)

?The aim of this thesis is to demonstrate that the Synoptic evangelists, particularly in the eschatological discourses Mt 24, Mk 13 and Lk 21, have employed traditions developed by Christian prophets; and to consider the origins and meanings of these traditions.

Houston, Walter.

391

Vygotsky, Consciousness, and the German Psycholinguistic Tradition  

Science.gov (United States)

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…

Leitch, David G.

2011-01-01

392

Traditional birth attendants in the Gambia.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In developing countries traditional birth attendants help at 60-70% of births, despite rapidly expanding "Western-style" health services. Recognising the potential of this established service, the World Health Organisation has been involved in a programme of training and supervision of traditional b...

Daly, C; Pollard, AJ

393

Enhancing collaborative filtering by user interest expansion via personalized ranking.  

UK PubMed Central (United Kingdom)

Recommender systems suggest a few items from many possible choices to the users by understanding their past behaviors. In these systems, the user behaviors are influenced by the hidden interests of the users. Learning to leverage the information about user interests is often critical for making better recommendations. However, existing collaborative-filtering-based recommender systems are usually focused on exploiting the information about the user's interaction with the systems; the information about latent user interests is largely underexplored. To that end, inspired by the topic models, in this paper, we propose a novel collaborative-filtering-based recommender system by user interest expansion via personalized ranking, named iExpand. The goal is to build an item-oriented model-based collaborative-filtering framework. The iExpand method introduces a three-layer, user-interests-item, representation scheme, which leads to more accurate ranking recommendation results with less computation cost and helps the understanding of the interactions among users, items, and user interests. Moreover, iExpand strategically deals with many issues that exist in traditional collaborative-filtering approaches, such as the overspecialization problem and the cold-start problem. Finally, we evaluate iExpand on three benchmark data sets, and experimental results show that iExpand can lead to better ranking performance than state-of-the-art methods with a significant margin.

Liu Q; Chen E; Xiong H; Ding CH; Chen J

2012-02-01

394

Spatial filtering of magnetoencephalographic data in spherical harmonics domain  

Science.gov (United States)

We introduce new spatial filtering methods in the spherical harmonics domain for constraining magnetoencephalographic (MEG) multichannel measurements to user-specified spherical regions of interests (ROI) inside the head. The main idea of the spatial filtering is to emphasize those signals arising from an ROI, while suppressing the signals coming from outside the ROI. We exploit a well-known method called the signal space separation (SSS), which can decompose MEG data into a signal component generated by neurobiological sources and a noise component generated by external sources outside the head. The novel methods presented in this work, expanded SSS (exSSS) and generalized expanded SSS (genexSSS) utilize a beamspace optimization criterion in order to linearly transform the inner signal SSS coefficients to represent the sources belonging to the ROI. The filters mainly depend on the radius and the center of the ROI. The simplicity of the derived formulations of our methods stems from the natural appropriateness to spherical domain and orthogonality properties of the SSS basis functions that are intimately related to the vector spherical harmonics. Thus, unlike the traditional MEG spatial filtering techniques, exSSS and genexSSS do not need any numerical computation procedures on discretized headspace. The validation and performance of the algorithms are demonstrated by experiments utilizing both simulated and real MEG data.

Ozkurt, Tolga Esat

395

Filter with filter case and filter cartridge for cleaning the lubricating oil of an internal combustion engine. Filter mit Filtergehaeuse und Filtereinsatz zur Reinigung von Schmieroel einer Brennkraftmaschine  

Energy Technology Data Exchange (ETDEWEB)

In order to empty a filter case with a filter cartridge during change of the filter, which is used to clean the lubricating oil of an internal combustion engine, the inside of the filter case is connected by a screw thread to an opening used to fix the filter case with a duct leading to the crankcase of the internal combustion engine. According to the invention, the filter case and filter cartridge form one unit, which can be screwed into the screw thread of a case below it with a counter thread where the opening of the counter thread is penetrated.

Brueggemann, H.

1985-06-20

396

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

2012-01-01

397

Towards filtering and alerting rule rewriting on single-component policies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The use of firewalls and network intrusion detection systems (NIDSs)is the dominant method to survey and guarantee the security policy in current corporate networks. On the one hand, firewalls are traditional security components which provide means to filter traffic within corporate networks, as wel...

