Moving object detection using background subtraction

CERN Document Server

Shaikh, Soharab Hossain; Chaki, Nabendu

2014-01-01

This Springer Brief presents a comprehensive survey of the existing methodologies of background subtraction methods. It presents a framework for quantitative performance evaluation of different approaches and summarizes the public databases available for research purposes. This well-known methodology has applications in moving object detection from video captured with a stationery camera, separating foreground and background objects and object classification and recognition. The authors identify common challenges faced by researchers including gradual or sudden illumination change, dynamic bac

Real-time digital X-ray subtraction imaging

International Nuclear Information System (INIS)

Mistretta, C.A.; Kruger, R.A.; Houk, T.L.

1979-01-01

A diagnostic anatomical X-ray apparatus comprising a converter and a television camera for converting an X-ray image of a subject into a series of television fields of video signals is described in detail. A digital memory system stores and integrates the video signals over a time interval corresponding to a plurality of successive television fields. The integrated video signals are recovered from storage and fed to a digital or analogue subtractor, the resulting output being displayed on a television monitor. Thus the display represents on-going changes in the anatomical X-ray image. In a modification, successive groups of fields are stored and integrated in three memories, cyclically, and subtractions are performed between successive pieces of integrated signals to provide a display of successive alterations in the X-ray image. For investigations of the heart, the integrating interval should be of the order of one cardiac cycle. (author)

Video frame processor

International Nuclear Information System (INIS)

Joshi, V.M.; Agashe, Alok; Bairi, B.R.

1993-01-01

This report provides technical description regarding the Video Frame Processor (VFP) developed at Bhabha Atomic Research Centre. The instrument provides capture of video images available in CCIR format. Two memory planes each with a capacity of 512 x 512 x 8 bit data enable storage of two video image frames. The stored image can be processed on-line and on-line image subtraction can also be carried out for image comparisons. The VFP is a PC Add-on board and is I/O mapped within the host IBM PC/AT compatible computer. (author). 9 refs., 4 figs., 19 photographs

Digital subtraction angiography

International Nuclear Information System (INIS)

Neuwirth, J. Jr.; Bohutova, J.

1987-01-01

The quality of radiodiagnostic methods to a great extent depends on the quality of the resulting image. The basic technical principles are summed up of the different parts of digital subtraction angiography apparatus and of methods of improving the image. The instrument is based on a videochain consisting of an X-ray tube, an intensifier of the radiographic image, optical parts, a video camera, an analog-to-digital converter and a computer. The main advantage of the digitally processed image is the possibility of optimizing the image into a form which will contain the biggest amount of diagnostically valuable information. Described are the mathematical operations for improving the digital image: spatial filtration, pixel shift, time filtration, image integration, time interval differentation and matched filtering. (M.D.). 8 refs., 3 figs

Two-dimensional real-time imaging system for subtraction angiography using an iodine filter

Science.gov (United States)

Umetani, Keiji; Ueda, Ken; Takeda, Tohoru; Anno, Izumi; Itai, Yuji; Akisada, Masayoshi; Nakajima, Teiichi

1992-01-01

A new type of subtraction imaging system was developed using an iodine filter and a single-energy broad bandwidth monochromatized x ray. The x-ray images of coronary arteries made after intravenous injection of a contrast agent are enhanced by an energy-subtraction technique. Filter chopping of the x-ray beam switches energies rapidly, so that a nearly simultaneous pair of filtered and nonfiltered images can be made. By using a high-speed video camera, a pair of two 512 × 512 pixel images can be obtained within 9 ms. Three hundred eighty-four images (raw data) are stored in a 144-Mbyte frame memory. After phantom studies, in vivo subtracted images of coronary arteries in dogs were obtained at a rate of 15 images/s.

A comparison of subtracted images from dental subtraction programs

International Nuclear Information System (INIS)

Han, Won Jeong

2002-01-01

To compare the standard deviation of gray levels on digital subtracted images obtained by different dental subtraction programs. Paired periapical films were taken at the lower premolar and molar areas of the phantoms involving human mandible. The bite registration group used Rinn XCP equipment and bite registration material, based on polyvinyl siloxane, for standardization. The no bite registration group used only Rinn XCP equipment. The periapical film images were digitized at 1200 dpi resolution and 256 gray levels by a flat bed scanner with transparency unit. Dental digital subtraction programs used for this study were Subtractor (Biomedisys Co., Korea) and Emago (Oral Diagnostic Systems, The Netherlands). To measure the similarities between the subtracted images, the standard deviations of the gray levels were obtained using a histogram of subtracted images, which were then analyzed statistically. Subtracted images obtained by using the Emago program without manual selection of corresponding points showed the lowest standard deviation of gray levels (p<0.01). And the standard deviation of gray levels was lower in subtracted images in the group of a bite registration than in the group of no use of bite registration (p<0.01). Digital radiographic subtraction without manual selection of reference points was found to be a convenient and superior method.

Subtractive Leadership

Science.gov (United States)

Larwin, K. H.; Thomas, Eugene M.; Larwin, David A.

2015-01-01

This paper introduces a new term and concept to the leadership discourse: Subtractive Leadership. As an extension of the distributive leadership model, the notion of subtractive leadership refers to a leadership style that detracts from organizational culture and productivity. Subtractive leadership fails to embrace and balance the characteristics…

A review of automatic exposure control of conventional and digital systems

International Nuclear Information System (INIS)

Workman, A.; Cowen, A.R.

1989-01-01

The desirable properties and methods of achieving automatic exposure control in film-screen radiography, fluoroscopy, spot-film fluorography and cinefluorography are discussed. Advantages of certain methods in achieving optimum image quality for minimal patient exposure are considered. In digital subtraction fluorography (DSF) where relatively large exposure levels per image are used, proper set-up of exposure conditions is of particular importance. These systems require a high degree of stability in exposure to maintain a high level of image quality. We have developed test methods for monitoring the set-up and reproducibility of exposure levels in DSF. (author)

A technique of scatter and glare correction for videodensitometric studies in digital subtraction videoangiography

International Nuclear Information System (INIS)

Shaw, C.G.; Ergun, D.L.; Myerowitz, P.D.; Van Lysel, M.S.; Mistretta, C.A.; Zarnstorff, W.C.; Crummy, A.B.

1982-01-01

The logarithmic amplification of video signals and the availability of data in digital form make digital subtraction videoangiography a suitable tool for videodensitometric estimation of physiological quantities. A system for this purpose was implemented with a digital video image processor. However, it was found that the radiation scattering and veiling glare present in the image-intensified video must be removed to make meaningful quantitations. An algorithm to make such a correction was developed and is presented. With this correction, the videodensitometry system was calibrated with phantoms and used to measure the left ventricular ejection fraction of a canine heart

Automatic video surveillance of outdoor scenes using track before detect

DEFF Research Database (Denmark)

Hansen, Morten; Sørensen, Helge Bjarup Dissing; Birkemark, Christian M.

2005-01-01

This paper concerns automatic video surveillance of outdoor scenes using a single camera. The first step in automatic interpretation of the video stream is activity detection based on background subtraction. Usually, this process will generate a large number of false alarms in outdoor scenes due...

[Design and development of the DSA digital subtraction workstation].

Science.gov (United States)

Peng, Wen-Xian; Peng, Tian-Zhou; Xia, Shun-Ren; Jin, Guang-Bo

2008-05-01

According to the patient examination criterion and the demands of all related departments, the DSA digital subtraction workstation has been successfully designed and is introduced in this paper by analyzing the characteristic of video source of DSA which was manufactured by GE Company and has no DICOM standard interface. The workstation includes images-capturing gateway and post-processing software. With the developed workstation, all images from this early DSA equipment are transformed into DICOM format and then are shared in different machines.

The use of Leeds Test Objects in the assessment of the performance of radiological imaging systems: an introduction

International Nuclear Information System (INIS)

Cowen, A.R.

1986-01-01

Over the preceding decade the Leeds Radiological Imaging Group have developed a range of test objects with which to assess the performance of radiological imaging systems. The types of imaging equipment which can be assessed include X-ray image intensifier television systems, small-format 100mm/105mm fluorography systems and radiographic screen-film combinations. We have recently extended our interest to the evaluation of digital radiological imaging equipment including digital subtraction fluorography and digital (greyscale) radiographic imaging systems. These test objects were initially developed for the purpose of evaluating imaging performance under laboratory conditions but they have also proved useful under field (clinical) conditions. (author)

Performance evaluation software moving object detection and tracking in videos

CERN Document Server

Karasulu, Bahadir

2013-01-01

Performance Evaluation Software: Moving Object Detection and Tracking in Videos introduces a software approach for the real-time evaluation and performance comparison of the methods specializing in moving object detection and/or tracking (D&T) in video processing. Digital video content analysis is an important item for multimedia content-based indexing (MCBI), content-based video retrieval (CBVR) and visual surveillance systems. There are some frequently-used generic algorithms for video object D&T in the literature, such as Background Subtraction (BS), Continuously Adaptive Mean-shift (CMS),

AUTOMATIC FAST VIDEO OBJECT DETECTION AND TRACKING ON VIDEO SURVEILLANCE SYSTEM

Directory of Open Access Journals (Sweden)

V. Arunachalam

2012-08-01

Full Text Available This paper describes the advance techniques for object detection and tracking in video. Most visual surveillance systems start with motion detection. Motion detection methods attempt to locate connected regions of pixels that represent the moving objects within the scene; different approaches include frame-to-frame difference, background subtraction and motion analysis. The motion detection can be achieved by Principle Component Analysis (PCA and then separate an objects from background using background subtraction. The detected object can be segmented. Segmentation consists of two schemes: one for spatial segmentation and the other for temporal segmentation. Tracking approach can be done in each frame of detected Object. Pixel label problem can be alleviated by the MAP (Maximum a Posteriori technique.

Iodine filter imaging system for subtraction angiography using synchrotron radiation

Science.gov (United States)

Umetani, K.; Ueda, K.; Takeda, T.; Itai, Y.; Akisada, M.; Nakajima, T.

1993-11-01

A new type of real-time imaging system was developed for transvenous coronary angiography. A combination of an iodine filter and a single energy broad-bandwidth X-ray produces two-energy images for the iodine K-edge subtraction technique. X-ray images are sequentially converted to visible images by an X-ray image intensifier. By synchronizing the timing of the movement of the iodine filter into and out of the X-ray beam, two output images of the image intensifier are focused side by side on the photoconductive layer of a camera tube by an oscillating mirror. Both images are read out by electron beam scanning of a 1050-scanning-line video camera within a camera frame time of 66.7 ms. One hundred ninety two pairs of iodine-filtered and non-iodine-filtered images are stored in the frame memory at a rate of 15 pairs/s. In vivo subtracted images of coronary arteries in dogs were obtained in the form of motion pictures.

Automatic dipole subtraction

International Nuclear Information System (INIS)

Hasegawa, K.

2008-01-01

The Catani-Seymour dipole subtraction is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. We automatized the procedure in a computer code. The code is useful especially for the processes with many parton legs. In this talk, we first explain the algorithm of the dipole subtraction and the whole structure of our code. After that we show the results for some processes where the infrared divergences of real emission processes are subtracted. (author)

Segmentation of Moving Object Using Background Subtraction Method in Complex Environments

Directory of Open Access Journals (Sweden)

S. Kumar

2016-06-01

Full Text Available Background subtraction is an extensively used approach to localize the moving object in a video sequence. However, detecting an object under the spatiotemporal behavior of background such as rippling of water, moving curtain and illumination change or low resolution is not a straightforward task. To deal with the above-mentioned problem, we address a background maintenance scheme based on the updating of background pixels by estimating the current spatial variance along the temporal line. The work is focused to immune the variation of local motion in the background. Finally, the most suitable label assignment to the motion field is estimated and optimized by using iterated conditional mode (ICM under a Markovian framework. Performance evaluation and comparisons with the other well-known background subtraction methods show that the proposed method is unaffected by the problem of aperture distortion, ghost image, and high frequency noise.

Rapid, low-cost, image analysis through video processing

International Nuclear Information System (INIS)

Levinson, R.A.; Marrs, R.W.; Grantham, D.G.

1976-01-01

Remote Sensing now provides the data necessary to solve many resource problems. However, many of the complex image processing and analysis functions used in analysis of remotely-sensed data are accomplished using sophisticated image analysis equipment. High cost of this equipment places many of these techniques beyond the means of most users. A new, more economical, video system capable of performing complex image analysis has now been developed. This report describes the functions, components, and operation of that system. Processing capability of the new video image analysis system includes many of the tasks previously accomplished with optical projectors and digital computers. Video capabilities include: color separation, color addition/subtraction, contrast stretch, dark level adjustment, density analysis, edge enhancement, scale matching, image mixing (addition and subtraction), image ratioing, and construction of false-color composite images. Rapid input of non-digital image data, instantaneous processing and display, relatively low initial cost, and low operating cost gives the video system a competitive advantage over digital equipment. Complex pre-processing, pattern recognition, and statistical analyses must still be handled through digital computer systems. The video system at the University of Wyoming has undergone extensive testing, comparison to other systems, and has been used successfully in practical applications ranging from analysis of x-rays and thin sections to production of color composite ratios of multispectral imagery. Potential applications are discussed including uranium exploration, petroleum exploration, tectonic studies, geologic mapping, hydrology sedimentology and petrography, anthropology, and studies on vegetation and wildlife habitat

Pediatric head and neck lesions: assessment of vascularity by MR digital subtraction angiography.

Science.gov (United States)

Chooi, Weng Kong; Woodhouse, Neil; Coley, Stuart C; Griffiths, Paul D

2004-08-01

Pediatric head and neck lesions can be difficult to characterize on clinical grounds alone. We investigated the use of dynamic MR digital subtraction angiography as a noninvasive adjunct for the assessment of the vascularity of these abnormalities. Twelve patients (age range, 2 days to 16 years) with known or suspected vascular abnormalities were studied. Routine MR imaging, time-of-flight MR angiography, and MR digital subtraction angiography were performed in all patients. The dynamic sequence was acquired in two planes at one frame per second by using a thick section (6-10 cm) selective radio-frequency spoiled fast gradient-echo sequence and an IV administered bolus of contrast material. The images were subtracted from a preliminary mask sequence and viewed as a video-inverted cine loop. In all cases, MR digital subtraction angiography was successfully performed. The technique showed the following: 1) slow flow lesions (two choroidal angiomas, eyelid hemangioma, and scalp venous malformation); 2) high flow lesions that were not always suspected by clinical examination alone (parotid hemangioma, scalp, occipital, and eyelid arteriovenous malformations plus a palatal teratoma); 3) a hypovascular tumor for which a biopsy could be safely performed (Burkitt lymphoma); and 4) a hypervascular tumor of the palate (cystic teratoma). Our early experience suggests that MR digital subtraction angiography can be reliably performed in children of all ages without complication. The technique provided a noninvasive assessment of the vascularity of each lesion that could not always have been predicted on the basis of clinical examination or routine MR imaging alone.

Tracking of Individuals in Very Long Video Sequences

DEFF Research Database (Denmark)

Fihl, Preben; Corlin, Rasmus; Park, Sangho

2006-01-01

In this paper we present an approach for automatically detecting and tracking humans in very long video sequences. The detection is based on background subtraction using a multi-mode Codeword method. We enhance this method both in terms of representation and in terms of automatically updating...

99mTc-RBC subtraction scintigraphy

International Nuclear Information System (INIS)

Inagaki, Syoichi; Tonami, Syuichi; Yasui, Masakazu; Kuranishi, Makoto; Sugishita, Kouki; Nakamura, Mamoru

1994-01-01

Sequential abdominal scintigrams with 99m Tc-labelled red blood cells (RBC) were subtracted for observing a site of gastrointestinal bleeding and calculating the bleeding rate. This method is technically very easy and can detect the site of bleeding with the minimum rate, as low as 0.2 ml/min., in a phantom experiment. In 23 cases with final diagnosis of gastrointestinal bleeding, conventional non-subtraction scintigraphy detected only 30% (7/23), but subtraction scintigraphy detected 61% (14/23). It was concluded that subtraction scintigraphy had higher sensitivity than conventional scintigraphy for early diagnosing bleeding. A combination of non-subtraction and subtraction scintigraphy is recommended to detect a site of gastrointestinal bleeding in a clinical setting. (author)

Initial clinical experience with an interactive, video-based patient-positioning system for head and neck treatment

International Nuclear Information System (INIS)

Johnson, L.; Hadley, Scott W.; Milliken, Barrett D.; Pelizzari, Charles A.; Haraf, Daniel J.; Nguyen, Ai; Chen, George T.Y.

1996-01-01

Objective: To evaluate an interactive, video-based system for positioning head and neck patients. Materials and Methods: System hardware includes two B and W CCD cameras (mounted to provide left-lateral and AP-inferior views), zoom lenses, and a PC equipped with a frame grabber. Custom software is used to acquire and archive video images, as well as to display real-time subtraction images revealing patient misalignment in multiple views. Live subtraction images are obtained by subtracting a reference image (i.e., an image of the patient in the correct position) from real-time video. As seen in the figure, darker regions of the subtraction image indicate where the patient is currently, while lighter regions indicate where the patient should be. Adjustments in the patient's position are updated and displayed in less than 0.07s, allowing the therapist to interactively detect and correct setup discrepancies. Patients selected for study are treated BID and immobilized with conventional litecast straps attached to a baseframe which is registered to the treatment couch. Morning setups are performed by aligning litecast marks and patient anatomy to treatment room lasers. Afternoon setups begin with the same procedure, and then live subtraction images are used to fine-tune the setup. At morning and afternoon setups, video images and verification films are taken after positioning is complete. These are visually registered offline to determine the distribution of setup errors per patient, with and without video assistance. Results: Without video assistance, the standard deviation of setup errors typically ranged from 5 to 7mm and was patient-dependent. With video assistance, standard deviations are reduced to 1 to 4mm, with the result depending on patient coopertiveness and the length of time spent fine-tuning the setups. At current levels of experience, 3 to 4mm accuracy is easily achieved in about 30s, while 1 to 3mm accuracy is achieved in about 1 to 2 minutes. Studies

Evaluation and quality control of digital subtraction angiography systems

International Nuclear Information System (INIS)

Louisot, P.

1986-04-01

After reviewing the development of systems used in angiography, we rewind the medical interest and describe the steps of an angiographic examination. The following chapter is dedicated to the techniques used for the digitalization of video images. The components of the system involved in the image acquisition are thoroughly investigated in chapter 4. Then, we analyse the capabilities of the machines available in France in 1985. Chapter 6 is devoted to the criteria of quality in digital imaging. In order to assign qualitative values to the above criteria, we design a control procedure which is described in chapter 7. The procedure thus allows the estimate of the physical performances of angiographic digital subtraction systems [fr

Evaluation of left ventricular function using digital subtraction ventriculography

International Nuclear Information System (INIS)

Yiannikas, J.; Detrano, R.

1986-01-01

Digital subtraction ventriculography following injections of contrast via peripheral veins provides excellent images to assess left ventricular function. The images are essentially identical to those following DCV, but allow more uniform mixing of contrast in the left ventricular chamber. Furthermore, few, if any, cardiac arrhythmias occur, hence obviating difficulties that arise from DCV. The spatial resolution of the method is such that regional wall motion assessment of ventricular function is more accurate than that of other noninvasive imaging methods. The use of video-densitometry allows accurate assessment of left ventricular function even when the left ventricular cavity is nonsymmetrically deformed and aneurysmal. In the setting of the cardiac catheterization laboratory, digital ventriculography may provide a safer means of assessing left ventricular function when critical coronary or myocardial disease is present and allows multiple assessments of ventricular function during the same study. Although excellent correlations with standard ventriculography have been noted by all workers, significant discrepancies still exist in individual patients, particularly in the calculations of end diastolic volumes. In the authors experience and in those of most workers, the largest discrepancies existed in patients in whom suboptimal studies are included for analysis. The most frequent reason for the occasional suboptimal study as with all digital subtraction work is the misregistration that results from motion

Temporal subtraction of dual-energy chest radiographs

International Nuclear Information System (INIS)

Armato, Samuel G. III; Doshi, Devang J.; Engelmann, Roger; Caligiuri, Philip; MacMahon, Heber

2006-01-01

Temporal subtraction and dual-energy imaging are two enhanced radiography techniques that are receiving increased attention in chest radiography. Temporal subtraction is an image processing technique that facilitates the visualization of pathologic change across serial chest radiographic images acquired from the same patient; dual-energy imaging exploits the differential relative attenuation of x-ray photons exhibited by soft-tissue and bony structures at different x-ray energies to generate a pair of images that accentuate those structures. Although temporal subtraction images provide a powerful mechanism for enhancing visualization of subtle change, misregistration artifacts in these images can mimic or obscure abnormalities. The purpose of this study was to evaluate whether dual-energy imaging could improve the quality of temporal subtraction images. Temporal subtraction images were generated from 100 pairs of temporally sequential standard radiographic chest images and from the corresponding 100 pairs of dual-energy, soft-tissue radiographic images. The registration accuracy demonstrated in the resulting temporal subtraction images was evaluated subjectively by two radiologists. The registration accuracy of the soft-tissue-based temporal subtraction images was rated superior to that of the conventional temporal subtraction images. Registration accuracy also was evaluated objectively through an automated method, which achieved an area-under-the-ROC-curve value of 0.92 in the distinction between temporal subtraction images that demonstrated clinically acceptable and clinically unacceptable registration accuracy. By combining dual-energy soft-tissue images with temporal subtraction, misregistration artifacts can be reduced and superior image quality can be obtained

Digital subtraction angiography of the heart and lungs

International Nuclear Information System (INIS)

Moodie, D.S.; Yiannikas, J.

1986-01-01

This book contains 12 chapters. Some of the chapter titles are: Physical Principles of Cardiac Digital Subtraction Angiography, The Use of Intravenous Digital Subtraction Angiography in Evaluating Patients with Complex Congenital Heart Disease, Exercise Intravenous Digital Subtraction Angiograpny, Cardiomyopathic and Cardiac Neoplastic Disease, Digital Subtraction Angiography in the Catheterization Laboratory, and Cardiac Digital Subtraction Angiography - Future Directions

An automatic fuzzy-based multi-temporal brain digital subtraction angiography image fusion algorithm using curvelet transform and content selection strategy.

Science.gov (United States)

Momeni, Saba; Pourghassem, Hossein

2014-08-01

Recently image fusion has prominent role in medical image processing and is useful to diagnose and treat many diseases. Digital subtraction angiography is one of the most applicable imaging to diagnose brain vascular diseases and radiosurgery of brain. This paper proposes an automatic fuzzy-based multi-temporal fusion algorithm for 2-D digital subtraction angiography images. In this algorithm, for blood vessel map extraction, the valuable frames of brain angiography video are automatically determined to form the digital subtraction angiography images based on a novel definition of vessel dispersion generated by injected contrast material. Our proposed fusion scheme contains different fusion methods for high and low frequency contents based on the coefficient characteristic of wrapping second generation of curvelet transform and a novel content selection strategy. Our proposed content selection strategy is defined based on sample correlation of the curvelet transform coefficients. In our proposed fuzzy-based fusion scheme, the selection of curvelet coefficients are optimized by applying weighted averaging and maximum selection rules for the high frequency coefficients. For low frequency coefficients, the maximum selection rule based on local energy criterion is applied to better visual perception. Our proposed fusion algorithm is evaluated on a perfect brain angiography image dataset consisting of one hundred 2-D internal carotid rotational angiography videos. The obtained results demonstrate the effectiveness and efficiency of our proposed fusion algorithm in comparison with common and basic fusion algorithms.

A subtraction scheme for computing QCD jet cross sections at NNLO: integrating the subtraction terms I

Science.gov (United States)

Somogyi, Gábor; Trócsányi, Zoltán

2008-08-01

In previous articles we outlined a subtraction scheme for regularizing doubly-real emission and real-virtual emission in next-to-next-to-leading order (NNLO) calculations of jet cross sections in electron-positron annihilation. In order to find the NNLO correction these subtraction terms have to be integrated over the factorized unresolved phase space and combined with the two-loop corrections. In this paper we perform the integration of all one-parton unresolved subtraction terms.

Moving object detection in video satellite image based on deep learning

Science.gov (United States)

Zhang, Xueyang; Xiang, Junhua

2017-11-01

Moving object detection in video satellite image is studied. A detection algorithm based on deep learning is proposed. The small scale characteristics of remote sensing video objects are analyzed. Firstly, background subtraction algorithm of adaptive Gauss mixture model is used to generate region proposals. Then the objects in region proposals are classified via the deep convolutional neural network. Thus moving objects of interest are detected combined with prior information of sub-satellite point. The deep convolution neural network employs a 21-layer residual convolutional neural network, and trains the network parameters by transfer learning. Experimental results about video from Tiantuo-2 satellite demonstrate the effectiveness of the algorithm.

Digital contrast subtraction radiography for proximal caries diagnosis

International Nuclear Information System (INIS)

Kang, Byung Cheol; Yoon, Suk Ja

2002-01-01

To determine whether subtraction images utilizing contrast media can improve the diagnostic performance of proximal caries diagnosis compared to conventional periapical radiographic images. Thirty-six teeth with 57 proximal surfaces were radiographied using a size no.2 RVG-ui sensor (Trophy Radiology, Marne-la-Vallee, France). The teeth immersed in water-soluble contrast media and subtraction images were taken. Each tooth was then sectioned for histologic examination. The digital radiographic images and subtraction images were examined and interpreted by three dentists for proximal caries. The results of the proximal caries diagnosis were then verified with the results of the histologic examination. The proximal caries sensitivity using digital subtraction radiography was significantly higher than simply examining a single digital radiograph. The sensitivity of the proximal dentinal carious lesion when analyzed with the subtraction radiograph and the radiograph together was higher than with the subtraction radiograph or the radiograph alone. The use of subtraction radiography with contrast media may be useful for detecting proximal dentinal carious lesions.

Digital subtraction angiography for breast cancer

International Nuclear Information System (INIS)

Tsurumi, Kiyohiko; Okuyama, Nobuo

1987-01-01

We performed digital subtraction angiography (DSA) on 42 patients with breast diseases to investigate its efficiency. As a result we came to the following conclusions: 1. The sensitivity was well evaluated in intraarterial digital subtraction angiography (IA-DSA) of breast. 2. IA-DSA could diagnose difficult cases like cancer which had undergone augmentation mammoplasty, or like Paget's disease and others. 3. DSA was a safe examination method. 4. The sensitivity of IA-DSA of breast cancer is superior to intravenous digital subtraction angiography (IV-DSA). (author)

Method and apparatus for performing digital intravenous subtraction angiography

International Nuclear Information System (INIS)

Stein, J.A.

1986-01-01

This invention relates to digital intravenous subtraction angiography (DISA), and more particularly concerns novel apparatus and techniques for providing high resolution angiograms with equipment that coacts with existing standard medical X-ray equipment. A typical medical X-ray generator provides low mA, continuous X-ray exposures illuminating a standard image intensifier producing an image scanned by a conventional television camera to produce a video signal. An analog-to-digital converter digitizes the signal, and adding means adds the digital frame signals together in real time to provide an intermediate digital signal representing the addition of 5 to 20 frames. Digital storage means store the intermediate image signals. Preferably there are two system memories with means for summing a subsequent intermediate image in the second memory while a previously-formed intermediate image is being transferred to disk storage

Digital subtraction angiography in ischemic cerebrovascular accidents

Energy Technology Data Exchange (ETDEWEB)

Manelfe, C.; Bonafe, A.; Ducos de Lahitte, M.; Rascol, A.; Prere, J.; Guiraud, B.; Marc-Vergnes, J.P. (Hopital Purpan, 31 - Toulouse (France))

1983-12-29

Recent advances in computer and radiological technology have permitted reassessment of intravenous angiography in the evaluation of cerebrovascular disorders. Although digital subtraction angiography is a relatively new technique, it has rapidly gained a widespread acceptance. It has extended the use of angiography to outpatients and to people in whom conventional angiography is contraindicated. This reliable, safe, and relatively noninvasive technique offers the user two benefits: real-time subtraction and enhanced image quality. The system allows angiographic evaluation of the extracranial and intracranial vessels by means of intravenous injection of contrast material. Extracranial studies clearly demonstrate stenoses and occlusions of the major cervicocephalic arteries. Intracranial studies usually detect major cerebrovascular occlusions and provide insight into the collateral flow patterns. Intravenous digital subtraction angiography permits accurate assessment of cervicocephalic vessels after surgical repair. Although intravenous digital subtraction angiography obviates the need for conventional angiography in many cases, movements from the patients, or superimposition of vascular structures can substantially degrade the quality of the images. Digital subtraction angiography with intra-arterial injection of contrast medium will be contemplated in patients with poor intravenous digital subtraction angiography studies prior to surgery.

Digital subtraction angiography in ischemic cerebrovascular accidents

International Nuclear Information System (INIS)

Manelfe, C.; Bonafe, A.; Ducos de Lahitte, M.; Rascol, A.; Prere, J.; Guiraud, B.; Marc-Vergnes, J.P.

1983-01-01

Recent advances in computer and radiological technology have permitted reassessment of intravenous angiography in the evaluation of cerebrovascular disorders. Although digital subtraction angiography is a relatively new technique, it has rapidly gained a widespread acceptance. It has extended the use of angiography to outpatients and to people in whom conventional angiography is contraindicated. This reliable, safe, and relatively noninvasive technique offers the user two benefits: real-time subtraction and enhanced image quality. The system allows angiographic evaluation of the extracranial and intracranial vessels by means of intravenous injection of contrast material. Extracranial studies clearly demonstrate stenoses and occlusions of the major cervicocephalic arteries. Intracranial studies usually detect major cerebrovascular occlusions and provide insight into the collateral flow patterns. Intravenous digital subtraction angiography permits accurate assessment of cervicocephalic vessels after surgical repair. Although intravenous digital subtraction angiography obviates the need for conventional angiography in many cases, movements from the patients, or superimposition of vascular structures can substantially degrade the quality of the images. Digital subtraction angiography with intra-arterial injection of contrast medium will be contemplated in patients with poor intravenous digital subtraction angiography studies prior to surgery [fr

Dynamic study of DSA by video-densitometry

International Nuclear Information System (INIS)

Imamura, Keiko; Tsukamoto, Hiroshi; Ashida, Hiroshi; Ishikawa, Tohru; Fujii, Masamichi; Uji, Teruyuki

1985-01-01

A system was developed for the dynamic study of DSA by video-densitometric technique. As subtraction images are stored to VTR in our DSA examinations, a frame counter was designed to select images on VTR at an arbitrary interval. ROI setting and video-densitometry were performed using a TV image processor and its host computer. Images were sampled at the rate of 3 frames per second, and clear time-density curves were obtained from brain DSA examinations. Although it takes about 30 minutes to analyse one examination, it is also possible to analyse previous data stored on VTR. For DSA systems having no additional digital storage unit, this method will be helpful. Reduction in image quality through VTR storage had no problem in video-densitometry. Phantom studies have been made concerning the temporal variation of the image brightness during the 20 second-exposure and also the effect of the subjects thickness on the contrast. Filtering for low-grade averaging is preferable for dynamic studies. (author)

People detection in nuclear plants by video processing for safety purpose

Energy Technology Data Exchange (ETDEWEB)

Jorge, Carlos Alexandre F.; Mol, Antonio Carlos A., E-mail: calexandre@ien.gov.b, E-mail: mol@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN), Rio de Janeiro, RJ (Brazil); Seixas, Jose M.; Silva, Eduardo Antonio B., E-mail: seixas@lps.ufrj.b, E-mail: eduardo@lps.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Eletrica; Cota, Raphael E.; Ramos, Bruno L., E-mail: brunolange@poli.ufrj.b [Universidade Federal do Rio de Janeiro (EP/UFRJ), RJ (Brazil). Dept. de Engenharia Eletronica e de Computacao

2011-07-01

This work describes the development of a surveillance system for safety purposes in nuclear plants. The final objective is to track people online in videos, in order to estimate the dose received by personnel, during the execution of working tasks in nuclear plants. The estimation will be based on their tracked positions and on dose rate mapping in a real nuclear plant at Instituto de Engenharia Nuclear, Argonauta nuclear research reactor. Cameras have been installed within Argonauta's room, supplying the data needed. Both video processing and statistical signal processing techniques may be used for detection, segmentation and tracking people in video. This first paper reports people segmentation in video using background subtraction, by two different approaches, namely frame differences, and blind signal separation based on the independent component analysis method. Results are commented, along with perspectives for further work. (author)

People detection in nuclear plants by video processing for safety purpose

International Nuclear Information System (INIS)

Jorge, Carlos Alexandre F.; Mol, Antonio Carlos A.; Seixas, Jose M.; Silva, Eduardo Antonio B.; Cota, Raphael E.; Ramos, Bruno L.

2011-01-01

This work describes the development of a surveillance system for safety purposes in nuclear plants. The final objective is to track people online in videos, in order to estimate the dose received by personnel, during the execution of working tasks in nuclear plants. The estimation will be based on their tracked positions and on dose rate mapping in a real nuclear plant at Instituto de Engenharia Nuclear, Argonauta nuclear research reactor. Cameras have been installed within Argonauta's room, supplying the data needed. Both video processing and statistical signal processing techniques may be used for detection, segmentation and tracking people in video. This first paper reports people segmentation in video using background subtraction, by two different approaches, namely frame differences, and blind signal separation based on the independent component analysis method. Results are commented, along with perspectives for further work. (author)

Digital subtraction angiography with an Isocon camera system: clinical applications

International Nuclear Information System (INIS)

Barbaric, Z.L.; Gomes, A.S.; Deckard, M.E.; Nelson, R.S.; Moler, C.L.

1984-01-01

A new imaging system for digital subtraction angiography (DSA) was evaluated in 30 clinical studies. The image receptor is a 25 X 25 cm, 12 par gadolinium oxysulfate rare-earth screen whose light output is focused to a low-light-level Isocon camera. The video signal is digitized and processed by an image-array processor containing 31 512 X 512 memories 8 bits deep. In most patients, intraarterial DSA studies were done in conjunction with conventional arteriography. In these arterial studies, images adequate to make a specific diagnosis were obtained using half the radiation dose and half the amount of contrast material needed for conventional angiography. In eight intravenous studies performed either to identify renal artery stenosis or for evaluation of congenital heart anomalies, the images were diagnostic but objectionably noisy

Use of images of ictal-inter-ictal SPECT subtraction superimposed on MRI in pharmaco-resistant partial epilepsies in infants

International Nuclear Information System (INIS)

Vera, P.; Kaminska, A.; Cieuta, C.; Mangin, F.; Frouin, V.; Dulac, O.; Chiron, C.

1997-01-01

To study the significance of ictal SPECT in the pre-surgical examination of infant epilepsies we have explored 16 infants aged 3 months to 18 years presenting partial pharmaco-resistant epilepsy. All of them have had an ictal SPECT under EEG - video recording than, two days after, an inter-ictal SPECT coupled to a 3D cerebral MRI. The perfusion tracer, the 99m Tc - ECD, was injected in average at 15 seconds after the outset of crisis. The image processing implied a matching of the two SPECT examinations by a 3D rigid superposition method, a normalization and than a inter-ictal-ictal image subtraction. Finally, the subtraction was matched and superimposed on the MRI. The SPECT subtraction image showed one or several centres of ictal hyper-output in 15 patients, while the separated visual ictal and inter-ictal images were contributory in 8 cases only. The 16. infant presented very short crises (<10 sec). In the cases when the outset point of crises could be established clinically (12 cases) and/or on EEG (8 cases) a hyper-output of concordant localization was recorded. In 5 infants who have had an electrocorticography, a concordance was obtained in all the cases except in an infant having very short crises the subtraction image did not show hyper-output. These preliminary results show that the ictal - inter-ictal SPECT subtraction images, adjusted on MRI, appears to be reliable in detecting the outset point of crises in infants and at the same time useful in guiding the positioning of intra-cranial electrodes prior to surgery intervention

BPHZL-subtraction scheme and axial gauges

Energy Technology Data Exchange (ETDEWEB)

Kreuzer, M.; Rebhan, A.; Schweda, M.; Piguet, O.

1986-03-27

The application of the BPHZL subtraction scheme to Yang-Mills theories in axial gauges is presented. In the auxillary mass formulation we show the validity of the convergence theorems for subtracted momentum space integrals, and we give the integral formulae necessary for one-loop calculations. (orig.).

Subtracted versus non-subtracted digital imaging in peripheral angiography

International Nuclear Information System (INIS)

Fink, U.; Heywang, S.; Mayr, B.; Berger, H.

1989-01-01

Digital subtraction angiography (DSA) plays an important role in the management of vascular diseases of the lower extremities. A disadvantage is the lack of an automatically moving table top. We used a 1,024x1,024 matrix with a large-screen intensifier system and an automated 'stepping' facility. In 161 examinations of the arteries of the lower extremity digital peripheral arteriography was performed with and without the subtraction technique. We compared the influence of different iodine concentrations in DA and DSA. Peripheral DA proved to be equal to peripheral DSA in the region of the pelvis, thigh and knee, with no adequate contrasting being obtained merely in the region of the lower leg arteries in about 45%. It is necessary to use contrast medium at a concentration of 300 mg I/ml. The installation of an automated 'stepping' facility reduces the amount of contrast' medium needed and the exposure time. (orig.)

Adaptive live multicast video streaming of SVC with UEP FEC

Science.gov (United States)

Lev, Avram; Lasry, Amir; Loants, Maoz; Hadar, Ofer

2014-09-01

Ideally, video streaming systems should provide the best quality video a user's device can handle without compromising on downloading speed. In this article, an improved video transmission system is presented which dynamically enhances the video quality based on a user's current network state and repairs errors from data lost in the video transmission. The system incorporates three main components: Scalable Video Coding (SVC) with three layers, multicast based on Receiver Layered Multicast (RLM) and an UnEqual Forward Error Correction (FEC) algorithm. The SVC provides an efficient method for providing different levels of video quality, stored as enhancement layers. In the presented system, a proportional-integral-derivative (PID) controller was implemented to dynamically adjust the video quality, adding or subtracting quality layers as appropriate. In addition, an FEC algorithm was added to compensate for data lost in transmission. A two dimensional FEC was used. The FEC algorithm came from the Pro MPEG code of practice #3 release 2. Several bit errors scenarios were tested (step function, cosine wave) with different bandwidth size and error values were simulated. The suggested scheme which includes SVC video encoding with 3 layers over IP Multicast with Unequal FEC algorithm was investigated under different channel conditions, variable bandwidths and different bit error rates. The results indicate improvement of the video quality in terms of PSNR over previous transmission schemes.

Self-masking subtraction tomosynthesis

International Nuclear Information System (INIS)

Chakraborty, D.P.; Yester, M.V.; Barnes, G.T.; Lakshminarayanan, A.V.

1984-01-01

The authors tested the image quality and dose savings of self-masking subtraction tomosynthesis (SST), which combines digital tomosynthesis with subtraction of a blurred self-mask. High-quality images of the inner ear of a head phantom were obtained at moderate dose savings. Although they were taken with linear motion, they did not exhibit the streaking due to off-fulcrum objects that is characteristic of conventional linear tomography. SST could reduce patient dose by a factor of at least 12 in examinations of the inner ear, and the mechanical aspects can be implemented with moderate modifications of existing instrumentation

Left-right subtraction of brain CT

International Nuclear Information System (INIS)

Ishiguchi, Tsuneo; Sakuma, Sadayuki

1986-01-01

A new image-processing method to obtain a left-right subtraction image of CT was designed for the automated detection of abnormalities in brain CT. An original CT image was divided in two by a centerline. Then the right half of the image was subtracted from the left half by calculating the absorption value of the pixels on the symmetrical positions against the centerline. The mean and the standard deviation of the absorption value of the pixels in the subtraction image were used as parameters for analysis, and the detectability of abnormal CT findings was evaluated in 100 cases - 50 cases each with normal and abnormal CT. The presence of abnormalities could be diagnosed with a sensitivity of 86 %, a specificity of 90 %, and an overall accuracy of 88 % when the borderline of these parameters between normal and abnormal CT was set at the mean + 2SD in the normal group. As a further analysis, the CT image was subdivided into several areas from a functional or anatomical viewpoint, such as cerebral vascular territories, and the left-right subtraction image of each area was obtained. The possibilities of diagnosing the location of an abnormality and of detecting smaller lesions with this method were shown. Left-right subtraction was considered to be a useful method for the detection of asymmetric abnormalities in the automated diagnosis of brain CT. (author)

Longitudinal development of subtraction performance in elementary school.

Science.gov (United States)

Artemenko, Christina; Pixner, Silvia; Moeller, Korbinian; Nuerk, Hans-Christoph

2017-10-05

A major goal of education in elementary mathematics is the mastery of arithmetic operations. However, research on subtraction is rather scarce, probably because subtraction is often implicitly assumed to be cognitively similar to addition, its mathematical inverse. To evaluate this assumption, we examined the relation between the borrow effect in subtraction and the carry effect in addition, and the developmental trajectory of the borrow effect in children using a choice reaction paradigm in a longitudinal study. In contrast to the carry effect in adults, carry and borrow effects in children were found to be categorical rather than continuous. From grades 3 to 4, children became more proficient in two-digit subtraction in general, but not in performing the borrow operation in particular. Thus, we observed no specific developmental progress in place-value computation, but a general improvement in subtraction procedures. Statement of contribution What is already known on this subject? The borrow operation increases difficulty in two-digit subtraction in adults. The carry effect in addition, as the inverse operation of borrowing, comprises categorical and continuous processing characteristics. What does this study add? In contrast to the carry effect in adults, the borrow and carry effects are categorical in elementary school children. Children generally improve in subtraction performance from grades 3 to 4 but do not progress in place-value computation in particular. © 2017 The British Psychological Society.

Development of Shimadzu digital subtraction system

International Nuclear Information System (INIS)

Nishioka, Hiroyuki; Shibata, Koichi; Shimizu, Yasumitsu; Shibata, Kenji; Wani, Hidenobu

1985-01-01

Shimadzu has recently developed a digital subtraction system. It can perform intra-arterial digital subtraction angiography (DSA) using low concentration of contrast medium, or can visualize arteries with intravenuous injection. It can extremely reduce patient's pain in angiography. Image quality of DSA has been much improved by the development of high quality image amplifiers, improvement of signal-to-noise ratio of the x-ray television unit and the development of digital disk recorders. The peak-hold subtraction method that is now under clinical study presents images of blood vessels as the trace of the flow of contrast medium. The maximum-hold memory where the maximum value of the brightness in some period is stored for every picture element is subtracted from the minimum-hold memory where the minimum value is stored, and thus images of blood vessels can be obtained. Hardware of this method is rather simple and it is expected that the amount of contrast medium may be reduced or x-ray dose of the patient may be decreased. (author)

An automated subtraction of NLO EW infrared divergences

Energy Technology Data Exchange (ETDEWEB)

Schoenherr, Marek [CERN, Theoretical Physics Department, Geneva (Switzerland)

2018-02-15

In this paper a generalisation of the Catani-Seymour dipole subtraction method to next-to-leading order electroweak calculations is presented. All singularities due to photon and gluon radiation off both massless and massive partons in the presence of both massless and massive spectators are accounted for. Particular attention is paid to the simultaneous subtraction of singularities of both QCD and electroweak origin which are present in the next-to-leading order corrections to processes with more than one perturbative order contributing at Born level. Similarly, embedding non-dipole-like photon splittings in the dipole subtraction scheme discussed. The implementation of the formulated subtraction scheme in the framework of the Sherpa Monte-Carlo event generator, including the restriction of the dipole phase space through the α-parameters and expanding its existing subtraction for NLO QCD calculations, is detailed and numerous internal consistency checks validating the obtained results are presented. (orig.)

Soft-collinear factorization and zero-bin subtractions

International Nuclear Information System (INIS)

Chiu Juiyu; Fuhrer, Andreas; Kelley, Randall; Manohar, Aneesh V.; Hoang, Andre H.

2009-01-01

We study the Sudakov form factor for a spontaneously broken gauge theory using a (new) Δ-regulator. To be well defined, the effective theory requires zero-bin subtractions for the collinear sectors. The zero-bin subtractions depend on the gauge boson mass M and are not scaleless. They have both finite and 1/ε contributions and are needed to give the correct anomalous dimension and low-scale matching contributions. We also demonstrate the necessity of zero-bin subtractions for soft-collinear factorization. We find that after zero-bin subtractions the form factor is the sum of the collinear contributions minus a soft mass-mode contribution, in agreement with a previous result of Idilbi and Mehen in QCD. This appears to conflict with the method-of-regions approach, where one gets the sum of contributions from different regions.

Subtraction and dynamic MR images of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Murakami, Yoshitaka; Aoki, Manabu; Harada, Junta (Jikei Univ., Tokyo (Japan). School of Medicine)

1993-04-01

The purpose of this study was to evaluate the diagnostic effectiveness of subtraction and dynamic MR imaging in patients with breast masses. In 23 breast cancers and six fibroadenomas, spin echo T1 images were obtained at 0.2 Tesla before and every minute after intravenous injection of Gd-DTPA (0.1 or 0.2 mmol/kg). Subtraction images were obtained sequentially on the CRT monitor. All breast masses were enhanced after gadolinium and stood out as bright lesions on subtraction images. The tumor margin and its extension were more precisely evaluated on subtraction MR images than on conventional postcontrast MR images. Breast cancer showed a characteristic time-intensity curve with an early peak, in contrast to fibroadenoma, which showed a gradual increase in signal intensity. Subtraction MR imaging is a simple method for the evaluation of breast masses, and further, the time-intensity curve obtained by dynamic study is helpful in the differential diagnosis of lesions. (author).

Spectral amplitude coding OCDMA using and subtraction technique.

Science.gov (United States)

Hasoon, Feras N; Aljunid, S A; Samad, M D A; Abdullah, Mohamad Khazani; Shaari, Sahbudin

2008-03-20

An optical decoding technique is proposed for a spectral-amplitude-coding-optical code division multiple access, namely, the AND subtraction technique. The theory is being elaborated and experimental results have been done by comparing a double-weight code against the existing code, Hadamard. We have proved that the and subtraction technique gives better bit error rate performance than the conventional complementary subtraction technique against the received power level.

Clinical application of digital radiography

Energy Technology Data Exchange (ETDEWEB)

Abe, Hiroyuki; Nagasaka, Hideo; Himi, Kazuhisa [Nihon Univ., Tokyo. School of Medicine

1983-04-01

Utility of digital subtraction angiography (DSA) by fluorography was advocated with demonstrable clinical cases. DSA is drawing attention for use at the outpatient clinic because it is relatively noninvasive, involves less risk than that by catheterization, and can be performed by intravenous injection. It also has a number of advantages such as instantaneous imaging and possible imaging of multiple sites by the same procedure. It still be extensively used in clinical practice not only as a screening method, but also as a functional imaging one.

Updates to Constituent Subtraction in Heavy Ions at CMS

CERN Document Server

CMS Collaboration

2018-01-01

The latest upgrades and performance of constituent subtraction in 5.02 TeV PbPb collisions is presented. The constituent subtraction is extended through the full tracker acceptance, increasing the rapidity reach of correctly subtracted jets. A modulation in azimuthal angle is added to the subtraction, accounting for flow on an event-by-event basis and improving jet energy resolution. Closure of jet energy scale after corrections and jet energy resolution is shown for R=0.4 and R=0.8 jets, the latter for the first time in CMS Heavy-Ions.

Improved people detection in nuclear plants by video processing for safety purpose

Energy Technology Data Exchange (ETDEWEB)

Jorge, Carlos Alexandre F.; Mol, Antonio Carlos A.; Carvalho, Paulo Victor R., E-mail: calexandre@ien.gov.br, E-mail: mol@ien.gov.br, E-mail: paulov@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Seixas, Jose M.; Silva, Eduardo Antonio B., E-mail: seixas@lps.ufrj.br, E-mail: eduardo@smt.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Eletrica; Waintraub, Fabio, E-mail: fabiowaintraub@hotmail.com [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola Politecnica. Departamento de Engenharia Eletronica e de Computacao

2013-07-01

This work describes improvements in a surveillance system for safety purposes in nuclear plants. The objective is to track people online in video, in order to estimate the dose received by personnel, during working tasks executed in nuclear plants. The estimation will be based on their tracked positions and on dose rate mapping in a nuclear research reactor, Argonauta. Cameras have been installed within Argonauta room, supplying the data needed. Video processing methods were combined for detecting and tracking people in video. More specifically, segmentation, performed by background subtraction, was combined with a tracking method based on color distribution. The use of both methods improved the overall results. An alternative approach was also evaluated, by means of blind source signal separation. Results are commented, along with perspectives. (author)

Improved people detection in nuclear plants by video processing for safety purpose

International Nuclear Information System (INIS)

Jorge, Carlos Alexandre F.; Mol, Antonio Carlos A.; Carvalho, Paulo Victor R.; Seixas, Jose M.; Silva, Eduardo Antonio B.; Waintraub, Fabio

2013-01-01

This work describes improvements in a surveillance system for safety purposes in nuclear plants. The objective is to track people online in video, in order to estimate the dose received by personnel, during working tasks executed in nuclear plants. The estimation will be based on their tracked positions and on dose rate mapping in a nuclear research reactor, Argonauta. Cameras have been installed within Argonauta room, supplying the data needed. Video processing methods were combined for detecting and tracking people in video. More specifically, segmentation, performed by background subtraction, was combined with a tracking method based on color distribution. The use of both methods improved the overall results. An alternative approach was also evaluated, by means of blind source signal separation. Results are commented, along with perspectives. (author)

Background-Modeling-Based Adaptive Prediction for Surveillance Video Coding.

