| 1. |
- Ibrahim, Muhammad Talal, et al.
(författare)
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Velocity and pressure-based partitions of horizontal and vertical trajectories for on-line signature verification
- 2010
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Ingår i: Pattern Recognition. - : Elsevier BV. - 0031-3203 .- 1873-5142. ; 43:8, s. 2817-2832
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Tidskriftsartikel (refereegranskat)abstract
- In general, shape of an on-line signature is used as a single discriminating feature. Sometimes shape of signature is used alone for verification purposes and sometimes it is used in combination with some other dynamic features such as velocity, pressure and acceleration. The shape of an on-line signature is basically formed due to the wrist and fingers movements where the wrist movement is represented by the horizontal trajectory and the movement of the fingers is represented by vertical trajectory. As the on-line signature is formed due to the combination of two movements that are essentially independent of each other, it will be more effective to use them as two separate discriminating features. Based on this observation, we propose to use these trajectories in isolation by first decomposing the pressure and velocity profiles into two partitions and then extracting the underlying horizontal and vertical trajectories. So the overall process can be thought as the process which exploits the inter-feature dependencies by decomposing signature trajectories depending upon pressure and velocity information and performs verification on each partition separately. As a result, we are able to extract eight discriminating features and among them the most stable discriminating feature is used in verification process. Further Principal Component Analysis (PCA) has been proposed to make the signatures rotation invariant. Experimental results demonstrate superiority of our approach in on-line signature verification in comparison with other techniques.
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| 2. |
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| 3. |
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| 4. |
- Niazi, Muhammad Khalid Khan, 1978-, et al.
(författare)
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Fully Automatic Heart Beat Rate Determination in Digital Video Recordings of Rat Embryos
- 2009
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Ingår i: Transactions on Mass-Data Analysis of Images and Signals. - Leipzig, Germany : IBAI Publishing. - 1868-6451. ; 1:2, s. 132-146
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Tidskriftsartikel (refereegranskat)abstract
- Embryo cultures of rodents is an established technique for monitoring adverse effects of chemicals on embryonic development. The assessment involves determination of the heart rate of the embryo which is usually done visually, a technique which is tedious and error prone. We present a new method for fully automatic heart detection in digital videos of rat embryos. First it detects the heart location by using decimation free directional filter bank along with first absolute moment, and then it counts the number of heart beats for a predetermined period of time. Using this automated method many more embryos can be evaluated at reasonable cost.
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| 5. |
- Niazi, Muhammad Khalid Khan, 1978-, et al.
(författare)
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Fully Automatic Heart Beat Rate Determination in Digital Video Recordings of Rat Embryos
- 2008
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Ingår i: ADVANCES IN MASS DATA ANALYSIS OF IMAGES AND SIGNALS IN MEDICINE, BIOTECHNOLOGY, CHEMISTRY AND FOOD INDUSTRY, PRCEEDINGS. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783540707141 ; , s. 27-37
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Konferensbidrag (refereegranskat)abstract
- Embryo cultures of rodents is an established technique for monitoring adverse effects of chemicals on embryonic development. The assessment involves determination of the heart rate of the embryo which is usually done visually, a technique which is tedious and error prone. We present a new method for fully automatic heart detection in digital videos of rat embryos. First it detects the heart location, and then it counts the number of heart beats for a predetermined period of time. Using this automated method many more embryos can be evaluated at reasonable cost.
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| 6. |
- Niazi, Muhammad Khalid Khan, 1978-, et al.
(författare)
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Measuring Heart Rate from Rat Embryo Videos
- 2008
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Ingår i: Swedish Symposium on Image Analysis. - Lund, Sweden : Swedish Society for Automated Image Analysis. ; , s. 35-38
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Embryo cultures of rodents is an established technique for monitoring adverse e®ects of chemicals on embryonic development. The assessment involves determination of the heart rate of the embryo which is usually done visually, a technique which is tedious and error prone. We present a new method for fully automatic heart detection in digital videos of mouse or rat embryos. First it detects the heart location, and then it counts the number of heart beats for a predetermined period of time.
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| 7. |
- Niazi, M. Khalid Khan, et al.
(författare)
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Robust Signal Generation and Analysis of Rat Embryonic Heart Rate In Vitro using Laplacian Eigenmaps and Empirical Mode Decomposition
- 2011
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Ingår i: Computer analysis of images and patterns. - Berlin, Heidelberg : Springer-Verlag. - 9783642236778 ; 6855, s. 523-530
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Konferensbidrag (refereegranskat)abstract
- To develop an accurate and suitable method for measuring the embryonic heart rate in vitro, a system combining Laplacian eigenmaps and empirical mode decomposition has been proposed. The proposed method assess the heart activity in two steps; signal generation and heart signal analysis. Signal generation is achieved by Laplacian eigenmaps (LEM) in conjunction with correlation co-efficient, while the signal analysis of the heart motion has been performed by the modified empirical mode decomposition (EMD). LEM helps to find the template for the atrium and the ventricle respectively, whereas EMD helps to find the non-linear trend term without defining any regression model. The proposed method also removes the motion artifacts produced due to the the non-rigid deformation in the shape of the embryo, the noise induced during the data acquisition, and the higher order harmonics. To check the authenticity of the proposed method, 151 videos have been investigated. Experimental results demonstrate the superiority of the proposed method in comparison to three recent methods.
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| 8. |
- Nilsson, Mats F., et al.
(författare)
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Improved methodology for identifying the teratogenic potential in early drug development of hERG channel blocking drugs
- 2010
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Ingår i: Reproductive Toxicology. - : Elsevier. - 0890-6238 .- 1873-1708. ; 29:2, s. 156-163
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Tidskriftsartikel (refereegranskat)abstract
- Drugs blocking the potassium current IKr of the heart (via hERG channel-inhibition) have the potential to cause hypoxia-related teratogenic effects. However, this activity may be missed in conventional teratology studies because repeat dosing may cause resorptions. The aim of the present study was to investigate an alternative protocol to reveal the teratogenic potential of IKr-blocking drugs. The IKr blocker astemizole, given as a single dose (80mg/kg) on gestation day (GD) 13 to pregnant rats caused digital defects. In whole rat embryo culture (2h) on GD 13, astemizole caused a decrease in embryonic heart rate at 20nM, and arrhythmias at 200-400nM. Cetirizine, without IKr-blocking properties, did not affect the rat embryonic heart in vitro. The present study shows that single dose testing on sensitive days of development, together with whole embryo culture, can be a useful methodology to better characterize the teratogenic potential of IKr-blocking drugs.
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