Garcia Alfaro, Joaquin; Cuppens, Frédéric; Cuppens-Boulahia, Nora

398

Numerical simulation of large fabric filter  

Science.gov (United States)

Fabric filters are used in the wide range of industrial technologies for cleaning of incoming or exhaust gases. To achieve maximal efficiency of the discrete phase separation and long lifetime of the filter hoses, it is necessary to ensure uniform load on filter surface and to avoid impacts of heavy particles with high velocities to the filter hoses. The paper deals with numerical simulation of two phase flow field in a large fabric filter. The filter is composed of six chambers with approx. 1600 filter hoses in total. The model was simplified to one half of the filter, the filter hoses walls were substituted by porous zones. The model settings were based on experimental data, especially on the filter pressure drop. Unsteady simulations with different turbulence models were done. Flow field together with particles trajectories were analyzed. The results were compared with experimental observations.

Sedlá?ek, Jan; Kova?ík, Petr

2012-04-01

399

Numerical simulation of large fabric filter  

Directory of Open Access Journals (Sweden)

Full Text Available Fabric filters are used in the wide range of industrial technologies for cleaning of incoming or exhaust gases. To achieve maximal efficiency of the discrete phase separation and long lifetime of the filter hoses, it is necessary to ensure uniform load on filter surface and to avoid impacts of heavy particles with high velocities to the filter hoses. The paper deals with numerical simulation of two phase flow field in a large fabric filter. The filter is composed of six chambers with approx. 1600 filter hoses in total. The model was simplified to one half of the filter, the filter hoses walls were substituted by porous zones. The model settings were based on experimental data, especially on the filter pressure drop. Unsteady simulations with different turbulence models were done. Flow field together with particles trajectories were analyzed. The results were compared with experimental observations.

Sedlá?ek Jan; Kova?ík Petr

2012-01-01

400

Design of a Finite-Impulse Response filter generator Konstruktion av en FIR filter generator  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this thesis a FIR filter generator has been designed. The program generates FIR filters in the form of VHDL-files. Four different filter structures have been implemented in the generator, Direct Form (DF), Differential Coefficients Method (DCM), polyphase filters and (2-by-2) filters. The focus ...

Broddfelt, Michel

 
 
 
 
401

Multiplier-free filters for wideband SAR  

DEFF Research Database (Denmark)

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.

Dall, JØrgen; Christensen, Erik Lintz

2001-01-01

402

Filtering of surface EMG using ensemble empirical mode decomposition.  

UK PubMed Central (United Kingdom)

Surface electromyogram (EMG) is often corrupted by three types of noises, i.e. power line interference (PLI), white Gaussian noise (WGN), and baseline wandering (BW). A novel framework based primarily on empirical mode decomposition (EMD) was developed to reduce all the three noise contaminations from surface EMG. In addition to regular EMD, the ensemble EMD (EEMD) was also examined for surface EMG denoising. The advantages of the EMD based methods were demonstrated by comparing them with the traditional digital filters, using signals derived from our routine electrode array surface EMG recordings. The experimental results demonstrated that the EMD based methods achieved better performance than the conventional digital filters, especially when the signal to noise ratio of the processed signal was low. Among all the examined methods, the EEMD based approach achieved the best surface EMG denoising performance.

Zhang X; Zhou P

2013-04-01

403

Filtering of surface EMG using ensemble empirical mode decomposition.  

Science.gov (United States)

Surface electromyogram (EMG) is often corrupted by three types of noises, i.e. power line interference (PLI), white Gaussian noise (WGN), and baseline wandering (BW). A novel framework based primarily on empirical mode decomposition (EMD) was developed to reduce all the three noise contaminations from surface EMG. In addition to regular EMD, the ensemble EMD (EEMD) was also examined for surface EMG denoising. The advantages of the EMD based methods were demonstrated by comparing them with the traditional digital filters, using signals derived from our routine electrode array surface EMG recordings. The experimental results demonstrated that the EMD based methods achieved better performance than the conventional digital filters, especially when the signal to noise ratio of the processed signal was low. Among all the examined methods, the EEMD based approach achieved the best surface EMG denoising performance. PMID:23245684