Science.gov (United States)

Zhang, Xianguo; Huang, Tiejun; Tian, Yonghong; Gao, Wen

2014-02-01

The exponential growth of surveillance videos presents an unprecedented challenge for high-efficiency surveillance video coding technology. Compared with the existing coding standards that were basically developed for generic videos, surveillance video coding should be designed to make the best use of the special characteristics of surveillance videos (e.g., relative static background). To do so, this paper first conducts two analyses on how to improve the background and foreground prediction efficiencies in surveillance video coding. Following the analysis results, we propose a background-modeling-based adaptive prediction (BMAP) method. In this method, all blocks to be encoded are firstly classified into three categories. Then, according to the category of each block, two novel inter predictions are selectively utilized, namely, the background reference prediction (BRP) that uses the background modeled from the original input frames as the long-term reference and the background difference prediction (BDP) that predicts the current data in the background difference domain. For background blocks, the BRP can effectively improve the prediction efficiency using the higher quality background as the reference; whereas for foreground-background-hybrid blocks, the BDP can provide a better reference after subtracting its background pixels. Experimental results show that the BMAP can achieve at least twice the compression ratio on surveillance videos as AVC (MPEG-4 Advanced Video Coding) high profile, yet with a slightly additional encoding complexity. Moreover, for the foreground coding performance, which is crucial to the subjective quality of moving objects in surveillance videos, BMAP also obtains remarkable gains over several state-of-the-art methods.

Parallel decompositions of Mueller matrices and polarimetric subtraction

Directory of Open Access Journals (Sweden)

Gil J.J.

2010-06-01

Full Text Available From a general formulation of the physically realizable parallel decompositions of the Mueller matrix M of a given depolarizing system, a procedure for determining the set of pure Mueller matrices susceptible to be subtracted from M is presented. This procedure provides a way to check if a given pure Mueller matrix N can be subtracted from M or not. If this check is positive, the value of the relative cross section of the subtracted component is also determined.

Developing a Model to Support Students in Solving Subtraction

Directory of Open Access Journals (Sweden)

Nila Mareta Murdiyani

2013-01-01

Full Text Available Subtraction has two meanings and each meaning leads to the different strategies. The meaning of “taking away something” suggests a direct subtraction, while the meaning of “determining the difference between two numbers” is more likely to be modeled as indirect addition. Many prior researches found that the second meaning and second strategy rarely appeared in the mathematical textbooks and teacher explanations, including in Indonesia. Therefore, this study was conducted to contribute to the development of a local instruction theory for subtraction by designing instructional activities that can facilitate first grade of primary school students to develop a model in solving two digit numbers subtraction. Consequently, design research was chosen as an appropriate approach for achieving the research aim and Realistic Mathematics Education (RME was used as a guide to design the lesson. This study involved 6 students in the pilot experiment, 31 students in the teaching experiment, and a first grade teacher of SDN 179 Palembang. The  result of this study shows that the beads string could bridge students from the contextual problems (taking ginger candies and making grains bracelets to the use of the empty number line. It also shows that the empty number line could promote students to  use different strategies (direct subtraction, indirect addition, and indirect subtraction in solving subtraction problems. Based on these findings, it is recommended to apply RME in the teaching learning process to make it more meaningful for students. Keywords: Subtraction, Design Research, Realistic Mathematics Education, The Beads String, The Empty Number Line DOI: http://dx.doi.org/10.22342/jme.4.1.567.95-112

Dual-energy subtraction radiography of the breast

International Nuclear Information System (INIS)

Asaga, Taro; Masuzawa, Chihiro; Kawahara, Satoru; Motohashi, Hisahiko; Okamoto, Takashi; Tamura, Nobuo

1988-01-01

Dual-energy projection radiography was applied to breast examination. To perform the dual-energy subtraction radiography using a digital radiography unit, high and low-energy exposures were made at an appropriate time interval under differing X-ray exposure conditions. Dual-energy subtraction radiography was performed in 41 cancer patients in whom the tumor shadow was equivocal or the border of cancer infiltration was not clearly demonstrated by compression mammography, and 15 patients with benign diseases such as fibrocystic disease, cyst and fibroadenoma. In 21 cases out of the 41 cancer patients, the dual-energy subtraction radiography clearly visualized the malignant tumor shadows and the border of cancer infiltration and the daughter nodules by removing the shadows of normal mammary gland. On the other hand, beign diseases such as fibrocystic disease and cyst could be diagnosed as such, because the tumor shadow and the irregularly concentrated image of mammary gland disappeared by the dual-energy subtraction. These results suggest that this new technique will be useful in examination of breast masses. (author)

Dual-energy subtraction radiography of the breast

Energy Technology Data Exchange (ETDEWEB)

Asaga, Taro; Masuzawa, Chihiro; Kawahara, Satoru; Motohashi, Hisahiko; Okamoto, Takashi; Tamura, Nobuo

1988-06-01

Dual-energy projection radiography was applied to breast examination. To perform the dual-energy subtraction radiography using a digital radiography unit, high and low-energy exposures were made at an appropriate time interval under differing X-ray exposure conditions. Dual-energy subtraction radiography was performed in 41 cancer patients in whom the tumor shadow was equivocal or the border of cancer infiltration was not clearly demonstrated by compression mammography, and 15 patients with benign diseases such as fibrocystic disease, cyst and fibroadenoma. In 21 cases out of the 41 cancer patients, the dual-energy subtraction radiography clearly visualized the malignant tumor shadows and the border of cancer infiltration and the daughter nodules by removing the shadows of normal mammary gland. On the other hand, beign diseases such as fibrocystic disease and cyst could be diagnosed as such, because the tumor shadow and the irregularly concentrated image of mammary gland disappeared by the dual-energy subtraction. These results suggest that this new technique will be useful in examination of breast masses.

Digital subtraction angiography system evaluation with phantoms

International Nuclear Information System (INIS)

Wenstrup, R.S.; Sweeney, K.P.; Scholz, F.J.

1985-01-01

Advances in digital subtraction angiography imaging demonstrate the need for critical evaluation of the performance of digital subtraction equipment. The design of a phantom set for noninvasive assessment of the imaging quality of digital subtraction equipment is described; components include a remotely controlled transport system and individual patterns to evaluate the contrast and detail properties of the image intensifier, low-contrast sensitivity and resolution of the system, geometric distortion of image, linearity, mechanical and electronic stability of equipment, and effects of bone and bowel gas on iodine perception. The performance of an add-on digital radiographic system is presented, along with radiation exposure levels at the image intensifier for a range of radiographic techniques

Motion subtraction of the larynx using digital radiography

International Nuclear Information System (INIS)

Kumakawa, Kohzoh; Miyakawa, Kouichi

1990-01-01

The development of digital radiography (DR) has made it possible to analyze the contour of the laryngeal soft tissue structures in more detail than the conventional screen-film method. The authors first used the DR system for time subtraction of the larynx during inspiration and phonation. The images are acquired by means of frontal tomography of the larynx using the imaging plate during inspiration and phonation separately, and stored into the memory of the DR system. The thickness of the slices is 5.0 mm. Time subtraction between the mask image during inspiration and the live image during phonation is performed using digital processing on CRT. Superimposing the two images at the upper trachea and the thyroid cartilage of the same depth, makes it possible to measure movement of the vocal cord and false vocal cord quantitatively in three dimensions. The authors named this time subtraction as motion subtraction of the larynx. This motion subtraction image can be obtained by on-line digital processing without complicated development technique, but has so high spatial resolution. This image processing seems to be useful in functional radiographic analysis of laryngeal diseases. (author)

Digital subtraction cerebral angiography by intraarterial injection: comparison with conventional angiography

International Nuclear Information System (INIS)

Brant-Zawadzki, M.; Gould, R.; Norman, D.; Newton, T.H.; Lane, B.

1983-01-01

For 4 months, a prototype digital subtraction system was used to obtain images of the cerebral vasculature after intraarterial contrast injections. In 12 instances, the intraarterial injections were recorded with both a digital subtraction unit and conventional direct magnification film-screen system. The digital subtraction and conventional film subtraction images were compared and graded for quality and information content by three skilled observers. In addition, quantitative measurements of contrast-detail performance and spatial resolution were obtained on both the digital system and the screen-film imaging chain. In a clinical setting, both the digital subtraction and conventional film-screen systems provided similar quality images and angiographic information. Contrast-detail curves demonstrated that digital subtraction angiography outperformed conventional film technique for low-contrast objects. Digital subtraction angiography also reduced the time required to obtain the angiogram, markedly reduced film cost, and lowered the contrast agent burden

Development of digital subtraction system DAR-1200

International Nuclear Information System (INIS)

Kawai, Masumi; Shimizu, Yasumitsu; Ozaki, Takeshi; Sawada, Hiroshi; Uzuyama, Kazuhiro; Nishioka, Hiroyuki

1989-01-01

Digital subtraction angiography (DSA) has been of widespread use clinically, and it has attracted considerable attention in angiographic examination today. The merits of Shimadzu high resolution digital subtraction system DAR-1200 are reported in this paper. Furthermore, the principle and clinical usefullness of a new method of DSA called the Peak-Hold DSA are explained especially in details. (author)

Advanced Background Subtraction Applied to Aeroacoustic Wind Tunnel Testing

Science.gov (United States)

Bahr, Christopher J.; Horne, William C.

2015-01-01

An advanced form of background subtraction is presented and applied to aeroacoustic wind tunnel data. A variant of this method has seen use in other fields such as climatology and medical imaging. The technique, based on an eigenvalue decomposition of the background noise cross-spectral matrix, is robust against situations where isolated background auto-spectral levels are measured to be higher than levels of combined source and background signals. It also provides an alternate estimate of the cross-spectrum, which previously might have poor definition for low signal-to-noise ratio measurements. Simulated results indicate similar performance to conventional background subtraction when the subtracted spectra are weaker than the true contaminating background levels. Superior performance is observed when the subtracted spectra are stronger than the true contaminating background levels. Experimental results show limited success in recovering signal behavior for data where conventional background subtraction fails. They also demonstrate the new subtraction technique's ability to maintain a proper coherence relationship in the modified cross-spectral matrix. Beam-forming and de-convolution results indicate the method can successfully separate sources. Results also show a reduced need for the use of diagonal removal in phased array processing, at least for the limited data sets considered.

Sky Subtraction with Fiber-Fed Spectrograph

Science.gov (United States)

Rodrigues, Myriam

2017-09-01

"Historically, fiber-fed spectrographs had been deemed inadequate for the observation of faint targets, mainly because of the difficulty to achieve high accuracy on the sky subtraction. The impossibility to sample the sky in the immediate vicinity of the target in fiber instruments has led to a commonly held view that a multi-object fibre spectrograph cannot achieve an accurate sky subtraction under 1% contrary to their slit counterpart. The next generation of multi-objects spectrograph at the VLT (MOONS) and the planed MOS for the E-ELT (MOSAIC) are fiber-fed instruments, and are aimed to observed targets fainter than the sky continuum level. In this talk, I will present the state-of-art on sky subtraction strategies and data reduction algorithm specifically developed for fiber-fed spectrographs. I will also present the main results of an observational campaign to better characterise the sky spatial and temporal variations ( in particular the continuum and faint sky lines)."

Tomography of photon-added and photon-subtracted states

NARCIS (Netherlands)

Bazrafkan, MR; Man'ko, [No Value

The purpose of this paper is to introduce symplectic and optical tomograms of photon-added and photon-subtracted quantum states. Explicit relations for the tomograms of photon-added and photon-subtracted squeezed coherent states and squeezed number states are obtained. Generating functions for the

Digital subtraction angiography in patients with central vertigo

International Nuclear Information System (INIS)

Inamori, Toru; Takayasu, Yukio; Umetani, Yoshio; Taruoka, Akinori.

1985-01-01

Digital subtraction angiography (DSA) is a recently developed non-invasive intravenous angiography which has become possible through real time digital subtraction of x-ray transmission data from an image intensifier and television system. The output signals of the image intensifier-television camera system are digitized by an analog-digital converter. The digital information, 512x512 pixels and 9 bits deep, is fed into the image processing assembly after logarithmic amplification, where 2-8 frames are added and subtracted from mask images for the final digital images. Intravenous digital subtraction angiography was performed in 21 patients with intractable dizzy spells of central origin resistant to treatment. These patients showed some signs of CNS disturbance, although there were no significant findings on CT scans. Surprisingly, findings were abnormal in 14 of 21 patients (66.7%). DSA is, therefore, considered to be an important aid in the diagnosis of vertigo of the central type. (J.P.N.)

A study on the geometric correction for the digital subtraction radiograph

International Nuclear Information System (INIS)

Lim, Suk Young; Koh, Kwang Joon

2001-01-01

To develop a new subtraction program for registering digital images based on the correspondence of anatomic structures. The digital periapical images were obtained by Digora system with Rinn XCP equipment after translation of 1-16 mm, and rotation of 2-20 at the premolar and molar areas of the human dried mandible. The new subtraction program, NIH Image program and Emago/Advanced program were compared by the peak-signal -to noise ratio (PSNR). The new subtraction program was superior to NIH Images program and Emago/Advanced program up to 16 mm translation and horizontal angulation up to 4. The new subtraction program can be used for subtracting digital periapical images

Model Checking Timed Automata with Priorities using DBM Subtraction

DEFF Research Database (Denmark)

David, Alexandre; Larsen, Kim Guldstrand; Pettersson, Paul

2006-01-01

In this paper we describe an extension of timed automata with priorities, and efficient algorithms to compute subtraction on DBMs (difference bounded matrices), needed in symbolic model-checking of timed automata with priorities. The subtraction is one of the few operations on DBMs that result...... in a non-convex set needing sets of DBMs for representation. Our subtraction algorithms are efficient in the sense that the number of generated DBMs is significantly reduced compared to a naive algorithm. The overhead in time is compensated by the gain from reducing the number of resulting DBMs since...... this number affects the performance of symbolic model-checking. The uses of the DBM subtraction operation extend beyond timed automata with priorities. It is also useful for allowing guards on transitions with urgent actions, deadlock checking, and timed games....

Evaluation of sacroiliitis: contrast-enhanced MRI with subtraction technique

Energy Technology Data Exchange (ETDEWEB)

Algin, Oktay; Gokalp, Gokhan; Baran, Bulent; Ocakoglu, Gokhan; Yazici, Zeynep [Uludag University, Medical Faculty, Department of Radiology, Gorukle, Bursa (Turkey)

2009-10-15

The purpose of the study was to investigate the diagnostic value of contrast-enhanced MRI using the subtraction technique in the detection of active sacroiliitis. Magnetic resonance imaging was performed in 8 asymptomatic volunteers and 50 patients with clinically suspected active sacroiliitis. On precontrast MR images, T1-weighted spin-echo images with and without fat saturation (T1WFS and T1W), STIR and 3D-FLASH images with fat saturation were obtained in the semicoronal plane using a 1.5 Tesla imager. Postcontrast MRI was performed using the same T1WFS sequence as before contrast injection for all volunteers and patients. Postcontrast images were subtracted from fat-suppressed precontrast images. Enhancement within the joint space and bone marrow was considered to demonstrate active sacroiliitis. In 50 patients (100 sacroiliac joints [SIJs]), 40 (76 SIJs) were considered to have active sacroiliitis based on MR images. Bone marrow edema was present in 33 patients (62 SIJs) on STIR images. Routine MRI allowed identification of contrast enhancement in SIJs on postcontrast T1WFS images in 31 patients (49 SIJs). Contrast enhancement was observed in 40 patients (76 SIJs) who were examined by MRI using the subtraction technique. Contrast enhancement was significantly more conspicuous on subtraction images than on non-subtracted postcontrast T1WFS images (Mann-Whitney U test, p<0.001). Contrast-enhanced MRI with subtraction technique may be useful for early detection of active sacroiliitis. (orig.)

Digital subtraction radiographic evaluation of the standardize periapical intraoral radiographs

International Nuclear Information System (INIS)

Cho, Bong Hae; Nah, Kyung Soo

1993-01-01

The geometrically standardized intraoral radiographs using 5 occlusal registration material were taken serially from immediate, 1 day, 2, 4, 8, 12 and 16 weeks after making the bite blocks. The qualities of those subtracted images were evaluated to check the degree of reproducibility of each impression material. The results were as follows: 1. The standard deviations of the grey scales of the overall subtracted images were 4.9 for Exaflex, 7.2 for Pattern resin, 9.0 for Tooth Shade Acrylic, 12.2 for XCP only, 14.8 for Impregum. 2. The standard deviation of the grey scales of the overall subtracted images were grossly related to those of the localized horizontal line of interest. 3. Exaflex which showed the best subtracted image quality had 15 cases of straight, 14 cases of wave, 1 case of canyon shape. Impregum which showed the worst subtracted image quality had 4 cases of straight, 8 cases of wave, 18 cases of canyon shape respectively.

Temporal subtraction in chest radiography: Automated assessment of registration accuracy

International Nuclear Information System (INIS)

Armato, Samuel G. III; Doshi, Devang J.; Engelmann, Roger; Croteau, Charles L.; MacMahon, Heber

2006-01-01

Radiologists routinely compare multiple chest radiographs acquired from the same patient over time to more completely understand changes in anatomy and pathology. While such comparisons are achieved conventionally through a side-by-side display of images, image registration techniques have been developed to combine information from two separate radiographic images through construction of a 'temporal subtraction image'. Although temporal subtraction images provide a powerful mechanism for the enhanced visualization of subtle change, errors in the clinical evaluation of these images may arise from misregistration artifacts that can mimic or obscure pathologic change. We have developed a computerized method for the automated assessment of registration accuracy as demonstrated in temporal subtraction images created from radiographic chest image pairs. The registration accuracy of 150 temporal subtraction images constructed from the computed radiography images of 72 patients was rated manually using a five-point scale ranging from '5-excellent' to '1-poor'; ratings of 3, 4, or 5 reflected clinically acceptable subtraction images, and ratings of 1 or 2 reflected clinically unacceptable images. Gray-level histogram-based features and texture measures are computed at multiple spatial scales within a 'lung mask' region that encompasses both lungs in the temporal subtraction images. A subset of these features is merged through a linear discriminant classifier. With a leave-one-out-by-patient training/testing paradigm, the automated method attained an A z value of 0.92 in distinguishing between temporal subtraction images that demonstrated clinically acceptable and clinically unacceptable registration accuracy. A second linear discriminant classifier yielded an A z value of 0.82 based on a feature subset selected from an independent database of digitized film images. These methods are expected to advance the clinical utility of temporal subtraction images for chest

On the usefulness of portal monitor unit subtraction in radiation therapy

International Nuclear Information System (INIS)

Kuperman, Vadim Y; Lubich, Leslie M

2003-01-01

In order to avoid additional dose to patients caused by portal imaging with megavoltage x-rays, portal monitor units (MUs) are frequently subtracted from the actual treatment MUs. This study examines the usefulness of portal MU subtraction in radiation therapy. For 11 prostate cancer patients treated with 23 MV photons, dose to prostate due to portal filming with 6 MV photons was determined. In all 11 patients subtraction of portal MU values from the actual treatment MUs resulted in a small underdosing of the prostate with an average treatment error of -0.5%. Portal filming without MU subtraction would cause small overdosing of the prostate with an average treatment error of 1.2%. The results of this study indicate that the benefits of portal MU subtraction are in doubt if (a) the energy of treatment x-rays is much higher than that of the portal x-rays and/or (b) when radiotherapy is performed with physical wedges. Based on the obtained results, we argue against unconditional use of the portal MU subtraction method to eliminate the dose from portal imaging

A new registration method with voxel-matching technique for temporal subtraction images

Science.gov (United States)

Itai, Yoshinori; Kim, Hyoungseop; Ishikawa, Seiji; Katsuragawa, Shigehiko; Doi, Kunio

2008-03-01

A temporal subtraction image, which is obtained by subtraction of a previous image from a current one, can be used for enhancing interval changes on medical images by removing most of normal structures. One of the important problems in temporal subtraction is that subtraction images commonly include artifacts created by slight differences in the size, shape, and/or location of anatomical structures. In this paper, we developed a new registration method with voxel-matching technique for substantially removing the subtraction artifacts on the temporal subtraction image obtained from multiple-detector computed tomography (MDCT). With this technique, the voxel value in a warped (or non-warped) previous image is replaced by a voxel value within a kernel, such as a small cube centered at a given location, which would be closest (identical or nearly equal) to the voxel value in the corresponding location in the current image. Our new method was examined on 16 clinical cases with MDCT images. Preliminary results indicated that interval changes on the subtraction images were enhanced considerably, with a substantial reduction of misregistration artifacts. The temporal subtraction images obtained by use of the voxel-matching technique would be very useful for radiologists in the detection of interval changes on MDCT images.

Combined nuclear and digital subtraction contrast arthrography in painful knee prosthesis

International Nuclear Information System (INIS)

Namasivayam, J.; Forrester, A.; Poon, F.W.; Cuthbert, G.F.; McKillop, J.H.; Bryan, A.S.

1992-01-01

The evaluation of a painful knee prosthesis remains a difficult problem for both orthopaedic surgeons and radiologists. We have compared digital subtraction arthrography with nuclear-arthrography in 7 patients with a painful knee prosthesis. Three patients showed a loose tibial component, demonstrated by both digital subtraction and nuclear arthrography. All 3 underwent revision of their prosthesis. One patient had an equivocal digital subtraction arthrogram and negative nuclear arthrogram, while both studies were negative in the 3 remaining patients. Nuclear arthrography is a simple procedure and can provide useful additional information when combined with digital subtraction arthrography. (orig.)

Arthrography of painful hips following arthroplasty: Digital versus plain film subtraction

Energy Technology Data Exchange (ETDEWEB)

Walker, C W; FitzRandolph, R L; Dalrymple, G V [Arkansas Univ. for Medical Sciences, Little Rock, AR (USA). Dept. of Radiology John McClellan Memorial Veterans Hospital, Little Rock, AR (USA); Collins, D N [Arkansas Univ. for Medical Sciences, Little Rock, AR (USA). Dept. of Orthopedics John McClellan Memorial Veterans Hospital, Little Rock, AR (USA)

1991-08-01

Digital and manual subtraction images obtained during the arthrographic evaluation of 78 painful hip prostheses were reviewed retrospectively. Revision arthroplasty was performed in 53 of these cases, and the arthrographic and surgical findings were correlated. The digital and manual subtraction images were evaluated without knowledge of the surgical results using established criteria for component loosening. The difference between detection of femoral component loosening on digital as opposed to manual subtraction images was statistically significant (P < 0.05). This study demonstrates that digital subtraction improves the evaluation of femoral component loosening in painful hip prostheses. (orig./GDG).

[sup 99m]Tc-RBC subtraction scintigraphy; Assessmet of bleeding site and rate

Energy Technology Data Exchange (ETDEWEB)

Inagaki, Syoichi; Tonami, Syuichi; Yasui, Masakazu; Kuranishi, Makoto; Sugishita, Kouki; Nakamura, Mamoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

1994-03-01

Sequential abdominal scintigrams with [sup 99m]Tc-labelled red blood cells (RBC) were subtracted for observing a site of gastrointestinal bleeding and calculating the bleeding rate. This method is technically very easy and can detect the site of bleeding with the minimum rate, as low as 0.2 ml/min., in a phantom experiment. In 23 cases with final diagnosis of gastrointestinal bleeding, conventional non-subtraction scintigraphy detected only 30% (7/23), but subtraction scintigraphy detected 61% (14/23). It was concluded that subtraction scintigraphy had higher sensitivity than conventional scintigraphy for early diagnosing bleeding. A combination of non-subtraction and subtraction scintigraphy is recommended to detect a site of gastrointestinal bleeding in a clinical setting. (author).

Bone marrow edema pattern identification in patients with lytic bone lesions using digital subtraction angiography-like bone subtraction on large-area detector computed tomography.

Science.gov (United States)

Gondim Teixeira, Pedro Augusto; Hossu, Gabriela; Lecocq, Sophie; Razeto, Marco; Louis, Matthias; Blum, Alain

2014-03-01

The objective of this study was to evaluate the performance of digital subtraction angiography (DSA)-like bone subtraction with 2 different registration methods for the identification of bone marrow edema pattern (BMEP) in patients with lytic bone lesions, using magnetic resonance imaging as the criterion standard. Fifty-five patients with a lytic bone lesion were included in this prospective study with approval from the ethics committee. All patients underwent magnetic resonance imaging and low-dose computed tomographic (CT) perfusion after signing an informed consent. Two CT volumes were used for bone subtraction, which was performed with 2 different algorithms (rigid and nonrigid). Enhancement at the nonlytic bone marrow was considered as a sign of BMEP. Two readers evaluated the images blindly. The presence of BMEP on bone-subtracted CT images was evaluated subjectively and quantitatively. Image quality was assessed. Magnetic resonance imaging was used as the criterion standard. Using a rigid registration method, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CT with DSA-like bone subtraction BMEP was 77%, 100%, 100%, 68%, and 85%, respectively. The interobserver agreement was good (κ, 0.782). Image quality was better using a nonrigid registration. With this algorithm, artifacts interfered with image interpretation in only 5% of cases. However, there was a noticeable drop in sensitivity and negative predictive value when a nonrigid algorithm was used: 56% and 52%, respectively. The interobserver agreement was average with a nonrigid subtraction algorithm. Computed tomography with DSA-like bone subtraction is sensitive and highly specific for the identification of BMEP associated with lytic bone lesions. Rigid registering should be preferred, but nonrigid algorithms can be used as a second option when artifacts interfere with image interpretation.

The study of myocardial ischemic quality with weighted-subtraction-bull's-eye analysis

International Nuclear Information System (INIS)

Chen Wuduan; Tian Jiahe; Hou Qingtian

1993-01-01

Weighted-Subtraction-Bull's-eye analysis was studied in 33 normal subjects and 58 patients with coronary artery disease after dipyridamole 99m Tc-MIBI myocardial SPECT imaging. Two kinds of Bull's-eye were produced: (1) subtract rest from 1.2 times dipyridamole from 1.2 times rest Bull's-eye; (2) subtract dipyridamole Bull's-eye. The results showed that the weighted-subtraction-Bull's-eye could clearly displayed the location and puality of ischemic myocardium. And also 74% segments showed so called combined ischemic i.e the blood perfusion reduced, increased and sustained simultaneously after dipyridamole. Therefore weighted-subtraction-Bull's-eye analysis had provided a new method for determination of the quality of ischemia

Digital subtraction cardiopulmonary angiography using FCR (Fuji computed radiography)

International Nuclear Information System (INIS)

Tanimura, Shigeo; Tomoyasu, Hiroshi; Banba, Jiro; Masaki, Mikio; Kanno, Yukio; Abe, Kazuo

1987-01-01

Digital subtraction cardiopulmonary angiography using FCR was performed on 46 patients including lung cancer, mediastinal tumor, giant bullous formation and others. The images of digital subtraction for pulmonary artery, pulmonary vein and thoracic aorta were studied by comparing to the conventional pulmonary angiogram. Good images of pulmonary artery due to digital subtraction were obtained in 80 % of the 45 cases. This method needed only half volume of contrast media compared to the conventional for obtaining good images and thus reduced side effect. Therefore this method seems to be an usefull pre-operative examination in various chest diseases, especially in case of lung cancer. (author)

N-jettiness Subtractions for NNLO QCD calculations

International Nuclear Information System (INIS)

Gaunt, Jonathan R.; Stahlhofen, Maximilian; Tackmann, Frank J.; Walsh, Jonathan R.; California Univ., CA

2015-05-01

We present a subtraction method utilizing the N-jettiness observable, Τ N , to perform QCD calculations for arbitrary processes at next-to-next-to-leading order (NNLO). Our method employs soft-collinear effective theory (SCET) to determine the IR singular contributions of N-jet cross sections for Τ N → 0, and uses these to construct suitable Τ N -subtractions. The construction is systematic and economic, due to being based on a physical observable. The resulting NNLO calculation is fully differential and in a form directly suitable for combining with resummation and parton showers. We explain in detail the application to processes with an arbitrary number of massless partons at lepton and hadron colliders together with the required external inputs in the form of QCD amplitudes and lower-order calculations. We provide explicit expressions for the Τ N -subtractions at NLO and NNLO. The required ingredients are fully known at NLO, and at NNLO for processes with two external QCD partons. The remaining NNLO ingredient for three or more external partons can be obtained numerically with existing NNLO techniques. As an example, we employ our method to obtain the NNLO rapidity spectrum for Drell-Yan and gluon-fusion Higgs production. We discuss aspects of numerical accuracy and convergence and the practical implementation. We also discuss and comment on possible extensions, such as more-differential subtractions, necessary steps for going to N 3 LO, and the treatment of massive quarks.

Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

Energy Technology Data Exchange (ETDEWEB)

Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. (Mt. Sinai Medical Center, New York, NY (USA))

1989-09-01

Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.

Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

International Nuclear Information System (INIS)

Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V.

1989-01-01

Blood-pool subtraction has been proposed to enhance 111 In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging

Ictal cerebral perfusion patterns in partial epilepsy: SPECT subtraction

International Nuclear Information System (INIS)

Lee, Hyang Woon; Hong, Seung Bong; Tae, Woo Suk; Kim, Sang Eun; Seo, Dae Won; Jeong, Seung Cheol; Yi, Ji Young; Hong, Seung Chyul

2000-01-01

To investigate the various ictal perfusion patterns and find the relationships between clinical factors and different perfusion patterns. Interictal and ictal SPECT and SPECT subtraction were performed in 61 patients with partial epilepsy. Both positive images showing ictal hyperperfusion and negative images revealing ictal hypoperfusion were obtained by SPECT subtraction. The ictal perfusion patterns of subtracted SPECT were classified into focal hyperperfusion, hyperperfusion-plus, combined hyperperfusion-hypoperfusion, and focal hypoperfusion only. The concordance rates with epileptic focus were 91.8% in combined analysis of ictal hyperperfusion and hypoperfusion images of subtracted SPECT, 85.2% in hyperperfusion images only of subtracted SPECT, and 68.9% in conventional ictal SPECT analysis. Ictal hypoperfusion occurred less frequently in temporal lobe epilepsy (TLE) than extratemporal lobe epilepsy. Mesial temporal hyperperfusion alone was seen only in mesial TLE while lateral temporal hyperperfusion alone was observed only in neocortical TLE. Hippocampal sclerosis had much lower incidence of ictal hypoperfusion than any other pathology. Some patients showed ictal hypoperfusion at epileptic focus with ictal hyperperfusion in the neighboring brain regions where ictal discharges propagated. Hypoperfusion as well as hyperperfusion in ictal SPECT should be considered for localizing epileptic focus. Although the mechanism of ictal hypoperfusion could be an intra-ictal early exhaustion of seizure focus or a steal phenomenon by the propagation of ictal discharges to adjacent brain areas, further study is needed to elucidate it.=20

Ictal cerebral perfusion patterns in partial epilepsy: SPECT subtraction

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyang Woon; Hong, Seung Bong; Tae, Woo Suk; Kim, Sang Eun; Seo, Dae Won; Jeong, Seung Cheol; Yi, Ji Young; Hong, Seung Chyul [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)

2000-06-01

To investigate the various ictal perfusion patterns and find the relationships between clinical factors and different perfusion patterns. Interictal and ictal SPECT and SPECT subtraction were performed in 61 patients with partial epilepsy. Both positive images showing ictal hyperperfusion and negative images revealing ictal hypoperfusion were obtained by SPECT subtraction. The ictal perfusion patterns of subtracted SPECT were classified into focal hyperperfusion, hyperperfusion-plus, combined hyperperfusion-hypoperfusion, and focal hypoperfusion only. The concordance rates with epileptic focus were 91.8% in combined analysis of ictal hyperperfusion and hypoperfusion images of subtracted SPECT, 85.2% in hyperperfusion images only of subtracted SPECT, and 68.9% in conventional ictal SPECT analysis. Ictal hypoperfusion occurred less frequently in temporal lobe epilepsy (TLE) than extratemporal lobe epilepsy. Mesial temporal hyperperfusion alone was seen only in mesial TLE while lateral temporal hyperperfusion alone was observed only in neocortical TLE. Hippocampal sclerosis had much lower incidence of ictal hypoperfusion than any other pathology. Some patients showed ictal hypoperfusion at epileptic focus with ictal hyperperfusion in the neighboring brain regions where ictal discharges propagated. Hypoperfusion as well as hyperperfusion in ictal SPECT should be considered for localizing epileptic focus. Although the mechanism of ictal hypoperfusion could be an intra-ictal early exhaustion of seizure focus or a steal phenomenon by the propagation of ictal discharges to adjacent brain areas, further study is needed to elucidate it.

Digital subtraction imaging in cardiac investigations

International Nuclear Information System (INIS)

Partridge, J.B.; Dickinson, D.F.

1984-01-01

The role of digital subtraction imaging (DSI) in the investigation of heart disease in patients of all ages, including neonates, was evaluated by the addition of a continuous fluoroscopy system to an existing, single-plane catheterisation laboratory. In some situations, DSI provided diagnostic images where conventional radiography could not and, in general, provided images of comparable quality to cineangiography. The total dose of contrast medium was usually less than that which would have been required for biplane cineangiography and the dose of radiation was always less. Digital subtraction imaging can make a significant contribution to the investigation of congenital heart disease and has some useful features in the study of acquired heart disease. (author)

Hardware Implementation of a Bilateral Subtraction Filter

Science.gov (United States)

Huertas, Andres; Watson, Robert; Villalpando, Carlos; Goldberg, Steven

2009-01-01

A bilateral subtraction filter has been implemented as a hardware module in the form of a field-programmable gate array (FPGA). In general, a bilateral subtraction filter is a key subsystem of a high-quality stereoscopic machine vision system that utilizes images that are large and/or dense. Bilateral subtraction filters have been implemented in software on general-purpose computers, but the processing speeds attainable in this way even on computers containing the fastest processors are insufficient for real-time applications. The present FPGA bilateral subtraction filter is intended to accelerate processing to real-time speed and to be a prototype of a link in a stereoscopic-machine- vision processing chain, now under development, that would process large and/or dense images in real time and would be implemented in an FPGA. In terms that are necessarily oversimplified for the sake of brevity, a bilateral subtraction filter is a smoothing, edge-preserving filter for suppressing low-frequency noise. The filter operation amounts to replacing the value for each pixel with a weighted average of the values of that pixel and the neighboring pixels in a predefined neighborhood or window (e.g., a 9 9 window). The filter weights depend partly on pixel values and partly on the window size. The present FPGA implementation of a bilateral subtraction filter utilizes a 9 9 window. This implementation was designed to take advantage of the ability to do many of the component computations in parallel pipelines to enable processing of image data at the rate at which they are generated. The filter can be considered to be divided into the following parts (see figure): a) An image pixel pipeline with a 9 9- pixel window generator, b) An array of processing elements; c) An adder tree; d) A smoothing-and-delaying unit; and e) A subtraction unit. After each 9 9 window is created, the affected pixel data are fed to the processing elements. Each processing element is fed the pixel value for

AutoDipole - Automated generation of dipole subtraction terms

International Nuclear Information System (INIS)

Hasegawa, K.; Uwer, P.

2009-11-01

We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for bothmassless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. (orig.)

AutoDipole - Automated generation of dipole subtraction terms

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, K.; Uwer, P. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2009-11-15

We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for bothmassless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. (orig.)

ECG-gating in non-cardiac digital subtraction angiography

International Nuclear Information System (INIS)

Gattoni, F.; Baldini, V.; Cairo, F.

1987-01-01

This paper reports the results of the ECG-gating in non-cardiac digital subtraction angiography (DSA). One hundred and fifteen patients underwent DSA (126 examinations); ECG-gating was applied in 66/126 examinations: images recorded at 70% of R wave were subtracted. Artifacts produced by vascular movements were evaluated in all patients: only 40 examinations, carried out whithout ECG-gating, showed vascular artifacts. The major advantage of the ECG-gated DSA is the more efficent subtraction because of the better images superimposition: therefore, ECG-gating can be clinically helpful. On the contrary, it could be a problem in arrhytmic or bradycardic patients. ECG-gating is helpful in DSA imaging of the thoracic and abdominal aorta and of the cervical and renal arteries. In the examinations of peripheral vessels of the limbs it is not so efficent as in the trunk or in the neck

Automating dipole subtraction

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, K.; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Uwer, P. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Theoretische Teilchenphysik

2008-07-15

We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg{yields}t anti tggg. (orig.)

Automating dipole subtraction

International Nuclear Information System (INIS)

Hasegawa, K.; Moch, S.; Uwer, P.

2008-07-01

We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg→t anti tggg. (orig.)

Colourful FKS subtraction

CERN Document Server

Frixione, Stefano

2011-01-01

I formulate in a colour-friendly way the FKS method for the computation of QCD cross sections at the next-to-leading order accuracy. This is achieved through the definition of subtraction terms for squared matrix elements, constructed with single colour-dressed or pairs of colour-ordered amplitudes. The latter approach relies on the use of colour flows, is exact to all orders in $N$, and is thus particularly suited to being organized as a systematic expansion in 1/N.

Nonenhanced magnetic resonance angiography (MRA) of the calf arteries at 3 Tesla: intraindividual comparison of 3D flow-dependent subtractive MRA and 2D flow-independent non-subtractive MRA.

Science.gov (United States)

Knobloch, Gesine; Lauff, Marie-Teres; Hirsch, Sebastian; Schwenke, Carsten; Hamm, Bernd; Wagner, Moritz

2016-12-01

To prospectively compare 3D flow-dependent subtractive MRA vs. 2D flow-independent non-subtractive MRA for assessment of the calf arteries at 3 Tesla. Forty-two patients with peripheral arterial occlusive disease underwent nonenhanced MRA of calf arteries at 3 Tesla with 3D flow-dependent subtractive MRA (fast spin echo sequence; 3D-FSE-MRA) and 2D flow-independent non-subtractive MRA (balanced steady-state-free-precession sequence; 2D-bSSFP-MRA). Moreover, all patients underwent contrast-enhanced MRA (CE-MRA) as standard-of-reference. Two readers performed a per-segment evaluation for image quality (4 = excellent to 0 = non-diagnostic) and severity of stenosis. Image quality scores of 2D-bSSFP-MRA were significantly higher compared to 3D-FSE-MRA (medians across readers: 4 vs. 3; p Tesla with significantly higher image quality and diagnostic accuracy compared to 3D flow-dependent subtractive MRA (3D-FSE-MRA). • 2D flow-independent non-subtractive MRA (2D-bSSFP-MRA) is a robust NE-MRA technique at 3T • 2D-bSSFP-MRA outperforms 3D flow-dependent subtractive MRA (3D-FSE-MRA) as NE-MRA of calf arteries • 2D-bSSFP-MRA is a promising alternative to CE-MRA for calf PAOD evaluation.

People counting in classroom based on video surveillance

Science.gov (United States)

Zhang, Quanbin; Huang, Xiang; Su, Juan

2014-11-01

Currently, the switches of the lights and other electronic devices in the classroom are mainly relied on manual control, as a result, many lights are on while no one or only few people in the classroom. It is important to change the current situation and control the electronic devices intelligently according to the number and the distribution of the students in the classroom, so as to reduce the considerable waste of electronic resources. This paper studies the problem of people counting in classroom based on video surveillance. As the camera in the classroom can not get the full shape contour information of bodies and the clear features information of faces, most of the classical algorithms such as the pedestrian detection method based on HOG (histograms of oriented gradient) feature and the face detection method based on machine learning are unable to obtain a satisfied result. A new kind of dual background updating model based on sparse and low-rank matrix decomposition is proposed in this paper, according to the fact that most of the students in the classroom are almost in stationary state and there are body movement occasionally. Firstly, combining the frame difference with the sparse and low-rank matrix decomposition to predict the moving areas, and updating the background model with different parameters according to the positional relationship between the pixels of current video frame and the predicted motion regions. Secondly, the regions of moving objects are determined based on the updated background using the background subtraction method. Finally, some operations including binarization, median filtering and morphology processing, connected component detection, etc. are performed on the regions acquired by the background subtraction, in order to induce the effects of the noise and obtain the number of people in the classroom. The experiment results show the validity of the algorithm of people counting.

Digital subtraction angiography (DSA)

International Nuclear Information System (INIS)

Ludwig, J.W.; Eikelboom, B.C.; Van Schaik, C.C.; Taams, A.J.; Teeuwen, C.

1985-01-01

Besides the non-invasive techniques, angiography remains essential. The disadvantages of angiography are the complexity of the procedure and the possibility of complications. Digital subtraction angiography (DSA) is a considerable improvement in the examination of vessels. In DSA, subtraction combined with enhancement of the signals allows the use of intravenous injection to obtain good images of the arteries. However, when the contrast material is supplied intravenously, a rather large amount of contrast material is necessary to obtain images of good quality. Quantities of 30-40 cc of contrast material are required. The advantage of the intravenous injection of contrast material rather than the use of a catheter to deliver the contrast material in loco is that it is almost non-invasive thus circumventing the complications caused by catheter manipulation in the arterial system. This makes it possible to apply this method on an out-patient basis. DSA can also be applied with intra-arterial selective injection of the contrast material. In this case, the strong enhancement with DSA allows the use of a small quantity of contrast material while still obtaining images of the vessels with good contrast definition

Video-based real-time on-street parking occupancy detection system

Science.gov (United States)

Bulan, Orhan; Loce, Robert P.; Wu, Wencheng; Wang, YaoRong; Bernal, Edgar A.; Fan, Zhigang

2013-10-01

Urban parking management is receiving significant attention due to its potential to reduce traffic congestion, fuel consumption, and emissions. Real-time parking occupancy detection is a critical component of on-street parking management systems, where occupancy information is relayed to drivers via smart phone apps, radio, Internet, on-road signs, or global positioning system auxiliary signals. Video-based parking occupancy detection systems can provide a cost-effective solution to the sensing task while providing additional functionality for traffic law enforcement and surveillance. We present a video-based on-street parking occupancy detection system that can operate in real time. Our system accounts for the inherent challenges that exist in on-street parking settings, including illumination changes, rain, shadows, occlusions, and camera motion. Our method utilizes several components from video processing and computer vision for motion detection, background subtraction, and vehicle detection. We also present three traffic law enforcement applications: parking angle violation detection, parking boundary violation detection, and exclusion zone violation detection, which can be integrated into the parking occupancy cameras as a value-added option. Our experimental results show that the proposed parking occupancy detection method performs in real-time at 5 frames/s and achieves better than 90% detection accuracy across several days of videos captured in a busy street block under various weather conditions such as sunny, cloudy, and rainy, among others.

REAL TIME TRACKING OBYEK BERGERAK DENGAN WEBCAM BERBASIS WARNA DENGAN METODE BACKGROUND SUBTRACTION

Directory of Open Access Journals (Sweden)

Aris Tri Jaka Harjanta

2017-07-01

Full Text Available Proses tracking obyek pada real time  video adalah salah satu topik yang penting dalam kajian suveillance system (Dhananjaya, Rama, and Thimmaiah 2015. deteksi dan ekstraksi informasi serta pelacakan obyek atau benda bergerak adalah sebagai salah satu bentuk aplikasi dari computer vision. Beberapa aplikasi yang memanfaatkan metode tracking object atau benda bergerak antara lain adalah UAV (Unmanned Aerial Vehicle surveillance atau lebih dikenal dengan mesin/kendaraan tak berawak, Indoor Monitoring system adalah sistem monitoring keadaan dalam ruangan, serta memonitor trafik lalu lintas yang dapat mengamati pergerakan semua benda dalam keadaan real time. Tracking obyek dalam keadaan real time banyak hal yang perlu diperhatikan dan perlu diperhitungkan dimana semua parameter dan noise atau gangguan object di sekitarnya yang tidak perlu kita amati namun berada dalam satu bagian bersama obyek yang kita amati. Dalam penelitian ini metode yang akan digunakan adalah background subtraction untuk pendeteksian serta tracking obyek dan benda bergerak secara real time berbasis warna dengan memanfaatkan kamera webcam dan menggunakan pustaka opensource OpenCv.

Subleading power corrections for N -jettiness subtractions

Science.gov (United States)

Moult, Ian; Rothen, Lorena; Stewart, Iain W.; Tackmann, Frank J.; Zhu, Hua Xing

2017-04-01

The N -jettiness observable TN provides a way of describing the leading singular behavior of the N -jet cross section in the τ =TN/Q →0 limit, where Q is a hard interaction scale. We consider subleading-power corrections in the τ ≪1 expansion, and employ soft-collinear effective theory to obtain analytic results for the dominant αsτ ln τ and αs2τ ln3τ subleading terms for thrust in e+e- collisions and 0-jettiness for q q ¯-initiated Drell-Yan-like processes at hadron colliders. These results can be used to significantly improve the numerical accuracy and stability of the N -jettiness subtraction technique for performing fixed-order calculations at next-to-leading order and next-to-next-to-leading order. They reduce the size of missing power corrections in the subtractions by an order of magnitude. We also point out that the precise definition of N -jettiness has an important impact on the size of the power corrections and thus the numerical accuracy of the subtractions. The sometimes employed definition of N -jettiness in the hadronic center-of-mass frame suffers from power corrections that grow exponentially with rapidity, causing the power expansion to deteriorate away from central rapidity. This degradation does not occur for the original N -jettiness definition, which explicitly accounts for the boost of the Born process relative to the frame of the hadronic collision, and has a well-behaved power expansion throughout the entire phase space. Integrated over rapidity, using this N -jettiness definition in the subtractions yields another order of magnitude improvement compared to employing the hadronic-frame definition.

Digital image comparison by subtracting contextual transformations—percentile rank order differentiation

Science.gov (United States)

Wehde, M. E.

1995-01-01

The common method of digital image comparison by subtraction imposes various constraints on the image contents. Precise registration of images is required to assure proper evaluation of surface locations. The attribute being measured and the calibration and scaling of the sensor are also important to the validity and interpretability of the subtraction result. Influences of sensor gains and offsets complicate the subtraction process. The presence of any uniform systematic transformation component in one of two images to be compared distorts the subtraction results and requires analyst intervention to interpret or remove it. A new technique has been developed to overcome these constraints. Images to be compared are first transformed using the cumulative relative frequency as a transfer function. The transformed images represent the contextual relationship of each surface location with respect to all others within the image. The process of differentiating between the transformed images results in a percentile rank ordered difference. This process produces consistent terrain-change information even when the above requirements necessary for subtraction are relaxed. This technique may be valuable to an appropriately designed hierarchical terrain-monitoring methodology because it does not require human participation in the process.

Late iodine enhancement computed tomography with image subtraction for assessment of myocardial infarction

Energy Technology Data Exchange (ETDEWEB)

Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Kouchi, Takanori; Fukuyama, Naoki; Yokoi, Takahiro; Miyagawa, Masao; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Radiology, Toon City, Ehime (Japan); Uetani, Teruyoshi [Department of Cardiology, Ehime University Graduate School of Medicine, Toon City, Ehime (Japan); Yamashita, Natsumi [National Hospital Organization Shikoku Cancer Center, Department of Clinical Biostatistics, Section of Cancer Prevention and Epidemiology, Clinical Research Center, Matsuyama City, Ehime (Japan)

2018-03-15

To evaluate the feasibility of image subtraction in late iodine enhancement CT (LIE-CT) for assessment of myocardial infarction (MI). A comprehensive cardiac CT protocol and late gadolinium enhancement MRI (LGE-MRI) was used to assess coronary artery disease in 27 patients. LIE-CT was performed after stress CT perfusion (CTP) and CT angiography. Subtraction LIE-CT was created by subtracting the mask volume of the left ventricle (LV) cavity from the original LIE-CT using CTP dataset. The %MI volume was quantified as the ratio of LIE to entire LV volume, and transmural extent (TME) of LIE was classified as 0%, 1-24%, 25-49%, 50-74% or 75-100%. These results were compared with LGE-MRI using the Spearman rank test, Bland-Altman method and chi-square test. One hundred twenty-five (29%) of 432 segments were positive on LGE-MRI. Correlation coefficients for original and subtraction LIE-CT to LGE-MRI were 0.79 and 0.85 for %MI volume. Concordances of the 5-point grading scale between original and subtraction LIE-CT with LGE-MRI were 75% and 84% for TME; concordance was significantly improved using the subtraction technique (p <0.05). Subtraction LIE-CT allowed more accurate assessment of MI extent than the original LIE-CT. (orig.)