Zhang, Xu; Zhou, Ping

2012-12-11

404

Research on Personalized Information Filtering of Search Engine  

Science.gov (United States)

Since network has been created and developing rapidly in recent years, the age of information exploding is coming. The Search Engine becomes more and more important for people, but the traditional search engine retrieves and provides information just according to the keywords that users input. How to recommend the right information to users has become the hot point. The technology of personalized information filtering brings people hope .The paper I present analyzed the achievements of those filtering technologies ,and adopted user-system complex-operating modeling to build User-activitycollecting module, User-interest-updating module and User-searching module, in order to meet theme-oriented searching's needs. Experiments showed that the user-interest model can provide personalized service and enhance search engine's precision.

Zhang, Shu; Chen, Xinrong; Luo, Changshou

405

Efficient Subband Adaptive Filtering With Oversampled Gdft Filter Banks  

UK PubMed Central (United Kingdom)

This paper addresses the numerical efficiency of adaptive filtering implemented in subbands. Ourapproach first focuses on oversampled GDFT filter banks and their potential benefits over other possible subbanddecompositions. Although the subband filters presented use complex arithmetic, the discussed methodallows factorization into a real valued polyphase network, followed by a complex GDFT modulation, whichcan be mostly implemented via an FFT. Secondly we discuss the advantages and potential savings that can begained by processing complex subband signals, with particular reference to adaptive system identification problems,for which we give demonstrations of the potential benefits of our GDFT approach compared to adaptiveidentification in both fullband and critically sampled DCT-IV based pseudo-QMF subbands.1. INTRODUCTIONAdaptive identification of long impulse responses, as required for acoustic echo cancellation, is unlikely to beimplemented as a fullband FIR system due ...

Stephan Wei; Lutz Lampe; Robert W. Stewart

406

Nonlinear filtering in oil/gas reservoir simulation: filter design  

Energy Technology Data Exchange (ETDEWEB)

In order to provide an additional mode of utility to the USGS reservoir model VARGOW, a nonlinear filter was designed and incorporated into the system. As a result, optimal (in the least squares sense) estimates of reservoir pressure, liquid mass, and gas cap plus free gas mass are obtained from an input of reservoir initial condition estimates and pressure history. These optimal estimates are provided continuously for each time after the initial time, and the input pressure history is allowed to be corrupted by measurement error. Preliminary testing of the VARGOW filter was begun and the results show promise. Synthetic data which could be readily manipulated during testing was used in tracking tests. The results were positive when the initial estimates of the reservoir initial conditions were reasonably close. Further testing is necessary to investigate the filter performance with real reservoir data.

Arnold, E.M.; Voss, D.A.; Mayer, D.W.

1980-10-01

407

Kalman filter input estimation. Kalman filter ni yoru nyuryoku suitei  

Energy Technology Data Exchange (ETDEWEB)

As system output includes information concerning system input, it is considered that system output can be used to estimate noisy system input. In this paper, the problem of input estimation using Kalman filter is examined for SISO (single input-single output) systems. Since the problem is different from an ordinary Kalman filter problem, it is first modified to an ordinary Kalman filter problem, and the input estimation accuracy is then calculated from the measurement accuracy through the Riccati equation. For a numerical example, a sinusoidal input is estimated using the simulated output of an integrator system when the noisy sinusoidal input is added, and effectiveness of this method is verified. This method seems useful to smooth the original signals with noisy signals which are derived from sensor output signals influenced by sensor dynamics, and so on. In the actual data treatment, it is important how to decide on values of noise variance, initial state estimation, and the covariance. 2 refs., 4 figs.

Sasa, S.; Nagayasu, M.

1992-11-01

408

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.

1982-01-01

409

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)

2005-01-01

410

Properties of Ceramic Candle Filters  

International Nuclear Information System (INIS)

Coal-fired Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) systems require ceramic candle filter elements which can withstand the mechanical, thermal, and chemical environment of hot gas cleanup applications. These systems demand filter elements to 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. The filter elements must also survive the mechanical loads associated with handling and assembly, normal operation, and process upsets. Objectives of the test program at Southern Research are as follows: (1) Provide material characterization to develop an understanding of the physical, mechanical, and thermal behavior of hot gas filter materials. (2) Develop a material property data base from which the behavior of materials in the hot gas cleanup environment may be predicted. (3) Perform testing and analysis of filter elements after exposure to actual operating conditions to determine the effects of the thermal and chemical environments in hot gas filtration on material properties. (4) Explore the glass-like nature of the matrix material.

1997-01-01

411

Testing HEPA filters with uranine  

International Nuclear Information System (INIS)

This paper reports experience gained at NASA's Goddard Space Flight Center in buying HEPA filters that were tested for efficiency without DOP. In preparing specifications for bid, we considered whether to test only a sample with DOP or to test every filter with some other aerosol. The choice of other aerosols was among air, salt, and uranine. The authors decided to specify that bidders choose between the British sodium flame test and the French uranine test or propose an acceptable alternative. One bidder proposed cutting an extra flap of paper off each filter, testing it with DOP, and checking the filter for leaks with air. The chosen supplier tested the efficiencies of his filters with uranine and counted the particles with a laser particle spectrometer. Part of this paper explains how the authors evaluated the different tests. The rest of it describes the test equipment, the upstream concentration and its constancy, the particle size distribution and its constancy, the penetration of different size particles, how discriminating the test was, and the issues that it raised

1987-01-01

412

Traditional and Non-Traditional Educational Outcomes: Trade-Off or Complementarity?  

Science.gov (United States)

Recently, schools have increasingly been charged with enhancing non-traditional academic competencies, in addition to traditional academic competencies. This article raises the question whether schools can implement these new educational goals in their curricula and simultaneously realise the traditional ones or whether a trade-off between…

van der Wal, Marieke; Waslander, Sietske

2007-01-01

413

Device for treating urinary bladder channel tissue disease by traditional Chinese medicines  

UK PubMed Central (United Kingdom)

A device for treating the urinary bladder channel tissue disease by traditional Chinese medicines is a treating device with the traditional Chinese medicines guided into a body through the skin. The device consists of a herring groove device, a herring groove cover, anesthetic earplugs, a water pipe, a water filter, a traditional Chinese medicine pan, a traditional Chinese medicine prescription for treating the urinary bladder channel tissue disease, an air pipe, an ozone generator, a high-pressure pump, an ultrasonic generator, a thermostat, a liquid discharge pipe, a pressure-reducing pump, a timer and a controller, wherein the traditional Chinese medicine prescription comprises the following materials in mass by weight: 2g of cassia twig, 1g of simpleleaf shrub chastetree fruit, 2g of golden cypress, 2g of radix sophorae flavescentis, 1g of radix angelicae pubescentis, 2g of radix clematidis, 1g of radix stephaniae tetrandrae, 1g of agaric, 2g of rhizoma alismatis, 1g of corn stigma, 1g of longhairy antenoron herb, 1g of szechwan Chinaberry fruit, 2g of combined spicebush root, 1g of endothelium corneum gigeriae galli, 2g of cogongrass rhizome, 1g of leonurus japonicas and 1g of lumbricus. The traditional Chinese medicine molecules are not decomposed, and the dirt in the body can be removed and the device is convenient to operate and is good in effect, can cure the urinary bladder channel tissue disease and can be applied in clinic.

JIANYOU WANG

414

Method for separating verticine total alkaloids in traditional Chinese medicine extract  

UK PubMed Central (United Kingdom)

The invention discloses a method for separating total alkaloid from traditional Chinese medicine, in particular a method for separating verticine total alkaloid from traditional Chinese medicine extract, which belongs to the field of traditional Chinese medicines. The method comprises the following technical proposal that the traditional Chinese medicine extract is taken and filtered, the pH value of the traditional Chinese medicine extract is adjusted to be between 1 and 7 filtrate is added to a cation exchange resin column, eluted with water to remove impurities and then eluted by use of 0.5 to 15 percent acid liquid and eluent is collected, added with alkali for neutralization and desalted so as to prepare verticine total alkaloid. The method overcomes the deficiency that the prior art is low in extraction ratio, large in the amount of organic solvents, complex in process, incapable of mass production and the like, and can efficiently separate high-purity verticine total alkaloid from the traditional Chinese medicine extract.