Decoupling Subtraction Conserving Full Gauge Symmetries : Particles and Fields

OpenAIRE

Noriyasu, OHTSUBO; Hideo, MIYATA; Department of Phycics, Kanazawa Technical College; Department of Information Science, Kanazawa Institute of Technolgy

1984-01-01

A new subtraction scheme (^^^) which realizes the decoupling and conserves the symmetries of full gauge group simultaneously, is proposed. One particle irreducible Green's functions subtracted by ^^^ reveal the effective low energy symmetries at -p^2≪M^2 and the full symmetries at -p^2≫M^2, where M denotes a heavy mass. Also discussed are conditions in order to carry out ^^^ under two-loop approximation.

Intravenous digital subtraction angiography of transplanted kidney artery

International Nuclear Information System (INIS)

Tessier, J.P; Teyssou, H.; Verdier, J.P.; Tison, E.; Meyblum, J.; Marchal, M.

1986-01-01

Results of 351 intravenous digital subtraction angiographs (AN) of transplanted kidneys emphasized reliability of this examination for detection of renal artery stenosis. A prospective study of 219 patients (188 interpretable AN) showed significant stenosis of grafted artery in 22% of cases: 17% of the 126 patients with normal blood pressure and 34% of the 62 cases of hypertension. Digital subtraction allows, with a single injection, assessment of renal artery, nephrogram and excretory cavities, but it is not a substitute for conventional intravenous urography 1 to 2 months after grafting [fr

Ictal hyperperfusion of cerebellum and basal ganglia in temporal lobe epilepsy: SPECT subtraction

Energy Technology Data Exchange (ETDEWEB)

Shin, Won Chul; Hong, Seung Bong; Tae, Woo Suk; Seo, Dae Won; Kim, Sang Eun [School of Medicine, Sungkyunkwan, Seoul (Korea, Republic of)

2001-02-01

The ictal perfusion patterns of cerebellum and basal ganglia have not been systematically investigated in patients with temporal lobe epilepsy (TLE). Their ictal perfusion patterns were analyzed in relation with temporal lobe and frontal lobe hyperperfusion during TLE seizures using SPECT subtraction. Thirty-three TLE patients had interictal and ictal SPECT, video-EEG monitoring. SPGR MRI, and SPECT subtraction with MRI co-registration. The vermian cerebellar hyperperfusion (CH) was observed in 26 patients (78.8%) and hemispheric CH in 25 (75.8%). Compared to the side of epileptogenic temporal lobe, there were seven ipsilateral hemispheric CH (28.0%), fifteen contralateral hemispheric CH( 60.0%) and three bilateral hemispheric CH( 12.0%). CH was more frequently observed in patients with additional frontal hyperperfusion (15/15, 93.3%) than in patients without frontal hyperperfusion (11/18, 61.1 %). The basal ganglia hyperperfusion (14/15, 93.3%) than in patients without frontal hyperperfusion (BGH) was seen in 11 of the 15 patients with frontotemporal hyperperfusion (73.3%) and 11 of the 18 with temporal hyperperfusion only (61.1%). In 17 patients with unilateral BGH, contralateral CH to the BGH was observed in 14 (82.5%) and ipsilateral CH to BGH in 2 (11.8%) and bilateral CH in 1 (5.9%). The cerebellar hyperperfusion and basal ganglia hyperperfusion during seizures of TLE can be contralateral, ipsilateral or bilateral to the seizure focus. The presence of additional frontal or basal ganglia hyperperfusion was more frequently associated with contralateral hemispheric CH to their sides. However, temporal lobe hyperperfusion appears to be related with both ipsilateral and contralateral hemispheric CH.

Ictal hyperperfusion of cerebellum and basal ganglia in temporal lobe epilepsy: SPECT subtraction

International Nuclear Information System (INIS)

Shin, Won Chul; Hong, Seung Bong; Tae, Woo Suk; Seo, Dae Won; Kim, Sang Eun

2001-01-01

The ictal perfusion patterns of cerebellum and basal ganglia have not been systematically investigated in patients with temporal lobe epilepsy (TLE). Their ictal perfusion patterns were analyzed in relation with temporal lobe and frontal lobe hyperperfusion during TLE seizures using SPECT subtraction. Thirty-three TLE patients had interictal and ictal SPECT, video-EEG monitoring. SPGR MRI, and SPECT subtraction with MRI co-registration. The vermian cerebellar hyperperfusion (CH) was observed in 26 patients (78.8%) and hemispheric CH in 25 (75.8%). Compared to the side of epileptogenic temporal lobe, there were seven ipsilateral hemispheric CH (28.0%), fifteen contralateral hemispheric CH( 60.0%) and three bilateral hemispheric CH( 12.0%). CH was more frequently observed in patients with additional frontal hyperperfusion (15/15, 93.3%) than in patients without frontal hyperperfusion (11/18, 61.1 %). The basal ganglia hyperperfusion (14/15, 93.3%) than in patients without frontal hyperperfusion (BGH) was seen in 11 of the 15 patients with frontotemporal hyperperfusion (73.3%) and 11 of the 18 with temporal hyperperfusion only (61.1%). In 17 patients with unilateral BGH, contralateral CH to the BGH was observed in 14 (82.5%) and ipsilateral CH to BGH in 2 (11.8%) and bilateral CH in 1 (5.9%). The cerebellar hyperperfusion and basal ganglia hyperperfusion during seizures of TLE can be contralateral, ipsilateral or bilateral to the seizure focus. The presence of additional frontal or basal ganglia hyperperfusion was more frequently associated with contralateral hemispheric CH to their sides. However, temporal lobe hyperperfusion appears to be related with both ipsilateral and contralateral hemispheric CH

Detection of intracranial aneurysms using three-dimensional multidetector-row CT angiography: Is bone subtraction necessary?

International Nuclear Information System (INIS)

Hwang, Seung Bae; Kwak, Hyo Sung; Han, Young Min; Chung, Gyung Ho

2011-01-01

Purpose: The aim of this study was to evaluate the usefulness of three-dimensional CT angiography (3D CTA) with bone subtraction in a comparison with 3D CTA without bone subtraction for the detection of intracranial aneurysms. Materials and methods: Among 337 consecutive patients who had intracranial aneurysms detected on 3D CTA, 170 patients who underwent digital subtraction angiography (DSA) were included in the study. CTA was performed with a 16-slice multidetector-row CT (MDCT) scanner. We created the 3D reconstruction images with and without bone subtraction by using the volume rendering technique. Three neuroradiologists in a blinded fashion interpreted both 3D CTA images with and without bone subtraction. The diagnostic accuracy of both techniques was evaluated using the alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive value were also evaluated. Results: A total of 200 aneurysms (size: 2-23 mm) were detected in 170 patients. The area under the receiver operating characteristic curve (Az) for 3D CTA with bone subtraction (mean, Az = 0.933) was significantly higher than that for 3D CTA without bone subtraction (mean, Az = 0.879) for all observers (P < 0.05). The sensitivity of 3D CTA with bone subtraction for three observers was 90.0, 92.0 and 92.5%, respectively, while the sensitivity of 3D CTA without bone subtraction was 83.5, 83.5 and 87.5%, respectively. No significant difference in positive predictive value was observed between the two modalities. Conclusions: 3D CTA with bone subtraction showed significantly higher diagnostic accuracy for the detection of intracranial aneurysms as compared to 3D CTA without bone subtraction.

Incidence of ischemic lesions in diffusion-weighted imaging after transbrachial digital subtraction angiography

International Nuclear Information System (INIS)

Aschenbach, R.; Majeed, A.; Eger, C.; Basche, S.; Kerl, J.M.; Vogl, T.J.

2008-01-01

Purpose: to evaluate the frequency of ischemia after transbrachial digital subtraction angiography under ambulant conditions using diffusion-weighted imaging. Materials and methods: 200 patients were included in a prospective study design and received transbrachial digital subtraction angiography under ambulant conditions. Before and after digital subtraction angiography, diffusion-weighted imaging of the brain was performed. Results: in our study population no new lesions were found in diffusion-weighted imaging after digital subtraction angiography during the 3-hour window after angiography. One new lesion was found 3 days after angiography as a late onset complication. Therefore, the frequency of neurological complications is at the level of the confidence interval of 0 - 1.5%. Conclusion: the transbrachial approach under ambulant conditions is a safe method for digital subtraction angiography resulting in a low rate of ischemic lesions in diffusion-weighted imaging. (orig.)

Digital subtraction angiography in traumatology

International Nuclear Information System (INIS)

Steudel, A.; Harder, T.; Lackner, K.; Schneider, B.; Orellano, L.; Bonn Univ.; Bonn Univ.

1986-01-01

The methods, indications and results of digital subtraction angiography in traumatology are presented, based on 56 examinations. The different use of intravenous or intraarterial DSA will be discussed with respect to expanding and localisation of traumatic vascular injury. DSA is recommended as the method of choice for follow-up after vascular reconstructive procedure. (orig.) [de

Subtractive Structural Modification of Morpho Butterfly Wings.

Science.gov (United States)

Shen, Qingchen; He, Jiaqing; Ni, Mengtian; Song, Chengyi; Zhou, Lingye; Hu, Hang; Zhang, Ruoxi; Luo, Zhen; Wang, Ge; Tao, Peng; Deng, Tao; Shang, Wen

2015-11-11

Different from studies of butterfly wings through additive modification, this work for the first time studies the property change of butterfly wings through subtractive modification using oxygen plasma etching. The controlled modification of butterfly wings through such subtractive process results in gradual change of the optical properties, and helps the further understanding of structural optimization through natural evolution. The brilliant color of Morpho butterfly wings is originated from the hierarchical nanostructure on the wing scales. Such nanoarchitecture has attracted a lot of research effort, including the study of its optical properties, its potential use in sensing and infrared imaging, and also the use of such structure as template for the fabrication of high-performance photocatalytic materials. The controlled subtractive processes provide a new path to modify such nanoarchitecture and its optical property. Distinct from previous studies on the optical property of the Morpho wing structure, this study provides additional experimental evidence for the origination of the optical property of the natural butterfly wing scales. The study also offers a facile approach to generate new 3D nanostructures using butterfly wings as the templates and may lead to simpler structure models for large-scale man-made structures than those offered by original butterfly wings. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studying fish near ocean energy devices using underwater video

Energy Technology Data Exchange (ETDEWEB)

Matzner, Shari; Hull, Ryan E.; Harker-Klimes, Genevra EL; Cullinan, Valerie I.

2017-09-18

The effects of energy devices on fish populations are not well-understood, and studying the interactions of fish with tidal and instream turbines is challenging. To address this problem, we have evaluated algorithms to automatically detect fish in underwater video and propose a semi-automated method for ocean and river energy device ecological monitoring. The key contributions of this work are the demonstration of a background subtraction algorithm (ViBE) that detected 87% of human-identified fish events and is suitable for use in a real-time system to reduce data volume, and the demonstration of a statistical model to classify detections as fish or not fish that achieved a correct classification rate of 85% overall and 92% for detections larger than 5 pixels. Specific recommendations for underwater video acquisition to better facilitate automated processing are given. The recommendations will help energy developers put effective monitoring systems in place, and could lead to a standard approach that simplifies the monitoring effort and advances the scientific understanding of the ecological impacts of ocean and river energy devices.

Organizational potentialities of photofluorography improvement

International Nuclear Information System (INIS)

Astrakhantsev, F.A.; Chikirdin, Eh.G.

1993-01-01

The necessity for fluorography application is connected with the possibility of identifying voluminus and deformable changes in lungs, mediastinum in a great number of patients within a short period of time. It is advisable to improve clinical and economical efficiency of fluorography. The fluorography efficiency is higher in groups with higher disease risk. The proposed fluorography quesionnaire for six groups of risk may be completed by computer

Digital subtraction angiography: first 900 cases

International Nuclear Information System (INIS)

Rodgers, H.

1984-01-01

The diagnostic technique of digital subtraction angiography (DSA) is briefly outlined. The operational and technical experiences with a DR-960 DSA system used in the examination of the first 900 cases at St. Thomas' Hospital, London are described. (U.K.)

Video deraining and desnowing using temporal correlation and low-rank matrix completion.

Science.gov (United States)

Kim, Jin-Hwan; Sim, Jae-Young; Kim, Chang-Su

2015-09-01

A novel algorithm to remove rain or snow streaks from a video sequence using temporal correlation and low-rank matrix completion is proposed in this paper. Based on the observation that rain streaks are too small and move too fast to affect the optical flow estimation between consecutive frames, we obtain an initial rain map by subtracting temporally warped frames from a current frame. Then, we decompose the initial rain map into basis vectors based on the sparse representation, and classify those basis vectors into rain streak ones and outliers with a support vector machine. We then refine the rain map by excluding the outliers. Finally, we remove the detected rain streaks by employing a low-rank matrix completion technique. Furthermore, we extend the proposed algorithm to stereo video deraining. Experimental results demonstrate that the proposed algorithm detects and removes rain or snow streaks efficiently, outperforming conventional algorithms.

Thallium-201 and technetium-99m pertechnetate subtraction scintigraphy in patients with hyperparathyroidism

International Nuclear Information System (INIS)

Kuwashima, Shigeko; Koizumi, Mitsuru; Goto, Masafumi; Nomura, Toshiharu; Fujioka, Mutsuhisa; Watari, Tsutomu

1992-01-01

A reliable technique for detecting and localizing abnormal parathyroid tissue has been a persistent problem. We evaluated thallium-technetium (Tl/Tc) subtraction scintigraphy in 16 patients with clinical biochemical evidence of hyperparathyroidism prior to other diagnostic methods and surgery. Seven patients had surgery and were confirmed to have parathyroid adenoma or hyperplasia. The other methods included ultrasonography (US) in 6 patients, computed tomography (CT) in 10 patients, magnetic resonance imaging (MRI) in 8 patients, and bone scintigraphy in 7 patients. In patients who had several imaging modalities, the detection rate was significantly better for Tl/Tc subtraction scan than for US, CT or MRI. Bote scintigraphy, though not so sensitive as Tl/Tc subtraction studies, was an important tool for evaluating metabolic bone disorder including hyperparathyroidism and renal osteodystrophy. Thus, Tl/Tc subtraction scan is more useful for diagnosis when hyperparathyroidism is suspected if both Tl/Tc subtraction scan and bone scan are performed. The detectability depended on the mass size, and detection of abnormal glands was greater for adenoma than for hyperplasia. The results suggest that Tl/Tc subtraction scan is a simple, non-invasive and useful tool for locating parathyroid abnormality even when compared with MRI. (author)

Color Addition and Subtraction Apps

Science.gov (United States)

Ruiz, Frances; Ruiz, Michael J.

2015-01-01

Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…

Power corrections in the N-jettiness subtraction scheme

Energy Technology Data Exchange (ETDEWEB)

Boughezal, Radja [High Energy Physics Division, Argonne National Laboratory,Argonne, IL 60439 (United States); Liu, Xiaohui [Department of Physics, Beijing Normal University,Beijing, 100875 (China); Center of Advanced Quantum Studies, Beijing Normal University,Beijing, 100875 (China); Center for High-Energy Physics, Peking University,Beijing, 100871 (China); Maryland Center for Fundamental Physics, University of Maryland,College Park, MD 20742 (United States); Petriello, Frank [Department of Physics & Astronomy, Northwestern University,Evanston, IL 60208 (United States); High Energy Physics Division, Argonne National Laboratory,Argonne, IL 60439 (United States)

2017-03-30

We discuss the leading-logarithmic power corrections in the N-jettiness subtraction scheme for higher-order perturbative QCD calculations. We compute the next-to-leading order power corrections for an arbitrary N-jet process, and we explicitly calculate the power correction through next-to-next-to-leading order for color-singlet production for both qq̄ and gg initiated processes. Our results are compact and simple to implement numerically. Including the leading power correction in the N-jettiness subtraction scheme substantially improves its numerical efficiency. We discuss what features of our techniques extend to processes containing final-state jets.

A simple digital subtraction angiographic instrument

International Nuclear Information System (INIS)

Ando, Hiroshi; Kobayashi, Tsuyoshi; Imai, Yutaka; Yanagishita, Akira

1983-01-01

A digital subtraction angiographic instrument was manufactured using a conventional x-ray TV for gastrointestinal series and a computer for processing of nuclear medical data. The results of visualization of the aorta and its primary branches were reviewed with demonstrable cases. (Chiba, N.)

FPGA implementation for real-time background subtraction based on Horprasert model.

Science.gov (United States)

Rodriguez-Gomez, Rafael; Fernandez-Sanchez, Enrique J; Diaz, Javier; Ros, Eduardo

2012-01-01

Background subtraction is considered the first processing stage in video surveillance systems, and consists of determining objects in movement in a scene captured by a static camera. It is an intensive task with a high computational cost. This work proposes an embedded novel architecture on FPGA which is able to extract the background on resource-limited environments and offers low degradation (produced because of the hardware-friendly model modification). In addition, the original model is extended in order to detect shadows and improve the quality of the segmentation of the moving objects. We have analyzed the resource consumption and performance in Spartan3 Xilinx FPGAs and compared to others works available on the literature, showing that the current architecture is a good trade-off in terms of accuracy, performance and resources utilization. With less than a 65% of the resources utilization of a XC3SD3400 Spartan-3A low-cost family FPGA, the system achieves a frequency of 66.5 MHz reaching 32.8 fps with resolution 1,024 × 1,024 pixels, and an estimated power consumption of 5.76 W.

FPGA Implementation for Real-Time Background Subtraction Based on Horprasert Model

Directory of Open Access Journals (Sweden)

Eduardo Ros

2012-01-01

Full Text Available Background subtraction is considered the first processing stage in video surveillance systems, and consists of determining objects in movement in a scene captured by a static camera. It is an intensive task with a high computational cost. This work proposes an embedded novel architecture on FPGA which is able to extract the background on resource-limited environments and offers low degradation (produced because of the hardware-friendly model modification. In addition, the original model is extended in order to detect shadows and improve the quality of the segmentation of the moving objects. We have analyzed the resource consumption and performance in Spartan3 Xilinx FPGAs and compared to others works available on the literature, showing that the current architecture is a good trade-off in terms of accuracy, performance and resources utilization. With less than a 65% of the resources utilization of a XC3SD3400 Spartan-3A low-cost family FPGA, the system achieves a frequency of 66.5 MHz reaching 32.8 fps with resolution 1,024 x 1,024 pixels, and an estimated power consumption of 5.76 W.

Automatic Video-based Analysis of Human Motion

DEFF Research Database (Denmark)

Fihl, Preben

The human motion contains valuable information in many situations and people frequently perform an unconscious analysis of the motion of other people to understand their actions, intentions, and state of mind. An automatic analysis of human motion will facilitate many applications and thus has...... received great interest from both industry and research communities. The focus of this thesis is on video-based analysis of human motion and the thesis presents work within three overall topics, namely foreground segmentation, action recognition, and human pose estimation. Foreground segmentation is often...... the first important step in the analysis of human motion. By separating foreground from background the subsequent analysis can be focused and efficient. This thesis presents a robust background subtraction method that can be initialized with foreground objects in the scene and is capable of handling...

Summation and subtraction using a modified autoshaping procedure in pigeons.

Science.gov (United States)

Ploog, Bertram O

2008-06-01

A modified autoshaping paradigm (significantly different from those previously reported in the summation literature) was employed to allow for the simultaneous assessment of stimulus summation and subtraction in pigeons. The response requirements and the probability of food delivery were adjusted such that towards the end of training 12 of 48 trials ended in food delivery, the same proportion as under testing. Stimuli (outlines of squares of three sizes and colors: A, B, and C) were used that could be presented separately or in any combination of two or three stimuli. Twelve of the pigeons (summation groups) were trained with either A, B, and C or with AB, BC, and CA, and tested with ABC. The remaining 12 pigeons (subtraction groups) received training with ABC but were tested with A, B, and C or with AB, BC, and CA. These groups were further subdivided according to whether stimulus elements were presented either in a concentric or dispersed manner. Summation did not occur; subtraction occurred in the two concentric groups. For interpretation of the results, configural theory, the Rescorla-Wagner model, and the composite-stimulus control model were considered. The results suggest different mechanisms responsible for summation and subtraction.

Appearance of the canine meninges in subtraction magnetic resonance images.

Science.gov (United States)

Lamb, Christopher R; Lam, Richard; Keenihan, Erin K; Frean, Stephen

2014-01-01

The canine meninges are not visible as discrete structures in noncontrast magnetic resonance (MR) images, and are incompletely visualized in T1-weighted, postgadolinium images, reportedly appearing as short, thin curvilinear segments with minimal enhancement. Subtraction imaging facilitates detection of enhancement of tissues, hence may increase the conspicuity of meninges. The aim of the present study was to describe qualitatively the appearance of canine meninges in subtraction MR images obtained using a dynamic technique. Images were reviewed of 10 consecutive dogs that had dynamic pre- and postgadolinium T1W imaging of the brain that was interpreted as normal, and had normal cerebrospinal fluid. Image-anatomic correlation was facilitated by dissection and histologic examination of two canine cadavers. Meningeal enhancement was relatively inconspicuous in postgadolinium T1-weighted images, but was clearly visible in subtraction images of all dogs. Enhancement was visible as faint, small-rounded foci compatible with vessels seen end on within the sulci, a series of larger rounded foci compatible with vessels of variable caliber on the dorsal aspect of the cerebral cortex, and a continuous thin zone of moderate enhancement around the brain. Superimposition of color-encoded subtraction images on pregadolinium T1- and T2-weighted images facilitated localization of the origin of enhancement, which appeared to be predominantly dural, with relatively few leptomeningeal structures visible. Dynamic subtraction MR imaging should be considered for inclusion in clinical brain MR protocols because of the possibility that its use may increase sensitivity for lesions affecting the meninges. © 2014 American College of Veterinary Radiology.

IR subtraction schemes. Integrating the counterterms at NNLO in QCD

Energy Technology Data Exchange (ETDEWEB)

Bolzoni, Paolo; Somogyi, Gabor

2010-06-15

We briefly review a subtraction scheme for computing radiative corrections to QCD jet cross sections that can be defined at any order in perturbation theory. Hereafter we discuss the computational methods used to evaluate analytically and numerically the integrated counterterms arising from such a subtraction scheme. Basically these methods the Mellin-Barnes (MB) representations technique together with the harmonic summation and the sector decomposition. (orig.)

IR subtraction schemes. Integrating the counterterms at NNLO in QCD

International Nuclear Information System (INIS)

Bolzoni, Paolo; Somogyi, Gabor

2010-06-01

We briefly review a subtraction scheme for computing radiative corrections to QCD jet cross sections that can be defined at any order in perturbation theory. Hereafter we discuss the computational methods used to evaluate analytically and numerically the integrated counterterms arising from such a subtraction scheme. Basically these methods the Mellin-Barnes (MB) representations technique together with the harmonic summation and the sector decomposition. (orig.)

Digital subtraction arthrography in preoperative evaluation of painful total hip arthroplasty

International Nuclear Information System (INIS)

Ginai, A.Z.; Biezen, F.C. van; Kint, P.A.M.; Oei, H.Y.; Hop, W.C.J.

1996-01-01

Digital subtraction arthrograms, scintigrams and plain radiographs of 70 consecutive patients who underwent revision hip arthroplasty were scored individually and in masked fashion for the presence or absence of features indicating loosening of femoral and/or acetabular components. The operative findings acted as the gold standard. Digital subtraction arthrography was best for predicting a loose acetabular component, while no significant additional predictive value was found for plain radiographs and scintigraphy. Digital subtraction arthrography was also the most important modality for predicting a loose femoral component, while the plain radiograph was of significant additional value and scintigraphy was of no additional value on multivariate analysis. (orig./MG)

3D temporal subtraction on multislice CT images using nonlinear warping technique

Science.gov (United States)

Ishida, Takayuki; Katsuragawa, Shigehiko; Kawashita, Ikuo; Kim, Hyounseop; Itai, Yoshinori; Awai, Kazuo; Li, Qiang; Doi, Kunio

2007-03-01

The detection of very subtle lesions and/or lesions overlapped with vessels on CT images is a time consuming and difficult task for radiologists. In this study, we have developed a 3D temporal subtraction method to enhance interval changes between previous and current multislice CT images based on a nonlinear image warping technique. Our method provides a subtraction CT image which is obtained by subtraction of a previous CT image from a current CT image. Reduction of misregistration artifacts is important in the temporal subtraction method. Therefore, our computerized method includes global and local image matching techniques for accurate registration of current and previous CT images. For global image matching, we selected the corresponding previous section image for each current section image by using 2D cross-correlation between a blurred low-resolution current CT image and a blurred previous CT image. For local image matching, we applied the 3D template matching technique with translation and rotation of volumes of interests (VOIs) which were selected in the current and the previous CT images. The local shift vector for each VOI pair was determined when the cross-correlation value became the maximum in the 3D template matching. The local shift vectors at all voxels were determined by interpolation of shift vectors of VOIs, and then the previous CT image was nonlinearly warped according to the shift vector for each voxel. Finally, the warped previous CT image was subtracted from the current CT image. The 3D temporal subtraction method was applied to 19 clinical cases. The normal background structures such as vessels, ribs, and heart were removed without large misregistration artifacts. Thus, interval changes due to lung diseases were clearly enhanced as white shadows on subtraction CT images.

Identification of hand motion using background subtraction method and extraction of image binary with backpropagation neural network on skeleton model

Science.gov (United States)

Fauziah; Wibowo, E. P.; Madenda, S.; Hustinawati

2018-03-01

Capturing and recording motion in human is mostly done with the aim for sports, health, animation films, criminality, and robotic applications. In this study combined background subtraction and back propagation neural network. This purpose to produce, find similarity movement. The acquisition process using 8 MP resolution camera MP4 format, duration 48 seconds, 30frame/rate. video extracted produced 1444 pieces and results hand motion identification process. Phase of image processing performed is segmentation process, feature extraction, identification. Segmentation using bakground subtraction, extracted feature basically used to distinguish between one object to another object. Feature extraction performed by using motion based morfology analysis based on 7 invariant moment producing four different classes motion: no object, hand down, hand-to-side and hands-up. Identification process used to recognize of hand movement using seven inputs. Testing and training with a variety of parameters tested, it appears that architecture provides the highest accuracy in one hundred hidden neural network. The architecture is used propagate the input value of the system implementation process into the user interface. The result of the identification of the type of the human movement has been clone to produce the highest acuracy of 98.5447%. The training process is done to get the best results.

The Use of Procedural Knowledge in Simple Addition and Subtraction Problems

Science.gov (United States)

Fayol, Michel; Thevenot, Catherine

2012-01-01

In a first experiment, adults were asked to solve one-digit additions, subtractions and multiplications. When the sign appeared 150 ms before the operands, addition and subtraction were solved faster than when the sign and the operands appeared simultaneously on screen. This priming effect was not observed for multiplication problems. A second…

Temporal subtraction of chest radiographs compensating pose differences

Science.gov (United States)

von Berg, Jens; Dworzak, Jalda; Klinder, Tobias; Manke, Dirk; Kreth, Adrian; Lamecker, Hans; Zachow, Stefan; Lorenz, Cristian

2011-03-01

Temporal subtraction techniques using 2D image registration improve the detectability of interval changes from chest radiographs. Although such methods are well known for some time they are not widely used in radiologic practice. The reason is the occurrence of strong pose differences between two acquisitions with a time interval of months to years in between. Such strong perspective differences occur in a reasonable number of cases. They cannot be compensated by available image registration methods and thus mask interval changes to be undetectable. In this paper a method is proposed to estimate a 3D pose difference by the adaptation of a 3D rib cage model to both projections. The difference between both is then compensated for, thus producing a subtraction image with virtually no change in pose. The method generally assumes that no 3D image data is available from the patient. The accuracy of pose estimation is validated with chest phantom images acquired under controlled geometric conditions. A subtle interval change simulated by a piece of plastic foam attached to the phantom becomes visible in subtraction images generated with this technique even at strong angular pose differences like an anterior-posterior inclination of 13 degrees.

Wilson expansion in the minimal subtraction scheme

International Nuclear Information System (INIS)

Smirnov, V.A.

1989-01-01

The small distance expansion of the product of composite fields is constructed for an arbitrary renormalization procedure of the type of minimal subtraction scheme. Coefficient functions of the expansion are expressed explicitly through the Green functions of composite fields. The expansion has the explicity finite form: the ultraviolet (UV) divergences of the coefficient functions and composite fields are removed by the initial renormalization procedure while the infrared (IR) divergences in massless diagrams with nonvanishing contribution into the coefficient functions are removed by the R-operation which is the IR part of the R-operation. The latter is the generalization of the dimensional renormalization in the case when both UV and IR divergences are present. To derive the expansion, a ''pre-subtracting operator'' is introduced and formulas of the counter-term technique are exploited

The design and imaging characteristics of dynamic, solid-state, flat-panel x-ray image detectors for digital fluoroscopy and fluorography

International Nuclear Information System (INIS)

Cowen, A.R.; Davies, A.G.; Sivananthan, M.U.

2008-01-01

Dynamic, flat-panel, solid-state, x-ray image detectors for use in digital fluoroscopy and fluorography emerged at the turn of the millennium. This new generation of dynamic detectors utilize a thin layer of x-ray absorptive material superimposed upon an electronic active matrix array fabricated in a film of hydrogenated amorphous silicon (a-Si:H). Dynamic solid-state detectors come in two basic designs, the indirect-conversion (x-ray scintillator based) and the direct-conversion (x-ray photoconductor based). This review explains the underlying principles and enabling technologies associated with these detector designs, and evaluates their physical imaging characteristics, comparing their performance against the long established x-ray image intensifier television (TV) system. Solid-state detectors afford a number of physical imaging benefits compared with the latter. These include zero geometrical distortion and vignetting, immunity from blooming at exposure highlights and negligible contrast loss (due to internal scatter). They also exhibit a wider dynamic range and maintain higher spatial resolution when imaging over larger fields of view. The detective quantum efficiency of indirect-conversion, dynamic, solid-state detectors is superior to that of both x-ray image intensifier TV systems and direct-conversion detectors. Dynamic solid-state detectors are playing a burgeoning role in fluoroscopy-guided diagnosis and intervention, leading to the displacement of x-ray image intensifier TV-based systems. Future trends in dynamic, solid-state, digital fluoroscopy detectors are also briefly considered. These include the growth in associated three-dimensional (3D) visualization techniques and potential improvements in dynamic detector design

Dynamic contrast-enhanced subtraction MR angiography in intracranial vascular abnormalities

International Nuclear Information System (INIS)

Takano, K.; Ono, H.; Utsunomiya, H.; Okazaki, M.; Tanaka, A.

1999-01-01

We present our clinical experience with dynamic contrast-enhanced MR angiography (MRA) with subtraction for assessing intracranial vascular abnormalities. Ten patients with various cerebrovascular disorders underwent dynamic contrast-enhanced MRA on a 1.0-T system. Thirty sections (2 mm) were acquired in 29-30 s. Maximum intensity projection images and subtracted source images were compared with those obtained by conventional angiography. In all cases, the presence or absence of abnormalities in the targeted vessels, as well as the morphology of the sagittal sinuses, was clearly visualized as in conventional angiography, without any obstructions such as hyperintense hematomas or thrombi, or intraluminal turbulence. Although the temporal and spatial resolutions with current hardware are insufficient, these preliminary results suggest that dynamic contrast-enhanced MRA with subtraction may be useful for assessing vascular lesions with hemorrhage or thrombus, and the dural sinuses. (orig.)

Research on the algorithm of infrared target detection based on the frame difference and background subtraction method

Science.gov (United States)

Liu, Yun; Zhao, Yuejin; Liu, Ming; Dong, Liquan; Hui, Mei; Liu, Xiaohua; Wu, Yijian

2015-09-01

As an important branch of infrared imaging technology, infrared target tracking and detection has a very important scientific value and a wide range of applications in both military and civilian areas. For the infrared image which is characterized by low SNR and serious disturbance of background noise, an innovative and effective target detection algorithm is proposed in this paper, according to the correlation of moving target frame-to-frame and the irrelevance of noise in sequential images based on OpenCV. Firstly, since the temporal differencing and background subtraction are very complementary, we use a combined detection method of frame difference and background subtraction which is based on adaptive background updating. Results indicate that it is simple and can extract the foreground moving target from the video sequence stably. For the background updating mechanism continuously updating each pixel, we can detect the infrared moving target more accurately. It paves the way for eventually realizing real-time infrared target detection and tracking, when transplanting the algorithms on OpenCV to the DSP platform. Afterwards, we use the optimal thresholding arithmetic to segment image. It transforms the gray images to black-white images in order to provide a better condition for the image sequences detection. Finally, according to the relevance of moving objects between different frames and mathematical morphology processing, we can eliminate noise, decrease the area, and smooth region boundaries. Experimental results proves that our algorithm precisely achieve the purpose of rapid detection of small infrared target.

A temporal subtraction method for thoracic CT images based on generalized gradient vector flow

International Nuclear Information System (INIS)

Miyake, Noriaki; Kim, H.; Maeda, Shinya; Itai, Yoshinori; Tan, J.K.; Ishikawa, Seiji; Katsuragawa, Shigehiko

2010-01-01

A temporal subtraction image, which is obtained by subtraction of a previous image from a current one, can be used for enhancing interval changes (such as formation of new lesions and changes in existing abnormalities) on medical images by removing most of the normal structures. If image registration is incorrect, not only the interval changes but also the normal structures would be appeared as some artifacts on the temporal subtraction image. In a temporal subtraction technique for 2-D X-ray image, the effectiveness is shown through a lot of clinical evaluation experiments, and practical use is advancing. Moreover, the MDCT (Multi-Detector row Computed Tomography) can easily introduced on medical field, the development of a temporal subtraction for thoracic CT Images is expected. In our study, a temporal subtraction technique for thoracic CT Images is developed. As the technique, the vector fields are described by use of GGVF (Generalized Gradient Vector Flow) from the previous and current CT images. Afterwards, VOI (Volume of Interest) are set up on the previous and current CT image pairs. The shift vectors are calculated by using nearest neighbor matching of the vector fields in these VOIs. The search kernel on previous CT image is set up from the obtained shift vector. The previous CT voxel which resemble standard the current voxel is detected by voxel value and vector of the GGVF in the kernel. And, the previous CT image is transformed to the same coordinate of standard voxel. Finally, temporal subtraction image is made by subtraction of a warping image from a current one. To verify the proposal method, the result of application to 7 cases and the effectiveness are described. (author)

Momentum-subtraction renormalization techniques in curved space-time

Energy Technology Data Exchange (ETDEWEB)

Foda, O.

1987-10-01

Momentum-subtraction techniques, specifically BPHZ and Zimmermann's Normal Product algorithm, are introduced as useful tools in the study of quantum field theories in the presence of background fields. In a model of a self-interacting massive scalar field, conformally coupled to a general asymptotically-flat curved space-time with a trivial topology, momentum-subtractions are shown to respect invariance under general coordinate transformations. As an illustration, general expressions for the trace anomalies are derived, and checked by explicit evaluation of the purely gravitational contributions in the free field theory limit. Furthermore, the trace of the renormalized energy-momentum tensor is shown to vanish at the Gell-Mann Low eigenvalue as it should.

Momentum-subtraction renormalization techniques in curved space-time

International Nuclear Information System (INIS)

Foda, O.

1987-01-01

Momentum-subtraction techniques, specifically BPHZ and Zimmermann's Normal Product algorithm, are introduced as useful tools in the study of quantum field theories in the presence of background fields. In a model of a self-interacting massive scalar field, conformally coupled to a general asymptotically-flat curved space-time with a trivial topology, momentum-subtractions are shown to respect invariance under general coordinate transformations. As an illustration, general expressions for the trace anomalies are derived, and checked by explicit evaluation of the purely gravitational contributions in the free field theory limit. Furthermore, the trace of the renormalized energy-momentum tensor is shown to vanish at the Gell-Mann Low eigenvalue as it should

Subtraction with hadronic initial states at NLO: an NNLO-compatible scheme

Science.gov (United States)

Somogyi, Gábor

2009-05-01

We present an NNLO-compatible subtraction scheme for computing QCD jet cross sections of hadron-initiated processes at NLO accuracy. The scheme is constructed specifically with those complications in mind, that emerge when extending the subtraction algorithm to next-to-next-to-leading order. It is therefore possible to embed the present scheme in a full NNLO computation without any modifications.

Subtraction with hadronic initial states at NLO: an NNLO-compatible scheme

International Nuclear Information System (INIS)

Somogyi, Gabor

2009-01-01

We present an NNLO-compatible subtraction scheme for computing QCD jet cross sections of hadron-initiated processes at NLO accuracy. The scheme is constructed specifically with those complications in mind, that emerge when extending the subtraction algorithm to next-to-next-to-leading order. It is therefore possible to embed the present scheme in a full NNLO computation without any modifications.

Continuous-variable measurement-device-independent quantum key distribution with photon subtraction

Science.gov (United States)

Ma, Hong-Xin; Huang, Peng; Bai, Dong-Yun; Wang, Shi-Yu; Bao, Wan-Su; Zeng, Gui-Hua

2018-04-01

It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We show the successful use of the non-Gaussian operation, in particular, photon subtraction operation, on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol. The proposed method can be implemented based on existing technologies. Security analysis shows that the photon subtraction operation can remarkably increase the maximal transmission distance of the CV-MDI-QKD protocol, which precisely make up for the shortcoming of the original CV-MDI-QKD protocol, and one-photon subtraction operation has the best performance. Moreover, the proposed protocol provides a feasible method for the experimental implementation of the CV-MDI-QKD protocol.

Digital subtraction radiography in the study of moving laryngeal structures

International Nuclear Information System (INIS)

Perri, G.; Falaschi, F.; Pieri, L.; Esposito, S.; Ursino, F.

1988-01-01

Digital subtraction radiography (DSR) was applied to the study of the larynx in 11 healthy subjects and 15 pathological cases. The method, consisting in the subtraction of images obtained at rest and during phonation or respiratory phases, allowed a clear definition of the normal moving structures - i.e. vocal cords, false cords, pyriform sinuses, thyroid cartilage. Moreover, several pathological conditions could be demonstrated. DSR asserts thus itself as a suitable technique in the functional evaluation of glottis

A method for dynamic subtraction MR imaging of the liver

Directory of Open Access Journals (Sweden)

Setti Ernesto

2006-06-01

Full Text Available Abstract Background Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time. Methods Nineteen consecutive patients (median age 45 years; range 37–67 were evaluated by VIBE T1-weighted sequences (TR 5.2 ms, TE 2.6 ms, flip angle 20°, slice thickness 1.5 mm acquired before and 45s after contrast injection. Acquisition parameters were optimized for best portal system enhancement. Pre and post-contrast liver volumes were realigned using our 3D registration method which combines: (a rigid 3D translation using maximization of normalized mutual information (NMI, and (b fast 2D non-rigid registration which employs a complex discrete wavelet transform algorithm to maximize pixel phase correlation and perform multiresolution analysis. Registration performance was assessed quantitatively by NMI. Results The new registration procedure was able to realign liver structures in all 19 patients. NMI increased by about 8% after rigid registration (native vs. rigid registration 0.073 ± 0.031 vs. 0.078 ± 0.031, n.s., paired t-test and by a further 23% (0.096 ± 0.035 vs. 0.078 ± 0.031, p t-test after non-rigid realignment. The overall average NMI increase was 31%. Conclusion This new method for realigning dynamic contrast-enhanced 3D MR volumes of liver leads to subtraction images that enhance diagnostic possibilities for liver lesions.

Mental Computation or Standard Algorithm? Children's Strategy Choices on Multi-Digit Subtractions

Science.gov (United States)

Torbeyns, Joke; Verschaffel, Lieven

2016-01-01

This study analyzed children's use of mental computation strategies and the standard algorithm on multi-digit subtractions. Fifty-eight Flemish 4th graders of varying mathematical achievement level were individually offered subtractions that either stimulated the use of mental computation strategies or the standard algorithm in one choice and two…

Removal of arterial wall calcifications in CT angiography by local subtraction

International Nuclear Information System (INIS)

Straten, Marcel van; Venema, Henk W.; Streekstra, Geert J.; Reekers, Jim A.; Heeten, Gerard J. den; Grimbergen, Cornelis A.

2003-01-01

CT Angiography (CTA) is an established technique for the minimally invasive imaging of arteries. The technique of maximum intensity projection (MIP) is often used to get a comprehensive overview of the vascular anatomy. On a MIP, however, arterial wall calcifications may hinder the visualization of the arterial lumen. These calcifications are in direct contact with the contrast-enhanced blood, which makes removal difficult. We present a local subtraction method for the automatic removal of these calcifications. In our approach a second CT scan has to be made, prior to contrast injection. The calcifications in both scans are registered prior to subtraction to compensate for displacements in between the two scans. Local subtraction results are compared with results obtained by thresholding. The method was tested in a phantom and with data from four patients. The phantom represented an artery with different types of stenosis. Data were used from patients for which CTA of the renal arteries was performed. For two patients the electrocardiogram (ECG) was recorded during the CTA examination, making retrospective cardiac gated reconstructions possible. Both the phantom and the patient study showed that the local subtraction method is capable of removing calcifications and visualizing the residual lumen. In the patient study it appeared that some artifacts remained for higher pitch values. We conclude that the local subtraction method is less subjective and more accurate than thresholding. Best results are obtained by use of a small pitch, at the expense of the volume covered during a single breath hold

Nonenhanced magnetic resonance angiography (MRA) of the calf arteries at 3 Tesla: intraindividual comparison of 3D flow-dependent subtractive MRA and 2D flow-independent non-subtractive MRA

Energy Technology Data Exchange (ETDEWEB)

Knobloch, Gesine; Lauff, Marie-Teres; Hirsch, Sebastian; Hamm, Bernd; Wagner, Moritz [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Schwenke, Carsten [SCO:SSiS Statistical Consulting, Berlin (Germany)

2016-12-15

To prospectively compare 3D flow-dependent subtractive MRA vs. 2D flow-independent non-subtractive MRA for assessment of the calf arteries at 3 Tesla. Forty-two patients with peripheral arterial occlusive disease underwent nonenhanced MRA of calf arteries at 3 Tesla with 3D flow-dependent subtractive MRA (fast spin echo sequence; 3D-FSE-MRA) and 2D flow-independent non-subtractive MRA (balanced steady-state-free-precession sequence; 2D-bSSFP-MRA). Moreover, all patients underwent contrast-enhanced MRA (CE-MRA) as standard-of-reference. Two readers performed a per-segment evaluation for image quality (4 = excellent to 0 = non-diagnostic) and severity of stenosis. Image quality scores of 2D-bSSFP-MRA were significantly higher compared to 3D-FSE-MRA (medians across readers: 4 vs. 3; p < 0.0001) with lower rates of non-diagnostic vessel segments on 2D-bSSFP-MRA (reader 1: <1 % vs. 15 %; reader 2: 1 % vs. 29 %; p < 0.05). Diagnostic performance of 2D-bSSFP-MRA and 3D-FSE-MRA across readers showed sensitivities of 89 % (214/240) vs. 70 % (168/240), p = 0.0153; specificities: 91 % (840/926) vs. 63 % (585/926), p < 0.0001; and diagnostic accuracies of 90 % (1054/1166) vs. 65 % (753/1166), p < 0.0001. 2D flow-independent non-subtractive MRA (2D-bSSFP-MRA) is a robust nonenhanced MRA technique for assessment of the calf arteries at 3 Tesla with significantly higher image quality and diagnostic accuracy compared to 3D flow-dependent subtractive MRA (3D-FSE-MRA). (orig.)

Digital subtraction angiography of carotid bifurcation

International Nuclear Information System (INIS)

Vries, A.R. de.

1984-01-01

This study demonstrates the reliability of digital subtraction angiography (DSA) by means of intra- and interobserver investigations as well as indicating the possibility of substituting catheterangiography by DSA in the diagnosis of carotid bifurcation. Whenever insufficient information is obtained from the combination of non-invasive investigation and DSA, a catheterangiogram will be necessary. (Auth.)

Digital subtraction angiography: myths and reality

International Nuclear Information System (INIS)

Levin, D.C.

1984-01-01

Some of the claims made about digital subtraction angiography (DSA) when it was first developed have turned out to be greatly exaggerated, and some members of the radiologic community have become disillusioned with its capabilities. The author discusses some of the limitations of DSA, and concludes that the advantages of DSA outweigh its limitations

The contribution of chemical shift imaging with digital subtracting images to the diagnosis of steatohepatitis

International Nuclear Information System (INIS)

Guo Xinghua; Wang Juanping; Zhang Chongjie; Zheng Guofang; Fan Ruiqiang; Zhu Sumei; Liu Qiwang

2006-01-01

Objective: To investigate the diagnosis value of chemical shift imaging with digital subtracting in steatohepatitis. Methods: The in-phase images were subtracted by the out-phase ones in 34 cases of steatohepatitis, and the CNR were measured on these subtracted images to estimate the steatosis of the liver. The relationship of CT grade of steatohepatitis and CNR from the subtracted images was analyzed to evaluate the relationship between CNR and the degree of hepatic steatosis. The sensitivity and specificity of the subtracting and eyeballing methods were compared with chi-square test. Results: On the subtracted images, the liver and spleen were seen nearly the same aspects as low signals, CNR=0.98±0.06, meanwhile the spongy vertebra and the subcutaneous or abdominal lipid were seen as obvious higher signals in 52 normal cases. On the 34 steatohepatitis, scattered high signals were seen in the liver, which made the signal of liver higher than that of spleen, CNR=3.25±0.91--14.35±6.10. There was positive correlation between CNR and CT grade in the 34 cases of steatohepatitis, r=0.893, P<0.01. The sensitivity and specificity of the subtracting method were 88.24% and 94. 23%, significantly higher than that of the eyeballing results, 32.35% and 80.77%, P<0.01 and P<0.05. Conclusion: Chemical shift imaging with digital subtracting is a sensitive, specific, objective method to diagnose steatohepatitis and it is of potential ability for quantitative diagnosis. (authors)

Evaluation of the minimum iodine concentration for contrast-enhanced subtraction mammography

International Nuclear Information System (INIS)

Baldelli, P; Bravin, A; Maggio, C Di; Gennaro, G; Sarnelli, A; Taibi, A; Gambaccini, M

2006-01-01

Early manifestation of breast cancer is often very subtle and is displayed in a complex and variable pattern of normal anatomy that may obscure the disease. The use of dual-energy techniques, that can remove the structural noise, and contrast media, that enhance the region surrounding the tumour, could help us to improve the detectability of the lesions. The aim of this work is to investigate the use of an iodine-based contrast medium in mammography with two different double exposure techniques: K-edge subtraction mammography and temporal subtraction mammography. Both techniques have been investigated by using an ideal source, like monochromatic beams produced at a synchrotron radiation facility and a clinical digital mammography system. A dedicated three-component phantom containing cavities filled with different iodine concentrations has been developed and used for measurements. For each technique, information about the minimum iodine concentration, which provides a significant enhancement of the detectability of the pathology by minimizing the risk due to high dose and high concentration of contrast medium, has been obtained. In particular, for cavities of 5 and 8 mm in diameter filled with iodine solutions, the minimum concentration needed to obtain a contrast-to-noise ratio of 5 with a mean glandular dose of 2 mGy has been calculated. The minimum concentrations estimated with monochromatic beams and K-edge subtraction mammography are 0.9 mg ml -1 and 1.34 mg ml -1 for the biggest and smallest details, respectively, while for temporal subtraction mammography they are 0.84 mg ml -1 and 1.31 mg ml -1 . With the conventional clinical system the minimum concentrations for the K-edge subtraction mammography are 4.13 mg ml -1 (8 mm diameter) and 5.75 mg ml -1 (5 mm diameter), while for the temporal subtraction mammography they are 1.01 mg ml -1 (8 mm diameter) and 1.57 mg ml -1 (5 mm diameter)

Sadhana | Indian Academy of Sciences

Indian Academy of Sciences (India)

Background subtraction is one of the efficient techniques to segment the targets from non-informative background of a video. The traditional background subtraction technique suits for videos with static background whereas the video obtained from unmanned aerial vehicle has dynamic background. Here, we propose an ...

[The backgroud sky subtraction around [OIII] line in LAMOST QSO spectra].

Science.gov (United States)

Shi, Zhi-Xin; Comte, Georges; Luo, A-Li; Tu, Liang-Ping; Zhao, Yong-Heng; Wu, Fu-Chao

2014-11-01

At present, most sky-subtraction methods focus on the full spectrum, not the particular location, especially for the backgroud sky around [OIII] line which is very important to low redshift quasars. A new method to precisely subtract sky lines in local region is proposed in the present paper, which sloves the problem that the width of Hβ-[OIII] line is effected by the backgroud sky subtraction. The exprimental results show that, for different redshift quasars, the spectral quality has been significantly improved using our method relative to the original batch program by LAMOST. It provides a complementary solution for the small part of LAMOST spectra which are not well handled by LAMOST 2D pipeline. Meanwhile, This method has been used in searching for candidates of double-peaked Active Galactic Nuclei.