YINGHUI LIU; MEISHAN PIAO; GUANGLU WANG

415

Method for separating cytospaz total alkaloid from traditional Chinese medicine extract liquid  

UK PubMed Central (United Kingdom)

The invention discloses a method for separating total alkaloid from traditional Chinese medicine, in particular a method for separating belladonna total alkaloid from traditional Chinese medicine extract, which belongs to the field of traditional Chinese medicines. The method comprises the following technical proposal that the traditional Chinese medicine extract is taken and filtered the pH value of the traditional Chinese medicine extract is adjusted to be between 1 and 7 filtrate is added to a cation exchange resin column, eluted with water to remove impurities and then eluted by use of 0.5 to 15 percent acid liquid and eluent is collected, added with alkali for neutralization and desalted so as to prepare belladonna total alkaloid. The method overcomes the deficiency that the prior art is low in extraction ratio, large in the amount of organic solvents, complex in process, incapable of mass production, and the like, and can efficiently separate high-purity belladonna total alkaloid from traditional Chinese medicine extract.

YINGHUI LIU; JIANZHUO WU

416

Traditional Chinese medicine for treating myopia  

UK PubMed Central (United Kingdom)

The invention belongs to the field of Traditional Chinese medicines, in particular discloses a traditional Chinese medicine for treating myopia, which consists of Chinese angelica, astragalus, medlar, honey-fried liquorice root, tribulus terrestris, swordlike atractylodes rhizome, red raspberry, Indian buead, szechwon tangshen root, common selfheal fruit-spike, grassleaf sweelflag rhizome, cassia seed, cassia bark, plantain herb and thinleaf milkwort root-bark serving as raw materials in a certain weight ratio. The traditional Chinese medicine has the advantages of simple preparation, good absorption effect, obvious curative effect, no side effect, high safety, and contribution to relieving symptoms of diseases in time.

YAN LI; JING LIU

417

RICE BALL USING KOREAN TRADITIONAL FERMENTED FOOD  

UK PubMed Central (United Kingdom)

PURPOSE: Rice balls using traditional fermented Korean food, and a producing method thereof are provided to use pickles, salted seafood, fermented sweet rice drink, and kimchi. CONSTITUTION: A producing method of rice balls using traditional fermented Korean food comprises the following steps: cooking rice with fermented grain water, and mixing the rice with soy sauce and sesame seed oil in a weight ratio of 85-95:4-6:6-4 to obtain a boiled rice mixture preparing one Korean traditional fermented food selected from pickles, salted seafood, fermented sweet rice drink, or kimchi as an upper material and placing the upper material on the rice mixture.

LEE DONH UK

418

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

1989-01-01

419

Quantum Diffusion, Measurement and Filtering  

CERN Multimedia

A brief presentation of the basic concepts in quantum probability theory is given in comparison to the classical one. The notion of quantum white noise, its explicit representation in Fock space, and necessary results of noncommutative stochastic analysis and integration are outlined. Algebraic differential equations that unify the quantum non Markovian diffusion with continuous non demolition observation are derived. A stochastic equation of quantum diffusion filtering generalising the classical Markov filtering equation to the quantum flows over arbitrary *-algebra is obtained. A Gaussian quantum diffusion with one dimensional continuous observation is considered.The a posteriori quantum state difusion in this case is reduced to a linear quantum stochastic filter equation of Kalman-Bucy type and to the operator Riccati equation for quantum correlations. An example of continuous nondemolition observation of the coordinate of a free quantum particle is considered, describing a continuous collase to the statio...

Belavkin, V P

1993-01-01

420

Depth-filtered digital holography.  

UK PubMed Central (United Kingdom)

We introduce depth-filtered digital holography (DFDH) as a method for quantitative tomographic phase imaging of buried layers in multilayer samples. The procedure is based on the acquisition of multiple holograms for different wavelengths. Analyzing the intensity over wavelength pixel wise and using an inverse Fourier transform leads to a depth-profile of the multilayered sample. Applying a windowed Fourier transform with a narrow window, we choose a depth-of interest (DOI) which is used to synthesize filtered interference patterns that just contain information of this limited depth. We use the angular spectrum method to introduce an additional spatial filtering and to reconstruct the corresponding holograms. After a short theoretical framework we show experimental proof-of-principle results for the method.

Koukourakis N; Jaedicke V; Adinda-Ougba A; Goebel S; Wiethoff H; Höpfner H; Gerhardt NC; Hofmann MR

2012-09-01

 
 
 
 
421

Depth-filtered digital holography.  

Science.gov (United States)

We introduce depth-filtered digital holography (DFDH) as a method for quantitative tomographic phase imaging of buried layers in multilayer samples. The procedure is based on the acquisition of multiple holograms for different wavelengths. Analyzing the intensity over wavelength pixel wise and using an inverse Fourier transform leads to a depth-profile of the multilayered sample. Applying a windowed Fourier transform with a narrow window, we choose a depth-of interest (DOI) which is used to synthesize filtered interference patterns that just contain information of this limited depth. We use the angular spectrum method to introduce an additional spatial filtering and to reconstruct the corresponding holograms. After a short theoretical framework we show experimental proof-of-principle results for the method. PMID:23037413

Koukourakis, Nektarios; Jaedicke, Volker; Adinda-Ougba, Adamou; Goebel, Sebastian; Wiethoff, Helge; Höpfner, Henning; Gerhardt, Nils C; Hofmann, Martin R

2012-09-24

422

Fast algorithm for Morphological Filters  

International Nuclear Information System (INIS)

[en] In surface metrology, morphological filters, which evolved from the envelope filtering system (E-system) work well for functional prediction of surface finish in the analysis of surfaces in contact. The naive algorithms are time consuming, especially for areal data, and not generally adopted in real practice. A fast algorithm is proposed based on the alpha shape. The hull obtained by rolling the alpha ball is equivalent to the morphological opening/closing in theory. The algorithm depends on Delaunay triangulation with time complexity O(nlogn). In comparison to the naive algorithms it generates the opening and closing envelope without combining dilation and erosion. Edge distortion is corrected by reflective padding for open profiles/surfaces. Spikes in the sample data are detected and points interpolated to prevent singularities. The proposed algorithm works well both for morphological profile and area filters. Examples are presented to demonstrate the validity and superiority on efficiency of this algorithm over the naive algorithm.

2011-08-19

423

REMOVABLE EMBOLUS BLOOD CLOT FILTER  

UK PubMed Central (United Kingdom)

A removable blood clot filter includes a number of locator members and anchor members disposed radially and extending angularly downward from a hub. The locator members include a number of linear portions having distinct axes configured to place a tip portion approximately parallel to the walls of a blood vessel when implanted and to apply sufficient force to the vessel walls to position the filter near the vessel centerline. The anchor members each include a hook configured to penetrate the vessel wall to prevent longitudinal movement due to blood flow. The hooks may have a cross section sized to allow for a larger radius of curvature under strain so that the filter can be removed without damaging the vessel wall.

CARR JR ROBERT M; CHANDUSZKO ANDRZEJ J; MCDERMOTT JOHN D; KAUFMAN JOHN A

424

Filtering reducer of flushing fluid  

Energy Technology Data Exchange (ETDEWEB)

This is a patent of a filtering reducer of flushing fluid on a water base with low content of solid particles used at temperatures of roughly 200/sup 0/C. With the use of the proposed filtering reducer, there is no excessive increase in viscosity and gelatinization of the flushing fluids without restriction in the quantity of reducer needed to guarantee the required filtering. There is a possibility of recovering the polyalkylphenol vat residues obtained in the production of nonyl phenol. It is possible to reduce the time of treatment and dissolving of the product; there is no danger of plugging of the productive oil beds. The process of hydration of clay is excluded.

Secu, P.; Apostu, M.; Basarabescu, T.; Popescu, F.