A study of transverse image reconstruction with digital subtraction angiography

International Nuclear Information System (INIS)

Sakamoto, Kiyoshi; Kotoura, Noriko; Terasawa, Yuuji; Oda, Masahiko; Gotou, Hiroshi; Nasada, Toshiya; Tanooka, Masao

1995-01-01

For digital subtraction angiography (DSA) with C-type equipment, it is possible to radiate an X-ray during rotation and to collect data at different angular settings. We tried to reconstruct transverse image from data obtained by scanning DSA images at different angular settings. 88 projection data were obtained by rotating the object at 180deg during radiation. Reconstruction was made using the convolution method with pixel value distribution for each projection. Similarly, the image quality of the reconstructed images were compared with the unsubtracted and subtracted ones. In case a part object was outside the calculating region, artifacts were generally produced. However, the artifacts were reduced by subtracting the background from the image. In addition, the cupping phenomenon caused by beam hardening was relaxed and high-quality imaging could be achieved. This method will become even more effective, if we will use it with selective angiography in which the limited area is enhanced. (author)

Subtracting and Fitting Histograms using Profile Likelihood

CERN Document Server

D'Almeida, F M L

2008-01-01

It is known that many interesting signals expected at LHC are of unknown shape and strongly contaminated by background events. These signals will be dif cult to detect during the rst years of LHC operation due to the initial low luminosity. In this work, one presents a method of subtracting histograms based on the pro le likelihood function when the background is previously estimated by Monte Carlo events and one has low statistics. Estimators for the signal in each bin of the histogram difference are calculated so as limits for the signals with 68.3% of Con dence Level in a low statistics case when one has a exponential background and a Gaussian signal. The method can also be used to t histograms when the signal shape is known. Our results show a good performance and avoid the problem of negative values when subtracting histograms.

Comparative study between rib imaging of DR dual energy subtraction technology and chest imaging

International Nuclear Information System (INIS)

Yu Jianming; Lei Ziqiao; Kong Xiangchuang

2006-01-01

Objective: To investigate the application value of DR dual energy subtraction technology in rib lesions. Methods: 200 patients were performed with chest DR dual energy subtraction, comparing the rib imaging between DR of thorax and chest imaging using ROC analysis. Results: Among the total of 200 patients, there are 50 cases of rib calcification, 7 cases of rib destruction, 22 cases of rib fracture. The calcification, destruction and fracture were displayed respectively by ribs below diaphragm and rib markings. The analytic parameter of rib imaging of DR dual energy subtraction Az is 0.9367, while that of rib imaging of chest Az is 0.6830. Conclusion: DR dual energy subtraction technology is superior to chest imaging in the displaying of rib lesion and ribs below diaphragm. (authors)

Subtraction of random coincidences in γ-ray spectroscopy: A new approach

International Nuclear Information System (INIS)

Pattabiraman, N.S.; Ghugre, S.S.; Basu, S.K.; Garg, U.; Ray, S.; Sinha, A.K.; Zhu, S.

2006-01-01

A new analytical method for estimation and subsequent subtraction of random coincidences has been developed. It utilizes the knowledge of the counts in the main diagonal of a background-subtracted symmetric data set for the estimation of the events originating from random coincidences. This procedure has been successfully applied to several data sets. It could be a valuable tool for low-fold data sets, especially for low-cross-section events

Scalable Video Coding with Interlayer Signal Decorrelation Techniques

Directory of Open Access Journals (Sweden)

Yang Wenxian

2007-01-01

Full Text Available Scalability is one of the essential requirements in the compression of visual data for present-day multimedia communications and storage. The basic building block for providing the spatial scalability in the scalable video coding (SVC standard is the well-known Laplacian pyramid (LP. An LP achieves the multiscale representation of the video as a base-layer signal at lower resolution together with several enhancement-layer signals at successive higher resolutions. In this paper, we propose to improve the coding performance of the enhancement layers through efficient interlayer decorrelation techniques. We first show that, with nonbiorthogonal upsampling and downsampling filters, the base layer and the enhancement layers are correlated. We investigate two structures to reduce this correlation. The first structure updates the base-layer signal by subtracting from it the low-frequency component of the enhancement layer signal. The second structure modifies the prediction in order that the low-frequency component in the new enhancement layer is diminished. The second structure is integrated in the JSVM 4.0 codec with suitable modifications in the prediction modes. Experimental results with some standard test sequences demonstrate coding gains up to 1 dB for I pictures and up to 0.7 dB for both I and P pictures.

A method for subtraction of the extrarenal 'background' in dynamic 131I-hippurate renoscintigraphy

International Nuclear Information System (INIS)

Mlodkowska, E.; Liniecki, J.; Surma, M.

1979-01-01

Using a Toshiba GC-401 gamma camera with MDS computer Trinary a new method was developed for subtracting the extrarenal (extracanalicular) 'background' from the count rate recorded over the kidneys after intravenous administration of 131 I-hippurate. Mean subtraction factors of the 'blood' activity curve were calculated from a study of 27 patients who were given 51 Cr-HSA for purposes of conventional renography with 'background' subtraction. The values of the mean subtraction factors anti Fsub(R,L) for the right and left kidney, by which a blood count rate should be multiplied amounted to 0.86 +- 0.12 and 0.79 +- 0.13, respectively. A comparison of the coefficients of variation of the pure renal signal when mean vs. individually determined subtraction factors were used, and the verification of the method in unilaterally nephrectomized patients have demonstrated that determination of the factors, anti Fsub(R,L), for each patient individually is not required and sufficient precision can be obtained by using the method and factors reported in this study. (orig.) [de

Quantitative analysis of planar technetium-99m-sestamibi myocardial perfusion images using modified background subtraction

International Nuclear Information System (INIS)

Koster, K.; Wackers, F.J.; Mattera, J.A.; Fetterman, R.C.

1990-01-01

Standard interpolative background subtraction, as used for thallium-201 ( 201 Tl), may create artifacts when applied to planar technetium-99m-Sestamibi ( 99m Tc-Sestamibi) images, apparently because of the oversubtraction of relatively high extra-cardiac activity. A modified background subtraction algorithm was developed and compared to standard background subtraction in 16 patients who had both exercise-delayed 201 Tl and exercise-rest 99m Tc-Sestamibi imaging. Furthermore, a new normal data base was generated. Normal 99m Tc-Sestamibi distribution was slightly different compared to 201 Tl. Using standard background subtraction, mean defect reversibility was significantly underestimated by 99m Tc-Sestamibi compared to 201 Tl (2.8 +/- 4.9 versus -1.8 +/- 8.4, p less than 0.05). Using the modified background subtraction, mean defect reversibility on 201 Tl and 99m Tc-Sestamibi images was comparable (2.8 +/- 4.9 versus 1.7 +/- 5.2, p = NS). We conclude, that for quantification of 99m Tc-Sestamibi images a new normal data base, as well as a modification of the interpolative background subtraction method should be employed to obtain quantitative results comparable to those with 201 Tl

The digital subtraction technique in lateral urethrocystography. Die laterale Urethrozystographie in digitaler Subtraktionstechnik

Energy Technology Data Exchange (ETDEWEB)

Wolf, K. (Radiologische Abt., Caritas-Krankenhaus, Bad Mergentheim (Germany)); Peterseim, H. (Frauenklinik, Caritas-Krankenhaus, Bad Mergentheim (Germany)); Grehn, S. (Radiologische Abt., Caritas-Krankenhaus, Bad Mergentheim (Germany))

1994-09-01

The first application of the digital subtraction technique to lateral urethrocystography is described. This methodology facilitates gynecological-urological operations by providing reliable investigation results and an unambiguous image interpretation. Methods and first experiences with the digital subtraction technique in gynecological-urological diagnosis are reported. (orig.)

Spectral Subtraction Approach for Interference Reduction of MIMO Channel Wireless Systems

Directory of Open Access Journals (Sweden)

Tomohiro Ono

2005-08-01

Full Text Available In this paper, a generalized spectral subtraction approach for reducing additive impulsive noise, narrowband signals, white Gaussian noise and DS-CDMA interferences in MIMO channel DS-CDMA wireless communication systems is investigated. The interference noise reduction or suppression is essential problem in wireless mobile communication systems to improve the quality of communication. The spectrum subtraction scheme is applied to the interference noise reduction problems for noisy MIMO channel systems. The interferences in space and time domain signals can effectively be suppressed by selecting threshold values, and the computational load with the FFT is not large. Further, the fading effects of channel are compensated by spectral modification with the spectral subtraction process. In the simulations, the effectiveness of the proposed methods for the MIMO channel DS-CDMA is shown to compare with the conventional MIMO channel DS-CDMA.

[Construction of forward and reverse subtracted cDNA libraries between muscle tissue of Meishan and Landrace pigs].

Science.gov (United States)

Xu, De-Quan; Zhang, Yi-Bing; Xiong, Yuan-Zhu; Gui, Jian-Fang; Jiang, Si-Wen; Su, Yu-Hong

2003-07-01

Using suppression subtractive hybridization (SSH) technique, forward and reverse subtracted cDNA libraries were constructed between Longissimus muscles from Meishan and Landrace pigs. A housekeeping gene, G3PDH, was used to estimate the efficiency of subtractive cDNA. In two cDNA libraries, G3PDH was subtracted very efficiently at appropriate 2(10) and 2(5) folds, respectively, indicating that some differentially expressed genes were also enriched at the same folds and the two subtractive cDNA libraries were very successful. A total of 709 and 673 positive clones were isolated from forward and reverse subtracted cDNA libraries, respectively. Analysis of PCR showed that most of all plasmids in the clones contained 150-750 bp inserts. The construction of subtractive cDNA libraries between muscle tissue from different pig breeds laid solid foundations for isolating and identifying the genes determining muscle growth and meat quality, which will be important to understand the mechanism of muscle growth, determination of meat quality and practice of molecular breeding.

Intraarterial digital subtraction angiography

International Nuclear Information System (INIS)

Davis, P.C.

1987-01-01

Digital subtraction angiography (DSA) refers to a radiographic technique of amplifying low levels of contrast from intravascular iodine into an acceptable image of vascular anatomy. Initial enthusiasm suggested that DSA using intravenous injections (IV-DSA) would eliminate most conventional film-screen angiographic studies. It was soon apparent, however, that IV-DSA examinations were often compromised in those patients who most needed a less invasive study. Indeed, only a 70 to 85 percent accuracy rate was achieved with IV-DSA, primarily due to motion artifact, poor cardiac output, overlap of pertinent vessels, and inability to resolve smaller vessels

On a gauge invariant subtraction scheme for massive quantum electrodynamics

International Nuclear Information System (INIS)

Abdalla, E.; Gomes, M.; Koeberle, R.

A momentum-space subtraction scheme for massive quantum electrodynamics is proposed which respects gauge invariance, in contrast to ordinary normal product techniques. As a consequence the dependence of Green functions on the ghost mass becomes very simple and formally gauge invariant normal products of degree up to four, when subtracted according to the proposed scheme, are automatically gauge invariant. As an aplication we discuss the proof of the Adler-Bardeen theorem. Zero mass limits can be taken for Green function after the integration over intermediate states has been carried out [pt

Digital subtraction arthrography of the hips and of the shoulders

International Nuclear Information System (INIS)

Fink, B.K.; Schedel, J.; Fink, U.; Hansen, M.; Hilbertz, T.; Hagena, F.W.

1991-01-01

In a study on 60 patients, it could be shown that very good results can be achieved in the region of the shoulder joint with the use of the digital subtraction technique and of digital image intensifier radiography. A further possibility of using the digital subtraction technique for proving endoprosthesis loosenings of the hip demonstrated its importance after a short time and has become a routine method in the meantime. These two examination techniques are displayed methodologically and their clinical possibilities of use are assessed in this contribution. (orig.)

Radionuclide identification using subtractive clustering method

International Nuclear Information System (INIS)

Farias, Marcos Santana; Mourelle, Luiza de Macedo

2011-01-01

Radionuclide identification is crucial to planning protective measures in emergency situations. This paper presents the application of a method for a classification system of radioactive elements with a fast and efficient response. To achieve this goal is proposed the application of subtractive clustering algorithm. The proposed application can be implemented in reconfigurable hardware, a flexible medium to implement digital hardware circuits. (author)

Subtraction imaging of the ECG gated cardiac CT

Energy Technology Data Exchange (ETDEWEB)

Tanegashima, K.; Fukui, M.; Hyodo, H.

1987-05-01

The subtracting manipulation of contrast-enhanced gated cardiac CT (GCCT) images was experimentally studied with TCT 60A - 30 type (Toshiba) for clinical use, thereby reducing the amount of contrast medium (CM). Initially the optimum relationship between the concentration of CM and its injected velocity was determined using the model of resected canine hearts and in actual dogs. The emphasized good-subtracted images were obtained when the difference of CT values was approximately 40 H.U. between cardiac cavity and myocardium. Such condition was feasible in the use of 25 % Diatrizoic acid and its injected velocity of 0.02 ml/kg/sec. Finally the reduction of the amount of CM by 1/3 became possible in clinical settings. The method is applicable to multi-slice GCCT in various heart diseases.

Preliminary study of lateral cerebral angiography with reverse rotation in the digital image registration and subtraction

International Nuclear Information System (INIS)

Shen Zhenglin; Liu Dongyang; Shen Zhenghai; Li Shuping; Zhang Ziyan; Wu Yongjuan; Liu Peijun

2012-01-01

Objective: Investigate the value and feasibility of image registration with reverse rotation in lateral cerebral DSA. Methods: (1) Experimental study: the target images were subtracted directly, and subtracted again after reverse rotation. Software of registration and subtraction with reverse rotation edited by the author utilizing Visual Basic. The function of the automatic angle detection by the software were evaluated to see whether it detected the angle of line. The subtraction function of DSA by the software was evaluated. (2) Clinical retrospective study: the untreated mask and target images of 15 patients with motion along vertical axis during lateral cerebral DSA were uploaded to the software. The target images were processed with and without the software to get two sets of images. (3) Evaluation: four experienced radiologists read and compared the two sets of the images,and graded their findings. Results: (1) The automatic detection by the software suggested that the target images should be rotated counterclockwise 1.3°. The subtraction result of the software was satisfactory. (2) In the 15 sets of images, there were only three sets of images deemed optimal after traditional subtraction. After reverse rotation, artifacts were significantly reduced and the image sharper. There were ten cases with significant artifacts after traditional subtraction, and those images were sharper and showed more peripheral vessels after reverse rotation. The traditional subtraction images of two sets could not be interpreted,the reverse rotation registration images reached the diagnostic quality. (3) Subjective evaluation: there were more information and less noise and distortion in the registration images with reverse rotation than in the traditional subtraction. But the image resolution decreased slightly after reverse rotation registration. Conclusion: The registration of digital angiography with reverse rotation can improve the image quality in lateral cerebral DSA

Exercise intravenous digital subtraction angiography

International Nuclear Information System (INIS)

Yiannikas, J.

1986-01-01

Attempts to use exercise ventriculography have been made, not only to give diagnostic and perhaps even prognostic information in patients with coronary artery disease, but also in patients with valvular heart disease both before and after surgical intervention. Clearly an accurate method of assessing ventricular function under conditions of stress in various cardiac diseases would provide important information that would help in patient management. Exercise ventriculography using gated blood pool equilibrium technetium studies are widely used, but are limited by spatial resolution and by the foreshortening affects of visualizing the left ventricular chamber in the left anterior oblique view. First pass radionuclide studies have the added advantage of being able to visualize the ventricular chamber in the anterior or even the right anterior oblique view, but are even more limited by their spatial resolution problems. Several investigations have shown that digital subtraction angiography produces left ventricular images with a spatial resolution almost identical to that of conventional contrast ventriculography, but without the inherent problems of cardiac arrhythmias, which often limit the assessment of left ventricular function. Because of its ability to accurately delineate wall motion abnormalities, the technique may provide an adequate assessment of global and regional left ventricular function after exercise. Digital subtraction angiography may identify ischemic wall motion abnormalities produced by exercise in patients who already had significant permanent left ventricular damage from myocardial infarction

A comparative study of additive and subtractive manufacturing for dental restorations.

Science.gov (United States)

Bae, Eun-Jeong; Jeong, Il-Do; Kim, Woong-Chul; Kim, Ji-Hwan

2017-08-01

Digital systems have recently found widespread application in the fabrication of dental restorations. For the clinical assessment of dental restorations fabricated digitally, it is necessary to evaluate their accuracy. However, studies of the accuracy of inlay restorations fabricated with additive manufacturing are lacking. The purpose of this in vitro study was to evaluate and compare the accuracy of inlay restorations fabricated by using recently introduced additive manufacturing with the accuracy of subtractive methods. The inlay (distal occlusal cavity) shape was fabricated using 3-dimensional image (reference data) software. Specimens were fabricated using 4 different methods (each n=10, total N=40), including 2 additive manufacturing methods, stereolithography apparatus and selective laser sintering; and 2 subtractive methods, wax and zirconia milling. Fabricated specimens were scanned using a dental scanner and then compared by overlapping reference data. The results were statistically analyzed using a 1-way analysis of variance (α=.05). Additionally, the surface morphology of 1 randomly (the first of each specimen) selected specimen from each group was evaluated using a digital microscope. The results of the overlap analysis of the dental restorations indicated that the root mean square (RMS) deviation observed in the restorations fabricated using the additive manufacturing methods were significantly different from those fabricated using the subtractive methods (Padditive manufacturing methods (P=.466). Similarly, no significant differences were found between wax and zirconia, the subtractive methods (P=.986). The observed RMS values were 106 μm for stereolithography apparatus, 113 μm for selective laser sintering, 116 μm for wax, and 119 μm for zirconia. Microscopic evaluation of the surface revealed a fine linear gap between the layers of restorations fabricated using stereolithography apparatus and a grooved hole with inconsistent weak scratches

Subtractions in the Adler sum rule and violation of charge symmetry

International Nuclear Information System (INIS)

Dominguez, C.A.; Moreno, H.; Zepeda, A.

1976-01-01

The consequences of a once-subtracted dispersion relation in the derivation of the Adler sum rule are investigated. It is shown that one can expect a breakdown of charge symmetry, of the isotriplet-current hypothesis, and of scaling of the structure functions. These breakdowns are related to the possible presence of a nonzero subtraction function at asymptotic energies and arbitrary q 2 . We also comment about second-class currents and PCAC (partial conservation of axial-vector current) relations

[Construction of fetal mesenchymal stem cell cDNA subtractive library].

Science.gov (United States)

Yang, Li; Wang, Dong-Mei; Li, Liang; Bai, Ci-Xian; Cao, Hua; Li, Ting-Yu; Pei, Xue-Tao

2002-04-01

To identify differentially expressed genes between fetal mesenchymal stem cell (MSC) and adult MSC, especially specified genes expressed in fetal MSC, a cDNA subtractive library of fetal MSC was constructed using suppression subtractive hybridization (SSH) technique. At first, total RNA was isolated from fetal and adult MSC. Using SMART PCR synthesis method, single-strand and double-strand cDNAs were synthesized. After Rsa I digestion, fetal MSC cDNAs were divided into two groups and ligated to adaptor 1 and adaptor 2 respectively. Results showed that the amplified library contains 890 clones. Analysis of 890 clones with PCR demonstrated that 768 clones were positive. The positive rate is 86.3%. The size of inserted fragments in these positive clones was between 0.2 - 1 kb, with an average of 400 - 600 bp. SSH is a convenient and effective method for screening differentially expressed genes. The constructed cDNA subtractive library of fetal MSC cDNA lays solid foundation for screening and cloning new and specific function related genes of fetal MSC.

IMPROVED BACKGROUND SUBTRACTION FOR THE SLOAN DIGITAL SKY SURVEY IMAGES

International Nuclear Information System (INIS)

Blanton, Michael R.; Kazin, Eyal; Muna, Demitri; Weaver, Benjamin A.; Price-Whelan, Adrian

2011-01-01

We describe a procedure for background subtracting Sloan Digital Sky Survey (SDSS) imaging that improves the resulting detection and photometry of large galaxies on the sky. Within each SDSS drift scan run, we mask out detected sources and then fit a smooth function to the variation of the sky background. This procedure has been applied to all SDSS-III Data Release 8 images, and the results are available as part of that data set. We have tested the effect of our background subtraction on the photometry of large galaxies by inserting fake galaxies into the raw pixels, reanalyzing the data, and measuring them after background subtraction. Our technique results in no size-dependent bias in galaxy fluxes up to half-light radii r 50 ∼ 100 arcsec; in contrast, for galaxies of that size the standard SDSS photometric catalog underestimates fluxes by about 1.5 mag. Our results represent a substantial improvement over the standard SDSS catalog results and should form the basis of any analysis of nearby galaxies using the SDSS imaging data.

Computed tomography lung iodine contrast mapping by image registration and subtraction

Science.gov (United States)

Goatman, Keith; Plakas, Costas; Schuijf, Joanne; Beveridge, Erin; Prokop, Mathias

2014-03-01

Pulmonary embolism (PE) is a relatively common and potentially life threatening disease, affecting around 600,000 people annually in the United States alone. Prompt treatment using anticoagulants is effective and saves lives, but unnecessary treatment risks life threatening haemorrhage. The specificity of any diagnostic test for PE is therefore as important as its sensitivity. Computed tomography (CT) angiography is routinely used to diagnose PE. However, there are concerns it may over-report the condition. Additional information about the severity of an occlusion can be obtained from an iodine contrast map that represents tissue perfusion. Such maps tend to be derived from dual-energy CT acquisitions. However, they may also be calculated by subtracting pre- and post-contrast CT scans. Indeed, there are technical advantages to such a subtraction approach, including better contrast-to-noise ratio for the same radiation dose, and bone suppression. However, subtraction relies on accurate image registration. This paper presents a framework for the automatic alignment of pre- and post-contrast lung volumes prior to subtraction. The registration accuracy is evaluated for seven subjects for whom pre- and post-contrast helical CT scans were acquired using a Toshiba Aquilion ONE scanner. One hundred corresponding points were annotated on the pre- and post-contrast scans, distributed throughout the lung volume. Surface-to-surface error distances were also calculated from lung segmentations. Prior to registration the mean Euclidean landmark alignment error was 2.57mm (range 1.43-4.34 mm), and following registration the mean error was 0.54mm (range 0.44-0.64 mm). The mean surface error distance was 1.89mm before registration and 0.47mm after registration. There was a commensurate reduction in visual artefacts following registration. In conclusion, a framework for pre- and post-contrast lung registration has been developed that is sufficiently accurate for lung subtraction

Clinical utility of Gd-DTPA subtraction MR imaging for spinal bone metastasis

International Nuclear Information System (INIS)

Ando, Keiichi; Murakami, Masao; Kuroda, Yasumasa

1993-01-01

Based on reports that Gd-DTPA contributes to the detection of tumors, we used it in 31 cases (97 lesions) of spinal bone metastases. The result was that Gd-DTPA increased the intensity of tumors and the surrounding bone marrow to almost the same level in 53%. To show the metastases clearly, an existing subtraction command system was utilized. The technique included the pixel-by-pixel method, to obtain a Gd-DTPA T1-weighted image (T1WI) subtracted by the original T1WI. The detectability of the subtraction image was improved up to 96%, but was less than the original T1WI (99%). Because of the different imaging rationale between two methods, a means to assess the quality of diagnosis must be proposed. To check the normal background, the same kind of postprocessing was performed in 21 patients without malignancy. Gd-DTPA prefusion was highest in the paravertebral veins, moderate in muscles and epidural fat, and lowest in the spinal cord, intervertebral disk and bone cortex. Gd-DTPA enhanced subtraction MR imaging provides a new diagnostic tool to detect and to assess bone metastasis. (author)

Hybrid intravenous digital subtraction angiography of the carotid bifurcation

International Nuclear Information System (INIS)

Burbank, F.H.; Enzmann, D.; Keyes, G.S.; Brody, W.R.

1984-01-01

A hybrid digital subtraction angiography technique and noise-reduction algorithm were used to evaluate the carotid bifurcation. Temporal, hybrid, and reduced-noise hybrid images were obtained in right and left anterior oblique projections, and both single- and multiple-frame images were created with each method. The resulting images were graded on a scale of 1 to 5 by three experienced neuroradiologists. Temporal images were preferred over hybrid images. The percentage of nondiagnostic examinations, as agreed upon by two readers, was higher for temporal alone than temporal + hybrid. In addition, also by agreement between two readers, temporal + hybrid images significantly increased the number of bifurcations seen in two views (87%) compared to temporal subtraction alone

Tomosynthesis applied to digital subtraction angiography

International Nuclear Information System (INIS)

Kruger, R.A.; Sedaghati, M.; Roy, D.G.; Liu, P.; Nelson, J.A.; Kubal, W.; Del Rio, P.

1984-01-01

This extension of the author's previous work on tomographic digital subtraction angiography (DSA) describes the theory of tomosynthetic DSA image reconstruction techniques. In addition to developing the resolution limits resulting from x-ray exposure length and image intensifier field curvature, the authors describe one method of image formation and show tomosynthetic DSA images of animal and human anatomy. Methods for improving the present technique are discussed

Preoperative radiological diagnosis by 99mTc·MIBI-99mTc subtraction scintigraphy for primary hyperparathyroidism

International Nuclear Information System (INIS)

Inouye, Takahiro; Tomita, Toshiki; Shinden, Seiichi; Takagi, Hitoshi; Kano, Shigeru.

1996-01-01

Preoperative radiological diagnosis constitutes the most important factor for the surgical treatment of hyperparathyroidism. In this regard, MRI is useful for detecting the abnormal parathyroid, but it is often difficult to localize it using MRI only. It is thus necessary to combine this procedure with excellent subtraction scintigraphy. We performed both 201 Tl- 99m Tc and 99m Tc·MIBI- 99m Tc subtraction scintigraphy in seven patients with primary hyperparathyroidism and compared them the radiological results. Five patients presented parathyroid adenomas and the rest hypertrophy of the parathyroid. We could detect the abnormal parathyroid in four patients (57.1%) by 201 Tl- 99m Tc subtraction scintigraphy and in six patients (85.7%) by 99m Tc·MIBI- 99m Tc subtraction scintigraphy. We therefore believe that 99m Tc·MIBI- 99m Tc subtraction scintigraphy will become an essential examination for primary hyperparathyroidism rather than the presently employed 201 Tl- 99m Tc subtraction scintigraphy. (author)

Parathyroid localizlation by 201Tl-99mTc subtraction scintigraphy

International Nuclear Information System (INIS)

Rademaker, P.; Meijer, S.; Piers, D.A.

1990-01-01

Subtraction scintigraphy with 201 Tl and 99m Tc for parathyroid localization was performed preoperatively in 13 patients with chronic renal failure and secondary hyperparathyroidism. Twenty of the 37 examined pathological glands were predicted correctly (sensitivity 54%). In 3 patients with recurrent hyperparathyroidism after surgery all pathological glands found at second operation had been detected correctly by subtraction scintigraphy. We conclude that this localization method has a limited value when used prior to first neck exploration in secondary hyperparathyroidism. In persistent hyperparathyroidism after surgery it may play a useful role in localizing missed and ectopic glands. (author)

Informed baseline subtraction of proteomic mass spectrometry data aided by a novel sliding window algorithm.

Science.gov (United States)

Stanford, Tyman E; Bagley, Christopher J; Solomon, Patty J

2016-01-01

Proteomic matrix-assisted laser desorption/ionisation (MALDI) linear time-of-flight (TOF) mass spectrometry (MS) may be used to produce protein profiles from biological samples with the aim of discovering biomarkers for disease. However, the raw protein profiles suffer from several sources of bias or systematic variation which need to be removed via pre-processing before meaningful downstream analysis of the data can be undertaken. Baseline subtraction, an early pre-processing step that removes the non-peptide signal from the spectra, is complicated by the following: (i) each spectrum has, on average, wider peaks for peptides with higher mass-to-charge ratios ( m / z ), and (ii) the time-consuming and error-prone trial-and-error process for optimising the baseline subtraction input arguments. With reference to the aforementioned complications, we present an automated pipeline that includes (i) a novel 'continuous' line segment algorithm that efficiently operates over data with a transformed m / z -axis to remove the relationship between peptide mass and peak width, and (ii) an input-free algorithm to estimate peak widths on the transformed m / z scale. The automated baseline subtraction method was deployed on six publicly available proteomic MS datasets using six different m/z-axis transformations. Optimality of the automated baseline subtraction pipeline was assessed quantitatively using the mean absolute scaled error (MASE) when compared to a gold-standard baseline subtracted signal. Several of the transformations investigated were able to reduce, if not entirely remove, the peak width and peak location relationship resulting in near-optimal baseline subtraction using the automated pipeline. The proposed novel 'continuous' line segment algorithm is shown to far outperform naive sliding window algorithms with regard to the computational time required. The improvement in computational time was at least four-fold on real MALDI TOF-MS data and at least an order of

Addition and Subtraction but Not Multiplication and Division Cause Shifts of Spatial Attention

Directory of Open Access Journals (Sweden)

Mengjin Li

2018-05-01

Full Text Available Many studies have shown that solving addition and subtraction problems can induce overt shifts of spatial attention. In particular, right-side targets are detected faster than left-side targets when preceded by an addition operation, while left-side targets are detected faster than right-side targets when preceded by a subtraction operation. However, the interaction between space and arithmetic in multiplication or division is hardly studied and remains controversial. In order to make a strong case for the interaction between space and mental arithmetic, we attempted to replicate the spatial-arithmetic association in addition and subtraction (Experiment 1, and at the same time investigated whether shift of spatial attention would also be induced by multiplication or division operations (Experiment 2. We found that solving addition problems facilitated the detection of right-side targets, whereas left-side targets were detected faster after solving subtraction problems. However, no interaction between space and arithmetic operation was observed in multiplication or division. The implication of these findings is discussed.

Proximal caries detection using digital subtraction radiography in the artificial caries activity model

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Young Ho; Kim, Kyung Soo; Jin, Hyun Seok; Hong, Kyung Won; Oh, Berm Seok; Park, Hun Kuk [Department of Biomedical Engineering, School of Medicine, Kyung Hee University, Seoul (Korea, Republic of); Choi, Yong Suk; Hwang, Eui Hwan [Department of Oral and Maxillofacial Radiology, Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

2009-03-15

The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Digital radiographs of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size no.2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. In artificial caries activity model, the range of lesional depth was 572-1,374 {mu}m and the range of lesional area was 36.95-138.52 mm{sup 2}. The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.

Proximal caries detection using digital subtraction radiography in the artificial caries activity model

International Nuclear Information System (INIS)

Park, Jong Hoon; Lee, Gi Ja; Choi, Sam Jin; Park, Young Ho; Kim, Kyung Soo; Jin, Hyun Seok; Hong, Kyung Won; Oh, Berm Seok; Park, Hun Kuk; Choi, Yong Suk; Hwang, Eui Hwan

2009-01-01

The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Digital radiographs of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size no.2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. In artificial caries activity model, the range of lesional depth was 572-1,374 μm and the range of lesional area was 36.95-138.52 mm 2 . The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.

Novel Ratio Subtraction and Isoabsorptive Point Methods for ...

African Journals Online (AJOL)

Purpose: To develop and validate two innovative spectrophotometric methods used for the simultaneous determination of ambroxol hydrochloride and doxycycline in their binary mixture. Methods: Ratio subtraction and isoabsorptive point methods were used for the simultaneous determination of ambroxol hydrochloride ...

A simultaneous all-optical half/full-subtraction strategy using cascaded highly nonlinear fibers

Science.gov (United States)

Singh, Karamdeep; Kaur, Gurmeet; Singh, Maninder Lal

2018-02-01

Using non-linear effects such as cross-gain modulation (XGM) and cross-phase modulation (XPM) inside two highly non-linear fibres (HNLF) arranged in cascaded configuration, a simultaneous half/full-subtracter is proposed. The proposed simultaneous half/full-subtracter design is attractive due to several features such as input data pattern independence and usage of minimal number of non-linear elements i.e. HNLFs. Proof of concept simulations have been conducted at 100 Gbps rate, indicating fine performance, as extinction ratio (dB) > 6.28 dB and eye opening factors (EO) > 77.1072% are recorded for each implemented output. The proposed simultaneous half/full-subtracter can be used as a key component in all-optical information processing circuits.

Background dose subtraction in personnel dosimetry

International Nuclear Information System (INIS)

Picazo, T.; Llorca, N.; Alabau, J.

1997-01-01

In this paper it is proposed to consider the mode of the frequency distribution of the low dose dosemeters from each clinic that uses X rays as the background environmental dose that should be subtracted from the personnel dosimetry to evaluate the doses due to practice. The problems and advantages of this indirect method to estimate the environmental background dose are discussed. The results for 60 towns are presented. (author)

Bone images from dual-energy subtraction chest radiography in the detection of rib fractures.

Science.gov (United States)

Szucs-Farkas, Zsolt; Lautenschlager, Katrin; Flach, Patricia M; Ott, Daniel; Strautz, Tamara; Vock, Peter; Ruder, Thomas D

2011-08-01

To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p=0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p=0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, prib fractures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Digital subtraction angiography in the assessment of cardiovascular disease

International Nuclear Information System (INIS)

Harrington, D.P.; Boxt, L.M.

1985-01-01

Digital subtraction angiography (DSA) is a new radiographic method for evaluating the cardiovascular system. It represents another in a continuing series of computer-assisted diagnostic imaging modalities. The advantages of this technique are its relatively noninvasive nature combined with diagnostically acceptable angiographic images of a variety of cardiovascular structures. Major clinical applications of DSA include its use in imaging of localized regions of peripheral arterial disease and as a screening procedure in evaluating extracranial carotid and vertebral artery disease and renovascular hypertension. Cardiac applications of DSA include assessment of ventricular function, recognition and quantification of intracardiac shunts, visualization of coronary artery bypass grafts, and the study of complex congenital cardiac malformations. Digital subtraction angiography may also be used to evaluate intracranial aneurysms and vascular tumors

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

Science.gov (United States)

Hyun, Seung-Jae; Kim, Yongjung J; Rhim, Seung-Chul

2013-01-01

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The long-term overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided. PMID:24340276

Introduction to the principles of Digital Subtraction Angiography (DSA)

Energy Technology Data Exchange (ETDEWEB)

Kaplanis, P [Medical Physics Department, Nicosia General Hospital, Nicosia (Cyprus)

1998-12-31

Medical applications of advanced technology have rapidly become more sophisticated and more widespread. The field of diagnostic imaging is by no means an exception. There has been a number of breathtaking developments in the field of medical imaging in recent years. Today higher quality, greater clarity and more minute precision are considered not advantages but necessities. Hence new developments are concentrated in the data acquisition and image processing based on the microprocessor controlled modules interfaced with state of the art radiological imaging equipment. One such development is the subtraction of x-rays vis a computer for better visualization of blood vessels, cavities of the heart and of the coronary and pulmonary vascular system. This procedure is termed Digital Subtraction Angiography (DSA). (author). 5 refs, 3 figs.

Introduction to the principles of Digital Subtraction Angiography (DSA)

International Nuclear Information System (INIS)

Kaplanis, P.

1997-01-01

Medical applications of advanced technology have rapidly become more sophisticated and more widespread. The field of diagnostic imaging is by no means an exception. There has been a number of breathtaking developments in the field of medical imaging in recent years. Today higher quality, greater clarity and more minute precision are considered not advantages but necessities. Hence new developments are concentrated in the data acquisition and image processing based on the microprocessor controlled modules interfaced with state of the art radiological imaging equipment. One such development is the subtraction of x-rays vis a computer for better visualization of blood vessels, cavities of the heart and of the coronary and pulmonary vascular system. This procedure is termed Digital Subtraction Angiography (DSA). (author)

Learning with Technology: Video Modeling with Concrete-Representational-Abstract Sequencing for Students with Autism Spectrum Disorder.

Science.gov (United States)

Yakubova, Gulnoza; Hughes, Elizabeth M; Shinaberry, Megan

2016-07-01

The purpose of this study was to determine the effectiveness of a video modeling intervention with concrete-representational-abstract instructional sequence in teaching mathematics concepts to students with autism spectrum disorder (ASD). A multiple baseline across skills design of single-case experimental methodology was used to determine the effectiveness of the intervention on the acquisition and maintenance of addition, subtraction, and number comparison skills for four elementary school students with ASD. Findings supported the effectiveness of the intervention in improving skill acquisition and maintenance at a 3-week follow-up. Implications for practice and future research are discussed.

ADP-ribosylation of actins in fibroblasts and myofibroblasts by botulinum C2 toxin: Influence on microfilament morphology and migratory behavior

DEFF Research Database (Denmark)

Rønnov-Jessen, Lone; Petersen, Ole William

1996-01-01

botulinum C2 toxin. The substrate for C2 toxin is globular actin, which upon ribosylation cannot incorporate into microfilaments. The pattern of actin ADP-ribosylation in (myo)fibroblasts in the presence of [32P]NAD was analyzed by isoelectric focusing, fluorography and immunoblotting. The influence of C2...... toxin on microfilaments in intact cells was further assessed by immunofluorescence, and motility was measured in a mass migration assay and by computerized video time-lapse microscopy. We show here that C2 toxin specifically ribosylates - and -actin in both fibroblasts and myofibroblasts. Whereas...

Four-State Continuous-Variable Quantum Key Distribution with Photon Subtraction

Science.gov (United States)

Li, Fei; Wang, Yijun; Liao, Qin; Guo, Ying

2018-06-01

Four-state continuous-variable quantum key distribution (CVQKD) is one of the discretely modulated CVQKD which generates four nonorthogonal coherent states and exploits the sign of the measured quadrature of each state to encode information rather than uses the quadrature \\hat {x} or \\hat {p} itself. It has been proven that four-state CVQKD is more suitable than Gaussian modulated CVQKD in terms of transmission distance. In this paper, we propose an improved four-state CVQKD using an non-Gaussian operation, photon subtraction. A suitable photon-subtraction operation can be exploited to improve the maximal transmission of CVQKD in point-to-point quantum communication since it provides a method to enhance the performance of entanglement-based (EB) CVQKD. Photon subtraction not only can lengthen the maximal transmission distance by increasing the signal-to-noise rate but also can be easily implemented with existing technologies. Security analysis shows that the proposed scheme can lengthen the maximum transmission distance. Furthermore, by taking finite-size effect into account we obtain a tighter bound of the secure distance, which is more practical than that obtained in the asymptotic limit.

A subtraction scheme for computing QCD jet cross sections at NNLO: integrating the doubly unresolved subtraction terms

CERN Document Server

Somogyi, Gabor

2013-01-01

We finish the definition of a subtraction scheme for computing NNLO corrections to QCD jet cross sections. In particular, we perform the integration of the soft-type contributions to the doubly unresolved counterterms via the method of Mellin-Barnes representations. With these final ingredients in place, the definition of the scheme is complete and the computation of the regularised doubly virtual contribution to the NNLO cross section becomes feasible.

Misconception on Addition and Subtraction of Fraction at Primary School Students in Fifth-Grade

Science.gov (United States)

Trivena, V.; Ningsih, A. R.; Jupri, A.

2017-09-01

This study aims to investigate the mastery concept of the student in mathematics learning especially in addition and subtraction of fraction at primary school level. By using qualitative research method, the data were collected from 23 grade five students (10-11-year-old). Instruments included a test, that is accompanied by Certainty Response Index (CRI) and interview with students and teacher. The result of the test has been obtained, then processed by analyzing the student’s answers for each item and then grouped by the CRI categories that combined with the results of the interview with students and teacher. The results showed that student’s mastery-concept on additional and subtraction dominated by category ‘misconception’. So, we can say that mastery-concept on addition and subtraction of fraction at fifth-grade students is still low. Finally, the impact can make most of primary student think that learning addition and subtraction of fraction in mathematics is difficult.

Venous digital subtraction angiography for diagnosis of renal artery stenosis in arterial hypertony

International Nuclear Information System (INIS)

Schoerner, W.; Kempter, H.; Banzer, D.; Aviles, C.; Weiss, T.; Felix, R.

1984-01-01

Venous digital subtraction angiography was performed in 248 patients for the diagnosis of renal arterial stenosis. In 88% of the investigations the stenosis could be found. Comparison of digital angiography and conventional angiography was made for 57 renal arteries (25 investigations). In 52 renal arteries we found the same results with both methods, in 5 renal arteries we found the same results with both methods, in 5 renal arteries the digital angiography showed false positive results. The spatial resolution of digital subtraction angiography is sufficient for the correct diagnosis of significant renal arterial stenosis. With regard to the lower invasion of digital subtraction angiography compared to conventional angiography the first method should be used for clarification of renal arterial hypertension. (orig.)

Digital Subtraction Angiography (DSA) "Road Map": An Angiographic Tool

Science.gov (United States)

Turski, P. A.; Stieghorst, M. F.; Strother, C. M.; Crummy, A. B.; Lieberman, R. P.; Mistretta, C. A.

1982-12-01

Continuous Digital subtraction combined with intraarterial injections of contrast medium permits the display of arterial structures during real time fluoroscopy. This DSA "road map" facilitates selective catheterization and has proved useful in interventional procedures.

Comparison of two interpolative background subtraction methods using phantom and clinical data

International Nuclear Information System (INIS)

Houston, A.S.; Sampson, W.F.D.

1989-01-01

Two interpolative background subtraction methods used in scintigraphy are tested using both phantom and clinical data. Cauchy integral subtraction was found to be relatively free of artefacts but required more computing time than bilinear interpolation. Both methods may be used with reasonable confidence for the quantification of relative measurements such as left ventricular ejection fraction and myocardial perfusion index but should be avoided if at all possible in the quantification of absolute measurements such as glomerular filtration rate. (author)

Clinical application of subtraction CT imaging for evaluation of pulmonary vascular permeability

International Nuclear Information System (INIS)

Kato, Shiro; Asai, Toshihiko; Yatagai, Shigeo; Oonuma, Noboru; Ohno, Kunihiko; Nakamoto, Takaaki; Iizuka, Masahiko

1991-01-01

In this clinical study, one normal subject, one patient with primary interstitial pneumonia, one patient with segmental pneumonia due to Staphylococcus aureus, one patient with post-operative esophageal carcinoma, and two patients with mitral stenosis were studied. Dynamic CT scan images under continuous injection of low osmotic contrast medium were analyzed in series, in an attempt to evaluate vascular permeability quantitatively. The following results were obtained. Subtraction CT scan image 10 minutes after the start of contrast medium injection in two patients with pneumonia, showed a reduction of pulmonary vascular permeability following therapy. Subtraction CT scan image of the patient with post-operative esophageal carcinoma treated with 25 Gy radiation showed a discrepancy between pulmonary vascular permeability and other findings. In hemodynamically stable patients with mitral stenosis, subtraction CT images demonstrated that pulmonary vascular permeability was not affected by pulmonary congestion, irrespective of its severity. (author)

A subtraction scheme for computing QCD jet cross sections at NNLO: integrating the doubly unresolved subtraction terms

Science.gov (United States)

Somogyi, Gábor

2013-04-01

We finish the definition of a subtraction scheme for computing NNLO corrections to QCD jet cross sections. In particular, we perform the integration of the soft-type contributions to the doubly unresolved counterterms via the method of Mellin-Barnes representations. With these final ingredients in place, the definition of the scheme is complete and the computation of fully differential rates for electron-positron annihilation into two and three jets at NNLO accuracy becomes feasible.

A subtraction scheme for computing QCD jet cross sections at NNLO: integrating the doubly unresolved subtraction terms

OpenAIRE

Somogyi, Gabor

2013-01-01

We finish the definition of a subtraction scheme for computing NNLO corrections to QCD jet cross sections. In particular, we perform the integration of the soft-type contributions to the doubly unresolved counterterms via the method of Mellin-Barnes representations. With these final ingredients in place, the definition of the scheme is complete and the computation of fully differential rates for electron-positron annihilation into two and three jets at NNLO accuracy becomes feasible.

Enriching Addition and Subtraction Fact Mastery through Games

Science.gov (United States)

Bay-Williams, Jennifer M.; Kling, Gina

2014-01-01

The learning of "basic facts"--single-digit combinations for addition, subtraction, multiplication, and division--has long been a focus of elementary school mathematics. Many people remember completing endless worksheets, timed tests, and flash card drills as they attempted to "master" their basic facts as children. However,…

Improvement in visibility of simulated lung nodules on computed radiography (CR) chest images by use of temporal subtraction technique

International Nuclear Information System (INIS)

Oda, Nobuhiro; Fujimoto, Keiji; Murakami, Seiichi; Katsuragawa, Shigehiko; Doi, Kunio; Nakata, Hajime

1999-01-01

A temporal subtraction image obtained by subtraction of a previous image from a current one can enhance interval change on chest images. In this study, we compared the visibility of simulated lung nodules on CR images with and without temporal subtraction. Chest phantom images without and with simulated nodules were obtained as previous and current images, respectively, by a CR system. Then, subtraction images were produced with an iterative image warping technique. Twelve simulated nodules were attached on various locations of the chest phantom. The diameter of nodules having a CT number of 47 ranged from 3 mm to 10 mm. Seven radiologists subjectively evaluated the visibility of simulated nodules on CR images with and without temporal subtraction using a three-point rating scale (0: invisible, +1: questionable, +2:visible). The minimum diameter of simulated nodules visible at a frequency greater than 50% was 4 mm on the CR images with temporal subtraction and 6 mm on those without. Our results indicated that the subtraction images clearly improved the visibility of simulated nodules. (author)

Big Bang Observer and the neutron-star-binary subtraction problem

International Nuclear Information System (INIS)

Cutler, Curt; Harms, Jan

2006-01-01

The Big Bang Observer (BBO) is a proposed space-based gravitational-wave (GW) mission designed primarily to search for an inflation-generated GW background in the frequency range ∼10 -1 Hz-1 Hz. The major astrophysical foreground in this range is gravitational radiation from inspiralling compact binaries. This foreground is expected to be much larger than the inflation-generated background, so to accomplish its main goal, BBO must be sensitive enough to identify and subtract out practically all such binaries in the observable universe. It is somewhat subtle to decide whether BBO's current baseline design is sufficiently sensitive for this task, since, at least initially, the dominant noise source impeding identification of any one binary is confusion noise from all the others (rather than instrumental noise). Here we present a self-consistent scheme for deciding whether BBO's baseline design is indeed adequate for subtracting out the binary foreground. We conclude that the current baseline should be sufficient. However, if BBO's sensitivity were degraded by a factor 2 from the current baseline, then its ability to detect an underlying primordial background would depend critically on the value of ρ th , the threshold signal-to-noise ratio marking the boundary between detectable and undetectable sources. If BBO's sensitivity were degraded by a factor 4 from the current baseline, it could not detect a primordial background below Ω GW ∼10 -15 . It is impossible to perfectly subtract out each of the binary inspiral waveforms, so an important question is how to deal with the 'residual' errors in the post-subtraction data stream. We sketch a strategy of 'projecting out' these residual errors, at the cost of some effective bandwidth. We also provide estimates of the sizes of various post-Newtonian effects in the inspiral waveforms that must be accounted for in the BBO analysis

Digital subtraction in gadolinium-enhanced MR imaging of the brain: a method to reduce contrast dosage

International Nuclear Information System (INIS)

Chan, J.H.M.; Tsui, E.Y.K.; Chan, C.Y.; Lai, K.F.; Cheung, Y.K.; Wong, K.P.C.; Yuen, M.K.; Chau, L.F.; Fong, D.; Mok, C.K.

2002-01-01

The aim of the study was to investigate the feasibility of using digital subtraction in contrast-enhanced MR imaging of the brain to reduce the MR contrast dosage without jeopardizing patient care. Fifty-two patients with intracranial lesions, either intra-axial or extra-axial, detected by computerized tomography were selected for contrast-enhanced MR imaging with half-dose and full-dose of gadopentetate dimeglumine. The half-dose unsubtracted, full-dose unsubtracted, and half-dose subtracted MR images were visually assessed by counting the number of enhancing brain lesions in the images and quantitatively analyzed by computing their lesion contrast-to-background ratios (CBR). The visual conspicuity of the half-dose subtracted MR images was comparable to that of the full-dose unsubtracted MR images (p>0.05), whereas the CBR of the half-dose subtracted images was approximately two to three times higher than that of the full-dose unsubtracted images. The half-dose subtracted T1-weighted spin-echo images might be able to replace the conventional standard-dose T1-weighted spin-echo images in MR imaging of the brain. (orig.)

[Development of a digital chest phantom for studies on energy subtraction techniques].

Science.gov (United States)

Hayashi, Norio; Taniguchi, Anna; Noto, Kimiya; Shimosegawa, Masayuki; Ogura, Toshihiro; Doi, Kunio

2014-03-01

Digital chest phantoms continue to play a significant role in optimizing imaging parameters for chest X-ray examinations. The purpose of this study was to develop a digital chest phantom for studies on energy subtraction techniques under ideal conditions without image noise. Computed tomography (CT) images from the LIDC (Lung Image Database Consortium) were employed to develop a digital chest phantom. The method consisted of the following four steps: 1) segmentation of the lung and bone regions on CT images; 2) creation of simulated nodules; 3) transformation to attenuation coefficient maps from the segmented images; and 4) projection from attenuation coefficient maps. To evaluate the usefulness of digital chest phantoms, we determined the contrast of the simulated nodules in projection images of the digital chest phantom using high and low X-ray energies, soft tissue images obtained by energy subtraction, and "gold standard" images of the soft tissues. Using our method, the lung and bone regions were segmented on the original CT images. The contrast of simulated nodules in soft tissue images obtained by energy subtraction closely matched that obtained using the gold standard images. We thus conclude that it is possible to carry out simulation studies based on energy subtraction techniques using the created digital chest phantoms. Our method is potentially useful for performing simulation studies for optimizing the imaging parameters in chest X-ray examinations.