1981-02-28

425

Radiant zone heated particulate filter  

Energy Technology Data Exchange (ETDEWEB)

A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

Gonze, Eugene V [Pinckney, MI

2011-12-27

426

Health Information in Chinese - Traditional (????): MedlinePlus  

Science.gov (United States)

... ???? (Chinese - Traditional) Bilingual PDF Health Information Translations CPAP (Continuous Positive Airway Pressure) CPAP???????????? - ???? (Chinese - Traditional) Bilingual PDF Health Information ...

427

Particle Kalman Filtering: A Nonlinear Bayesian Framework for Ensemble Kalman Filters  

CERN Document Server

This paper investigates an approximation scheme of the optimal nonlinear Bayesian filter based on the Gaussian mixture representation of the state probability distribution function. The resulting filter is similar to the particle filter, but is different from it in that, the standard weight-type correction in the particle filter is complemented by the Kalman-type correction with the associated covariance matrices in the Gaussian mixture. We show that this filter is an algorithm in between the Kalman filter and the particle filter, and therefore is referred to as the particle Kalman filter (PKF). In the PKF, the solution of a nonlinear filtering problem is expressed as the weighted average of an "ensemble of Kalman filters" operating in parallel. Running an ensemble of Kalman filters is, however, computationally prohibitive for realistic atmospheric and oceanic data assimilation problems. For this reason, we consider the construction of the PKF through an "ensemble" of ensemble Kalman filters (EnKFs) instead, ...

Hoteit, Ibrahim; Pham, Dinh-Tuan

2011-01-01

428

Particle filtering for dispersion curve tracking in ocean acoustics.  

UK PubMed Central (United Kingdom)

A particle filtering method is developed for dispersion curve extraction from spectrograms of broadband acoustic signals propagating in underwater media. The goal is to obtain accurate representation of modal dispersion which can be employed for source localization and geoacoustic inversion. Results are presented from the application of the method to synthetic data, demonstrating the potential of the approach for accurate estimation of waveguide dispersion characteristics. The method outperforms simple time-frequency analysis providing estimates that are very close to numerically calculated dispersion curves. The method also provides uncertainty information on modal arrival time estimates, typically unavailable when traditional methods are used.

Zorych I; Michalopoulou ZH

2008-08-01

429

Particle filtering for dispersion curve tracking in ocean acoustics.  

Science.gov (United States)

A particle filtering method is developed for dispersion curve extraction from spectrograms of broadband acoustic signals propagating in underwater media. The goal is to obtain accurate representation of modal dispersion which can be employed for source localization and geoacoustic inversion. Results are presented from the application of the method to synthetic data, demonstrating the potential of the approach for accurate estimation of waveguide dispersion characteristics. The method outperforms simple time-frequency analysis providing estimates that are very close to numerically calculated dispersion curves. The method also provides uncertainty information on modal arrival time estimates, typically unavailable when traditional methods are used. PMID:18681501

Zorych, Ivan; Michalopoulou, Zoi-Heleni

2008-08-01

430

Plasmonic nanoresonators for high-resolution colour filtering and spectral imaging.  

UK PubMed Central (United Kingdom)

Colour and spectral imaging systems typically use filters and glass prisms to disperse light of different wavelengths. With the miniaturization of integrated devices, current research on imaging sensors focuses on novel designs aiming at high efficiency, low power consumption and slim dimension, which poses great challenges to the traditional colourant-based filtering and prism-based spectral splitting techniques. In this context, surface plasmon-based nanostructures are attractive due to their small dimensions and the ability to efficiently manipulate light. In this article we use selective conversion between free-space waves and spatially confined modes in plasmonic nanoresonators formed by subwavelength metal-insulator-metal stack arrays to show that the transmission spectra through such arrays can be well controlled by using simple design rules, and high-efficiency colour filters capable of transmitting arbitrary colours can be achieved. These artificial nanostructures provide an approach for high spatial resolution colour filtering and spectral imaging with extremely compact device architectures.

Xu T; Wu YK; Luo X; Guo LJ

2010-01-01

431

Color filters including infrared cut-off integrated on CMOS image sensor.  