Practical applications and methods in performing cardiac digital subtraction angiography

International Nuclear Information System (INIS)

Markovic, D.M.; Withrow, S.; Moodie, D.S.

1986-01-01

One of the purposes of this book is to outline the utility of digital subtraction angiography (DSA) in common clinical practice. No text has dealt with the actual physical setup of the room or the patient prior and during a digital subtraction angiographic study at rest and with exercise. This chapter outlines the steps commonly used when cardiac DSA is performed on patients in the authors' laboratory. The authors have learned over the last few years the best way to prepare the patient and the equipment and it is hoped that utilizing this experience, other centers may avoid the mistakes the authors have made in the past and develop new techniques for the future

Subtracted Dispersion Relations for In-medium Meson Correlators in QCD Sum Rules

Energy Technology Data Exchange (ETDEWEB)

Florkowski, W; Broniowski, W [The H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

1999-01-01

We analyze subtracted dispersion relations for meson correlators at finite baryon density and temperature. Such relations are needed for QCD sum rules. We point out that importance of scattering terms, as well as finite, well-defined subtraction constants. Both are necessary for consistency, in particular for the equality of the longitudinal and transverse correlators in the limit of the vanishing three-momentum of mesons relative to the medium. We present detailed calculations in various mesonic channels of the Fermi gas of nucleons. (author)

Higgs boson production in association with a jet using jettiness subtraction

Directory of Open Access Journals (Sweden)

Radja Boughezal

2015-09-01

Full Text Available We use the recently proposed jettiness-subtraction scheme to provide the complete calculation of Higgs boson production in association with a jet in hadronic collisions through next-to-next-to-leading order in perturbative QCD. This method exploits the observation that the N-jettiness event-shape variable completely describes the singularity structure of QCD when final-state colored particles are present. Our results are in agreement with a recent computation of the gg and qg partonic initial states based on sector-improved residue subtraction. We present phenomenological results for both fiducial cross sections and distributions at the LHC.

Subtraction method of computing QCD jet cross sections at NNLO accuracy

Science.gov (United States)

Trócsányi, Zoltán; Somogyi, Gábor

2008-10-01

We present a general subtraction method for computing radiative corrections to QCD jet cross sections at next-to-next-to-leading order accuracy. The steps needed to set up this subtraction scheme are the same as those used in next-to-leading order computations. However, all steps need non-trivial modifications, which we implement such that that those can be defined at any order in perturbation theory. We give a status report of the implementation of the method to computing jet cross sections in electron-positron annihilation at the next-to-next-to-leading order accuracy.

Subtraction method of computing QCD jet cross sections at NNLO accuracy

Energy Technology Data Exchange (ETDEWEB)

Trocsanyi, Zoltan [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen P.O.Box 51 (Hungary)], E-mail: Zoltan.Trocsanyi@cern.ch; Somogyi, Gabor [University of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland)], E-mail: sgabi@physik.unizh.ch

2008-10-15

We present a general subtraction method for computing radiative corrections to QCD jet cross sections at next-to-next-to-leading order accuracy. The steps needed to set up this subtraction scheme are the same as those used in next-to-leading order computations. However, all steps need non-trivial modifications, which we implement such that that those can be defined at any order in perturbation theory. We give a status report of the implementation of the method to computing jet cross sections in electron-positron annihilation at the next-to-next-to-leading order accuracy.

Increasing Entanglement between Gaussian States by Coherent Photon Subtraction

DEFF Research Database (Denmark)

Ourjoumtsev, Alexei; Dantan, Aurelien Romain; Tualle Brouri, Rosa

2007-01-01

We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a nondegenerate parametric amplifier, produces delocalized states...

Improvement of temporal and dynamic subtraction images on abdominal CT using 3D global image matching and nonlinear image warping techniques

International Nuclear Information System (INIS)

Okumura, E; Sanada, S; Suzuki, M; Takemura, A; Matsui, O

2007-01-01

Accurate registration of the corresponding non-enhanced and arterial-phase CT images is necessary to create temporal and dynamic subtraction images for the enhancement of subtle abnormalities. However, respiratory movement causes misregistration at the periphery of the liver. To reduce these misregistration errors, we developed a temporal and dynamic subtraction technique to enhance small HCC by 3D global matching and nonlinear image warping techniques. The study population consisted of 21 patients with HCC. Using the 3D global matching and nonlinear image warping technique, we registered current and previous arterial-phase CT images or current non-enhanced and arterial-phase CT images obtained in the same position. The temporal subtraction image was obtained by subtracting the previous arterial-phase CT image from the warped current arterial-phase CT image. The dynamic subtraction image was obtained by the subtraction of the current non-enhanced CT image from the warped current arterial-phase CT image. The percentage of fair or superior temporal subtraction images increased from 52.4% to 95.2% using the new technique, while on the dynamic subtraction images, the percentage increased from 66.6% to 95.2%. The new subtraction technique may facilitate the diagnosis of subtle HCC based on the superior ability of these subtraction images to show nodular and/or ring enhancement

Multivariate spatial condition mapping using subtractive fuzzy cluster means.

Science.gov (United States)

Sabit, Hakilo; Al-Anbuky, Adnan

2014-10-13

Wireless sensor networks are usually deployed for monitoring given physical phenomena taking place in a specific space and over a specific duration of time. The spatio-temporal distribution of these phenomena often correlates to certain physical events. To appropriately characterise these events-phenomena relationships over a given space for a given time frame, we require continuous monitoring of the conditions. WSNs are perfectly suited for these tasks, due to their inherent robustness. This paper presents a subtractive fuzzy cluster means algorithm and its application in data stream mining for wireless sensor systems over a cloud-computing-like architecture, which we call sensor cloud data stream mining. Benchmarking on standard mining algorithms, the k-means and the FCM algorithms, we have demonstrated that the subtractive fuzzy cluster means model can perform high quality distributed data stream mining tasks comparable to centralised data stream mining.

Countermeasures for unintentional and intentional video watermarking attacks

Science.gov (United States)

Deguillaume, Frederic; Csurka, Gabriela; Pun, Thierry

2000-05-01

These last years, the rapidly growing digital multimedia market has revealed an urgent need for effective copyright protection mechanisms. Therefore, digital audio, image and video watermarking has recently become a very active area of research, as a solution to this problem. Many important issues have been pointed out, one of them being the robustness to non-intentional and intentional attacks. This paper studies some attacks and proposes countermeasures applied to videos. General attacks are lossy copying/transcoding such as MPEG compression and digital/analog (D/A) conversion, changes of frame-rate, changes of display format, and geometrical distortions. More specific attacks are sequence edition, and statistical attacks such as averaging or collusion. Averaging attack consists of averaging locally consecutive frames to cancel the watermark. This attack works well for schemes which embed random independent marks into frames. In the collusion attack the watermark is estimated from single frames (based on image denoising), and averaged over different scenes for better accuracy. The estimated watermark is then subtracted from each frame. Collusion requires that the same mark is embedded into all frames. The proposed countermeasures first ensures robustness to general attacks by spread spectrum encoding in the frequency domain and by the use of an additional template. Secondly, a Bayesian criterion, evaluating the probability of a correctly decoded watermark, is used for rejection of outliers, and to implement an algorithm against statistical attacks. The idea is to embed randomly chosen marks among a finite set of marks, into subsequences of videos which are long enough to resist averaging attacks, but short enough to avoid collusion attacks. The Bayesian criterion is needed to select the correct mark at the decoding step. Finally, the paper presents experimental results showing the robustness of the proposed method.

New electronic filtering technique in digital subtraction angiography

Energy Technology Data Exchange (ETDEWEB)

Stacul, F; Pozzi-Mucelli, R; Predonzan, F; Magnaldi, S; Godina, G

1986-01-01

The authors report their experience with a new electronic filtering technique in digital subtraction angiography (DSA). The principles of the technique are reported and the advantages in comparison with conventional filters are stressed (accurate and fast placement without fluoroscopic exposure). The system provided excellent results in about 900 DSA examinations.

Bone images from dual-energy subtraction chest radiography in the detection of rib fractures

Energy Technology Data Exchange (ETDEWEB)

Szucs-Farkas, Zsolt, E-mail: zsolt.szuecs@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Lautenschlager, Katrin, E-mail: katrin@students.unibe.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Flach, Patricia M., E-mail: patricia.flach@irm.unibe.ch [Institute of Forensic Medicine, University of Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Ott, Daniel, E-mail: daniel.ott@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Strautz, Tamara, E-mail: tamara.strautz@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Vock, Peter, E-mail: peter.vock@insel.ch [Department of Diagnostic, Interventional and Pediatric Radiology, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland); Ruder, Thomas D., E-mail: thomas.ruder@irm.unibe.ch [Institute of Forensic Medicine, University of Bern, Freiburgstrasse 4, Bern CH-3010 (Switzerland)

2011-08-15

Objective: To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. Materials and methods: In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. Results: The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p = 0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p = 0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p < 0.001). Conclusions: Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures.

NNLO jet cross sections by subtraction

International Nuclear Information System (INIS)

Somogyi, G.; Bolzoni, P.; Trocsanyi, Z.

2010-06-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of an earlier NNLO subtraction scheme over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state. (orig.)

NNLO jet cross sections by subtraction

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Bolzoni, P. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Trocsanyi, Z. [CERN, Geneva (Switzerland)

2010-06-15

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of an earlier NNLO subtraction scheme over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state. (orig.)

NNLO jet cross sections by subtraction

CERN Document Server

Somogyi, Gabor; Trocsanyi, Zoltan

2010-01-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of [1-4], over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Digital subtraction angiography

International Nuclear Information System (INIS)

Gmelin, E.; Arlart, I.P.

1987-01-01

The introduction explains the technical and physical fundamentals of digital radiography, the principles of digital subtraction, and the various filtering methods. The authors then define the requirements to be met by a DSA equipment in terms of technical components and operational performance. A very extensive chapter deals with the indications supporting intravenous or intraarterial DSA and compares the two methods, showing advantages and drawbacks with respect to practical results. Another chapter discusses the applications of DSA for cardiological diagnostics, as e.g. imaging of the coronary arteries or arterial bypasses, and explains the densitometric and planimetric evaluation of the coronary functional processes. The book also discusses less customary applications of DSA such as the sialography or dacryocystography, as well as angiologic examinations in children. The limits of the DSA methods are discussed in the last chapter, together with aspects such as the radiation exposure of the patient, and cost-benefit analyses, and potential future improvements. With 204 figs., 44 tabs [de

VideoSET: Video Summary Evaluation through Text

OpenAIRE

Yeung, Serena; Fathi, Alireza; Fei-Fei, Li

2014-01-01

In this paper we present VideoSET, a method for Video Summary Evaluation through Text that can evaluate how well a video summary is able to retain the semantic information contained in its original video. We observe that semantics is most easily expressed in words, and develop a text-based approach for the evaluation. Given a video summary, a text representation of the video summary is first generated, and an NLP-based metric is then used to measure its semantic distance to ground-truth text ...

Comparison of iodine K-edge subtraction and fluorescence subtraction imaging in an animal system

International Nuclear Information System (INIS)

Zhang, H.; Zhu, Y.; Bewer, B.; Zhang, L.; Korbas, M.; Pickering, I.J.; George, G.N.; Gupta, M.; Chapman, D.

2008-01-01

K-Edge Subtraction (KES) utilizes the discontinuity in the X-ray absorption across the absorption edge of the selected contrast element and creates an image of the projected density of the contrast element from two images acquired just above and below the K-edge of the contrast element. KES has proved to be powerful in coronary angiography, micro-angiography, bronchography, and lymphatic imaging. X-ray fluorescence imaging is a successful technique for the detection of dilute quantities of elements in specimens. However, its application at high X-ray energies (e.g. at the iodine K-edge) is complicated by significant Compton background, which may enter the energy window set for the contrast material's fluorescent X-rays. Inspired by KES, Fluorescence Subtraction Imaging (FSI) is a technique for high-energy (>20 keV) fluorescence imaging using two different incident beam energies just above and below the absorption edge of a contrast element (e.g. iodine). The below-edge image can be assumed as a 'background' image, which includes Compton scatter and fluorescence from other elements. The above-edge image will contain nearly identical spectral content as the below-edge image but will contain the additional fluorescence of the contrast element. This imaging method is especially promising with thick objects with dilute contrast materials, significant Compton background, and/or competing fluorescence lines from other materials. A quality factor is developed to facilitate the comparison. The theoretical value of the quality factor sets the upper limit that an imaging method can achieve when the noise is Poisson limited. The measured value of this factor makes two or more imaging methods comparable. Using the Hard X-ray Micro-Analysis (HXMA) beamline at the Canadian Light Source (CLS), the techniques of FSI and KES were critically compared, with reference to radiation dose, image acquisition time, resolution, signal-to-noise ratios, and quality factor

A Feature Subtraction Method for Image Based Kinship Verification under Uncontrolled Environments

DEFF Research Database (Denmark)

Duan, Xiaodong; Tan, Zheng-Hua

2015-01-01

The most fundamental problem of local feature based kinship verification methods is that a local feature can capture the variations of environmental conditions and the differences between two persons having a kin relation, which can significantly decrease the performance. To address this problem...... the feature distance between face image pairs with kinship and maximize the distance between non-kinship pairs. Based on the subtracted feature, the verification is realized through a simple Gaussian based distance comparison method. Experiments on two public databases show that the feature subtraction method...

Clinical usefulness of subtraction scintigraphy of the liver with Ga-67-citrate and Tc-99m-colloid

International Nuclear Information System (INIS)

Oyamada, H.; Terui, S.; Nagaiwa, K.; Kawai, H.; Fukukita, H.

1983-01-01

Subtraction scintigraphy of the liver with Ga-67-citrate and Tc-99m-colloid was performed for the radionuclide image diagnosis of intrahepatic masses, especially hepatoma. In this method the Tc-99m image was subtracted from the Ga-67 image. After normalizing both images, 4 different factors (0.6, 0.8, 1.0, and 1.2) were applied to the Tc-99m image before the subtraction. Finally, 4 subtraction images with different contrasts were obtained in one X-ray film. This method was found to be very useful in the assessment of intrahepatic focal accumulation of Ga-67, especially in cases with hepatoma, because it eliminated the uncertainty in the former method in which only visual judgment was done

Speech Enhancement by Multichannel Crosstalk Resistant ANC and Improved Spectrum Subtraction

Directory of Open Access Journals (Sweden)

Zeng Qingning

2006-01-01

Full Text Available A scheme combining multichannel crosstalk resistant adaptive noise cancellation (MCRANC algorithm and improved spectrum subtraction (ISS algorithm is presented to enhance noise carrying speech signals. The scheme would permit locating the microphones in close proximity by virtue of using MCRANC which has the capability of removing the crosstalk effect. MCRANC would also permit canceling out nonstationary noise and making the residual noise more stationary for further treatment by ISS algorithm. Experimental results have indicated that this scheme outperforms many commonly used techniques in the sense of SNR improvement and music effect reduction which is an inevitable byproduct of the spectrum subtraction algorithm.

Effects of global signal regression and subtraction methods on resting-state functional connectivity using arterial spin labeling data.

Science.gov (United States)

Silva, João Paulo Santos; Mônaco, Luciana da Mata; Paschoal, André Monteiro; Oliveira, Ícaro Agenor Ferreira de; Leoni, Renata Ferranti

2018-05-16

Arterial spin labeling (ASL) is an established magnetic resonance imaging (MRI) technique that is finding broader applications in functional studies of the healthy and diseased brain. To promote improvement in cerebral blood flow (CBF) signal specificity, many algorithms and imaging procedures, such as subtraction methods, were proposed to eliminate or, at least, minimize noise sources. Therefore, this study addressed the main considerations of how CBF functional connectivity (FC) is changed, regarding resting brain network (RBN) identification and correlations between regions of interest (ROI), by different subtraction methods and removal of residual motion artifacts and global signal fluctuations (RMAGSF). Twenty young healthy participants (13 M/7F, mean age = 25 ± 3 years) underwent an MRI protocol with a pseudo-continuous ASL (pCASL) sequence. Perfusion-based images were obtained using simple, sinc and running subtraction. RMAGSF removal was applied to all CBF time series. Independent Component Analysis (ICA) was used for RBN identification, while Pearson' correlation was performed for ROI-based FC analysis. Temporal signal-to-noise ratio (tSNR) was higher in CBF maps obtained by sinc subtraction, although RMAGSF removal had a significant effect on maps obtained with simple and running subtractions. Neither the subtraction method nor the RMAGSF removal directly affected the identification of RBNs. However, the number of correlated and anti-correlated voxels varied for different subtraction and filtering methods. In an ROI-to-ROI level, changes were prominent in FC values and their statistical significance. Our study showed that both RMAGSF filtering and subtraction method might influence resting-state FC results, especially in an ROI level, consequently affecting FC analysis and its interpretation. Taking our results and the whole discussion together, we understand that for an exploratory assessment of the brain, one could avoid removing RMAGSF to

Simultaneous optical digital half-subtraction and -addition using SOAs and a PPLN waveguide.

Science.gov (United States)

McGeehan, John E; Kumar, Saurabh; Willner, Alan E

2007-04-30

We demonstrate an optical half-subtracter and half-adder module that performs simultaneous bit-wise subtraction and addition of two 5 Gbit/s RZ data streams. We generate Borrow (/X*Y) and Difference/Sum (X plus sign in circleY, or XOR) outputs using cross-gain modulation (XGM) in two parallel SOAs. Taking advantage of the gain saturation inherent to SOAs, we generate two signals, /X*Y, and X*/Y, and combine them using a passive optical coupler to generate the XOR Difference/Sum output. We use difference-frequency-generation-based lambda-conversion in a PPLN waveguide to generate the Carry (X*Y) output. The PPLN waveguide allows bit-synchronous wavelength shifting, is wide-bandwidth, and offers no intrinsic chirp. Our module uses three active elements to perform simultaneous half-subtraction and addition, and carries a maximum power penalty of 1.0 dB.

Improved detection of pulmonary nodules on energy-subtracted chest radiographs with a commercial computer-aided diagnosis software: comparison with human observers

International Nuclear Information System (INIS)

Szucs-Farkas, Zsolt; Patak, Michael A.; Yuksel-Hatz, Seyran; Ruder, Thomas; Vock, Peter

2010-01-01

To retrospectively analyze the performance of a commercial computer-aided diagnosis (CAD) software in the detection of pulmonary nodules in original and energy-subtracted (ES) chest radiographs. Original and ES chest radiographs of 58 patients with 105 pulmonary nodules measuring 5-30 mm and images of 25 control subjects with no nodules were randomized. Five blinded readers evaluated firstly the original postero-anterior images alone and then together with the subtracted radiographs. In a second phase, original and ES images were analyzed by a commercial CAD program. CT was used as reference standard. CAD results were compared to the readers' findings. True-positive (TP) and false-positive (FP) findings with CAD on subtracted and non-subtracted images were compared. Depending on the reader's experience, CAD detected between 11 and 21 nodules missed by readers. Human observers found three to 16 lesions missed by the CAD software. CAD used with ES images produced significantly fewer FPs than with non-subtracted images: 1.75 and 2.14 FPs per image, respectively (p=0.029). The difference for the TP nodules was not significant (40 nodules on ES images and 34 lesions in non-subtracted radiographs, p = 0.142). CAD can improve lesion detection both on energy subtracted and non-subtracted chest images, especially for less experienced readers. The CAD program marked less FPs on energy-subtracted images than on original chest radiographs. (orig.)

Can approximate mental calculation account for operational momentum in addition and subtraction?

Science.gov (United States)

Knops, André; Dehaene, Stanislas; Berteletti, Ilaria; Zorzi, Marco

2014-01-01

The operational momentum (OM) effect describes a cognitive bias whereby we overestimate the results of mental addition problems while underestimating for subtraction. To test whether the OM emerges from psychophysical characteristics of the mental magnitude representation we measured two basic parameters (Weber fraction and numerical estimation accuracy) characterizing the mental magnitude representation and participants' performance in cross-notational addition and subtraction problems. Although participants were able to solve the cross-notational problems, they consistently chose relatively larger results in addition problems than in subtraction problems, thus replicating and extending previous results. Combining the above measures in a psychophysical model allowed us to partially predict the chosen results. Most crucially, however, we were not able to fully model the OM bias on the basis of these psychophysical parameters. Our results speak against the idea that the OM is due to basic characteristics of the mental magnitude representation. In turn, this might be interpreted as evidence for the assumption that the OM effect is better explained by attentional shifts along the mental magnitude representation during mental calculation.

Detection of aneurysms in subarachnoidal hemorrhage - CT-angiography versus digital subtraction angiography

International Nuclear Information System (INIS)

Roehnert, W.; Haenig, V.; Hietschold, V.; Abolmaali, N.

1998-01-01

Purpose: The value of CT-angiography (CT-A) for the visualization of intracranial aneurysms was more closely defined by comparison with digital subtraction angiography (DSA). Methods: Over a period of 18 months a total of 106 patients in whom a subarachnoidal hemorrhage had been detected on native CT were examined in parallel by spiral CT and DSA. CT-angiography was performed under standardized parameters and included processing with 3D surface reconstructions. Results: In 64 patients (60.4%) at total of 72 aneurysms were detected. In four cases (6.2%) there were two and in two cases (3.1%) even three aneurysms. The findings of DSA and CTA agreed in 98 cases (92.5%). In four patients (3.8%) a false negative results was obtained in CTA and the initial DSA. Conclusions: Digital subtraction angiography must still be considered as the gold standard in the diagnosis of cerebral aneurysms. On account of its excellent spatial delineation of aneurysms and possibilities for exact measurements, CT-angiography represents a valuable, supplementary method - in some cases also an alternative method - to digital subtraction angiography. (orig.) [de

Children's Understanding of the Addition/Subtraction Complement Principle

Science.gov (United States)

Torbeyns, Joke; Peters, Greet; De Smedt, Bert; Ghesquière, Pol; Verschaffel, Lieven

2016-01-01

Background: In the last decades, children's understanding of mathematical principles has become an important research topic. Different from the commutativity and inversion principles, only few studies have focused on children's understanding of the addition/subtraction complement principle (if a - b = c, then c + b = a), mainly relying on verbal…

Visualization of the renal venous system by renal arteriography with digital subtraction angiography

International Nuclear Information System (INIS)

Nagai, Jun

1989-01-01

The purpose of this study was to obtain vivid and precise images of intrarenal venous branching using DSA for renal arteriography. The type of system used was an ADAC DPS-4100C with 70-80 kVp, and 320 mA, 25-50 msec at 6 frames/sec. The duration was 10 sec and the matrix size was 512x512. In order to retain clear subtracted images of intrarenal venous branching with minimal noise the three frames were selected on the time-density curve of DSA: (Fig.3). 1) a frame on which renal arteries disappear (frame X), 2) the frame with highest renal venous density value as (frame Y), 3) the difference of the nephrogram density between X and Y frames in which only the density of the nephrogram decreases (frame Z). The mask image is the image subtracted by the equation of the weighted averaging method on X and Z frame and is subtracted from the image of Y frame in the final step. By this method, 40 kidneys in 36 patients were studied, and the intrarenal venous branches up to the interlobar vein was clearly demonstrated in 28 of these cases (70%). This method is useful to estimate the extent of intrarenal lesions and detect abnormal renal blood flow compared with conventional temporal subtraction method. (author)

The role of contrast-enhanced digital subtraction MRI in the diagnosis of vertebral metastasic tumors

International Nuclear Information System (INIS)

Xiao Yeyu; Yang Jun; Qi Weili; Liu Qize; Hong Bikai; Wu Renhua

2008-01-01

Objective: To evaluate the contrast-enhanced digital subtraction MRI in the diagnosis of vertebral metastasic tumors. Methods 66 vertebral metastasic tumors in 43 patients were examined with conventional MRI (T 1 WI, STIR and Contrast-enhanced T 1 WI) and contrast-enhanced digital subtraction MR imaging. All lesions were histologically proved. The quantity and characteristic imaging signs (including spiculation, bull eye sign and irregular edge) of lesions were detected separately by different sequences. K independent samples test was used. Results: The detection rates of 35 vertebral metastasic tumors with vertebral morphological changes were same in all MR sequences. But in the other 31 lesions without vertebral morphological changes, the detection rates were different and STIR was the highest in all sequences. Contrast-enhanced digital subtraction MRI was more sensitive than all the conventional MR sequences in finding characteristic imaging signs with statistically significant differences. Conclusion: Contrast enhanced subtraction MRI is an useful and convenient technique which has great value in finding vertebral metastasic tumors and depicting the characteristic imaging signs. (authors)

Magnetization transfer contrast (MTC) and MTC-subtraction: enhancement of cartilage lesions and intracartilaginous degeneration in vitro

International Nuclear Information System (INIS)

Vahlensieck, M.; Dombrowski, F.; Leutner, C.; Wagner, U.; Reiser, M.

1994-01-01

Human articular cartilage from 16 cadaveric or amputated knees was studied using standard magnetic resonance imaging (MRI), on-resonance magnetization transfer contrast (MTC) and MTC-subtraction MRI. Results were compared with subsequent macroscopic and histopathological findings. MTC-subtraction and T2-weighted spin-echo images visualized cartilaginous surface defects with high sensitivity and specificity. MTC and T2-weighted spin-echo images revealed intra-cartilaginous signal loss without surface defects in 80% of the cases, corresponding to an increased collagen concentration. It is concluded that MTC is sensitive to early cartilage degeneration and MTC-subtraction can be helpful in detecting cartilage defects. (orig.)

Evaluation of the pulmonary vascular bed by digital subtraction angiography

International Nuclear Information System (INIS)

Shikuwa, Masahiro; Asai, Sadahiro; Hara, Shiro; Yamasa, Toshihiko; Miyahara, Yoshiyuki; Hara, Kohei; Nishijima, Kyoji.

1995-01-01

We studied the usefulness of digital subtraction angiography for evaluating the pulmonary capillary bed. Four individuals underwent the procedure. One was a healthy volunteer and the others were patients with chronic pulmonary emphysema. During catheterization, an 8 F balloon catheter was manipulated into the right pulmonary artery. A total of 20 ml of contrast material was injected at a rate of 10 ml/sec at full inspiration. In the normal subject, the capillary bed filled homogeneously and no defect was seen. In the patients, the pulmonary artery was nearly normal, but severe defects were observed in the pulmonary capillaries. Contrast resolvability was greater with digital subtraction pulmonary angiography than with pulmonary perfusion scintigraphy or pulmonary arteriography. This technique makes possible the visual evaluation of the pulmonary capillary bed. (author)

Evaluation of the utility of temporal subtraction images in successive whole-body bone scans: a prospective clinical study

International Nuclear Information System (INIS)

Shiraishi, J.; Appelbaum, D.; Pu, Y.; Engelmann, R.; Li Qiang; Doi, K.

2007-01-01

We have begun a prospective clinical study for evaluating the clinical utility of temporal subtraction images in successive whole-body bone scans. The computerized temporal subtraction technique has been developed in order to highlight interval changes of abnormal lesions due to skeletal metastases, primary bone tumors, osteomyelitis, and fractures. In our initial preliminary results of the prospective study which was started on November 22, 2006 in our hospital, radiologists reported some interval changes which were not recognized in the initial standard readings, but were obvious when temporal subtraction images were viewed. The usefulness of the temporal subtraction images will be investigated in terms of its clinical utility by the prospective clinical study. (orig.)

Dynamic gadolinium-enhanced subtraction MR imaging - a simple technique for the early diagnosis of Legg-Calve-Perthes disease: preliminary results

International Nuclear Information System (INIS)

Sebag, G.; Ducou Le Pointe, H.; Klein, I.; Maiza, D.; Mazda, K.; Bensahel, H.; Hassan, M.

1997-01-01

To determine whether the simple technique of dynamic gadolinium-enhanced subtraction MR imaging, which is available on standard MR units, can detect ischemia of the femoral head in children with early Legg-Calve-Perthes disease (LCP). Bone perfusion of eight hips in four patients (mean age 7.5 years) was studied using dynamic gadolinium-enhanced substraction MR imaging at the onset of proven LCP (with initial negative plain films). Enhancement of subtracted images was compared with that on standard MR images and with bone scintigraphy findings. Subtraction MR imaging depicted ischemia as a widespread absence of enhancement and was in good agreement with bone scintigraphy. The subtraction technique improved the sensitivity and the specificity of MR imaging in two children. Furthermore, subtraction MR imaging allowed recognition of the pattern of early reperfusion. Our preliminary results indicate that dynamic gadolinium-enhanced subtraction MRI is a simple and promising means of early recognition of ischemia in LCP. (orig.)

A multiple regression analysis for accurate background subtraction in 99Tcm-DTPA renography

International Nuclear Information System (INIS)

Middleton, G.W.; Thomson, W.H.; Davies, I.H.; Morgan, A.

1989-01-01

A technique for accurate background subtraction in 99 Tc m -DTPA renography is described. The technique is based on a multiple regression analysis of the renal curves and separate heart and soft tissue curves which together represent background activity. It is compared, in over 100 renograms, with a previously described linear regression technique. Results show that the method provides accurate background subtraction, even in very poorly functioning kidneys, thus enabling relative renal filtration and excretion to be accurately estimated. (author)

Detection of pulmonary nodules on lung X-ray images. Studies on multi-resolutional filter and energy subtraction images

International Nuclear Information System (INIS)

Sawada, Akira; Sato, Yoshinobu; Kido, Shoji; Tamura, Shinichi

1999-01-01

The purpose of this work is to prove the effectiveness of an energy subtraction image for the detection of pulmonary nodules and the effectiveness of multi-resolutional filter on an energy subtraction image to detect pulmonary nodules. Also we study influential factors to the accuracy of detection of pulmonary nodules from viewpoints of types of images, types of digital filters and types of evaluation methods. As one type of images, we select an energy subtraction image, which removes bones such as ribs from the conventional X-ray image by utilizing the difference of X-ray absorption ratios at different energy between bones and soft tissue. Ribs and vessels are major causes of CAD errors in detection of pulmonary nodules and many researches have tried to solve this problem. So we select conventional X-ray images and energy subtraction X-ray images as types of images, and at the same time select ∇ 2 G (Laplacian of Guassian) filter, Min-DD (Minimum Directional Difference) filter and our multi-resolutional filter as types of digital filters. Also we select two evaluation methods and prove the effectiveness of an energy subtraction image, the effectiveness of Min-DD filter on a conventional X-ray image and the effectiveness of multi-resolutional filter on an energy subtraction image. (author)

Relation between thallium-201/iodine 123-BMIPP subtraction and fluorine 18 deoxyglucose polar maps in patients with hypertrophic cardiomyopathy.

Science.gov (United States)

Ito, Y; Hasegawa, S; Yamaguchi, H; Yoshioka, J; Uehara, T; Nishimura, T

2000-01-01

Clinical studies have shown discrepancies in the distribution of thallium-201 and iodine 123-beta-methyl-iodophenylpentadecanoic acid (BMIPP) in patients with hypertrophic cardiomyopathy (HCM). Myocardial uptake of fluorine 18 deoxyglucose (FDG) is increased in the hypertrophic area in HCM. We examined whether the distribution of a Tl-201/BMIPP subtraction polar map correlates with that of an FDG polar map. We normalized to maximum count each Tl-201 and BMIPP bull's-eye polar map of 6 volunteers and obtained a standard Tl-201/BMIPP subtraction polar map by subtracting a normalized BMIPP bull's-eye polar map from a normalized Tl-201 bull's-eye polar map. The Tl-201/BMIPP subtraction polar map was then applied to 8 patients with HCM (mean age 65+/-12 years) to evaluate the discrepancy between Tl-201 and BMIPP distribution. We compared the Tl-201/BMIPP subtraction polar map with an FDG polar map. In patients with HCM, the Tl-201/BMIPP subtraction polar map showed a focal uptake pattern in the hypertrophic area similar to that of the FDG polar map. By quantitative analysis, the severity score of the Tl-201/BMIPP subtraction polar map was significantly correlated with the percent dose uptake of the FDG polar map. These results suggest that this new quantitative method may be an alternative to FDG positron emission tomography for the routine evaluation of HCM.

Digital subtraction CT angiography for the detection of posterior inferior cerebellar artery aneurysms: comparison with digital subtraction angiography

Energy Technology Data Exchange (ETDEWEB)

Chen, Guo Zhong; Luo, Song; Zhou, Chang Sheng; Zhang, Long Jiang; Lu, Guang Ming [Jinling Hospital, Medical School of Nanjing University, Department of Medical Imaging, Nanjing, Jiangsu (China)

2017-09-15

To evaluate the diagnostic accuracy of digital subtraction CT angiography (DS-CTA) in detecting posterior inferior cerebellar artery (PICA) aneurysms with digital subtraction angiography (DSA) as reference standard. A total of 115 patients, including 56 patients diagnosed with PICA aneurysms by CTA or DSA and 59 non-PICA-aneurysm patients were included in this retrospective study. All patients underwent DS-CTA and DSA. The site of PICA aneurysms and the pattern of haemorrhage were analysed. Sensitivity and specificity of DS-CTA without and with combining haemorrhage pattern in diagnosing PICA aneurysms were evaluated on a per patient and per aneurysm basis with DSA. Of 115 patients, 56 patients (48.7%) had 61 PICA aneurysms (size range, 1.1-13.5 mm; mean size, 4.9 ± 2.8 mm) on DSA. The sensitivity and specificity in depicting PICA aneurysms were 89.3% and 96.6% on a per patient basis and 90.2% and 93.4% on a per aneurysm basis, while the corresponding values were 94.6% and 96.6% on a per patient basis and 95.1% and 93.4% on a per aneurysm basis when combining with haemorrhage site. DS-CTA has a high sensitivity and specificity in detecting PICA aneurysms compared with DSA. It may be helpful for clinical diagnosis of PICA aneurysms to combine with haemorrhage sites. (orig.)

Deblurring in digital tomosynthesis by iterative self-layer subtraction

Science.gov (United States)

Youn, Hanbean; Kim, Jee Young; Jang, SunYoung; Cho, Min Kook; Cho, Seungryong; Kim, Ho Kyung

2010-04-01

Recent developments in large-area flat-panel detectors have made tomosynthesis technology revisited in multiplanar xray imaging. However, the typical shift-and-add (SAA) or backprojection reconstruction method is notably claimed by a lack of sharpness in the reconstructed images because of blur artifact which is the superposition of objects which are out of planes. In this study, we have devised an intuitive simple method to reduce the blur artifact based on an iterative approach. This method repeats a forward and backward projection procedure to determine the blur artifact affecting on the plane-of-interest (POI), and then subtracts it from the POI. The proposed method does not include any Fourierdomain operations hence excluding the Fourier-domain-originated artifacts. We describe the concept of the self-layer subtractive tomosynthesis and demonstrate its performance with numerical simulation and experiments. Comparative analysis with the conventional methods, such as the SAA and filtered backprojection methods, is addressed.

Self-mixing differential vibrometer based on electronic channel subtraction

International Nuclear Information System (INIS)

Donati, Silvano; Norgia, Michele; Giuliani, Guido

2006-01-01

An instrument for noncontact measurement of differential vibrations is developed, based on the self-mixing interferometer. As no reference arm is available in the self-mixing configuration, the differential mode is obtained by electronic subtraction of signals from two (nominally equal) vibrometer channels, taking advantage that channels are servo stabilized and thus insensitive to speckle and other sources of amplitude fluctuation. We show that electronic subtraction is nearly as effective as field superposition. Common-mode suppression is 25-30 dB, the dynamic range (amplitude) is in excess of 100 μm, and the minimum measurable (differential) amplitude is 20 nm on aB=10 kHz bandwidth. The instrument has been used to measure vibrations of two metal samples kept in contact, revealing the hysteresis cycle in the microslip and gross-slip regimes, which are of interest in the study of friction induced vibration damping of gas turbine blades for aircraft applications

Accuracy of digital subtraction radiography in combination with a contrast media in assessment of proximal caries depth

Directory of Open Access Journals (Sweden)

Farzad Esmaeili

2008-07-01

Full Text Available Background and aims. Radiography is used to diagnose the demineralization process and carious lesions; however, conventional radiography and direct digital images do not show these lesions when the amount of demineralization is less than 40%. Digital subtraction radiography has recently been used to improve the diagnostic quality of these lesions. The purpose of this study was to compare the caries depth estimated by digital subtraction radiography in combination with barium sulfate in diagnosing proximal dental caries with histopathologic evaluation. Materials and methods. In this study 30 molars and premolars (24 demineralized lesions with cavity, 8 without cavity were studied. Direct digital images were taken (kVp: 68, mA: 8; t: 0.12 for premolars and t: 0.16 for molars whereas the position of X-ray tube and CCD receptor and teeth was fixed. To prepare the second images 135 gr/L barium sulfate was used. The images obtained with the same exposure and geometry and then subtracted. The depth of the lesions in direct digital and subtracted images were assessed and compared with the depth measured in histopathologic assessments. Results. The mean depths (± SD of the lesions were 1.80 ± 0.77 mm in direct digital radiography, 2.32 ± 0.76 mm in subtracted images after barium sulfate treatment, and 2.51 ± 0.43 mm in histopathologic sections. The statistical difference between direct digital radiography and the other methods was significant (P < 0.05. However, the differences were not statistically significant between subtracted images and histopathologic sections. The average intra-class correlation coefficient was 0.7241 (CI: 95%. Conclusion. The present study has demonstrated that digital subtraction radiography images have the potential to measure the depth of proximal caries with no significant difference with histopathologic evaluation.

An evaluation of the subtraction photoshop software accuracy to detect minor changes in optical density by radiovisiography

Directory of Open Access Journals (Sweden)

Talaeipour AR.

2004-06-01

Full Text Available Statement of Problem: Subtraction is a newly presented radiography technique to detect minor density"nchanges that are not visible by conventional radiography."nPurpose: The aim of this In-vitro study was to evaluate the efficacy of photoshop subtraction software for"ndetecting minor density changes between two dental images."nMaterials and Methods: In this research, five dried human mandibles were held in fixed position while thin"naluminium sheets were superimposed on each mandible on the 1th and 2nd molar teeth regions."nA reference image, without aluminium sheet placement, was obtained from each mandible subsequently series"nconsist of 20 images with aluminium sheets, ranging from 50p. to "5Q0"x were recorded by radiovisiography"n(RVG system. Initial images were subtracted from subsequent ones by Photoshop subtraction software. The"ndifference in density between the two images at the 1st and 2nd molar sites was related to the aluminium"nsheets. The optical density of aluminium sheets was determined by densitometer."nResults: In the present study, 6.6% of the optical density changes of the minimum aluminium thickness as"n300u. could be detected by photoshop software software."nConclusion: The findings of this study showed that the accuracy of photoshop subtraction software was equal"nto that of the conventional subtraction softwares. Additionally, the accuracy of this software was proved to be"nsuitable for clinical investigations of small localized changes in alveolar bone.

Dynamic subtraction magnetic resonance venography: a new real time imaging technique for the detection of dural sinus thrombosis

International Nuclear Information System (INIS)

Mandel, C.; Birchall, D.; Connolly, D.; English, P.

2002-01-01

Full text: Requests for imaging suspected dural sinus thrombosis are increasing. Conventional magnetic imaging (MRI) and magnetic resonance venography (MRV) are often used to detect venous sinus thrombosis, but these techniques are prone to technical problems. Catheter angiography is sometimes required as the final arbiter in the evaluation of the dural venous sinuses. Recent technical developments in MR scanning have allowed the development of dynamic subtraction MRA. This technique is beginning to be applied to the assessment of intracranial vascular malformations. We have recently applied the technique to the imaging of the dural venous sinuses, and describe our early experience with the technique. Imaging was performed on a Philips Intera 1.5T scanner with gradient strength 33 mT and slew rate 130 T/m/sec. T1-weighed fast field echo imaging was performed (flip angle 400, TR 1.5 msec) during bolus injection of gadolinium (5ml gadolinium followed by a 10 ml saline chaser) at 5-6 ml/sec using a MRI-compatible pump injector. Slice thickness depended on the plane of acquisition, but was between 100- 150 mm. Images were acquired in three orthogonal projections in each case, using 3 separate contrast injections. Mask images were obtained before the arrival of contrast, and subtracted reconstructed images were obtained in real time, providing a dynamic display of the intracranial circulation including the dural venous sinuses. Frame rate was 1 frame per 0.8 seconds. We will present dynamic MR angiographic images in a number of patients. Normal appearances and those seen in venous sinus thrombosis will be presented in the video display. Dynamic MR venography is a new technique for the imaging of dural venous sinuses. In our practice, it has proved a valuable adjunct for the imaging of patients with dural venous sinus thrombosis. Copyright (2002) Blackwell Science Pty Ltd

Digital subtraction angiography in the diagnosis of Fallot's tetralogy

International Nuclear Information System (INIS)

Ivanitskij, A.V.; Tereshkin, Ya.A.; Sobolev, A.V.; Stolyar, V.L.; Slyunyastikov, M.A.

1995-01-01

The authors analyze the efficacy of digital subtraction angiography (DSA) in the diagnosis of Fallot's tetralogy (FT); this method helps simplity and cut down their scope of investigations but does not deteriorate their informative value. DSA findings in 120 patients with TF are analyzed. 5 refs.; 6 figs

Tumor scintigraphy by the method for subtracting the initial image with technetium-99m labeled antibody

International Nuclear Information System (INIS)

Karube, Yoshiharu; Katsuno, Kentaro; Ito, Sanae; Matsunaga, Kazuhisa; Takata, Jiro; Kuroki, Masahide; Murakami, Masaaki; Matsuoka, Yuji

1999-01-01

The method for subtracting the initial image from the localization image was evaluated for radioimmunoscintigraphy of tumors with technetium-99m (Tc-99m) labeled antibodies. Monoclonal antibodies were parental mouse and mouse-human chimeric antibodies to carcinoembryonic antigen (CEA), designated F11-39 and ChF11-39, respectively, both of which have been found to discriminate CEA in tumor tissues from the CEA-related antigens. After reduction of the intrinsic disulfide bonds, these antibodies were labeled with Tc-99m. In vivo studies were performed on athymic nude mice bearing the human CEA-producing gastric carcinoma xenografts. Though biodistribution results showed selective and progressive accumulation of Tc-99m labeled antibodies at the tumor site, high radioactivity in blood was inappropriate for scintigraphic visualization of the tumors within a few hours. We examined the subtraction of the initial Tc-99m image from the Tc-99m localization image after a few hours. Subtracted images of the same count reflected the in vivo behavior of the Tc-99m radioactivity. The subtracted scintigrams revealed excellent tumor images with no significant extrarenal background. Visualization of the tumor site was dependent on antigen-specific binding and nonspecific exudation. These results demonstrate that a method of subtraction of the initial image may serve as a potentially useful diagnostic method for an abnormal site for agents with a low pharmacokinetic value. (author)

Counting the mismatches - lung ventilation/perfusion subtraction index

International Nuclear Information System (INIS)

Anderson, T.C.; Evans, S.G.; Larcos, G.; Farlow, D.C.

1998-01-01

Full text: There is potential for interobserver variability in interpretation of ventilation/perfusion (V/Q) scans. Objective quantification of V/Q mismatch could be useful. Thus, the aim of this study is to determine the validity of image subtraction in a group of 27 patients (11 men, 8 women; mean age 59.4 years [range 21-81 years])investigated by V/Q scans for suspected pulmonary emboli. A standard 6 view V/Q scan was obtained with two cobalt markers used on the anterior and posterior surfaces for image alignment. Ventilation images were normalised to the perfusion using an area of normal ventilation and perfusion. With the use of automated, and if required, manual alignment, perfusion images were subtracted from ventilation, with a median filter applied. A summed index of mismatch for each lung scan was calculated from the difference. This index was then retrospectively compared to the result reported by one of four experienced physicians. Two patients with chronic obstructive airways disease were excluded from analysis. We conclude that high probability V/Q scans can be differentiated from low probability studies using this index; further prospective investigation in a larger cohort is warranted

Determination of the kalium-subtracted total beta in food

International Nuclear Information System (INIS)

Liu Guofan

1985-01-01

A procedure for measuring the kalium-subtracted total beta in food can be applied to estimating the contamination of beta nuclides except 40 K. The procedure, calculating formula, and some experiences in practice are described in this paper. The method is simple, rapid, and very useful to food contamination monitoring

Content-based video retrieval by example video clip

Science.gov (United States)

Dimitrova, Nevenka; Abdel-Mottaleb, Mohamed

1997-01-01

This paper presents a novel approach for video retrieval from a large archive of MPEG or Motion JPEG compressed video clips. We introduce a retrieval algorithm that takes a video clip as a query and searches the database for clips with similar contents. Video clips are characterized by a sequence of representative frame signatures, which are constructed from DC coefficients and motion information (`DC+M' signatures). The similarity between two video clips is determined by using their respective signatures. This method facilitates retrieval of clips for the purpose of video editing, broadcast news retrieval, or copyright violation detection.

Continuous-variable measurement-device-independent quantum key distribution with virtual photon subtraction

Science.gov (United States)

Zhao, Yijia; Zhang, Yichen; Xu, Bingjie; Yu, Song; Guo, Hong

2018-04-01

The method of improving the performance of continuous-variable quantum key distribution protocols by postselection has been recently proposed and verified. In continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocols, the measurement results are obtained from untrusted third party Charlie. There is still not an effective method of improving CV-MDI QKD by the postselection with untrusted measurement. We propose a method to improve the performance of coherent-state CV-MDI QKD protocol by virtual photon subtraction via non-Gaussian postselection. The non-Gaussian postselection of transmitted data is equivalent to an ideal photon subtraction on the two-mode squeezed vacuum state, which is favorable to enhance the performance of CV-MDI QKD. In CV-MDI QKD protocol with non-Gaussian postselection, two users select their own data independently. We demonstrate that the optimal performance of the renovated CV-MDI QKD protocol is obtained with the transmitted data only selected by Alice. By setting appropriate parameters of the virtual photon subtraction, the secret key rate and tolerable excess noise are both improved at long transmission distance. The method provides an effective optimization scheme for the application of CV-MDI QKD protocols.

Venous digital subtraction angiography of the renal arteries in hypertensive patients

International Nuclear Information System (INIS)

Brecht, G.; Harder, T.; Franken, T.

1984-01-01

We carried out 1890 venous digital subtraction angiograms; this included 113 patients with hypertension in order to exclude renal artery stenosis. On four occasions it was used following surgery on a renal artery. Renal artery stenosis or occlusion was demonstrated in twelve patients, and other vascular diseases or anomalies were found in 24. Two abnormal renal arteries were found following renal artery surgery. The results are compared with smaller groups of patients examined by DSA, and with the results of conventional subtraction methods reported in the literature. In only eight patients (6.8%) DSA provided insufficient information and had to be supplemented by aortography. The method has proved to be a valuable and simple screening method for the investigation of hypertension. (orig.) [de

[X-ray semiotics of sialolithiasis in functional digital subtraction sialography].

Science.gov (United States)

Iudin, L A; Kondrashin, S A; Afanas'ev, V V; Shchipskiĭ, A V

1995-01-01

Twenty-seven patients with sialolithiasis were examined using functional subtraction sialography developed by the authors. Differential diagnostic signs characterizing the degree of involvement of the salivary gland were defined. High efficacy of the method helps correctly plan the treatment strategy.

Immersive video

Science.gov (United States)

Moezzi, Saied; Katkere, Arun L.; Jain, Ramesh C.

1996-03-01

Interactive video and television viewers should have the power to control their viewing position. To make this a reality, we introduce the concept of Immersive Video, which employs computer vision and computer graphics technologies to provide remote users a sense of complete immersion when viewing an event. Immersive Video uses multiple videos of an event, captured from different perspectives, to generate a full 3D digital video of that event. That is accomplished by assimilating important information from each video stream into a comprehensive, dynamic, 3D model of the environment. Using this 3D digital video, interactive viewers can then move around the remote environment and observe the events taking place from any desired perspective. Our Immersive Video System currently provides interactive viewing and `walkthrus' of staged karate demonstrations, basketball games, dance performances, and typical campus scenes. In its full realization, Immersive Video will be a paradigm shift in visual communication which will revolutionize television and video media, and become an integral part of future telepresence and virtual reality systems.

PCA-based approach for subtracting thermal background emission in high-contrast imaging data

Science.gov (United States)

Hunziker, S.; Quanz, S. P.; Amara, A.; Meyer, M. R.