Science.gov (United States)

A color image was taken with a CMOS image sensor without any infrared cut-off filter, using red, green and blue metal/dielectric filters arranged in Bayer pattern with 1.75 µm pixel pitch. The three colors were obtained by a thickness variation of only two layers in the 7-layer stack, with a technological process including four photolithography levels. The thickness of the filter stack was only half of the traditional color resists, potentially enabling a reduction of optical crosstalk for smaller pixels. Both color errors and signal to noise ratio derived from optimized spectral responses are expected to be similar to color resists associated with infrared filter. PMID:21747459

Frey, Laurent; Parrein, Pascale; Raby, Jacques; Pellé, Catherine; Hérault, Didier; Marty, Michel; Michailos, Jean

2011-07-01

432

Computerized tomographic scanner with shaped radiation filter  

International Nuclear Information System (INIS)

The invention comprises a shaped filter and a filter correction circuitry for computerized tomographic scanners. The shaped filter is a generally u-shaped block of filter material which is adapted to be mounted between the source of radiation and the scan circle. The u-shaped block has a parabolic recess. The filter material may be beryllium, aluminum, sulphur, calcium, titanium, erbium, copper, and compounds including oxides and alloys thereof. The filter correction circuit comprises a first filter correction profile adding circuit for adding a first scaler valve to each intensity valve in a data line. The data line is operated on by a beam hardness correction polynomial. After the beam hardness polynomial correction operation, a second filter correction circuit adds a second filter correction profile consisting of a table of scalor values, one corresponding to each intensity reading in the data line.

1981-01-01

433

Hot gas cross flow filtering module  

Science.gov (United States)

A filter module for use in filtering particulates from a high temperature gas has a central gas duct and at least one horizontally extending support mount affixed to the duct. The support mount supports a filter element thereon and has a chamber therein, which communicates with an inner space of the duct through an opening in the wall of the duct, and which communicates with the clean gas face of the filter element. The filter element is secured to the support mount over an opening in the top wall of the support mount, with releasable securement provided to enable replacement of the filter element when desired. Ceramic springs may be used in connection with the filter module either to secure a filter element to a support mount or to prevent delamination of the filter element during blowback.

Lippert, Thomas E. (Murrysville Boro, PA); Ciliberti, David F. (Murrysville Boro, PA)

1988-01-01

434

In Situ Cleanable Alternative HEPA Filter Media  

International Nuclear Information System (INIS)

[en] The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of Energy's Hazardous Facilities'', found that conventional glass fiber HEPA filters are structurally weak and easily damaged by water or fire. The structurally stronger sintered metal and ceramic filters would reduce the potential of a catastrophic HEPA filter failure due to filter media breakthrough in the process ventilation system. An in situ regenerable system may also find application in recovering nuclear materials, such as plutonium, collected on glove box exhaust HEPA filters. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters

2002-01-01

435

Measurements of filter-cake properties  

Energy Technology Data Exchange (ETDEWEB)

The Pressurized Fluidized-Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) programs of the U.S. Department of Energy require filtration, at temperatures from about 600 to 900 {degrees}C, of fine particles of coal ash, char, or spent and unreacted sorbent from hot-gas streams. Achieving acceptable filter lifetimes requires solutions to or avoidance of, such problems as incomplete filter cleaning, re-entrainment (i.e., re-filtration) of particles from filter cleaning, and bridging of filter cake between adjacent filters. These and other potential problems may arise from the materials properties of filter cakes, from the filter-bank design, and from the mechanisms of filter cleaning. Avoiding re-entrainment requires that some bonding and agglomeration of particles occur in the cakes (so that the agglomerates from filter cleaning are too large to be re-entrained), but excessive agglomeration can produce poor cleaning or bridging. For both PFBC and IGCC applications, we can form filter cakes at process temperatures, gas compositions, and gas flow rates, and measure the gas-phase permeabilities, porosities, tensile strengths, and deformation coefficients of these filter cakes to determine their dependencies on temperature, reaction time, gas composition, particle compositions, and particle size distributions. Filter-cake shear strengths and flow factors can be measured for powders ``as received,`` for filter cakes that we have heated to process temperatures, or for powders heated in reactive gases to simulate gas-solid reactions in process filter cakes.

Smith, D.H.; Grimm, U.; Haddad, G.J.

1996-12-31

436