2018-03-01

Aims.Ground-based observations at thermal infrared wavelengths suffer from large background radiation due to the sky, telescope and warm surfaces in the instrument. This significantly limits the sensitivity of ground-based observations at wavelengths longer than 3 μm. The main purpose of this work is to analyse this background emission in infrared high-contrast imaging data as illustrative of the problem, show how it can be modelled and subtracted and demonstrate that it can improve the detection of faint sources, such as exoplanets. Methods: We used principal component analysis (PCA) to model and subtract the thermal background emission in three archival high-contrast angular differential imaging datasets in the M' and L' filter. We used an M' dataset of β Pic to describe in detail how the algorithm works and explain how it can be applied. The results of the background subtraction are compared to the results from a conventional mean background subtraction scheme applied to the same dataset. Finally, both methods for background subtraction are compared by performing complete data reductions. We analysed the results from the M' dataset of HD 100546 only qualitatively. For the M' band dataset of β Pic and the L' band dataset of HD 169142, which was obtained with an angular groove phase mask vortex vector coronagraph, we also calculated and analysed the achieved signal-to-noise ratio (S/N). Results: We show that applying PCA is an effective way to remove spatially and temporarily varying thermal background emission down to close to the background limit. The procedure also proves to be very successful at reconstructing the background that is hidden behind the point spread function. In the complete data reductions, we find at least qualitative improvements for HD 100546 and HD 169142, however, we fail to find a significant increase in S/N of β Pic b. We discuss these findings and argue that in particular datasets with strongly varying observing conditions or

Analytical optimization of digital subtraction mammography with contrast medium using a commercial unit.

Science.gov (United States)

Rosado-Méndez, I; Palma, B A; Brandan, M E

2008-12-01

Contrast-medium-enhanced digital mammography (CEDM) is an image subtraction technique which might help unmasking lesions embedded in very dense breasts. Previous works have stated the feasibility of CEDM and the imperative need of radiological optimization. This work presents an extension of a former analytical formalism to predict contrast-to-noise ratio (CNR) in subtracted mammograms. The goal is to optimize radiological parameters available in a clinical mammographic unit (x-ray tube anode/filter combination, voltage, and loading) by maximizing CNR and minimizing total mean glandular dose (D(gT)), simulating the experimental application of an iodine-based contrast medium and the image subtraction under dual-energy nontemporal, and single- or dual-energy temporal modalities. Total breast-entrance air kerma is limited to a fixed 8.76 mGy (1 R, similar to screening studies). Mathematical expressions obtained from the formalism are evaluated using computed mammographic x-ray spectra attenuated by an adipose/glandular breast containing an elongated structure filled with an iodinated solution in various concentrations. A systematic study of contrast, its associated variance, and CNR for different spectral combinations is performed, concluding in the proposal of optimum x-ray spectra. The linearity between contrast in subtracted images and iodine mass thickness is proven, including the determination of iodine visualization limits based on Rose's detection criterion. Finally, total breast-entrance air kerma is distributed between both images in various proportions in order to maximize the figure of merit CNR2/D(gT). Predicted results indicate the advantage of temporal subtraction (either single- or dual-energy modalities) with optimum parameters corresponding to high-voltage, strongly hardened Rh/Rh spectra. For temporal techniques, CNR was found to depend mostly on the energy of the iodinated image, and thus reduction in D(gT) could be achieved if the spectral energy

Intraarterial digital subtraction angiography in neuroradiology

International Nuclear Information System (INIS)

Zeumer, H.

1987-01-01

Neuroradiology always could make best use of subtraction methods, due to the relative immobility and constant shape of the skull. Arterial DSA now has extended the potential uses while reducing the patient's radiation exposure, the contrast medium dosage and osmolarity. The considerable cut-back in time required for invasive examination has reduced the risk of diagnostic and therapeutic measures. The advantages consisting of immediate image display with high contrast resolution in most of the diagnostic tasks counterbalance the disadvantage of low focal resolution of the DSA in neuroradiology. Interventional neuroradiology today cannot do without i.a. DSA. (orig.) [de

Aggression-related brain function assessed with the Point Subtraction Aggression Paradigm in fMRI

DEFF Research Database (Denmark)

Skibsted, Anine P; Cunha-Bang, Sofi da; Carré, Justin M

2017-01-01

The Point Subtraction Aggression Paradigm (PSAP) measures aggressive behavior in response to provocations. The aim of the study was to implement the PSAP in a functional neuroimaging environment (fMRI) and evaluate aggression-related brain reactivity including response to provocations and associa......The Point Subtraction Aggression Paradigm (PSAP) measures aggressive behavior in response to provocations. The aim of the study was to implement the PSAP in a functional neuroimaging environment (fMRI) and evaluate aggression-related brain reactivity including response to provocations...... and associations with aggression within the paradigm. Twenty healthy participants completed two 12-min PSAP sessions within the scanner. We evaluated brain responses to aggressive behavior (removing points from an opponent), provocations (point subtractions by the opponent), and winning points. Our results showed...... with the involvement of these brain regions in emotional and impulsive behavior. Striatal reactivity may suggest an involvement of reward during winning and stealing points....

Effect of relative nanohole position on colour purity of ultrathin plasmonic subtractive colour filters

International Nuclear Information System (INIS)

Sun, L B; Hu, X L; Zhang, D X; Zeng, Beibei; Wang, L S; Yang, S M; Tai, R Z; Fecht, H J; Jiang, J Z

2015-01-01

Plasmonic subtractive color filters through patterning periodic nanostructures on ultrathin Ag films deposited on a glass substrate, exhibiting good durability, simple fabrication, and flexible color tunability, have attracted considerable attention due to their tremendous potential applications. While previous studies have mainly focused on their extraordinary physical mechanisms, color purity, which is another key parameter for high quality imaging applications, has been much less investigated. In this work, we demonstrate that the relative position of nanoholes patterned on ultrathin Ag films can largely affect the color purity of plasmonic subtractive color filters. The calculated results agree reasonably well with the experimental data, revealing that the purity of subtractive colors can be improved by changing the nanohole arrays from square lattice to triangular lattice without reducing transmission at visible frequencies. In addition, underlying mechanisms are clarified by systematically analyzing the dominant valley in transmission spectra. (paper)

A study on computer-aided diagnosis based on temporal subtraction of sequential chest radiographs (in Japanese)

International Nuclear Information System (INIS)

Kano, Akiko

2001-01-01

An automated digital image subtraction technique for use with pairs of temporally sequential chest radiographs has been developed to aid radiologists in the detection of interval changes. Automated image registration based on nonlinear geometric warping is performed prior to subtraction in order to deal with complicated radiographic misregistration. Processing includes global matching, to achieve rough registration between the entire lung fields in the two images, and local matching, based on a cross-correlation method, to determine local shift values for a number of small regions. A proper warping of x,y-coordinates is determined by fitting two-dimensional polynomials to the distributions of the shift values. One image is warped and then subtracted from the other. The resultant subtraction images were able to enhance the conspicuity of various types of interval changes. Improved global matching based on a weighted template matching method achieved robust registration even with photofluorographs taken in chest mass screening programs, which had previously presented us with a relatively large number of poor-registration images. The new method was applied to 129 pairs of chest mass screening images, and offered registration accuracy as good as manual global matching. An observer test using 114 cases including 57 lung cancer cases presented better sensitivity and specificity on average compared to conventional comparison readings. In addition, newly developed image processing that eliminates the rib edge artifacts in subtraction images was applied to 26 images having pathological interval changes; results showed the potential for application to automated schemes for the detection of interval change patterns. With its capacity to improve the diagnostic accuracy of chest radiographs, the chest temporal subtraction technique promises to become an important element of computer-aided diagnosis (CAD) systems

Video demystified

CERN Document Server

Jack, Keith

2004-01-01

This international bestseller and essential reference is the "bible" for digital video engineers and programmers worldwide. This is by far the most informative analog and digital video reference available, includes the hottest new trends and cutting-edge developments in the field. Video Demystified, Fourth Edition is a "one stop" reference guide for the various digital video technologies. The fourth edition is completely updated with all new chapters on MPEG-4, H.264, SDTV/HDTV, ATSC/DVB, and Streaming Video (Video over DSL, Ethernet, etc.), as well as discussions of the latest standards throughout. The accompanying CD-ROM is updated to include a unique set of video test files in the newest formats. *This essential reference is the "bible" for digital video engineers and programmers worldwide *Contains all new chapters on MPEG-4, H.264, SDTV/HDTV, ATSC/DVB, and Streaming Video *Completely revised with all the latest and most up-to-date industry standards.

Construction and identification of subtracted cDNA library in bone marrow cells of radon-exposed mice

International Nuclear Information System (INIS)

Li Jianxiang; Nie Jihua; Tong Jian; Fu Chunling; Zhou Jianwei

2008-01-01

Objective: To construct and identify subtracted cDNA library in bone marrow cells of mice exposed to radon inhalation. Methods: Adult male BALB/c mice, weighing 18-22 g, were placed in a multi- functional radon chamber. One group of mice was exposed to radon up to the accumulative dose of 105 work level month (WLM). The control group of mice was housed in a room with an accumulative dose of 1 WLM. To construct a subtracted cDNA library enriched with differentially expressed genes, the SMART technique and the suppression subtractive hybridization were performed. The obtained forward and reverse cDNA fragments were directly inserted into pMD18-T vector and transformed into E. coli JM109. The inserting cDNA fragments were screened by the blue-and-white blot screening and nested PCR of bacterium liquid. Results: The 244 of 285 white bacteria clones obtained randomly were positive clones contained 100-1100 bp inserted cDNA fragments. Conclusions: The forward and reverse subtracted cDNA library in bone marrow cells of mice exposed to radon inhalation is successfully constructed. (authors)

Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition

Energy Technology Data Exchange (ETDEWEB)

Lee, Su-Yong; Kim, Ho-Joon [Department of Physics, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar); Ji, Se-Wan [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea, Republic of); Nha, Hyunchul [Department of Physics, Texas A and M University at Qatar, P.O. Box 23874, Doha (Qatar); Institute fuer Quantenphysik, Universitaet Ulm, D-89069 Ulm (Germany)

2011-07-15

We investigate how the entanglement properties of a two-mode state can be improved by performing a coherent superposition operation ta+ra{sup {dagger}} of photon subtraction and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each mode. We show that the degree of entanglement, the Einstein-Podolsky-Rosen-type correlation, and the performance of quantum teleportation can be all enhanced for the output state when the coherent operation is applied to a two-mode squeezed state. The effects of the coherent operation are more prominent than those of the mere photon subtraction a and the addition a{sup {dagger}} particularly in the small-squeezing regime, whereas the optimal operation becomes the photon subtraction (case of r=0) in the large-squeezing regime.

Video pedagogy

OpenAIRE

Länsitie, Janne; Stevenson, Blair; Männistö, Riku; Karjalainen, Tommi; Karjalainen, Asko

2016-01-01

The short film is an introduction to the concept of video pedagogy. The five categories of video pedagogy further elaborate how videos can be used as a part of instruction and learning process. Most pedagogical videos represent more than one category. A video itself doesn’t necessarily define the category – the ways in which the video is used as a part of pedagogical script are more defining factors. What five categories did you find? Did you agree with the categories, or are more...

An analysis of the influence of background subtraction and quenching on jet observables in heavy-ion collisions

CERN Document Server

Apolinario, Liliana; Cunqueiro, Leticia

2013-01-01

Subtraction of the large background in reconstruction is a key ingredient in jet studies in high-energy heavy-ion collisions at RHIC and the LHC. Here we address the question to which extent the most commonly used subtraction techniques are able to eliminate the effects of the background on the most commonly discussed observables at present: single inclusive jet distributions, dijet asymmetry and azimuthal distributions. We consider two different background subtraction methods, an area-based one implemented through the FastJet pack- age and a pedestal subtraction method, that resemble the ones used by the experimental collaborations at the LHC. We also analyze different ways of defining the optimal parame- ters in the second method. We use a toy model that easily allows variations of the background characteristics: average background level and fluctuations and azimuthal structure, but cross- checks are also done with a Monte Carlo simulator. Furthermore, we consider the influence of quenching using Q-PYTHIA o...

Sky subtraction at the Poisson limit with fibre-optic multiobject spectroscopy

Science.gov (United States)

Sharp, R.; Parkinson, H.

2010-11-01

We report on the limitations of sky-subtraction accuracy for long-duration fibre-optic multiobject spectroscopy of faint astronomical sources during long-duration exposures. We show that while standard sky subtraction techniques yield accuracies consistent with the Poisson noise limit for exposures of 1h duration, there are large-scale systematic defects that inhibit the sensitivity gains expected on the summation of longer duration exposures. For the AAOmega system at the Anglo-Australian Telescope, we identify a limiting systematic sky-subtraction accuracy, which is reached after integration times of 4-10h. We show that these systematic defects can be avoided through the use of the fibre nod-and-shuffle (N+S) observing mode, but with a potential cost in observing efficiency. Finally, we demonstrate that these disadvantages can be overcome through the application of a Principal Components Analysis (PCA) sky-subtraction routine. Such an approach minimize systematic residuals across long-duration exposures, allowing deep integrations. We apply the PCA approach to over 200h of on-sky observations and conclude that for the AAOmega system, the residual error in long-duration observations falls at a rate proportional to τ-0.32 in contrast to the τ-0.5 rate expected from theoretical considerations. With this modest rate of decline, the PCA approach represents a more efficient mode of observation than the N+S technique for observations in the sky limited regime with durations of 10-100h (even before accounting for the additional signal-to-noise ratio and targeting efficiency losses often associated with the N+S technique). This conclusion has important implications for the observing strategies of the next generation of fibre-optics redshift surveys with existing facilities as well as design implications for fibre-optic systems destined for new facilities. It argues against the use of the inherently inefficient N+S technique for faint object fibre-optic survey

Clinical evaluation of dual-energy bone removal in CT angiography of the head and neck: comparison with conventional bone-subtraction CT angiography

International Nuclear Information System (INIS)

Deng, K.; Liu, C.; Ma, R.; Sun, C.; Wang, X.-M.; Ma, Z.-T.; Sun, X.-L.

2009-01-01

Aim: To evaluate the bone-subtraction effect of dual-energy bone removal in computed tomography angiography (CTA) of the head and neck in comparison with conventional bone-subtraction CTA. Material and Methods: The study comprised 52 patients who were divided into two groups at random, and examined using dual-source CT for head and neck CTA. Dual-energy bone removal CTA and conventional bone-subtraction CTA were applied to each of the two groups, respectively. The bone subtraction was performed automatically in both methods. Vascular structures, as well as brain tissue remained visible. The subtracted images were further processed with maximum intensity projection (MIP) and volume-rendering technique (VRT) for image evaluation. Two experienced radiologists reviewed the resulting subtracted and non-subtracted volume data with respect to the delineation and detection of image quality and vascular pathology. Results: The means of the weighted CT dose index (CTDIvol) for bone-removal dual-energy CTA and conventional bone-subtraction CTA were 20.56 ± 0.01 mGy and 25.57 ± 0.56 mGy, respectively. There was a significant difference between them. The percentage of carotid and vertebral arteries and all other vessels that could be successfully assessed with these two methods were 87.8, 68, and 83%, and 93.5, 91.8, and 92.6%, respectively. There were no significant differences in the visualization of the carotid arteries; however, there were significant differences in the visualization of the vertebral arteries. Conclusion: Compared with conventional bone-subtraction CTA, dual-energy bone-removal CTA had a lower radiation dose. It eliminated most bones in the head and neck successfully; however, the bone subtraction effect around the vertebral artery was unsatisfactory. Dual-energy bone-removal CTA provides a new method for detecting vascular diseases in routine clinical work.

Similarity renormalization group evolution of N N interactions within a subtractive renormalization scheme

Directory of Open Access Journals (Sweden)

Durães F.O.

2010-04-01

Full Text Available We apply the similarity renormalization group (SRG approach to evolve a nucleon-nucleon (N N interaction in leading-order (LO chiral effective field theory (ChEFT, renormalized within the framework of the subtracted kernel method (SKM. We derive a fixed-point interaction and show the renormalization group (RG invariance in the SKM approach. We also compare the evolution of N N potentials with the subtraction scale through a SKM RG equation in the form of a non-relativistic Callan-Symanzik (NRCS equation and the evolution with the similarity cutoff through the SRG transformation.

Video microblogging

DEFF Research Database (Denmark)

Bornoe, Nis; Barkhuus, Louise

2010-01-01

Microblogging is a recently popular phenomenon and with the increasing trend for video cameras to be built into mobile phones, a new type of microblogging has entered the arena of electronic communication: video microblogging. In this study we examine video microblogging, which is the broadcasting...... of short videos. A series of semi-structured interviews offers an understanding of why and how video microblogging is used and what the users post and broadcast....

Removing ECG Artifact from the Surface EMG Signal Using Adaptive Subtraction Technique

Science.gov (United States)

Abbaspour, S; Fallah, A

2014-01-01

Background: The electrocardiogram artifact is a major contamination in the electromyogram signals when electromyogram signal is recorded from upper trunk muscles and because of that the contaminated electromyogram is not useful. Objective: Removing electrocardiogram contamination from electromyogram signals. Methods: In this paper, the clean electromyogram signal, electrocardiogram artifact and electrocardiogram signal were recorded from leg muscles, the pectoralis major muscle of the left side and V4, respectively. After the pre-processing, contaminated electromyogram signal is simulated with a combination of clean electromyogram and electrocardiogram artifact. Then, contaminated electromyogram is cleaned using adaptive subtraction method. This method contains some steps; (1) QRS detection, (2) formation of electrocardiogram template by averaging the electrocardiogram complexes, (3) using low pass filter to remove undesirable artifacts, (4) subtraction. Results: Performance of our method is evaluated using qualitative criteria, power spectrum density and coherence and quantitative criteria signal to noise ratio, relative error and cross correlation. The result of signal to noise ratio, relative error and cross correlation is equal to 10.493, 0.04 and %97 respectively. Finally, there is a comparison between proposed method and some existing methods. Conclusion: The result indicates that adaptive subtraction method is somewhat effective to remove electrocardiogram artifact from contaminated electromyogram signal and has an acceptable result. PMID:25505766

Photon Subtraction by Many-Body Decoherence

DEFF Research Database (Denmark)

Murray, C. R.; Mirgorodskiy, I.; Tresp, C.

2018-01-01

We experimentally and theoretically investigate the scattering of a photonic quantum field from another stored in a strongly interacting atomic Rydberg ensemble. Considering the many-body limit of this problem, we derive an exact solution to the scattering-induced spatial decoherence of multiple...... stored photons, allowing for a rigorous understanding of the underlying dissipative quantum dynamics. Combined with our experiments, this analysis reveals a correlated coherence-protection process in which the scattering from one excitation can shield all others from spatial decoherence. We discuss how...... this effect can be used to manipulate light at the quantum level, providing a robust mechanism for single-photon subtraction, and experimentally demonstrate this capability....

Intraarterial digital subtraction angiography applied to diagnosis of hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Nishizawa, Sadahiko; Sano, Akira; Imanaka, Kazufumi; Sasai, Keisuke; Nagae, Toshiyuki; Mizutani, Masaru; Hatabu, Hiroto; Sadatou, Norihiro; Kuroda, Yasumasa

1985-12-01

This paper deals with diagnostic values of intraarterial digital subtraction angiography (IADSA) for evaluating hepatocellular carcinoma. The present series consists of 44 patients with hepatocellular carcinoma, who underwent IADSA combined with conventional hepatic angiography 67 times in total. The evaluated vessels by IADSA included 70 hepatic arteries and 36 portal veins. Comparative studies on the image quality of IADSA with conventional angiography were made in referring to the tumor stain for arteriograms and resolution of intrahepatic portal branches for portograms. Diagnostic superiority including equality of DSA image to conventional was noted in arteriograms: 72.7 % in the right lobe and 86 % in the left. Most deteriorated DSA images were caused by misregistration artifacts. IADSA portography revealed basically diagnostic values to demonstrate lobar, segmental or more peripheral branches in about 95 % of cases studied. DSA, characterized by high contrast resolution and real-time subtraction, offered important and effective informations for interventional angiography as well as resectability of the tumors, requiring less contrast medium.

Digital subtraction angiography in pediatric cerebrovascular occlusive disease

International Nuclear Information System (INIS)

Faerber, E.N.; Griska, L.A.B.; Swartz, J.D.; Capitanio, M.A.; Popky, G.L.

1984-01-01

While conventional angiography has been used to demonstrate cerebrovascular occlusive disease in the past, digital subtraction angiography (DSA) is capable of showing progressive vascular involvement with ease, simplicity, and extremely low morbidity, making it particularly well suited for children and outpatients either alone or coordinated with computed tomography. The authors discuss the usefulness and advantages of DSA as demonstrated in 7 infants and children with hemiplegia, 4 of whom had sickle-cell disease

Digital subtraction angiography of the thoracic aorta

International Nuclear Information System (INIS)

Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.

1984-01-01

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram

Digital subtraction angiography of the thoracic aorta

Energy Technology Data Exchange (ETDEWEB)

Grossman, L.B.; Buonocore, E.; Modic, M.T.; Meaney, T.F.

1984-02-01

Forty-three patients with acquired and congenital abnormalities of the thoracic aorta were studied using digital subtraction angiography (DSA) after an intravenous bolus injection of 40 ml of contrast material. Abnormalities studied included coarctation, pseudocoarctation, Marfan syndrome, cervical aorta, double aortic arch, aneurysm, dissection, and tumor. Twenty-four patients also had conventional angiography. DSA was accurate in 95% of cases; in the other 5%, involving patients with acute type I dissection, the coronary arteries could not be seen. The authors concluded that in 92% of their patients, DSA could have replaced the standard aortogram.

Clinical application of digital subtraction angiography (DSA)

International Nuclear Information System (INIS)

Morimoto, Tadashi; Kaku, Suiei; Morikawa, Eiji

1984-01-01

Intra-arterial digital subtraction angiography (IA-DSA) by the direct puncture of the carotid artery was described with special reference to its techniques, and cases were presented. This method was safe and painless and could be performed repeatedly. Cerebral angiographic images obtained by this method were either superior or fully compatible to the conventional cerebral angiography. It is therefore of great diagnostic value and can replace the conventional method. Furthermore, since the pretreatment is unnecessary and the time required is short, IA-DSA can be used as an adjuvant method for emergency diagnosis. (Namekawa, K)

Procedures for imaging of hemodialysis fistulas with particular reference to digital subtraction angiography (DSA)

International Nuclear Information System (INIS)

Neufang, K.F.R.; Erasmi-Koerber, H.; Wimmer, G.; Koeln Univ.

1983-01-01

All angiographic procedures established for imaging of hemodialysis fistulas, such as direct venous angiography, intravenous subtraction angiography and arteriography by direct puncture of the brachial artery of by Seldinger's transfemoral technique, can also be effected with digital image processing. Depending on the angiographic technique, the use of digital subtraction angiography has several advantages: lower doses and concentrations of the contrast agent, lower risk of complications (thrombosis of the fistula, vasospasm) and freedom from pain. In addition, there is a marked reduction of examination time and film cost. (orig.)

A single injection technique for subtraction of blood background in 131I-hippuran renograms

International Nuclear Information System (INIS)

Rutland, M.D.

1979-01-01

A method of subtracting blood background during probe-renography is presented which does not require a prior injection of RIHSA and which produces results approximately 11% higher than the RIHSA method. The new method treats the renogram up to two-and-a-half minutes as a combination of a fraction of the blood curve and a fraction of the integral of the blood curve. Analysis of the data, using either a computer or a programmed calculator, enables these two fractions to be calculated, hence producing the 'background subtraction factor' and the 'uptake constant'. (author)

Use of the water-soluble fluor sodium salicylate for fluorographic detection of tritium in thin-layer chromatograms and nitrocellulose blots

International Nuclear Information System (INIS)

Lucher, L.A.; Lego, T.

1989-01-01

We have determined that sodium salicylate, a water-soluble fluor which we use routinely for fluorography with polyacrylamide gels, is also useful for fluorography with thin-layer media. Detection of 3 H-labeled material applied to thin-layer chromatography plates, or nitrocellulose membranes, can be enhanced up to 150-fold after treatment with an aqueous solution of 2 M sodium salicylate, while detection of 35 S-labeled material is enhanced only about 2-fold. We demonstrate the utility of sodium salicylate fluorography in detecting 3H-labeled palmitic acid following thin-layer chromatography and 3 H-labeled proteins following blotting to nitrocellulose

Evaluation of chronic periapical lesions by digital subtraction radiography by using Adobe Photoshop CS: a technical report.

Science.gov (United States)

Carvalho, Fabiola B; Gonçalves, Marcelo; Tanomaru-Filho, Mário

2007-04-01

The purpose of this study was to describe a new technique by using Adobe Photoshop CS (San Jose, CA) image-analysis software to evaluate the radiographic changes of chronic periapical lesions after root canal treatment by digital subtraction radiography. Thirteen upper anterior human teeth with pulp necrosis and radiographic image of chronic periapical lesion were endodontically treated and radiographed 0, 2, 4, and 6 months after root canal treatment by using a film holder. The radiographic films were automatically developed and digitized. The radiographic images taken 0, 2, 4, and 6 months after root canal therapy were submitted to digital subtraction in pairs (0 and 2 months, 2 and 4 months, and 4 and 6 months) choosing "image," "calculation," "subtract," and "new document" tools from Adobe Photoshop CS image-analysis software toolbar. The resulting images showed areas of periapical healing in all cases. According to this methodology, the healing or expansion of periapical lesions can be evaluated by means of digital subtraction radiography by using Adobe Photoshop CS software.

Increasing LIGO sensitivity by feedforward subtraction of auxiliary length control noise

International Nuclear Information System (INIS)

Meadors, Grant David; Riles, Keith; Kawabe, Keita

2014-01-01

LIGO, the Laser Interferometer Gravitational-wave Observatory, has been designed and constructed to measure gravitational wave strain via differential arm length. The LIGO 4 km Michelson arms with Fabry–Perot cavities have auxiliary length control servos for suppressing Michelson motion of the beam-splitter and arm cavity input mirrors, which degrades interferometer sensitivity. We demonstrate how a post facto pipeline improves a data sample from LIGO Science Run 6 with feedforward subtraction. Dividing data into 1024 s windows, we numerically fit filter functions representing the frequency-domain transfer functions from Michelson length channels into the gravitational-wave strain data channel for each window, then subtract the filtered Michelson channel noise (witness) from the strain channel (target). In this paper we describe the algorithm, assess achievable improvements in sensitivity to astrophysical sources, and consider relevance to future interferometry. (paper)

Use of digital subtraction angiography for renal transplant evaluation

International Nuclear Information System (INIS)

Fanucci, E.; Orlacchio, A.; Pocek, M.; Svegliati, F.

1986-01-01

Intravenous digital subtraction angiography (IVDSA) was used to evaluate 6 renal allograft recipients and 3 potential renal donors. In 4 potential renal donors and in 2 allograft recipients, angiographic data were confirmed by surgery. IVDSA is a safe, accurate, easily performed, outpatient procedure; in our opinion DSA should became the procedure of choice to study vascular anatomy in renal transplant evaluation

Evaluation of carotid vessel wall enhancement with image subtraction after gadobenate dimeglumine-enhanced MR angiography

International Nuclear Information System (INIS)

Sardanelli, Francesco; Di Leo, Giovanni; Aliprandi, Alberto; Flor, Nicola; Papini, Giacomo D.E.; Roccatagliata, Luca; Cotticelli, Biagio; Nano, Giovanni; Cornalba, Gianpaolo

2009-01-01

Objectives: This study was aimed at testing the value of image subtraction for evaluating carotid vessel wall enhancement in contrast-enhanced MR angiography (MRA). Materials and methods: IRB approval was obtained. The scans of 81 consecutive patients who underwent carotid MRA with 0.1 mmol/kg of gadobenate dimeglumine were reviewed. Axial carotid 3D T1-weighted fast low-angle shot sequence before and 3 min after contrast injection were acquired and subtracted (enhanced minus unenhanced). Vessel wall enhancement was assigned a four-point score using native or subtracted images from 0 (no enhancement) to 3 (strong enhancement). Stenosis degree was graded according to NASCET. Results: With native images, vessel wall enhancement was detected in 20/81 patients (25%) and in 20/161 carotids (12%), and scored 2.0 ± 0.6 (mean ± standard deviation); with subtracted images, in 21/81 (26%) and 22/161 (14%), and scored 2.5 ± 0.6, respectively (P < 0.001, Sign test). The overall stenosis degree distribution was: mild, 41/161 (25%); moderate, 77/161 (48%); severe, 43/161 (27%). Carotids with moderate stenosis showed vessel wall enhancement with a frequency (17/77, 22%) significantly higher than that observed in carotids with mild stenosis (1/41, 2%) (P = 0.005, Fisher exact test) and higher, even though with borderline significance (P = 0.078, Fisher exact test), than that observed in carotids with severe stenosis (4/43, 9%). Conclusion: Roughly a quarter of patients undergoing carotid MRA showed vessel wall enhancement. Image subtraction improved vessel wall enhancement conspicuity. Vessel wall enhancement seems to be an event relatively independent from the degree of stenosis. Further studies are warranted to define the relation between vessel wall enhancement and histopathology, inflammatory status, and instability.

Reduction of Musical Noise in Spectral Subtraction Method Using Subframe Phase Randomization

Energy Technology Data Exchange (ETDEWEB)

Seok, J.W.; Bae, K.S. [Kyungpook National University, Taegu (Korea)

1999-06-01

The Subframe phase randomization method is applied to the spectral subtraction method to reduce the musical noise in nonvoicing region after speech enhancement. The musical noise in the spectral subtraction method is the result of the narrowband tonal components that appearing somewhat periodically in the spectrogram of unvoiced and silence regions. Thus each synthesis frame in nonvoicing region is divided into several subframes to broaden the narrowband spectrum, and then phases of silence and unvoiced regions are randomized to eliminate the tonal components in the spectrum while keeping the shape of the amplitude spectrum. Performance assessments based on visual inspection of spectrogram, objective measure, and informal subjective listening tests demonstrate the superiority of the proposed algorithm. (author). 7 refs., 5 figs.

Dashboard Videos

Science.gov (United States)

Gleue, Alan D.; Depcik, Chris; Peltier, Ted

2012-01-01

Last school year, I had a web link emailed to me entitled "A Dashboard Physics Lesson." The link, created and posted by Dale Basier on his "Lab Out Loud" blog, illustrates video of a car's speedometer synchronized with video of the road. These two separate video streams are compiled into one video that students can watch and analyze. After seeing…

The Relationship Between Problem Size and Fixation Patterns During Addition, Subtraction, Multiplication, and Division

Directory of Open Access Journals (Sweden)

Evan T. Curtis

2016-08-01

Full Text Available Eye-tracking methods have only rarely been used to examine the online cognitive processing that occurs during mental arithmetic on simple arithmetic problems, that is, addition and multiplication problems with single-digit operands (e.g., operands 2 through 9; 2 + 3, 6 x 8 and the inverse subtraction and division problems (e.g., 5 – 3; 48 ÷ 6. Participants (N = 109 solved arithmetic problems from one of the four operations while their eye movements were recorded. We found three unique fixation patterns. During addition and multiplication, participants allocated half of their fixations to the operator and one-quarter to each operand, independent of problem size. The pattern was similar on small subtraction and division problems. However, on large subtraction problems, fixations were distributed approximately evenly across the three stimulus components. On large division problems, over half of the fixations occurred on the left operand, with the rest distributed between the operation sign and the right operand. We discuss the relations between these eye tracking patterns and other research on the differences in processing across arithmetic operations.

Motion compensation in digital subtraction angiography using graphics hardware.

Science.gov (United States)

Deuerling-Zheng, Yu; Lell, Michael; Galant, Adam; Hornegger, Joachim

2006-07-01

An inherent disadvantage of digital subtraction angiography (DSA) is its sensitivity to patient motion which causes artifacts in the subtraction images. These artifacts could often reduce the diagnostic value of this technique. Automated, fast and accurate motion compensation is therefore required. To cope with this requirement, we first examine a method explicitly designed to detect local motions in DSA. Then, we implement a motion compensation algorithm by means of block matching on modern graphics hardware. Both methods search for maximal local similarity by evaluating a histogram-based measure. In this context, we are the first who have mapped an optimizing search strategy on graphics hardware while paralleling block matching. Moreover, we provide an innovative method for creating histograms on graphics hardware with vertex texturing and frame buffer blending. It turns out that both methods can effectively correct the artifacts in most case, as the hardware implementation of block matching performs much faster: the displacements of two 1024 x 1024 images can be calculated at 3 frames/s with integer precision or 2 frames/s with sub-pixel precision. Preliminary clinical evaluation indicates that the computation with integer precision could already be sufficient.

Video game addiction, ADHD symptomatology, and video game reinforcement.

Science.gov (United States)

Mathews, Christine L; Morrell, Holly E R; Molle, Jon E

2018-06-06

Up to 23% of people who play video games report symptoms of addiction. Individuals with attention deficit hyperactivity disorder (ADHD) may be at increased risk for video game addiction, especially when playing games with more reinforcing properties. The current study tested whether level of video game reinforcement (type of game) places individuals with greater ADHD symptom severity at higher risk for developing video game addiction. Adult video game players (N = 2,801; Mean age = 22.43, SD = 4.70; 93.30% male; 82.80% Caucasian) completed an online survey. Hierarchical multiple linear regression analyses were used to test type of game, ADHD symptom severity, and the interaction between type of game and ADHD symptomatology as predictors of video game addiction severity, after controlling for age, gender, and weekly time spent playing video games. ADHD symptom severity was positively associated with increased addiction severity (b = .73 and .68, ps .05. The relationship between ADHD symptom severity and addiction severity did not depend on the type of video game played or preferred most, ps > .05. Gamers who have greater ADHD symptom severity may be at greater risk for developing symptoms of video game addiction and its negative consequences, regardless of type of video game played or preferred most. Individuals who report ADHD symptomatology and also identify as gamers may benefit from psychoeducation about the potential risk for problematic play.

A novel approach to background subtraction in contrast-enhanced dual-energy digital mammography with commercially available mammography devices: Noise minimization

International Nuclear Information System (INIS)

Contillo, Adriano; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo

2016-01-01

Purpose: Dual-energy image subtraction represents a useful tool to improve the detectability of small lesions, especially in dense breasts. A feature it shares with all x-ray imaging techniques is the appearance of fluctuations in the texture of the background, which can obscure the visibility of interesting details. The aim of the work is to investigate the main noise sources, in order to create a better performing subtraction mechanism. In particular, the structural noise cancellation was achieved by means of a suitable extension of the dual-energy algorithm. Methods: The effect of the cancellation procedure was tested on an analytical simulation of a target with varying structural composition. Subsequently, the subtraction algorithm was also applied to a set of actual radiographs of a breast phantom exhibiting a nonuniform background pattern. The background power spectra of the outcomes were computed and compared to the ones obtained from a standard subtraction algorithm. Results: The comparison between the standard and the proposed cancellations showed an overall suppression of the magnitudes of the spectra, as well as a flattening of the frequency dependence of the structural component of the noise. Conclusions: The proposed subtraction procedure provides an effective cancellation of the residual background fluctuations. When combined with the polychromatic correction already described in a companion publication, it results in a high performing dual-energy subtraction scheme for commercial mammography units.

A novel approach to background subtraction in contrast-enhanced dual-energy digital mammography with commercially available mammography devices: Noise minimization

Energy Technology Data Exchange (ETDEWEB)

Contillo, Adriano, E-mail: contillo@fe.infn.it; Di Domenico, Giovanni; Cardarelli, Paolo; Gambaccini, Mauro; Taibi, Angelo [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, I-44122 Ferrara (Italy)

2016-06-15

Purpose: Dual-energy image subtraction represents a useful tool to improve the detectability of small lesions, especially in dense breasts. A feature it shares with all x-ray imaging techniques is the appearance of fluctuations in the texture of the background, which can obscure the visibility of interesting details. The aim of the work is to investigate the main noise sources, in order to create a better performing subtraction mechanism. In particular, the structural noise cancellation was achieved by means of a suitable extension of the dual-energy algorithm. Methods: The effect of the cancellation procedure was tested on an analytical simulation of a target with varying structural composition. Subsequently, the subtraction algorithm was also applied to a set of actual radiographs of a breast phantom exhibiting a nonuniform background pattern. The background power spectra of the outcomes were computed and compared to the ones obtained from a standard subtraction algorithm. Results: The comparison between the standard and the proposed cancellations showed an overall suppression of the magnitudes of the spectra, as well as a flattening of the frequency dependence of the structural component of the noise. Conclusions: The proposed subtraction procedure provides an effective cancellation of the residual background fluctuations. When combined with the polychromatic correction already described in a companion publication, it results in a high performing dual-energy subtraction scheme for commercial mammography units.

DESIGN STUDY: INTEGER SUBTRACTION OPERATION TEACHING LEARNING USING MULTIMEDIA IN PRIMARY SCHOOL

Directory of Open Access Journals (Sweden)

Rendi Muhammad Aris

2016-12-01

Full Text Available This study aims to develop a learning trajectory to help students understand concept of subtraction of integers using multimedia in the fourth grade. This study is thematic integrative learning in Curriculum 2013 PMRI based. The method used is design research consists of three stages; preparing for the experiment, design experiment, retrospective analysis. The studied was conducted on 20 students of grade four SDN 1 Muara Batun, OKI. The activities of students in this study consisted of six learning trajectories. The first activity asks the students to classify heroism and non-heroism acts, summarize, and classify integers and non-integer. The second activity asks the students to answer the questions in the film given. The third activity asks students to count the remaining gravel in the film. The fourth activity asks students to count remaining spent money in the film. The fifth activity invites students to play rubber seeds in the bag. The last activity asks students to answer the questions in the student worksheet. The media used along the learning activities are a ruler, rubber seed, student worksheet, money, gravel, and film. The results indicate that the learning trajectory using multimedia help students understand the concept of integer subtraction integer. Keywords: Subtraction Integer, PMRI, Multimedia DOI: http://dx.doi.org/10.22342/jme.8.1.3233.95-102

Enhancement system of nighttime infrared video image and visible video image

Science.gov (United States)

Wang, Yue; Piao, Yan

2016-11-01

Visibility of Nighttime video image has a great significance for military and medicine areas, but nighttime video image has so poor quality that we can't recognize the target and background. Thus we enhance the nighttime video image by fuse infrared video image and visible video image. According to the characteristics of infrared and visible images, we proposed improved sift algorithm andαβ weighted algorithm to fuse heterologous nighttime images. We would deduced a transfer matrix from improved sift algorithm. The transfer matrix would rapid register heterologous nighttime images. And theαβ weighted algorithm can be applied in any scene. In the video image fusion system, we used the transfer matrix to register every frame and then used αβ weighted method to fuse every frame, which reached the time requirement soft video. The fused video image not only retains the clear target information of infrared video image, but also retains the detail and color information of visible video image and the fused video image can fluency play.

Intravenous digital subtraction angiography investigation of reversible cerebral ischemia

International Nuclear Information System (INIS)

Pistolesi, G.F.; Maso, R.; Filosto, L.; Piovan, E.; Morgante, D.; Taddei, G.; Tonegutti, M.; Portuese, A.

1986-01-01

The brachio-cephalic, carotid, vertebral and intra-cranial vessels of 497 patients presenting reversible ischemic attacks (R.I.A) were evaluated with venous digital subtraction angiography (V.D.S.A.). Alterations of the vascular wall were observed in 289/497 (58.2%) patients, of whom 60% presented multiple locations (539 lesions): obstruction (12%), stenosis >50% (29%), stenosis 50%. The incidence of vascular lesions was higher (p [fr

SnapVideo: Personalized Video Generation for a Sightseeing Trip.

Science.gov (United States)

Zhang, Luming; Jing, Peiguang; Su, Yuting; Zhang, Chao; Shaoz, Ling

2017-11-01

Leisure tourism is an indispensable activity in urban people's life. Due to the popularity of intelligent mobile devices, a large number of photos and videos are recorded during a trip. Therefore, the ability to vividly and interestingly display these media data is a useful technique. In this paper, we propose SnapVideo, a new method that intelligently converts a personal album describing of a trip into a comprehensive, aesthetically pleasing, and coherent video clip. The proposed framework contains three main components. The scenic spot identification model first personalizes the video clips based on multiple prespecified audience classes. We then search for some auxiliary related videos from YouTube 1 according to the selected photos. To comprehensively describe a scenery, the view generation module clusters the crawled video frames into a number of views. Finally, a probabilistic model is developed to fit the frames from multiple views into an aesthetically pleasing and coherent video clip, which optimally captures the semantics of a sightseeing trip. Extensive user studies demonstrated the competitiveness of our method from an aesthetic point of view. Moreover, quantitative analysis reflects that semantically important spots are well preserved in the final video clip. 1 https://www.youtube.com/.

[Myocardial perfusion imaging by digital subtraction angiography].

Science.gov (United States)

Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

1986-03-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

Using a digital signal processor as a data stream controller for digital subtraction angiography

International Nuclear Information System (INIS)

Meng, J.D.; Katz, J.E.

1991-10-01

High speed, flexibility, and good arithmetic abilities make digital signal processors (DSP) a good choice as input/output controllers for real time applications. The DSP can be made to pre-process data in real time to reduce data volume, to open early windows on what is being acquired and to implement local servo loops. We present an example of a DSP as an input/output controller for a digital subtraction angiographic imaging system. The DSP pre-processes the raw data, reducing data volume by a factor of two, and is potentially capable of producing real-time subtracted images for immediate display

Augmented video viewing: transforming video consumption into an active experience

OpenAIRE

WIJNANTS, Maarten; Leën, Jeroen; QUAX, Peter; LAMOTTE, Wim

2014-01-01

Traditional video productions fail to cater to the interactivity standards that the current generation of digitally native customers have become accustomed to. This paper therefore advertises the \\activation" of the video consumption process. In particular, it proposes to enhance HTML5 video playback with interactive features in order to transform video viewing into a dynamic pastime. The objective is to enable the authoring of more captivating and rewarding video experiences for end-users. T...

Non-perturbative subtractions in the heavy quark effective field theory

International Nuclear Information System (INIS)

Maiani, L.; Martinelli, G.; Sachrajda, C.T.

1992-01-01

We demonstrate the presence of ultraviolet power divergences in the O(1/m h ) corrections to matrix elements of hadronic operators containing a heavy quark field (where m h is the mass of the heavy quark). These power divergences must be subtracted non-perturbatively. The implications for lattice computations are discussed in detail. (orig.)

Operator expansions in the minimal subtraction scheme. II. Explicit formulas for coefficient functions

International Nuclear Information System (INIS)

Chetyrkin, K.G.

1989-01-01

It is shown in an arbitrary model that the coefficient functions of the operator expansion (renormalized in the minimal subtraction scheme) are finite. Explicit formulas convenient for calculating them in practice are obtained. The gluing method and the formalism of the R* operation are used to transform the formulas in such a way that the coefficient functions can be expressed in terms of ordinary diagrams containing neither nonstandard propagators nor an additional loop integration. An important feature of the representation for the coefficient functions is that the R* operation, which subtracts simultaneously the ultraviolet and infrared divergences, guarantees the existence of the coefficient functions in the limit when the dimensional regularization is lifted without any restrictions

Digital subtraction angiography in the evaluation of chemodectomas

International Nuclear Information System (INIS)

Vlahos, L.; Papathanasiou, M.; Gouliamos, A.; Dimakakos, P.; Papavassiliou, C.

1988-01-01

During the last 2 years eleven patients with surgically confirmed chemodectomas have been investigated by means of digital subtraction angiography (DSA). Seven patients underwent i.v. DSA, which revealed eight carotid body tumours, and in the remaining four with jugulotympanic chemodectomas intra-arterial (i.a.) DSA was performed. We found i.v. DSA an easy and satisfactory method for the investigation of carotid body tumours but when glomus intravagale, tympanicum or jugulare is suspected an i.a. selective injection is required. (orig.) [de

Digital subtraction angiography in the evaluation of chemodectomas

Energy Technology Data Exchange (ETDEWEB)

Vlahos, L.; Papathanasiou, M.; Gouliamos, A.; Dimakakos, P.; Papavassiliou, C.

1988-05-01

During the last 2 years eleven patients with surgically confirmed chemodectomas have been investigated by means of digital subtraction angiography (DSA). Seven patients underwent i.v. DSA, which revealed eight carotid body tumours, and in the remaining four with jugulotympanic chemodectomas intra-arterial (i.a.) DSA was performed. We found i.v. DSA an easy and satisfactory method for the investigation of carotid body tumours but when glomus intravagale, tympanicum or jugulare is suspected an i.a. selective injection is required.

Construction and partial sequencing of a subtractive library in Calcutta 4 (Musa AA in early stage of infection with Mycosphaerella fijiensis Morelet

Directory of Open Access Journals (Sweden)

Milady Mendoza-Rodríguez

2006-10-01

Full Text Available The study of genes involved in plant defense response against pathogen attack, is one of most important steps leading to the elucidation of disease resistance molecular mechanisms. The generation of subtracted deoxyribonucleic acid libraries (cDNA, by means of suppression subtractive hybridization technique (SSH, has been used for this purpose. A subtractive hybridization was made between a cDNA population obtained from ‘Calcutta 4’ inoculated leaves with M. fijiensis (CCIBP-Pf83 and a mixture of cDNA from ‘Calcutta 4’ non inoculated leaves and mycelium. Leaves samples were taken at 6, 10 and 12 days after inoculation. The subtracted library was obtained by cloning and transformation of subtracted products and as a result, 600 recombinants clones were obtained. Sequence analysis of sixty nine clones, revealed redundancy of the expressed sequence tags and most of them showed no homology with reported sequences at databases and only 13 % had a high homology with metalothioneins. The results constitute a step in advance in the molecular study of Musa-Mycosphaerella fijiensis interaction. Key words: Banana-Mycosphaerella fijiensis interaction, BlackSigatoka, Musa spp., suppression subtractive hybridization

Multi-Task Video Captioning with Video and Entailment Generation

OpenAIRE

Pasunuru, Ramakanth; Bansal, Mohit

2017-01-01

Video captioning, the task of describing the content of a video, has seen some promising improvements in recent years with sequence-to-sequence models, but accurately learning the temporal and logical dynamics involved in the task still remains a challenge, especially given the lack of sufficient annotated data. We improve video captioning by sharing knowledge with two related directed-generation tasks: a temporally-directed unsupervised video prediction task to learn richer context-aware vid...

Video Quality Prediction Models Based on Video Content Dynamics for H.264 Video over UMTS Networks

Directory of Open Access Journals (Sweden)

Asiya Khan

2010-01-01

Full Text Available The aim of this paper is to present video quality prediction models for objective non-intrusive, prediction of H.264 encoded video for all content types combining parameters both in the physical and application layer over Universal Mobile Telecommunication Systems (UMTS networks. In order to characterize the Quality of Service (QoS level, a learning model based on Adaptive Neural Fuzzy Inference System (ANFIS and a second model based on non-linear regression analysis is proposed to predict the video quality in terms of the Mean Opinion Score (MOS. The objective of the paper is two-fold. First, to find the impact of QoS parameters on end-to-end video quality for H.264 encoded video. Second, to develop learning models based on ANFIS and non-linear regression analysis to predict video quality over UMTS networks by considering the impact of radio link loss models. The loss models considered are 2-state Markov models. Both the models are trained with a combination of physical and application layer parameters and validated with unseen dataset. Preliminary results show that good prediction accuracy was obtained from both the models. The work should help in the development of a reference-free video prediction model and QoS control methods for video over UMTS networks.

Streaming Video--The Wave of the Video Future!

Science.gov (United States)

Brown, Laura

2004-01-01

Videos and DVDs give the teachers more flexibility than slide projectors, filmstrips, and 16mm films but teachers and students are excited about a new technology called streaming. Streaming allows the educators to view videos on demand via the Internet, which works through the transfer of digital media like video, and voice data that is received…

Digital subtraction angiography (DSA) of the heart and coronary arteries

International Nuclear Information System (INIS)

Struyven, J.J.; Delcour, C.; Brion, J.P.; Vandenbosch, G.; Claessens, J.

1986-01-01

Digital subtraction angiography has potential advantages over conventional radiography. The removal of background structures makes possible to visualize chambers of the heart, great vessels and coronary arteries with a lower iodine signal than with conventional cineangiography. Digital data used for imaging can been manipulated for assessment and quantitation of the ventricular fonction and the coronary circulation

A video authentication technique

International Nuclear Information System (INIS)

Johnson, C.S.

1987-01-01

Unattended video surveillance systems are particularly vulnerable to the substitution of false video images into the cable that connects the camera to the video recorder. New technology has made it practical to insert a solid state video memory into the video cable, freeze a video image from the camera, and hold this image as long as desired. Various techniques, such as line supervision and sync detection, have been used to detect video cable tampering. The video authentication technique described in this paper uses the actual video image from the camera as the basis for detecting any image substitution made during the transmission of the video image to the recorder. The technique, designed for unattended video systems, can be used for any video transmission system where a two-way digital data link can be established. The technique uses similar microprocessor circuitry at the video camera and at the video recorder to select sample points in the video image for comparison. The gray scale value of these points is compared at the recorder controller and if the values agree within limits, the image is authenticated. If a significantly different image was substituted, the comparison would fail at a number of points and the video image would not be authenticated. The video authentication system can run as a stand-alone system or at the request of another system

K-edge subtraction synchrotron X-ray imaging in bio-medical research.

Science.gov (United States)

Thomlinson, W; Elleaume, H; Porra, L; Suortti, P

2018-05-01

High contrast in X-ray medical imaging, while maintaining acceptable radiation dose levels to the patient, has long been a goal. One of the most promising methods is that of K-edge subtraction imaging. This technique, first advanced as long ago as 1953 by B. Jacobson, uses the large difference in the absorption coefficient of elements at energies above and below the K-edge. Two images, one taken above the edge and one below the edge, are subtracted leaving, ideally, only the image of the distribution of the target element. This paper reviews the development of the KES techniques and technology as applied to bio-medical imaging from the early low-power tube sources of X-rays to the latest high-power synchrotron sources. Applications to coronary angiography, functional lung imaging and bone growth are highlighted. A vision of possible imaging with new compact sources is presented. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

The LivePhoto Physics videos and video analysis site

Science.gov (United States)

Abbott, David

2009-09-01

The LivePhoto site is similar to an archive of short films for video analysis. Some videos have Flash tools for analyzing the video embedded in the movie. Most of the videos address mechanics topics with titles like Rolling Pencil (check this one out for pedagogy and content knowledge—nicely done!), Juggler, Yo-yo, Puck and Bar (this one is an inelastic collision with rotation), but there are a few titles in other areas (E&M, waves, thermo, etc.).

Ranking Highlights in Personal Videos by Analyzing Edited Videos.

Science.gov (United States)

Sun, Min; Farhadi, Ali; Chen, Tseng-Hung; Seitz, Steve

2016-11-01

We present a fully automatic system for ranking domain-specific highlights in unconstrained personal videos by analyzing online edited videos. A novel latent linear ranking model is proposed to handle noisy training data harvested online. Specifically, given a targeted domain such as "surfing," our system mines the YouTube database to find pairs of raw and their corresponding edited videos. Leveraging the assumption that an edited video is more likely to contain highlights than the trimmed parts of the raw video, we obtain pair-wise ranking constraints to train our model. The learning task is challenging due to the amount of noise and variation in the mined data. Hence, a latent loss function is incorporated to mitigate the issues caused by the noise. We efficiently learn the latent model on a large number of videos (about 870 min in total) using a novel EM-like procedure. Our latent ranking model outperforms its classification counterpart and is fairly competitive compared with a fully supervised ranking system that requires labels from Amazon Mechanical Turk. We further show that a state-of-the-art audio feature mel-frequency cepstral coefficients is inferior to a state-of-the-art visual feature. By combining both audio-visual features, we obtain the best performance in dog activity, surfing, skating, and viral video domains. Finally, we show that impressive highlights can be detected without additional human supervision for seven domains (i.e., skating, surfing, skiing, gymnastics, parkour, dog activity, and viral video) in unconstrained personal videos.

Video processing for human perceptual visual quality-oriented video coding.

Science.gov (United States)

Oh, Hyungsuk; Kim, Wonha

2013-04-01

We have developed a video processing method that achieves human perceptual visual quality-oriented video coding. The patterns of moving objects are modeled by considering the limited human capacity for spatial-temporal resolution and the visual sensory memory together, and an online moving pattern classifier is devised by using the Hedge algorithm. The moving pattern classifier is embedded in the existing visual saliency with the purpose of providing a human perceptual video quality saliency model. In order to apply the developed saliency model to video coding, the conventional foveation filtering method is extended. The proposed foveation filter can smooth and enhance the video signals locally, in conformance with the developed saliency model, without causing any artifacts. The performance evaluation results confirm that the proposed video processing method shows reliable improvements in the perceptual quality for various sequences and at various bandwidths, compared to existing saliency-based video coding methods.

No Reference Video-Quality-Assessment Model for Monitoring Video Quality of IPTV Services

Science.gov (United States)

Yamagishi, Kazuhisa; Okamoto, Jun; Hayashi, Takanori; Takahashi, Akira

Service providers should monitor the quality of experience of a communication service in real time to confirm its status. To do this, we previously proposed a packet-layer model that can be used for monitoring the average video quality of typical Internet protocol television content using parameters derived from transmitted packet headers. However, it is difficult to monitor the video quality per user using the average video quality because video quality depends on the video content. To accurately monitor the video quality per user, a model that can be used for estimating the video quality per video content rather than the average video quality should be developed. Therefore, to take into account the impact of video content on video quality, we propose a model that calculates the difference in video quality between the video quality of the estimation-target video and the average video quality estimated using a packet-layer model. We first conducted extensive subjective quality assessments for different codecs and video sequences. We then model their characteristics based on parameters related to compression and packet loss. Finally, we verify the performance of the proposed model by applying it to unknown data sets different from the training data sets used for developing the model.

Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques

International Nuclear Information System (INIS)

Altaha, Mustafa A.; Jaskolka, Jeffrey D.; Tan, Kongteng; Menezes, Ravi J.; Rick, Manuela; Schmitt, Peter; Wintersperger, Bernd J.

2017-01-01

The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI). Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 x 1 mm 2 ) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 x 1.2 x 1.3 mm 3 ) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA). Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated. QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI. (orig.)

Non-contrast-enhanced MR angiography in critical limb ischemia: performance of quiescent-interval single-shot (QISS) and TSE-based subtraction techniques

Energy Technology Data Exchange (ETDEWEB)

Altaha, Mustafa A. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); Jaskolka, Jeffrey D.; Tan, Kongteng; Menezes, Ravi J. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Rick, Manuela; Schmitt, Peter [Siemens Healthcare, Erlangen (Germany); Wintersperger, Bernd J. [University Health Network, Department of Medical Imaging, Peter Munk Cardiac Centre, Toronto, Ontario (Canada); University of Toronto, Department of Medical Imaging, Toronto, Ontario (Canada); Toronto General Hospital, Department of Medical Imaging, Toronto, Ontario (Canada)

2017-03-15

The aim of this study was to evaluate diagnostic performance of non-contrast-enhanced 2D quiescent-interval single-shot (QISS) and 3D turbo spin-echo (TSE)-based subtraction magnetic resonance angiography (MRA) in the assessment of peripheral arteries in patients with critical limb ischemia (CLI). Nineteen consecutive patients (74 % male, 72.8 ± 9.9 years) with CLI underwent 2D QISS and 3D TSE-based subtraction MRA at 1.5 T. Axial-overlapping QISS MRA (3 mm/2 mm; 1 x 1 mm{sup 2}) covered from the toes to the aortic bifurcation while coronal 3D TSE-based subtraction MRA (1.3 x 1.2 x 1.3 mm{sup 3}) was restricted to the calf only. MRA data sets (two readers) were evaluated for stenosis (≥50 %) and image quality. Results were compared with digital subtraction angiography (DSA). Two hundred and sixty-seven (267) segments were available for MRA-DSA comparison, with a prevalence of stenosis ≥50 % of 41.9 %. QISS MRA was rated as good to excellent in 79.5-96.0 % of segments without any nondiagnostic segments; 89.8-96.1 % of segments in 3D TSE-based subtraction MRA were rated as nondiagnostic or poor. QISS MRA sensitivities and specificities (segmental) were 92 % and 95 %, respectively, for reader one and 81-97 % for reader two. Due to poor image quality of 3D TSE-based subtraction MRA, diagnostic performance measures were not calculated. QISS MRA demonstrates excellent diagnostic performance and higher robustness than 3D TSE-based subtraction MRA in the challenging patient population with CLI. (orig.)

Physics and Video Analysis

Science.gov (United States)

Allain, Rhett

2016-05-01

We currently live in a world filled with videos. There are videos on YouTube, feature movies and even videos recorded with our own cameras and smartphones. These videos present an excellent opportunity to not only explore physical concepts, but also inspire others to investigate physics ideas. With video analysis, we can explore the fantasy world in science-fiction films. We can also look at online videos to determine if they are genuine or fake. Video analysis can be used in the introductory physics lab and it can even be used to explore the make-believe physics embedded in video games. This book covers the basic ideas behind video analysis along with the fundamental physics principles used in video analysis. The book also includes several examples of the unique situations in which video analysis can be used.

Video games

OpenAIRE

Kolář, Vojtěch

2012-01-01

This thesis is based on a detailed analysis of various topics related to the question of whether video games can be art. In the first place it analyzes the current academic discussion on this subject and confronts different opinions of both supporters and objectors of the idea, that video games can be a full-fledged art form. The second point of this paper is to analyze the properties, that are inherent to video games, in order to find the reason, why cultural elite considers video games as i...

A subtraction scheme for computing QCD jet cross sections at NNLO. Integrating the iterated singly-unresolved subtraction terms

Energy Technology Data Exchange (ETDEWEB)

Bolzoni, Paolo [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik; Somogyi, Gabor [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Trocsanyi, Zoltan [Debrecen Univ. (Hungary); Hungarian Academy of Sciences, Debrecen (Hungary). Inst. of Nuclear Research

2010-11-15

We perform the integration of all iterated singly-unresolved subtraction terms over the two-particle factorized phase space. We also sum over the unresolved parton flavours. The final result can be written as a convolution (in colour space) of the Born cross section and an insertion operator. We spell out the insertion operator in terms of 24 basic integrals that are defined explicitly. We compute the coefficients of the Laurent-expansion of these integrals in two different ways, with the method of Mellin-Barnes representations and sector decomposition. Finally, we present the Laurentexpansion of the full insertion operator for the specific examples of electron-positron annihilation into two and three jets. (orig.)

A subtraction scheme for computing QCD jet cross sections at NNLO: integrating the iterated singly-unresolved subtraction terms

Science.gov (United States)

Bolzoni, Paolo; Somogyi, Gábor; Trócsányi, Zoltán

2011-01-01

We perform the integration of all iterated singly-unresolved subtraction terms, as defined in ref. [1], over the two-particle factorized phase space. We also sum over the unresolved parton flavours. The final result can be written as a convolution (in colour space) of the Born cross section and an insertion operator. We spell out the insertion operator in terms of 24 basic integrals that are defined explicitly. We compute the coefficients of the Laurent expansion of these integrals in two different ways, with the method of Mellin-Barnes representations and sector decomposition. Finally, we present the Laurent-expansion of the full insertion operator for the specific examples of electron-positron annihilation into two and three jets.

A Novel Morphometry-Based Protocol of Automated Video-Image Analysis for Species Recognition and Activity Rhythms Monitoring in Deep-Sea Fauna

Directory of Open Access Journals (Sweden)

Paolo Menesatti

2009-10-01

Full Text Available The understanding of ecosystem dynamics in deep-sea areas is to date limited by technical constraints on sampling repetition. We have elaborated a morphometry-based protocol for automated video-image analysis where animal movement tracking (by frame subtraction is accompanied by species identification from animals’ outlines by Fourier Descriptors and Standard K-Nearest Neighbours methods. One-week footage from a permanent video-station located at 1,100 m depth in Sagami Bay (Central Japan was analysed. Out of 150,000 frames (1 per 4 s, a subset of 10.000 was analyzed by a trained operator to increase the efficiency of the automated procedure. Error estimation of the automated and trained operator procedure was computed as a measure of protocol performance. Three displacing species were identified as the most recurrent: Zoarcid fishes (eelpouts, red crabs (Paralomis multispina, and snails (Buccinum soyomaruae. Species identification with KNN thresholding produced better results in automated motion detection. Results were discussed assuming that the technological bottleneck is to date deeply conditioning the exploration of the deep-sea.

Relacije umetnosti i video igara / Relations of Art and Video Games

OpenAIRE

Manojlo Maravić

2012-01-01

When discussing the art of video games, three different contexts need to be considered: the 'high' art (video games and the art); commercial video games (video games as the art) and the fan art. Video games are a legitimate artistic medium subject to modifications and recontextualisations in the process of creating a specific experience of the player/user/audience and political action by referring to particular social problems. They represent a high technological medium that increases, with p...

Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

Energy Technology Data Exchange (ETDEWEB)

Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J. [Department of Radiology, ' ' Aretaieion' ' Hospital,University of Athens Medical School, Athens (Greece); Voumvourakis, C.; Sfagos, C. [Department of Neurology, ' ' Eginiteion' ' Hospital, University of Athens Medical School, Athens (Greece)

2004-03-01

Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

International Nuclear Information System (INIS)

Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J.; Voumvourakis, C.; Sfagos, C.

2004-01-01

Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

Performance of computed tomography for contrast agent concentration measurements with monochromatic x-ray beams: comparison of K-edge versus temporal subtraction

International Nuclear Information System (INIS)

Elleaume, H.; Charvet, A.M.; Corde, S.; Esteve, F.; Le Bas, J.F.

2002-01-01

We investigated the performance of monochromatic computed tomography for the quantification of contrast agent concentrations. Two subtraction methods (K-edge subtraction and temporal subtraction) were evaluated and compared theoretically and experimentally in terms of detection limit, precision and accuracy. Measurements were performed using synchrotron x-rays with Lucite phantoms (10 cm and 17.5 cm in diameter) containing iodine or gadolinium solutions ranging from 50 μg ml -1 to 5 mg ml -1 . The experiments were carried out using monochromators developed at the European Synchrotron Radiation Facility (ESRF) medical beamline. The phantoms were imaged either above and below the contrast agent K-edge, or before and after the addition of the contrast agent. Both methods gave comparable performance for phantoms less than 10 cm in diameter. For large phantoms, equivalent to a human head, the temporal subtraction is more suitable for detecting elements such as iodine, keeping a reasonable x-ray dose delivered to the phantom. A good agreement was obtained between analytical calculations, simulations and measurements. The beam harmonic content was taken into account in the simulations. It explains the performance degradation with high contrast agent concentrations. The temporal subtraction technique has the advantage of energy tunability and is well suited for imaging elements, such as iodine or gadolinium, in highly absorbing samples. For technical reasons, the K-edge method is preferable when the imaged organ is moving since the two measurements can be performed simultaneously, which is mandatory for obtaining a good subtraction. (author)

Subtractive fabrication of ferroelectric thin films with precisely controlled thickness

Science.gov (United States)

Ievlev, Anton V.; Chyasnavichyus, Marius; Leonard, Donovan N.; Agar, Joshua C.; Velarde, Gabriel A.; Martin, Lane W.; Kalinin, Sergei V.; Maksymovych, Petro; Ovchinnikova, Olga S.

2018-04-01

The ability to control thin-film growth has led to advances in our understanding of fundamental physics as well as to the emergence of novel technologies. However, common thin-film growth techniques introduce a number of limitations related to the concentration of defects on film interfaces and surfaces that limit the scope of systems that can be produced and studied experimentally. Here, we developed an ion-beam based subtractive fabrication process that enables creation and modification of thin films with pre-defined thicknesses. To accomplish this we transformed a multimodal imaging platform that combines time-of-flight secondary ion mass spectrometry with atomic force microscopy to a unique fabrication tool that allows for precise sputtering of the nanometer-thin layers of material. To demonstrate fabrication of thin-films with in situ feedback and control on film thickness and functionality we systematically studied thickness dependence of ferroelectric switching of lead-zirconate-titanate, within a single epitaxial film. Our results demonstrate that through a subtractive film fabrication process we can control the piezoelectric response as a function of film thickness as well as improve on the overall piezoelectric response versus an untreated film.

Rare Disease Video Portal

OpenAIRE

Sánchez Bocanegra, Carlos Luis

2011-01-01

Rare Disease Video Portal (RD Video) is a portal web where contains videos from Youtube including all details from 12 channels of Youtube. Rare Disease Video Portal (RD Video) es un portal web que contiene los vídeos de Youtube incluyendo todos los detalles de 12 canales de Youtube. Rare Disease Video Portal (RD Video) és un portal web que conté els vídeos de Youtube i que inclou tots els detalls de 12 Canals de Youtube.

Quantitative analysis of alveolar bone change following implant placement using intraoral radiographic subtraction

International Nuclear Information System (INIS)

Kimura, Hiroyuki; Kanda, Shigenobu; Tanaka, Takemasa

2002-01-01

The purpose of this study was to develop a procedure for quantitative analysis using intraoral radiographs of alveolar bone after placement of dental implants and to consider the validity of the method. We evaluated the ten patients (2 males and 8 females, average age: 48.4 years-old), who were treated with dental implant operation in the site of mandibular molar region, since October of 1999 until September of 2000 in Kimura Dental Clinic (Kumamoto, Japan). We evaluated the intraoral radiographs taken pre- and post- operatively and at follow-up examination. To detect alveolar bone change on radiograph, we adopted the digital subtraction method. Although the radiographs were taken under an ordinary technique with cone indicator, we did not apply the standardized technique with fixing material customized for each patient. Therefore, we used geometric correction and density compensation before subtraction. We assessed the basic statistical values (mean, variance, kurtosis and skewness) of the region of interest (ROI) of the subtracted images. Also, we noted PPD (probing pocket depth) and BOP (bleeding on probing) at each site as indicators of clinical findings and all implanted sites were classified according to the PPD or BOP, i.e. PPD increased group ''PPD (+)'' and PPD stable group ''PPD (-)'', likewise BOP positive group ''BOP (+)'' and negative group ''BOP (-)''. We considered the statistical values of ROI in each group and compared these findings. Mean and variance values of PPD (+) were higher than those of PPD (-) and there was a significant difference in mean value (p=0.031). Similarly, mean and variance values of BOP (+) were statistically higher than those of BOP (-) (p=0.041 and p=0.0087, respectively). Concerning kurtosis and skewness, there was no difference between PPD (+) and PPD (-), or between BOP (+) and BOP (-). Using our method, the radiographs taken for follow-up examination could be assessed quantitatively. It is suggested that geometric

Analysis of luminosity distributions of strong lensing galaxies: subtraction of diffuse lensed signal

Science.gov (United States)

Biernaux, J.; Magain, P.; Hauret, C.

2017-08-01

Context. Strong gravitational lensing gives access to the total mass distribution of galaxies. It can unveil a great deal of information about the lenses' dark matter content when combined with the study of the lenses' light profile. However, gravitational lensing galaxies, by definition, appear surrounded by lensed signal, both point-like and diffuse, that is irrelevant to the lens flux. Therefore, the observer is most often restricted to studying the innermost portions of the galaxy, where classical fitting methods show some instabilities. Aims: We aim at subtracting that lensed signal and at characterising some lenses' light profile by computing their shape parameters (half-light radius, ellipticity, and position angle). Our objective is to evaluate the total integrated flux in an aperture the size of the Einstein ring in order to obtain a robust estimate of the quantity of ordinary (luminous) matter in each system. Methods: We are expanding the work we started in a previous paper that consisted in subtracting point-like lensed images and in independently measuring each shape parameter. We improve it by designing a subtraction of the diffuse lensed signal, based only on one simple hypothesis of symmetry. We apply it to the cases where it proves to be necessary. This extra step improves our study of the shape parameters and we refine it even more by upgrading our half-light radius measurement method. We also calculate the impact of our specific image processing on the error bars. Results: The diffuse lensed signal subtraction makes it possible to study a larger portion of relevant galactic flux, as the radius of the fitting region increases by on average 17%. We retrieve new half-light radii values that are on average 11% smaller than in our previous work, although the uncertainties overlap in most cases. This shows that not taking the diffuse lensed signal into account may lead to a significant overestimate of the half-light radius. We are also able to measure

Medical students' perceptions of video-linked lectures and video-streaming

Directory of Open Access Journals (Sweden)

Karen Mattick

2010-12-01

Full Text Available Video-linked lectures allow healthcare students across multiple sites, and between university and hospital bases, to come together for the purposes of shared teaching. Recording and streaming video-linked lectures allows students to view them at a later date and provides an additional resource to support student learning. As part of a UK Higher Education Academy-funded Pathfinder project, this study explored medical students' perceptions of video-linked lectures and video-streaming, and their impact on learning. The methodology involved semi-structured interviews with 20 undergraduate medical students across four sites and five year groups. Several key themes emerged from the analysis. Students generally preferred live lectures at the home site and saw interaction between sites as a major challenge. Students reported that their attendance at live lectures was not affected by the availability of streamed lectures and tended to be influenced more by the topic and speaker than the technical arrangements. These findings will inform other educators interested in employing similar video technologies in their teaching.Keywords: video-linked lecture; video-streaming; student perceptions; decisionmaking; cross-campus teaching.

Automated Indexing and Search of Video Data in Large Collections with inVideo

Directory of Open Access Journals (Sweden)

Shuangbao Paul Wang

2017-08-01

Full Text Available In this paper, we present a novel system, inVideo, for automatically indexing and searching videos based on the keywords spoken in the audio track and the visual content of the video frames. Using the highly efficient video indexing engine we developed, inVideo is able to analyze videos using machine learning and pattern recognition without the need for initial viewing by a human. The time-stamped commenting and tagging features refine the accuracy of search results. The cloud-based implementation makes it possible to conduct elastic search, augmented search, and data analytics. Our research shows that inVideo presents an efficient tool in processing and analyzing videos and increasing interactions in video-based online learning environment. Data from a cybersecurity program with more than 500 students show that applying inVideo to current video material, interactions between student-student and student-faculty increased significantly across 24 sections program-wide.

NEI You Tube Videos: Amblyopia

Medline Plus

Full Text Available ... YouTube Videos » NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: ...

Geometrical accuracy of metallic objects produced with additive or subtractive manufacturing: A comparative in vitro study.

Science.gov (United States)

Braian, Michael; Jönsson, David; Kevci, Mir; Wennerberg, Ann

2018-04-06

To evaluate the accuracy and precision of objects produced by additive manufacturing systems (AM) for use in dentistry and to compare with subtractive manufacturing systems (SM). Ten specimens of two geometrical objects were produced by five different AM machines and one SM machine. Object A mimics an inlay-shaped object, while object B imitates a four-unit bridge model. All the objects were sorted into different measurement dimensions (x, y, z), linear distances, angles and corner radius. None of the additive manufacturing or subtractive manufacturing groups presented a perfect match to the CAD file with regard to all parameters included in the present study. Considering linear measurements, the precision for subtractive manufacturing group was consistent in all axes for object A, presenting results of additive manufacturing groups had consistent precision in the x-axis and y-axis but not in the z-axis. With regard to corner radius measurements, the SM group had the best overall accuracy and precision for both objects A and B when compared to the AM groups. Within the limitations of this in vitro study, the conclusion can be made that subtractive manufacturing presented overall precision on all measurements below 0.050mm. The AM machines also presented fairly good precision, additive techniques are now being implemented. Thus all these production techniques need to be tested, compared and validated. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Guerrilla Video: A New Protocol for Producing Classroom Video

Science.gov (United States)

Fadde, Peter; Rich, Peter

2010-01-01

Contemporary changes in pedagogy point to the need for a higher level of video production value in most classroom video, replacing the default video protocol of an unattended camera in the back of the classroom. The rich and complex environment of today's classroom can be captured more fully using the higher level, but still easily manageable,…

The potential for neurovascular intravenous angiography using K-edge digital subtraction angiography

International Nuclear Information System (INIS)

Schueltke, E.; Fiedler, S.; Kelly, M.; Griebel, R.; Juurlink, B.; LeDuc, G.; Esteve, F.; Le Bas, J.-F.; Renier, M.; Nemoz, C.; Meguro, K.

2005-01-01

Background: Catheterization of small-caliber blood vessels in the central nervous system can be extremely challenging. Alternatively, intravenous (i.v.) administration of contrast agent is minimally invasive and therefore carries a much lower risk for the patient. With conventional X-ray equipment, volumes of contrast agent that could be safely administered to the patient do not allow acquisition of high-quality images after i.v. injection, because the contrast bolus is extremely diluted by passage through the heart. However, synchrotron-based digital K-edge subtraction angiography does allow acquisition of high-quality images after i.v. administration of relatively small doses of contrast agent. Materials and methods: Eight adult male New Zealand rabbits were used for our experiments. Animals were submitted to both angiography with conventional X-ray equipment and synchrotron-based digital subtraction angiography. Results: With conventional X-ray equipment, no contrast was seen in either cerebral or spinal blood vessels after i.v. injection of iodinated contrast agent. However, using K-edge digital subtraction angiography, as little as 1 ml iodinated contrast agent, when administered as i.v. bolus, yielded images of small-caliber blood vessels in the central nervous system (both brain and spinal cord). Conclusions: If it would be possible to image blood vessels of the same diameter in the central nervous system of human patients, the synchrotron-based technique could yield high-quality images at a significantly lower risk for the patient than conventional X-ray imaging. Images could be acquired where catheterization of feeding blood vessels has proven impossible

The value of subtraction MRI in detection of amyloid-related imaging abnormalities with oedema or effusion in Alzheimer's patients: An interobserver study.

Science.gov (United States)

Martens, Roland M; Bechten, Arianne; Ingala, Silvia; van Schijndel, Ronald A; Machado, Vania B; de Jong, Marcus C; Sanchez, Esther; Purcell, Derk; Arrighi, Michael H; Brashear, Robert H; Wattjes, Mike P; Barkhof, Frederik

2018-03-01

Immunotherapeutic treatments targeting amyloid-β plaques in Alzheimer's disease (AD) are associated with the presence of amyloid-related imaging abnormalities with oedema or effusion (ARIA-E), whose detection and classification is crucial to evaluate subjects enrolled in clinical trials. To investigate the applicability of subtraction MRI in the ARIA-E detection using an established ARIA-E-rating scale. We included 75 AD patients receiving bapineuzumab treatment, including 29 ARIA-E cases. Five neuroradiologists rated their brain MRI-scans with and without subtraction images. The accuracy of evaluating the presence of ARIA-E, intraclass correlation coefficient (ICC) and specific agreement was calculated. Subtraction resulted in higher sensitivity (0.966) and lower specificity (0.970) than native images (0.959, 0.991, respectively). Individual rater detection was excellent. ICC scores ranged from excellent to good, except for gyral swelling (moderate). Excellent negative and good positive specific agreement among all ARIA-E imaging features was reported in both groups. Combining sulcal hyperintensity and gyral swelling significantly increased positive agreement for subtraction images. Subtraction MRI has potential as a visual aid increasing the sensitivity of ARIA-E assessment. However, in order to improve its usefulness isotropic acquisition and enhanced training are required. The ARIA-E rating scale may benefit from combining sulcal hyperintensity and swelling. • Subtraction technique can improve detection amyloid-related imaging-abnormalities with edema/effusion in Alzheimer's patients. • The value of ARIA-E detection, classification and monitoring using subtraction was assessed. • Validation of an established ARIA-E rating scale, recommendations for improvement are reported. • Complementary statistical methods were employed to measure accuracy, inter-rater-reliability and specific agreement.

Using the hydrophobic subtraction model to choose orthogonal columns for online comprehensive two-dimensional liquid chromatography

DEFF Research Database (Denmark)

Græsbøll, Rune; Nielsen, Nikoline Juul; Christensen, Jan H.

2014-01-01

A method for choosing orthogonal columns for a specific sample set in on-line comprehensive two-dimensional liquid chromatography (LC×LC) was developed on the basis of the hydrophobic subtraction model. The method takes into account the properties of the sample analytes by estimating new F...... neutral and 4 acidic oxygenated polycyclic aromatic compounds (PACs) and 3 nitrogen-containing PAC bases was measured isocratically on 12 columns. The isocratic runs were used to determine the hydrophobic subtraction model analyte parameters, and these were used to estimate new F-weights and predict...

Video Comparator

International Nuclear Information System (INIS)

Rose, R.P.

1978-01-01

The Video Comparator is a comparative gage that uses electronic images from two sources, a standard and an unknown. Two matched video cameras are used to obtain the electronic images. The video signals are mixed and displayed on a single video receiver (CRT). The video system is manufactured by ITP of Chatsworth, CA and is a Tele-Microscope II, Model 148. One of the cameras is mounted on a toolmaker's microscope stand and produces a 250X image of a cast. The other camera is mounted on a stand and produces an image of a 250X template. The two video images are mixed in a control box provided by ITP and displayed on a CRT. The template or the cast can be moved to align the desired features. Vertical reference lines are provided on the CRT, and a feature on the cast can be aligned with a line on the CRT screen. The stage containing the casts can be moved using a Boeckleler micrometer equipped with a digital readout, and a second feature aligned with the reference line and the distance moved obtained from the digital display

A video event trigger for high frame rate, high resolution video technology

Science.gov (United States)

Williams, Glenn L.

1991-12-01

When video replaces film the digitized video data accumulates very rapidly, leading to a difficult and costly data storage problem. One solution exists for cases when the video images represent continuously repetitive 'static scenes' containing negligible activity, occasionally interrupted by short events of interest. Minutes or hours of redundant video frames can be ignored, and not stored, until activity begins. A new, highly parallel digital state machine generates a digital trigger signal at the onset of a video event. High capacity random access memory storage coupled with newly available fuzzy logic devices permits the monitoring of a video image stream for long term or short term changes caused by spatial translation, dilation, appearance, disappearance, or color change in a video object. Pretrigger and post-trigger storage techniques are then adaptable for archiving the digital stream from only the significant video images.

Application of digital subtraction angiography in disease of large cardiac vessel

Energy Technology Data Exchange (ETDEWEB)

Arisawa, Jun; Sone, Shusuke; Morimoto, Shizuo; Ikezoe, Junpei; Higashibara, Tokuro; Hanayama, Masayuki

1983-06-01

Digital subtraction angiography (DSA) was performed in 31 cases of disease of large cardiac vessel. DSA was useful for the diagnosis of aortic aneurysm and malformation of large vessels, follow-up after A-C bypass operation and Blalock's shunt operation for tetralogy of Fallot and as an adjuvant modality in cardiac catheterization.

Application of digital subtraction angiography in disease of large cardiac vessel

International Nuclear Information System (INIS)

Arisawa, Jun; Sone, Shusuke; Morimoto, Shizuo; Ikezoe, Junpei; Higashibara, Tokuro; Hanayama, Masayuki

1983-01-01

Digital subtraction angiography (DSA) was performed in 31 cases of disease of large cardiac vessel. DSA was useful for the diagnosis of aortic aneurysm and malformation of large vessels, follow-up after A-C bypass operation and Blalock's shunt operation for tetralogy of Fallot and as an adjuvant modality in cardiac catheterization. (Chiba, N.)

Myocardial perfusion imaging by digital subtraction angiography

International Nuclear Information System (INIS)

Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

1986-01-01

Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

Learning Science Through Digital Video: Views on Watching and Creating Videos

Science.gov (United States)

Wade, P.; Courtney, A. R.

2013-12-01

In science, the use of digital video to document phenomena, experiments and demonstrations has rapidly increased during the last decade. The use of digital video for science education also has become common with the wide availability of video over the internet. However, as with using any technology as a teaching tool, some questions should be asked: What science is being learned from watching a YouTube clip of a volcanic eruption or an informational video on hydroelectric power generation? What are student preferences (e.g. multimedia versus traditional mode of delivery) with regard to their learning? This study describes 1) the efficacy of watching digital video in the science classroom to enhance student learning, 2) student preferences of instruction with regard to multimedia versus traditional delivery modes, and 3) the use of creating digital video as a project-based educational strategy to enhance learning. Undergraduate non-science majors were the primary focus group in this study. Students were asked to view video segments and respond to a survey focused on what they learned from the segments. Additionally, they were asked about their preference for instruction (e.g. text only, lecture-PowerPoint style delivery, or multimedia-video). A majority of students indicated that well-made video, accompanied with scientific explanations or demonstration of the phenomena was most useful and preferred over text-only or lecture instruction for learning scientific information while video-only delivery with little or no explanation was deemed not very useful in learning science concepts. The use of student generated video projects as learning vehicles for the creators and other class members as viewers also will be discussed.

N-jettiness subtractions for gg→H at subleading power

Energy Technology Data Exchange (ETDEWEB)

Moult, Ian [California Univ., Berkeley, CA (United States). Berkeley Center for Theoretical Physics; Lawrence Berkeley National Laboratory, CA (United States). Theoretical Physics Group; Rothen, Lorena; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie; Stewart, Iain W. [Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics; Zhu, Hua Xing [Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics; Zhejiang Univ. (China). Dept. of Physics

2017-10-15

N-jettiness subtractions provide a general approach for performing fully-differential next-to-next-to-leading order (NNLO) calculations. Since they are based on the physical resolution variable N-jettiness, T{sub N}, subleading power corrections in τ =T{sub N}/Q, with Q a hard interaction scale, can also be systematically computed. We study the structure of power corrections for 0-jettiness, T{sub 0}, for the gg→H process. Using the soft-collinear effective theory we analytically compute the leading power corrections α{sub s}τ ln τ and α{sub s}{sup 2}τ ln{sup 3}τ (finding partial agreement with a previous result in the literature), and perform a detailed numerical study of the power corrections in the gg, gq, and q anti q channels. This includes a numerical extraction of the α{sub s}τ and α{sub s}{sup 2}τ ln{sup 2}τ corrections, and a study of the dependence on the T{sub 0} definition. Including such power suppressed logarithms significantly reduces the size of missing power corrections, and hence improves the numerical efficiency of the subtraction method. Having a more detailed understanding of the power corrections for both q anti q and gg initiated processes also provides insight into their universality, and hence their behavior in more complicated processes where they have not yet been analytically calculated.

N-jettiness subtractions for gg→H at subleading power

International Nuclear Information System (INIS)

Moult, Ian; Lawrence Berkeley National Laboratory, CA; Rothen, Lorena; Tackmann, Frank J.; Stewart, Iain W.; Zhu, Hua Xing; Zhejiang Univ.

2017-10-01

N-jettiness subtractions provide a general approach for performing fully-differential next-to-next-to-leading order (NNLO) calculations. Since they are based on the physical resolution variable N-jettiness, T N , subleading power corrections in τ =T N /Q, with Q a hard interaction scale, can also be systematically computed. We study the structure of power corrections for 0-jettiness, T 0 , for the gg→H process. Using the soft-collinear effective theory we analytically compute the leading power corrections α s τ ln τ and α s 2 τ ln 3 τ (finding partial agreement with a previous result in the literature), and perform a detailed numerical study of the power corrections in the gg, gq, and q anti q channels. This includes a numerical extraction of the α s τ and α s 2 τ ln 2 τ corrections, and a study of the dependence on the T 0 definition. Including such power suppressed logarithms significantly reduces the size of missing power corrections, and hence improves the numerical efficiency of the subtraction method. Having a more detailed understanding of the power corrections for both q anti q and gg initiated processes also provides insight into their universality, and hence their behavior in more complicated processes where they have not yet been analytically calculated.

Digital subtraction radiography evaluation of the bone repair process of chronic apical periodontitis after root canal treatment.

Science.gov (United States)

Benfica e Silva, J; Leles, C R; Alencar, A H G; Nunes, C A B C M; Mendonça, E F

2010-08-01

To monitor radiographically the progress of bone repair within chronic periapical lesions after root canal treatment using digital subtraction radiography (DSR). Twelve patients with 17 single-rooted teeth with chronic apical periodontitis associated with an infected necrotic pulp were selected for root canal treatment. Periapical radiographs were taken before treatment (baseline) and immediately post-treatment, 45, 90, 135 and 180 days after treatment. The radiographic protocol included the use of individualized film holders with silicone bite blocks. The six radiographic images were digitized and submitted to digital subtraction using DSR software, resulting in five subtracted images (SI). Quantitative analysis of these SI was performed using Image Tool software to assess pixel value changes, considering a step-wedge as the gold standard and a cut-off value of 128 pixels. The aim was to identify any increase or decrease in mineral density in the region of the periapical lesion. A minor decrease in mineral density at the canal filling session and a significant progressive mineral gain in the following evaluations (P < 0.001) occurred. Pairwise comparison of pixel grey values revealed that only the 180-day follow-up differed significantly from the previous SI. Digital subtraction radiography is a useful method for evaluating the progress of bone repair after root canal treatment. Noticeable mineral gain was observed approximately 90 days after root canal filling and definite bone repair after 180 days.

Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads.

Science.gov (United States)

Ohara, Yoshikazu; Horinouchi, Satoshi; Hashimoto, Makoto; Shintaku, Yohei; Yamanaka, Kazushi

2011-08-01

To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks varies, resulting in an intensity change of responses at cracks. In contrast, objects other than cracks are independent of external load. Therefore, only cracks can be extracted by subtracting responses at different loads. In this study, we performed fundamental experiments on a closed fatigue crack formed in an aluminum alloy compact tension (CT) specimen using the proposed method. We examined the static load dependence of SPACE images and the dynamic load dependence of linear phased array (PA) images by simulating the external loads with a servohydraulic fatigue testing machine. By subtracting the images at different external loads, we show that this method is useful in extracting only the intensity change of responses related to closed cracks, while canceling the responses of objects other than cracks. Copyright © 2010 Elsevier B.V. All rights reserved.

Double-nuclide subtraction scintiscanning of the pancreas

International Nuclear Information System (INIS)

Streithoff, E.C.

1978-01-01

The paper intends to find out if there is a correlation between clinical pancreas diagnoses and diagnoses by subtraction scintiscanning; furthermore, the findings of scintiscanning are compared with those of radiological and sonographic methods. In order to get a picture of the efficiency of the methods applied, not only their accuracy is determined but also their validity sum and validity product. The best results are achieved here with angiography, ERCP, and sonography. In the case of pancreatic scintiscanning, an optimal result well above the international standard is only obtained for sensitivity. On the basis of these results, the indications for an optimal and useful application of pancreatic scintiscanning are determined. (orig./AJ) [de

Video Design Games

DEFF Research Database (Denmark)

Smith, Rachel Charlotte; Christensen, Kasper Skov; Iversen, Ole Sejer

We introduce Video Design Games to train educators in teaching design. The Video Design Game is a workshop format consisting of three rounds in which participants observe, reflect and generalize based on video snippets from their own practice. The paper reports on a Video Design Game workshop...... in which 25 educators as part of a digital fabrication and design program were able to critically reflect on their teaching practice....

Videodensitometric assessment of right and left ventricular functions by digital subtraction angiography

International Nuclear Information System (INIS)

Ikeda, Hisao; Yoshiga, Osamu; Shibao, Keigo

1987-01-01

Intravenous digital subtraction (DS) ventriculography was performed in a series of 50 patients with heart diseases to determine right and left ventricular volumes and systolic indices. Right ventricular volume and right ventricular ejection fraction obtained by DS ventriculography were well correlated with those by geometric methods. In 43 patients with left ventricular ejection fraction of 55 % or greater, end-diastolic volume, stroke volume, and ejection fraction in the right ventricle did not differ from those in the left ventricle ; however, both the 1/3 ejection fraction and the peak ejection rate of the right ventricle were significantly lower than those of the left ventricle, suggesting the different modes of left and right ventricular contraction. In the other seven patients with chronic left ventricular failure, right ventricular systolic function may be preserved, even when left ventricular function is severely impaired. Digital subtraction ventriculography has proved to be a simple, useful method in the quanlitative and quantitative assessments of the right and left ventricles. (Namekawa, K.)

Ability of subtraction and dynamic MR imaging to detect breast tumors. Comparison with ultrasonography and mammography

International Nuclear Information System (INIS)

Terao, Eri; Takeuchi, Hiroaki; Iwamura, Akira; Murakami, Yoshitaka; Harada, Junta; Tada, Shinpei

1994-01-01

We evaluated the ability of subtraction and dynamic MR imaging to accurately detect breast tumors. Sixty-five breast carcinomas and 24 fibroadenomas were examined by an SE pulse sequence using a 0.2 Tesla unit. Subtraction MR images were obtained every minute during dynamic study with Gd-DTPA. Almost all breast tumors were seen as very bright masses, and the margin of the mass was clearly demonstrated on subtraction MR images. Breast carcinomas and fibroadenomas showed characteristic time-intensity curves on dynamic study. Time-intensity curves of the early peak type and plateau type were seen in 97% of breast carcinomas, while the gradually increasing type was seen in 92% of fibroadenomas. The detectability of breast carcinoma was 98% by MRI, 98% by ultrasonography, and 87% by mammography. That of fibroadenoma was 95% by MRI, 91% by ultrasonography and 60% by mammography. Sensitivity and specificity for breast carcinoma were 98% and 92% for MRI and 97% and 71% for ultrasonography. For fibroadenoma, they were 96% and 98% for MRI and 89% and 92% for ultrasonography. (author)

Ability of subtraction and dynamic MR imaging to detect breast tumors. Comparison with ultrasonography and mammography

Energy Technology Data Exchange (ETDEWEB)

Terao, Eri; Takeuchi, Hiroaki; Iwamura, Akira; Murakami, Yoshitaka; Harada, Junta; Tada, Shinpei (Jikei Univ., Tokyo (Japan). School of Medicine)

1994-09-01

We evaluated the ability of subtraction and dynamic MR imaging to accurately detect breast tumors. Sixty-five breast carcinomas and 24 fibroadenomas were examined by an SE pulse sequence using a 0.2 Tesla unit. Subtraction MR images were obtained every minute during dynamic study with Gd-DTPA. Almost all breast tumors were seen as very bright masses, and the margin of the mass was clearly demonstrated on subtraction MR images. Breast carcinomas and fibroadenomas showed characteristic time-intensity curves on dynamic study. Time-intensity curves of the early peak type and plateau type were seen in 97% of breast carcinomas, while the gradually increasing type was seen in 92% of fibroadenomas. The detectability of breast carcinoma was 98% by MRI, 98% by ultrasonography, and 87% by mammography. That of fibroadenoma was 95% by MRI, 91% by ultrasonography and 60% by mammography. Sensitivity and specificity for breast carcinoma were 98% and 92% for MRI and 97% and 71% for ultrasonography. For fibroadenoma, they were 96% and 98% for MRI and 89% and 92% for ultrasonography. (author).

Digital subtraction angiography in head and neck radiology

Energy Technology Data Exchange (ETDEWEB)

Carmody, R F; Seeger, J F; Smith, R L; Horsley, W W; Miller, R W

1984-07-01

Intravenous digital subtraction angiography (IVDSA) was used to evaluate 44 patients with suspected otolaryngologic abnormalities. Sixteen had IVDSA for pulsatile tinnitus or suspected glomus tumor of the petrous bone. Nine patients were evaluated because of pulsatile neck masses, and 12 others had suspected tumors of the neck, face, and paranasal sinuses. Seven had IVDSA following head and neck trauma. The technique of examination is described. The current indications of IVDSA in head and neck radiology are discussed. It is concluded that IVDSA is a suitable substitute for conventional angiography for many otolaryngologic conditions and, because of its safety, can be used more liberally.

Flip Video for Dummies

CERN Document Server

Hutsko, Joe

2010-01-01

The full-color guide to shooting great video with the Flip Video camera. The inexpensive Flip Video camera is currently one of the hottest must-have gadgets. It's portable and connects easily to any computer to transfer video you shoot onto your PC or Mac. Although the Flip Video camera comes with a quick-start guide, it lacks a how-to manual, and this full-color book fills that void! Packed with full-color screen shots throughout, Flip Video For Dummies shows you how to shoot the best possible footage in a variety of situations. You'll learn how to transfer video to your computer and then edi

Hierarchical video summarization

Science.gov (United States)

Ratakonda, Krishna; Sezan, M. Ibrahim; Crinon, Regis J.

1998-12-01

We address the problem of key-frame summarization of vide in the absence of any a priori information about its content. This is a common problem that is encountered in home videos. We propose a hierarchical key-frame summarization algorithm where a coarse-to-fine key-frame summary is generated. A hierarchical key-frame summary facilitates multi-level browsing where the user can quickly discover the content of the video by accessing its coarsest but most compact summary and then view a desired segment of the video with increasingly more detail. At the finest level, the summary is generated on the basis of color features of video frames, using an extension of a recently proposed key-frame extraction algorithm. The finest level key-frames are recursively clustered using a novel pairwise K-means clustering approach with temporal consecutiveness constraint. We also address summarization of MPEG-2 compressed video without fully decoding the bitstream. We also propose efficient mechanisms that facilitate decoding the video when the hierarchical summary is utilized in browsing and playback of video segments starting at selected key-frames.

NNLO jet cross sections by subtraction

Energy Technology Data Exchange (ETDEWEB)

Somogyi, G.; Bolzoni, P. [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Trocsanyi, Z. [CERN PH-TH, on leave from University of Debrecen and Institute of Nuclear Research of HAS, H-4001 P.O.Box 51 (Hungary)

2010-08-15

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 06, 024 (2005), (arXiv:hep-ph/0502226); G. Somogyi and Z. Trocsanyi, (2006), (arXiv:hep-ph/0609041); G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 01, 070 (2007), (arXiv:hep-ph/0609042); G. Somogyi and Z. Trocsanyi, JHEP 01, 052 (2007), (arXiv:hep-ph/0609043)] over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

NNLO jet cross sections by subtraction

International Nuclear Information System (INIS)

Somogyi, G.; Bolzoni, P.; Trocsanyi, Z.

2010-01-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 06, 024 (2005), (arXiv:hep-ph/0502226); G. Somogyi and Z. Trocsanyi, (2006), (arXiv:hep-ph/0609041); G. Somogyi, Z. Trocsanyi, and V. Del Duca, JHEP 01, 070 (2007), (arXiv:hep-ph/0609042); G. Somogyi and Z. Trocsanyi, JHEP 01, 052 (2007), (arXiv:hep-ph/0609043)] over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Low-cost addition-subtraction sequences for the final exponentiation computation in pairings

DEFF Research Database (Denmark)

Guzmán-Trampe, Juan E; Cruz-Cortéz, Nareli; Dominguez Perez, Luis

2014-01-01

In this paper, we address the problem of finding low cost addition–subtraction sequences for situations where a doubling step is significantly cheaper than a non-doubling one. One application of this setting appears in the computation of the final exponentiation step of the reduced Tate pairing d...

Usefulness of computerized method for lung nodule detection on digital chest radiographs using similar subtraction images from different patients

International Nuclear Information System (INIS)

Aoki, Takatoshi; Oda, Nobuhiro; Yamashita, Yoshiko; Yamamoto, Keiji; Korogi, Yukunori

2012-01-01

Purpose: The purpose of this study is to evaluate the usefulness of a novel computerized method to select automatically the similar chest radiograph for image subtraction in the patients who have no previous chest radiographs and to assist the radiologists’ interpretation by presenting the “similar subtraction image” from different patients. Materials and methods: Institutional review board approval was obtained, and the requirement for informed patient consent was waived. A large database of approximately 15,000 normal chest radiographs was used for searching similar images of different patients. One hundred images of candidates were selected according to two clinical parameters and similarity of the lung field in the target image. We used the correlation value of chest region in the 100 images for searching the most similar image. The similar subtraction images were obtained by subtracting the similar image selected from the target image. Thirty cases with lung nodules and 30 cases without lung nodules were used for an observer performance test. Four attending radiologists and four radiology residents participated in this observer performance test. Results: The AUC for all radiologists increased significantly from 0.925 to 0.974 with the CAD (P = .004). When the computer output images were available, the average AUC for the residents was more improved (0.960 vs. 0.890) than for the attending radiologists (0.987 vs. 0.960). Conclusion: The novel computerized method for lung nodule detection using similar subtraction images from different patients would be useful to detect lung nodules on digital chest radiographs, especially for less experienced readers.

Rate control scheme for consistent video quality in scalable video codec.

Science.gov (United States)

Seo, Chan-Won; Han, Jong-Ki; Nguyen, Truong Q

2011-08-01

Multimedia data delivered to mobile devices over wireless channels or the Internet are complicated by bandwidth fluctuation and the variety of mobile devices. Scalable video coding has been developed as an extension of H.264/AVC to solve this problem. Since scalable video codec provides various scalabilities to adapt the bitstream for the channel conditions and terminal types, scalable codec is one of the useful codecs for wired or wireless multimedia communication systems, such as IPTV and streaming services. In such scalable multimedia communication systems, video quality fluctuation degrades the visual perception significantly. It is important to efficiently use the target bits in order to maintain a consistent video quality or achieve a small distortion variation throughout the whole video sequence. The scheme proposed in this paper provides a useful function to control video quality in applications supporting scalability, whereas conventional schemes have been proposed to control video quality in the H.264 and MPEG-4 systems. The proposed algorithm decides the quantization parameter of the enhancement layer to maintain a consistent video quality throughout the entire sequence. The video quality of the enhancement layer is controlled based on a closed-form formula which utilizes the residual data and quantization error of the base layer. The simulation results show that the proposed algorithm controls the frame quality of the enhancement layer in a simple operation, where the parameter decision algorithm is applied to each frame.

Pollen Bearing Honey Bee Detection in Hive Entrance Video Recorded by Remote Embedded System for Pollination Monitoring

Science.gov (United States)

Babic, Z.; Pilipovic, R.; Risojevic, V.; Mirjanic, G.

2016-06-01

Honey bees have crucial role in pollination across the world. This paper presents a simple, non-invasive, system for pollen bearing honey bee detection in surveillance video obtained at the entrance of a hive. The proposed system can be used as a part of a more complex system for tracking and counting of honey bees with remote pollination monitoring as a final goal. The proposed method is executed in real time on embedded systems co-located with a hive. Background subtraction, color segmentation and morphology methods are used for segmentation of honey bees. Classification in two classes, pollen bearing honey bees and honey bees that do not have pollen load, is performed using nearest mean classifier, with a simple descriptor consisting of color variance and eccentricity features. On in-house data set we achieved correct classification rate of 88.7% with 50 training images per class. We show that the obtained classification results are not far behind from the results of state-of-the-art image classification methods. That favors the proposed method, particularly having in mind that real time video transmission to remote high performance computing workstation is still an issue, and transfer of obtained parameters of pollination process is much easier.

Part Two: Learning Science Through Digital Video: Student Views on Watching and Creating Videos

Science.gov (United States)

Wade, P.; Courtney, A. R.

2014-12-01

The use of digital video for science education has become common with the wide availability of video imagery. This study continues research into aspects of using digital video as a primary teaching tool to enhance student learning in undergraduate science courses. Two survey instruments were administered to undergraduate non-science majors. Survey One focused on: a) What science is being learned from watching science videos such as a "YouTube" clip of a volcanic eruption or an informational video on geologic time and b) What are student preferences with regard to their learning (e.g. using video versus traditional modes of delivery)? Survey Two addressed students' perspectives on the storytelling aspect of the video with respect to: a) sustaining interest, b) providing science information, c) style of video and d) quality of the video. Undergraduate non-science majors were the primary focus group in this study. Students were asked to view video segments and respond to a survey focused on what they learned from the segments. The storytelling aspect of each video was also addressed by students. Students watched 15-20 shorter (3-15 minute science videos) created within the last four years. Initial results of this research support that shorter video segments were preferred and the storytelling quality of each video related to student learning.

Temporal digital subtraction radiography with a personal computer digital workstation

International Nuclear Information System (INIS)

Kircos, L.; Holt, W.; Khademi, J.

1990-01-01

Technique have been developed and implemented on a personal computer (PC)-based digital workstation to accomplish temporal digital subtraction radiography (TDSR). TDSR is useful in recording radiologic change over time. Thus, this technique is useful not only for monitoring chronic disease processes but also for monitoring the temporal course of interventional therapies. A PC-based digital workstation was developed on a PC386 platform with add-in hardware and software. Image acquisition, storage, and processing was accomplished using 512 x 512 x 8- or 12-bit frame grabber. Software and hardware were developed to accomplish image orientation, registration, gray scale compensation, subtraction, and enhancement. Temporal radiographs of the jaws were made in a fixed and reproducible orientation between the x-ray source and image receptor enabling TDSR. Temporal changes secondary to chronic periodontal disease, osseointegration of endosseous implants, and wound healing were demonstrated. Use of TDSR for chest imaging was also demonstrated with identification of small, subtle focal masses that were not apparent with routine viewing. The large amount of radiologic information in images of the jaws and chest may obfuscate subtle changes that TDSR seems to identify. TDSR appears to be useful as a tool to record temporal and subtle changes in radiologic images

77 FR 48102 - Closed Captioning and Video Description of Video Programming

Science.gov (United States)

2012-08-13

... Captioning and Video Description of Video Programming AGENCY: Federal Communications Commission. [[Page 48103... show that providing captions on their programming would be economically burdensome. DATES: Effective...) establishing requirements for closed captioning on video programming to ensure access by persons with hearing...

Low-complexity JPEG-based progressive video codec for wireless video transmission

DEFF Research Database (Denmark)

Ukhanova, Ann; Forchhammer, Søren

2010-01-01

This paper discusses the question of video codec enhancement for wireless video transmission of high definition video data taking into account constraints on memory and complexity. Starting from parameter adjustment for JPEG2000 compression algorithm used for wireless transmission and achieving...

In vivo optical imaging of amblyopia: Digital subtraction autofluorescence and split-spectrum amplitude-decorrelation angiography.

Science.gov (United States)

Guo, Lei; Tao, Jun; Xia, Fan; Yang, Zhi; Ma, Xiaoli; Hua, Rui

2016-09-01

Amblyopia is a visual impairment that is attributed to either abnormal binocular interactions or visual deprivation. The retina and choroids have been shown to be involved in the development of amblyopia. The purpose of this study was to investigate the retinal and choroidal microstructural abnormalities of amblyopia using digital subtraction autofluorescence and split-spectrum amplitude-decorrelation angiography (SSADA) approaches. This prospective study included 44 eyes of 22 patients with unilateral amblyopia. All patients who received indirect ophthalmoscopy, combined depth imaging spectral domain optical coherence tomography (OCT), SSADA-OCT, and macular blue light (BL-) and near-infrared (NIR-) autofluorescences underwent pupil dilation. The subfoveal choroidal thickness (SFCT) was measured. BL- and NIR-autofluorescences were determined for all patients and used to generate subtraction images with ImageJ software. The superficial, deep layers of the retina, and inner choroid layer were required for SSADA-OCT. For the normal eyes, a regularly increasing signal was observed in the central macula based on the subtraction images. In contrast, a decreased signal for the central patch or a reduced peak was detected in 16 of 22 amblyopic eyes (72.7%). The mean SFCT of the amblyopic eyes was greater than that of the fellow normal eyes (399.25 ± 4.944 µm vs. 280.58 ± 6.491 µm, respectively, P autofluorescence. The mechanistic relationship of a thicker choroid and choroidal capillary atrophy with amblyopia remains to be described. The digital subtraction image confirmed the changes in the microstructure of the amblyopic retina as a supplementary approach to detect the progression of amblyopia. Lasers Surg. Med. 48:660-667, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The Pedestrian Detection Method Using an Extension Background Subtraction about the Driving Safety Support Systems

Science.gov (United States)

Muranaka, Noriaki; Date, Kei; Tokumaru, Masataka; Imanishi, Shigeru

In recent years, the traffic accident occurs frequently with explosion of traffic density. Therefore, we think that the safe and comfortable transportation system to defend the pedestrian who is the traffic weak is necessary. First, we detect and recognize the pedestrian (the crossing person) by the image processing. Next, we inform all the drivers of the right or left turn that the pedestrian exists by the sound and the image and so on. By prompting a driver to do safe driving in this way, the accident to the pedestrian can decrease. In this paper, we are using a background subtraction method for the movement detection of the movement object. In the background subtraction method, the update method in the background was important, and as for the conventional way, the threshold values of the subtraction processing and background update were identical. That is, the mixing rate of the input image and the background image of the background update was a fixation value, and the fine tuning which corresponded to the environment change of the weather was difficult. Therefore, we propose the update method of the background image that the estimated mistake is difficult to be amplified. We experiment and examines in the comparison about five cases of sunshine, cloudy, evening, rain, sunlight change, except night. This technique can set separately the threshold values of the subtraction processing and background update processing which suited the environmental condition of the weather and so on. Therefore, the fine tuning becomes possible freely in the mixing rate of the input image and the background image of the background update. Because the setting of the parameter which suited an environmental condition becomes important to minimize mistaking percentage, we examine about the setting of a parameter.

Infinity subtraction in a quantum field theory of charges and monopoles

International Nuclear Information System (INIS)

Panagiotakopoulos, C.

1982-03-01

Subtraction of ultraviolet infinities in Zwanziger's local quantum field theory of charges and monopoles is described. It involves an infinite number of graphs. The whole programme rests on the assumption that the infinite summations involved do not give rise to pathological situations and the Ward identities are satisfied even after the string cancellations. The resulting finite theory is Lorentz invariant. (author)

Digital subtraction angiography and intraarterial contrast medium injection for coronary examinations

Energy Technology Data Exchange (ETDEWEB)

Tobio, R; Kallmeyer, C; Castello, J

1985-01-01

Digital subtraction angiography (DSA) is an established method of vasography, most extensively used as i.v. DSA. Intraarterial injection, however, applying selective or non-selective contrast medium injection, seems to be at least as important a technique although it has not yet met with corresponding interest. The article explains advantages of the technique for angiographic examinations, in particular of coronary angiography.

Effective Educational Videos: Principles and Guidelines for Maximizing Student Learning from Video Content

Science.gov (United States)

Brame, Cynthia J.

2016-01-01

Educational videos have become an important part of higher education, providing an important content-delivery tool in many flipped, blended, and online classes. Effective use of video as an educational tool is enhanced when instructors consider three elements: how to manage cognitive load of the video; how to maximize student engagement with the video; and how to promote active learning from the video. This essay reviews literature relevant to each of these principles and suggests practical ways instructors can use these principles when using video as an educational tool. PMID:27789532

Performance Analysis of Video Transmission Using Sequential Distortion Minimization Method for Digital Video Broadcasting Terrestrial

Directory of Open Access Journals (Sweden)

Novita Astin

2016-12-01

Full Text Available This paper presents about the transmission of Digital Video Broadcasting system with streaming video resolution 640x480 on different IQ rate and modulation. In the video transmission, distortion often occurs, so the received video has bad quality. Key frames selection algorithm is flexibel on a change of video, but on these methods, the temporal information of a video sequence is omitted. To minimize distortion between the original video and received video, we aimed at adding methodology using sequential distortion minimization algorithm. Its aim was to create a new video, better than original video without significant loss of content between the original video and received video, fixed sequentially. The reliability of video transmission was observed based on a constellation diagram, with the best result on IQ rate 2 Mhz and modulation 8 QAM. The best video transmission was also investigated using SEDIM (Sequential Distortion Minimization Method and without SEDIM. The experimental result showed that the PSNR (Peak Signal to Noise Ratio average of video transmission using SEDIM was an increase from 19,855 dB to 48,386 dB and SSIM (Structural Similarity average increase 10,49%. The experimental results and comparison of proposed method obtained a good performance. USRP board was used as RF front-end on 2,2 GHz.

Digital subtraction angiography in 105 living renal transplant donors

International Nuclear Information System (INIS)

Suh, Ho Jong; Oh, Kyung Seung; Kim, So Sun; Huh, Jin Do; Kim, Ho Joon; Chun, Byung Hee; Joh, Young Duck

1989-01-01

In order to analyze the number and length of the renal arteries and to evaluate abnormalities of the renal parenchyma and vessel, digital subtraction angiogram images of 105 potential renal donors (45 men and 60 women aged 17-66 years) were studied retrospectively. For the entire series, 31 donors had multiple renal arteries on one side (15 on the left, 11 on the right) and 5 donors on the both sides. 89 donors were family related either parents or siblings of recipients. The estimation of the length of the renal artery was based on the mean height of the second lumbar vertebral body (L2). The right renal artery is significant longer than on the left and measured more than the height of L2 vertebral body in 84 cases on the right and 60 cases on the left. Twenty two donors underwent right nephrectomy due to presence of multiple renal arteries on the left (N=14), proximal bifurcation of left main renal artery (N=3), and young females in reproductive age (N=5). Unexpected abnormalities found with angiogram were seen in 7 cases and they include renal artery stenosis (N=2), renal cysts (N=4) and focal infarction (N=1). In cases of the renal cysts and focal infarction, there were no serious complications related to the abnormalities. It is conclude that intra-arterial digital subtraction angiography is safe and efficient method to image renal anatomy of the potential renal donors

High Definition Video Streaming Using H.264 Video Compression

OpenAIRE

Bechqito, Yassine

2009-01-01

This thesis presents high definition video streaming using H.264 codec implementation. The experiment carried out in this study was done for an offline streaming video but a model for live high definition streaming is introduced, as well. Prior to the actual experiment, this study describes digital media streaming. Also, the different technologies involved in video streaming are covered. These include streaming architecture and a brief overview on H.264 codec as well as high definition t...

Online video examination

DEFF Research Database (Denmark)

Qvist, Palle

have large influence on their own teaching, learning and curriculum. The programme offers streamed videos in combination with other learning resources. It is a concept which offers video as pure presentation - video lectures - but also as an instructional tool which gives the students the possibility...... to construct their knowledge, collaboration and communication. In its first years the programme has used Skype video communication for collaboration and communication within and between groups, group members and their facilitators. Also exams have been mediated with the help of Skype and have for all students......, examiners and external examiners been a challenge and opportunity and has brought new knowledge and experience. This paper brings results from a questionnaire focusing on how the students experience the video examination....

SWCD: a sliding window and self-regulated learning-based background updating method for change detection in videos

Science.gov (United States)

Işık, Şahin; Özkan, Kemal; Günal, Serkan; Gerek, Ömer Nezih

2018-03-01

Change detection with background subtraction process remains to be an unresolved issue and attracts research interest due to challenges encountered on static and dynamic scenes. The key challenge is about how to update dynamically changing backgrounds from frames with an adaptive and self-regulated feedback mechanism. In order to achieve this, we present an effective change detection algorithm for pixelwise changes. A sliding window approach combined with dynamic control of update parameters is introduced for updating background frames, which we called sliding window-based change detection. Comprehensive experiments on related test videos show that the integrated algorithm yields good objective and subjective performance by overcoming illumination variations, camera jitters, and intermittent object motions. It is argued that the obtained method makes a fair alternative in most types of foreground extraction scenarios; unlike case-specific methods, which normally fail for their nonconsidered scenarios.

Innovative Solution to Video Enhancement

Science.gov (United States)

2001-01-01

Through a licensing agreement, Intergraph Government Solutions adapted a technology originally developed at NASA's Marshall Space Flight Center for enhanced video imaging by developing its Video Analyst(TM) System. Marshall's scientists developed the Video Image Stabilization and Registration (VISAR) technology to help FBI agents analyze video footage of the deadly 1996 Olympic Summer Games bombing in Atlanta, Georgia. VISAR technology enhanced nighttime videotapes made with hand-held camcorders, revealing important details about the explosion. Intergraph's Video Analyst System is a simple, effective, and affordable tool for video enhancement and analysis. The benefits associated with the Video Analyst System include support of full-resolution digital video, frame-by-frame analysis, and the ability to store analog video in digital format. Up to 12 hours of digital video can be stored and maintained for reliable footage analysis. The system also includes state-of-the-art features such as stabilization, image enhancement, and convolution to help improve the visibility of subjects in the video without altering underlying footage. Adaptable to many uses, Intergraph#s Video Analyst System meets the stringent demands of the law enforcement industry in the areas of surveillance, crime scene footage, sting operations, and dash-mounted video cameras.

Clinical use of the ABO-Scoring Index: reliability and subtraction frequency.

Science.gov (United States)

Lieber, William S; Carlson, Sean K; Baumrind, Sheldon; Poulton, Donald R

2003-10-01

This study tested the reliability and subtraction frequency of the study model-scoring system of the American Board of Orthodontists (ABO). We used a sample of 36 posttreatment study models that were selected randomly from six different orthodontic offices. Intrajudge and interjudge reliability was calculated using nonparametric statistics (Spearman rank coefficient, Wilcoxon, Kruskal-Wallis, and Mann-Whitney tests). We found differences ranging from 3 to 6 subtraction points (total score) for intrajudge scoring between two sessions. For overall total ABO score, the average correlation was .77. Intrajudge correlation was greatest for occlusal relationships and least for interproximal contacts. Interjudge correlation for ABO score averaged r = .85. Correlation was greatest for buccolingual inclination and least for overjet. The data show that some judges, on average, were much more lenient than others and that this resulted in a range of total scores between 19.7 and 27.5. Most of the deductions were found in the buccal segments and most were related to the second molars. We present these findings in the context of clinicians preparing for the ABO phase III examination and for orthodontists in their ongoing evaluation of clinical results.

Identification of proteins involved in the functioning of Riftia pachyptila symbiosis by Subtractive Suppression Hybridization.

Science.gov (United States)

Sanchez, Sophie; Hourdez, Stéphane; Lallier, François H

2007-09-24

Since its discovery around deep sea hydrothermal vents of the Galapagos Rift about 30 years ago, the chemoautotrophic symbiosis between the vestimentiferan tubeworm Riftia pachyptila and its symbiotic sulfide-oxidizing gamma-proteobacteria has been extensively studied. However, studies on the tubeworm host were essentially targeted, biochemical approaches. We decided to use a global molecular approach to identify new proteins involved in metabolite exchanges and assimilation by the host. We used a Subtractive Suppression Hybridization approach (SSH) in an unusual way, by comparing pairs of tissues from a single individual. We chose to identify the sequences preferentially expressed in the branchial plume tissue (the only organ in contact with the sea water) and in the trophosome (the organ housing the symbiotic bacteria) using the body wall as a reference tissue because it is supposedly not involved in metabolite exchanges in this species. We produced four cDNA libraries: i) body wall-subtracted branchial plume library (BR-BW), ii) and its reverse library, branchial plume-subtracted body wall library (BW-BR), iii) body wall-subtracted trophosome library (TR-BW), iv) and its reverse library, trophosome-subtracted body wall library (BW-TR). For each library, we sequenced about 200 clones resulting in 45 different sequences on average in each library (58 and 59 cDNAs for BR-BW and TR-BW libraries respectively). Overall, half of the contigs matched records found in the databases with good E-values. After quantitative PCR analysis, it resulted that 16S, Major Vault Protein, carbonic anhydrase (RpCAbr), cathepsin and chitinase precursor transcripts were highly represented in the branchial plume tissue compared to the trophosome and the body wall tissues, whereas carbonic anhydrase (RpCAtr), myohemerythrin, a putative T-Cell receptor and one non identified transcript were highly specific of the trophosome tissue. Quantitative PCR analyses were congruent with our libraries

Identification of proteins involved in the functioning of Riftia pachyptila symbiosis by Subtractive Suppression Hybridization

Directory of Open Access Journals (Sweden)

Lallier François H

2007-09-01

Full Text Available Abstract Background Since its discovery around deep sea hydrothermal vents of the Galapagos Rift about 30 years ago, the chemoautotrophic symbiosis between the vestimentiferan tubeworm Riftia pachyptila and its symbiotic sulfide-oxidizing γ-proteobacteria has been extensively studied. However, studies on the tubeworm host were essentially targeted, biochemical approaches. We decided to use a global molecular approach to identify new proteins involved in metabolite exchanges and assimilation by the host. We used a Subtractive Suppression Hybridization approach (SSH in an unusual way, by comparing pairs of tissues from a single individual. We chose to identify the sequences preferentially expressed in the branchial plume tissue (the only organ in contact with the sea water and in the trophosome (the organ housing the symbiotic bacteria using the body wall as a reference tissue because it is supposedly not involved in metabolite exchanges in this species. Results We produced four cDNA libraries: i body wall-subtracted branchial plume library (BR-BW, ii and its reverse library, branchial plume-subtracted body wall library (BW-BR, iii body wall-subtracted trophosome library (TR-BW, iv and its reverse library, trophosome-subtracted body wall library (BW-TR. For each library, we sequenced about 200 clones resulting in 45 different sequences on average in each library (58 and 59 cDNAs for BR-BW and TR-BW libraries respectively. Overall, half of the contigs matched records found in the databases with good E-values. After quantitative PCR analysis, it resulted that 16S, Major Vault Protein, carbonic anhydrase (RpCAbr, cathepsin and chitinase precursor transcripts were highly represented in the branchial plume tissue compared to the trophosome and the body wall tissues, whereas carbonic anhydrase (RpCAtr, myohemerythrin, a putative T-Cell receptor and one non identified transcript were highly specific of the trophosome tissue. Conclusion Quantitative PCR

Clinical application of digital subtraction angiography for arterial portography

International Nuclear Information System (INIS)

Ohtomo, Kuni; Furui, Shigeru; Yashiro, Naofumi; Itai, Yuji; Iio, Masahiro

1983-01-01

Intra-arterial digital subtraction portography(IADSP) after superior mesenteric artery injection was described. A total dose of 15 ml to 20 ml of 76% contrast medium was injected at a rate of 5 ml/sec in 14 cases (9 hepatomas, 2 metastatic liver tumors, 2 cavernous hemangiomas, 1 liver cirrhosis). In 11 cases, portal venous system was clearly demonstrated by IADSP. In 8 hepatomas tumor thrombus of portal venous system could be ruled out by IADSP and embolization therapy was carried out. IADSP was also useful for demonstrating esophageal varix and splenorenal shunt. (author)

Industrial-Strength Streaming Video.

Science.gov (United States)

Avgerakis, George; Waring, Becky

1997-01-01

Corporate training, financial services, entertainment, and education are among the top applications for streaming video servers, which send video to the desktop without downloading the whole file to the hard disk, saving time and eliminating copyrights questions. Examines streaming video technology, lists ten tips for better net video, and ranks…

Digital subtraction angiography in head and neck radiology

International Nuclear Information System (INIS)

Carmody, R.F.; Seeger, J.F.; Smith, R.L.; Horsley, W.W.; Miller, R.W.

1984-01-01

Intravenous digital subtraction angiography (IVDSA) was used to evaluate 44 patients with suspected otolaryngologic abnormalities. Sixteen had IVDSA for pulsatile tinnitus or suspected glomus tumor of the petrous bone. Nine patients were evaluated because of pulsatile neck masses, and 12 others had suspected tumors of the neck, face, and paranasal sinuses. Seven had IVDSA following head and neck trauma. The technique of examination is described. The current indications of IVDSA in head and neck radiology are discussed. It is concluded that IVDSA is a suitable substitute for conventional angiography for many otolaryngologic conditions and, because of its safety, can be used more liberally. (orig.)

Video modeling by experts with video feedback to enhance gymnastics skills.

Science.gov (United States)

Boyer, Eva; Miltenberger, Raymond G; Batsche, Catherine; Fogel, Victoria

2009-01-01

The effects of combining video modeling by experts with video feedback were analyzed with 4 female competitive gymnasts (7 to 10 years old) in a multiple baseline design across behaviors. During the intervention, after the gymnast performed a specific gymnastics skill, she viewed a video segment showing an expert gymnast performing the same skill and then viewed a video replay of her own performance of the skill. The results showed that all gymnasts demonstrated improved performance across three gymnastics skills following exposure to the intervention.

A Novel Quantum Video Steganography Protocol with Large Payload Based on MCQI Quantum Video

Science.gov (United States)

Qu, Zhiguo; Chen, Siyi; Ji, Sai

2017-11-01

As one of important multimedia forms in quantum network, quantum video attracts more and more attention of experts and scholars in the world. A secure quantum video steganography protocol with large payload based on the video strip encoding method called as MCQI (Multi-Channel Quantum Images) is proposed in this paper. The new protocol randomly embeds the secret information with the form of quantum video into quantum carrier video on the basis of unique features of video frames. It exploits to embed quantum video as secret information for covert communication. As a result, its capacity are greatly expanded compared with the previous quantum steganography achievements. Meanwhile, the new protocol also achieves good security and imperceptibility by virtue of the randomization of embedding positions and efficient use of redundant frames. Furthermore, the receiver enables to extract secret information from stego video without retaining the original carrier video, and restore the original quantum video as a follow. The simulation and experiment results prove that the algorithm not only has good imperceptibility, high security, but also has large payload.

Confirmation of T1-Bright Vein of Galen Aneurysm Spontaneous Thrombosis by Subtraction Magnetic Resonance Venography: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Irfan, M.; Lohman, B.; McKinney, A.M. (Dept. of Radiology/Neuroradiology, Univ. of Minnesota, Minneapolis, Minnesota (United States))

2009-08-15

Spontaneous thrombosis of a vein of Galen aneurysmal malformation (VOGM) is rare. We describe a 2-month-old patient with a patent VOGM and hydrocephalus, also confirmed patent at 6 months, but with subsequent lack of filling on pre-embolization catheter digital subtraction angiography (DSA) at 9 months' age. Due to the presence of T1- and T2-bright signal, noncontrast T1-weighted images (T1WI), T2-weighted images (T2WI), two-dimensional (2D) time-of-flight (TOF) magnetic resonance venography (MRV), and postcontrast T1WI were ambiguous for patency. However, subtracting the pre- from the postcontrast MRV images confirmed closure compared to subtracted images at 6 months' age. The factors contributing to thrombosis were likely a combination of a disproportionately small straight sinus, ventriculostomy, and contrast medium from DSA.

Intra-arterial digital subtraction angiography in the diagnosis of insulinomas

International Nuclear Information System (INIS)

Moulopoulou, A.; Vlahos, L.

1988-01-01

Two cases of surgically proved benign insulinoma of the pancreas were correctly localized with intra-arterial digital subtraction angiography (IA-DSA) of the coeliac and the superior mesenteric artery, while the respective dynamic computed tomography (CT) and ultrasound (US) examinations were negative. In a third case of organic hyperinsulinism, IA-DSA, CT and US suggested a pancreatic islet-cell tumor, but the histological examination of the resected suspicious area was that of focal hyperplasia. 17 refs.; 3 figs

Quantifying the relative contributions of divisive and subtractive feedback to rhythm generation.

Directory of Open Access Journals (Sweden)

Joël Tabak

2011-04-01

Full Text Available Biological systems are characterized by a high number of interacting components. Determining the role of each component is difficult, addressed here in the context of biological oscillations. Rhythmic behavior can result from the interplay of positive feedback that promotes bistability between high and low activity, and slow negative feedback that switches the system between the high and low activity states. Many biological oscillators include two types of negative feedback processes: divisive (decreases the gain of the positive feedback loop and subtractive (increases the input threshold that both contribute to slowly move the system between the high- and low-activity states. Can we determine the relative contribution of each type of negative feedback process to the rhythmic activity? Does one dominate? Do they control the active and silent phase equally? To answer these questions we use a neural network model with excitatory coupling, regulated by synaptic depression (divisive and cellular adaptation (subtractive feedback. We first attempt to apply standard experimental methodologies: either passive observation to correlate the variations of a variable of interest to system behavior, or deletion of a component to establish whether a component is critical for the system. We find that these two strategies can lead to contradictory conclusions, and at best their interpretive power is limited. We instead develop a computational measure of the contribution of a process, by evaluating the sensitivity of the active (high activity and silent (low activity phase durations to the time constant of the process. The measure shows that both processes control the active phase, in proportion to their speed and relative weight. However, only the subtractive process plays a major role in setting the duration of the silent phase. This computational method can be used to analyze the role of negative feedback processes in a wide range of biological rhythms.

Social Properties of Mobile Video

Science.gov (United States)

Mitchell, April Slayden; O'Hara, Kenton; Vorbau, Alex

Mobile video is now an everyday possibility with a wide array of commercially available devices, services, and content. These new technologies have created dramatic shifts in the way video-based media can be produced, consumed, and delivered by people beyond the familiar behaviors associated with fixed TV and video technologies. Such technology revolutions change the way users behave and change their expectations in regards to their mobile video experiences. Building upon earlier studies of mobile video, this paper reports on a study using diary techniques and ethnographic interviews to better understand how people are using commercially available mobile video technologies in their everyday lives. Drawing on reported episodes of mobile video behavior, the study identifies the social motivations and values underpinning these behaviors that help characterize mobile video consumption beyond the simplistic notion of viewing video only to kill time. This paper also discusses the significance of user-generated content and the usage of video in social communities through the description of two mobile video technology services that allow users to create and share content. Implications for adoption and design of mobile video technologies and services are discussed as well.

Video Podcasts

DEFF Research Database (Denmark)

Nortvig, Anne Mette; Sørensen, Birgitte Holm

2016-01-01

This project’s aim was to support and facilitate master’s students’ preparation and collaboration by making video podcasts of short lectures available on YouTube prior to students’ first face-to-face seminar. The empirical material stems from group interviews, from statistical data created through...... YouTube analytics and from surveys answered by students after the seminar. The project sought to explore how video podcasts support learning and reflection online and how students use and reflect on the integration of online activities in the videos. Findings showed that students engaged actively...

Video games.

Science.gov (United States)

Funk, Jeanne B

2005-06-01

The video game industry insists that it is doing everything possible to provide information about the content of games so that parents can make informed choices; however, surveys indicate that ratings may not reflect consumer views of the nature of the content. This article describes some of the currently popular video games, as well as developments that are on the horizon, and discusses the status of research on the positive and negative impacts of playing video games. Recommendations are made to help parents ensure that children play games that are consistent with their values.

A Monte Carlo simulation study of an improved K-edge log-subtraction X-ray imaging using a photon counting CdTe detector

Energy Technology Data Exchange (ETDEWEB)

Lee, Youngjin, E-mail: radioyoungj@gmail.com [Department of Radiological Science, Eulji University, 553, Sanseong-daero, Sujeong-gu, Seongnam-si, Gyeonggi-do (Korea, Republic of); Lee, Amy Candy [Department of Mathematics and Statistics, McGill University (Canada); Kim, Hee-Joung [Department of Radiological Science and Radiation Convergence Engineering, Yonsei University (Korea, Republic of)

2016-09-11

Recently, significant effort has been spent on the development of photons counting detector (PCD) based on a CdTe for applications in X-ray imaging system. The motivation of developing PCDs is higher image quality. Especially, the K-edge subtraction (KES) imaging technique using a PCD is able to improve image quality and useful for increasing the contrast resolution of a target material by utilizing contrast agent. Based on above-mentioned technique, we presented an idea for an improved K-edge log-subtraction (KELS) imaging technique. The KELS imaging technique based on the PCDs can be realized by using different subtraction energy width of the energy window. In this study, the effects of the KELS imaging technique and subtraction energy width of the energy window was investigated with respect to the contrast, standard deviation, and CNR with a Monte Carlo simulation. We simulated the PCD X-ray imaging system based on a CdTe and polymethylmethacrylate (PMMA) phantom which consists of the various iodine contrast agents. To acquired KELS images, images of the phantom using above and below the iodine contrast agent K-edge absorption energy (33.2 keV) have been acquired at different energy range. According to the results, the contrast and standard deviation were decreased, when subtraction energy width of the energy window is increased. Also, the CNR using a KELS imaging technique is higher than that of the images acquired by using whole energy range. Especially, the maximum differences of CNR between whole energy range and KELS images using a 1, 2, and 3 mm diameter iodine contrast agent were acquired 11.33, 8.73, and 8.29 times, respectively. Additionally, the optimum subtraction energy width of the energy window can be acquired at 5, 4, and 3 keV for the 1, 2, and 3 mm diameter iodine contrast agent, respectively. In conclusion, we successfully established an improved KELS imaging technique and optimized subtraction energy width of the energy window, and based on

Characterization of unknown genetic modifications using high throughput sequencing and computational subtraction

Directory of Open Access Journals (Sweden)

Butenko Melinka A

2009-10-01

Full Text Available Abstract Background When generating a genetically modified organism (GMO, the primary goal is to give a target organism one or several novel traits by using biotechnology techniques. A GMO will differ from its parental strain in that its pool of transcripts will be altered. Currently, there are no methods that are reliably able to determine if an organism has been genetically altered if the nature of the modification is unknown. Results We show that the concept of computational subtraction can be used to identify transgenic cDNA sequences from genetically modified plants. Our datasets include 454-type sequences from a transgenic line of Arabidopsis thaliana and published EST datasets from commercially relevant species (rice and papaya. Conclusion We believe that computational subtraction represents a powerful new strategy for determining if an organism has been genetically modified as well as to define the nature of the modification. Fewer assumptions have to be made compared to methods currently in use and this is an advantage particularly when working with unknown GMOs.

Video steganography based on bit-plane decomposition of wavelet-transformed video

Science.gov (United States)

Noda, Hideki; Furuta, Tomofumi; Niimi, Michiharu; Kawaguchi, Eiji

2004-06-01

This paper presents a steganography method using lossy compressed video which provides a natural way to send a large amount of secret data. The proposed method is based on wavelet compression for video data and bit-plane complexity segmentation (BPCS) steganography. BPCS steganography makes use of bit-plane decomposition and the characteristics of the human vision system, where noise-like regions in bit-planes of a dummy image are replaced with secret data without deteriorating image quality. In wavelet-based video compression methods such as 3-D set partitioning in hierarchical trees (SPIHT) algorithm and Motion-JPEG2000, wavelet coefficients in discrete wavelet transformed video are quantized into a bit-plane structure and therefore BPCS steganography can be applied in the wavelet domain. 3-D SPIHT-BPCS steganography and Motion-JPEG2000-BPCS steganography are presented and tested, which are the integration of 3-D SPIHT video coding and BPCS steganography, and that of Motion-JPEG2000 and BPCS, respectively. Experimental results show that 3-D SPIHT-BPCS is superior to Motion-JPEG2000-BPCS with regard to embedding performance. In 3-D SPIHT-BPCS steganography, embedding rates of around 28% of the compressed video size are achieved for twelve bit representation of wavelet coefficients with no noticeable degradation in video quality.

Statistical Analysis of Video Frame Size Distribution Originating from Scalable Video Codec (SVC

Directory of Open Access Journals (Sweden)

Sima Ahmadpour

2017-01-01

Full Text Available Designing an effective and high performance network requires an accurate characterization and modeling of network traffic. The modeling of video frame sizes is normally applied in simulation studies and mathematical analysis and generating streams for testing and compliance purposes. Besides, video traffic assumed as a major source of multimedia traffic in future heterogeneous network. Therefore, the statistical distribution of video data can be used as the inputs for performance modeling of networks. The finding of this paper comprises the theoretical definition of distribution which seems to be relevant to the video trace in terms of its statistical properties and finds the best distribution using both the graphical method and the hypothesis test. The data set used in this article consists of layered video traces generating from Scalable Video Codec (SVC video compression technique of three different movies.

Robust Adaptable Video Copy Detection

DEFF Research Database (Denmark)

Assent, Ira; Kremer, Hardy

2009-01-01

in contrast). Our query processing combines filtering and indexing structures for efficient multistep computation of video copies under this model. We show that our model successfully identifies altered video copies and does so more reliably than existing models.......Video copy detection should be capable of identifying video copies subject to alterations e.g. in video contrast or frame rates. We propose a video copy detection scheme that allows for adaptable detection of videos that are altered temporally (e.g. frame rate change) and/or visually (e.g. change...

Development of P4140 video data wall projector; Video data wall projector

Energy Technology Data Exchange (ETDEWEB)

Watanabe, H.; Inoue, H. [Toshiba Corp., Tokyo (Japan)

1998-12-01

The P4140 is a 3 cathode-ray tube (CRT) video data wall projector for super video graphics array (SVGA) signals. It is used as an image display unit, providing a large screen when several sets are put together. A high-quality picture has been realized by higher resolution and improved color uniformity technology. A new convergence adjustment system has also been developed through the optimal combination of digital and analog technologies. This video data wall installation has been greatly enhanced by the automation of cubes and cube performance settings. The P4140 video data wall projector can be used for displaying not only data but video as well. (author)

Signal-to-noise ratio measurement in parallel MRI with subtraction mapping and consecutive methods

International Nuclear Information System (INIS)

Imai, Hiroshi; Miyati, Tosiaki; Ogura, Akio; Doi, Tsukasa; Tsuchihashi, Toshio; Machida, Yoshio; Kobayashi, Masato; Shimizu, Kouzou; Kitou, Yoshihiro

2008-01-01

When measuring the signal-to-noise ratio (SNR) of an image the used parallel magnetic resonance imaging, it was confirmed that there was a problem in the application of past SNR measurement. With the method of measuring the noise from the background signal, SNR with parallel imaging was higher than that without parallel imaging. In the subtraction method (NEMA standard), which sets a wide region of interest, the white noise was not evaluated correctly although SNR was close to the theoretical value. We proposed two techniques because SNR in parallel imaging was not uniform according to inhomogeneity of the coil sensitivity distribution and geometry factor. Using the first method (subtraction mapping), two images were scanned with identical parameters. The SNR in each pixel divided the running mean (7 by 7 pixels in neighborhood) by standard deviation/√2 in the same region of interest. Using the second (consecutive) method, more than fifty consecutive scans of the uniform phantom were obtained with identical scan parameters. Then the SNR was calculated from the ratio of mean signal intensity to the standard deviation in each pixel on a series of images. Moreover, geometry factors were calculated from SNRs with and without parallel imaging. The SNR and geometry factor using parallel imaging in the subtraction mapping method agreed with those of the consecutive method. Both methods make it possible to obtain a more detailed determination of SNR in parallel imaging and to calculate the geometry factor. (author)

Advanced video coding systems

CERN Document Server

Gao, Wen

2015-01-01

This comprehensive and accessible text/reference presents an overview of the state of the art in video coding technology. Specifically, the book introduces the tools of the AVS2 standard, describing how AVS2 can help to achieve a significant improvement in coding efficiency for future video networks and applications by incorporating smarter coding tools such as scene video coding. Topics and features: introduces the basic concepts in video coding, and presents a short history of video coding technology and standards; reviews the coding framework, main coding tools, and syntax structure of AV

Intelligent video surveillance systems

CERN Document Server

Dufour, Jean-Yves

2012-01-01

Belonging to the wider academic field of computer vision, video analytics has aroused a phenomenal surge of interest since the current millennium. Video analytics is intended to solve the problem of the incapability of exploiting video streams in real time for the purpose of detection or anticipation. It involves analyzing the videos using algorithms that detect and track objects of interest over time and that indicate the presence of events or suspect behavior involving these objects.The aims of this book are to highlight the operational attempts of video analytics, to identify possi

Video Vectorization via Tetrahedral Remeshing.

Science.gov (United States)

Wang, Chuan; Zhu, Jie; Guo, Yanwen; Wang, Wenping

2017-02-09

We present a video vectorization method that generates a video in vector representation from an input video in raster representation. A vector-based video representation offers the benefits of vector graphics, such as compactness and scalability. The vector video we generate is represented by a simplified tetrahedral control mesh over the spatial-temporal video volume, with color attributes defined at the mesh vertices. We present novel techniques for simplification and subdivision of a tetrahedral mesh to achieve high simplification ratio while preserving features and ensuring color fidelity. From an input raster video, our method is capable of generating a compact video in vector representation that allows a faithful reconstruction with low reconstruction errors.

Low-latency video transmission over high-speed WPANs based on low-power video compression

DEFF Research Database (Denmark)

Belyaev, Evgeny; Turlikov, Andrey; Ukhanova, Ann

2010-01-01

This paper presents latency-constrained video transmission over high-speed wireless personal area networks (WPANs). Low-power video compression is proposed as an alternative to uncompressed video transmission. A video source rate control based on MINMAX quality criteria is introduced. Practical...

Video Self-Modeling

Science.gov (United States)

Buggey, Tom; Ogle, Lindsey

2012-01-01

Video self-modeling (VSM) first appeared on the psychology and education stage in the early 1970s. The practical applications of VSM were limited by lack of access to tools for editing video, which is necessary for almost all self-modeling videos. Thus, VSM remained in the research domain until the advent of camcorders and VCR/DVD players and,…

Video dosimetry: evaluation of X-radiation dose by video fluoroscopic image

International Nuclear Information System (INIS)

Nova, Joao Luiz Leocadio da; Lopes, Ricardo Tadeu

1996-01-01

A new methodology to evaluate the entrance surface dose on patients under radiodiagnosis is presented. A phantom is used in video fluoroscopic procedures in on line video signal system. The images are obtained from a Siemens Polymat 50 and are digitalized. The results show that the entrance surface dose can be obtained in real time from video imaging

NNLO jet cross sections by subtraction

Science.gov (United States)

Somogyi, G.; Bolzoni, P.; Trócsányi, Z.

2010-08-01

We report on the computation of a class of integrals that appear when integrating the so-called iterated singly-unresolved approximate cross section of the NNLO subtraction scheme of Refs. [G. Somogyi, Z. Trócsányi, and V. Del Duca, JHEP 06, 024 (2005), arXiv:hep-ph/0502226; G. Somogyi and Z. Trócsányi, (2006), arXiv:hep-ph/0609041; G. Somogyi, Z. Trócsányi, and V. Del Duca, JHEP 01, 070 (2007), arXiv:hep-ph/0609042; G. Somogyi and Z. Trócsányi, JHEP 01, 052 (2007), arXiv:hep-ph/0609043] over the factorised phase space of unresolved partons. The integrated approximate cross section itself can be written as the product of an insertion operator (in colour space) times the Born cross section. We give selected results for the insertion operator for processes with two and three hard partons in the final state.

Akademisk video

DEFF Research Database (Denmark)

Frølunde, Lisbeth

2017-01-01

Dette kapitel har fokus på metodiske problemstillinger, der opstår i forhold til at bruge (digital) video i forbindelse med forskningskommunikation, ikke mindst online. Video har længe været benyttet i forskningen til dataindsamling og forskningskommunikation. Med digitaliseringen og internettet ...

Statistically tuned Gaussian background subtraction technique for ...

Indian Academy of Sciences (India)

temporal median method and mixture of Gaussian model and performance evaluation ... to process the videos captured by unmanned aerial vehicle (UAV). ..... The output is obtained by simulation using MATLAB 2010 in a standalone PC with ...

Application of the singularity subtraction method for (d,p) reactions on light nuclei

International Nuclear Information System (INIS)

Borbely, I.

1974-01-01

It is shown that the method of subtraction the nearest singularity can be used successfully for data processing of (d,p) reactions. The data on the nuclear structure, thus obtained, can then be used for a more efficient study of the reaction mechanism with the use of traditional methods

The identification of genes specific to Prevotella intermedia and Prevotella nigrescens using genomic subtractive hybridization.

Science.gov (United States)

Masakiyo, Yoshiaki; Yoshida, Akihiro; Shintani, Yasuyuki; Takahashi, Yusuke; Ansai, Toshihiro; Takehara, Tadamichi

2010-06-01

Prevotella intermedia and Prevotella nigrescens, which are often isolated from periodontal sites, were once considered two different genotypes of P. intermedia. Although the genomic sequence of P. intermedia was determined recently, little is known about the genetic differences between P. intermedia and P. nigrescens. The subtractive hybridization technique is a powerful method for generating a set of DNA fragments differing between two closely related bacterial strains or species. We used subtractive hybridization to identify the DNA regions specific to P. intermedia ATCC 25611 and P. nigrescens ATCC 25261. Using this method, four P. intermedia ATCC 25611-specific and three P. nigrescens ATCC 25261-specific regions were determined. From the species-specific regions, insertion sequence (IS) elements were isolated for P. intermedia. IS elements play an important role in the pathogenicity of bacteria. For the P. intermedia-specific regions, the genes adenine-specific DNA-methyltransferase and 8-amino-7-oxononanoate synthase were isolated. The P. nigrescens-specific region contained a Flavobacterium psychrophilum SprA homologue, a cell-surface protein involved in gliding motility, Prevotella melaninogenica ATCC 25845 glutathione peroxide, and Porphyromonas gingivalis ATCC 33277 leucyl-tRNA synthetase. The results demonstrate that the subtractive hybridization technique was useful for distinguishing between the two closely related species. Furthermore, this technique will contribute to our understanding of the virulence of these species. 2009 Elsevier Ltd. All rights reserved.

VBR video traffic models

CERN Document Server

Tanwir, Savera

2014-01-01

There has been a phenomenal growth in video applications over the past few years. An accurate traffic model of Variable Bit Rate (VBR) video is necessary for performance evaluation of a network design and for generating synthetic traffic that can be used for benchmarking a network. A large number of models for VBR video traffic have been proposed in the literature for different types of video in the past 20 years. Here, the authors have classified and surveyed these models and have also evaluated the models for H.264 AVC and MVC encoded video and discussed their findings.

The reduction of motion artifacts in digital subtraction angiography by geometrical image transformation

International Nuclear Information System (INIS)

Fitzpatrick, J.M.; Pickens, D.R.; Mandava, V.R.; Grefenstette, J.J.

1988-01-01

In the diagnosis of arteriosclerosis, radio-opaque dye is injected into the interior of the arteries to make them visible. Because of its increased contrast sensitivity, digital subtraction angiography has the potential for providing diagnostic images of arteries with reduced dye volumes. In the conventional technique, a mask image, acquired before the introduction of the dye, is subtracted from the contrast image, acquired after the dye is introduced, to produce a difference image in which only the dye in the arteries is visible. The usefulness of this technique has been severely limited by the image degradation caused by patient motion during image acquisition. This motion produces artifacts in the difference image that obscure the arteries. One technique for dealing with the problem is to reduce the degradation by means of image registration. The registration is carried out by means of a geometrical transformation of the mask image before subtraction so that it is in registration with the contrast image. This paper describes a technique for determining an optimal transformation. The authors employ a one-to-one elastic mapping and the Jacobian of that mapping to produce a geometrical image transformation. They choose a parameterized class of such mappings and use a heuristic search algorithm to optimize the parameters to minimize the severity of the motion artifacts. To increase the speed of the optimization process they use a statistical image comparison technique that provides a quick approximate evaluation of each image transformation. They present the experimental results of the application of their registration system to mask-contrast pairs, for images acquired from a specially designed phantom, and for clinical images

Tracking of ball and players in beach volleyball videos.

Directory of Open Access Journals (Sweden)

Gabriel Gomez

Full Text Available This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points.

Tracking of Ball and Players in Beach Volleyball Videos

Science.gov (United States)

Gomez, Gabriel; Herrera López, Patricia; Link, Daniel; Eskofier, Bjoern

2014-01-01

This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points. PMID:25426936

Video Games as a Multifaceted Medium: A Review of Quantitative Social Science Research on Video Games and a Typology of Video Game Research Approaches

Directory of Open Access Journals (Sweden)

James D. Ivory

2013-01-01

Full Text Available Although there is a vast and useful body of quantitative social science research dealing with the social role and impact of video games, it is difficult to compare studies dealing with various dimensions of video games because they are informed by different perspectives and assumptions, employ different methodologies, and address different problems. Studies focusing on different social dimensions of video games can produce varied findings about games’ social function that are often difficult to reconcile— or even contradictory. Research is also often categorized by topic area, rendering a comprehensive view of video games’ social role across topic areas difficult. This interpretive review presents a novel typology of four identified approaches that categorize much of the quantitative social science video game research conducted to date: “video games as stimulus,” “video games as avocation,” “video games as skill,” and “video games as social environment.” This typology is useful because it provides an organizational structure within which the large and growing number of studies on video games can be categorized, guiding comparisons between studies on different research topics and aiding a more comprehensive understanding of video games’ social role. Categorizing the different approaches to video game research provides a useful heuristic for those critiquing and expanding that research, as well as an understandable entry point for scholars new to video game research. Further, and perhaps more importantly, the typology indicates when topics should be explored using different approaches than usual to shed new light on the topic areas. Lastly, the typology exposes the conceptual disconnects between the different approaches to video game research, allowing researchers to consider new ways to bridge gaps between the different approaches’ strengths and limitations with novel methods.

Digital Video in Research

DEFF Research Database (Denmark)

Frølunde, Lisbeth

2012-01-01

Is video becoming “the new black” in academia, if so, what are the challenges? The integration of video in research methodology (for collection, analysis) is well-known, but the use of “academic video” for dissemination is relatively new (Eriksson and Sørensen). The focus of this paper is academic......). In the video, I appear (along with other researchers) and two Danish film directors, and excerpts from their film. My challenges included how to edit the academic video and organize the collaborative effort. I consider video editing as a semiotic, transformative process of “reassembling” voices....... In the discussion, I review academic video in terms of relevance and implications for research practice. The theoretical background is social constructivist, combining social semiotics (Kress, van Leeuwen, McCloud), visual anthropology (Banks, Pink) and dialogic theory (Bakhtin). The Bakhtinian notion of “voices...

The Role of Bone Subtraction Computed Tomographic Angiography in Determining Intracranial Aneurysms in Non-Traumatic Subarachnoid Hemorrhage

International Nuclear Information System (INIS)

Kayhan, Aysegul; Koc, Osman; Keskin, Suat; Keskin, Fatih

2014-01-01

The presence of blood in the subarachnoid space is an acute pathology with a serious risk of death and complications. The most common etiology (approximately 80%) is intracranial aneurysm. The aim of this study was to assess the role of bone subtracted computed tomographic angiography (BSCTA), a novel and noninvasive method for determining and characterizing intracranial aneurysms. Sixty consecutive patients with clinically suspected non-traumatic subarachnoid hemorrhage (SAH) were considered to enter the study. The subtraction quality was inadequate in ten patients; thus, they were excluded, leaving 50 patients (84.4%) in the study. Bone subtracted and non-subtracted 3D images were obtained from the BSCTA raw data sets. All images obtained by digital subtraction angiography (DSA), BSCTA, and computed tomographic angiography (CTA) were evaluated for the presence or absence of an aneurysm and the location, minimal sac diameter, and neck size ratio of the aneurysm. DSA was considered as the gold standard during the evaluation of the data. Of the 50 patients who participated in this study, 11 had no aneurysms as determined by both CTA and DSA. Examination of the remaining 39 patients revealed the presence of 51 aneurysms. While 3D-CTA could not detect six aneurysms that were located in the base of the skull, 3D-BSCTA easily detected them. Moreover, five aneurysms were only partially detected by 3D-CTA. According to this data, the sensitivity of 3D-BSCTA and 3D-CTA was calculated as 98% and 86.3%, respectively; the specificity was calculated as 100% and 90.9%, respectively, per aneurysm; and the sensitivity of 100% for 3D-BSCTA and 98% for 3D-CTA was achieved by using combined images with multi-planar reconstruction (MPR) and maximum intensity projection (MIP). BSCTA detected and characterized the aneurysms as well as DSA, and BSCTA and DSA gave concordant results in detecting aneurysms. BSCTA is easily accessible, less time consuming, and most importantly, a non

The Role of Bone Subtraction Computed Tomographic Angiography in Determining Intracranial Aneurysms in Non-Traumatic Subarachnoid Hemorrhage

Science.gov (United States)

Kayhan, Aysegul; Koc, Osman; Keskin, Suat; Keskin, Fatih

2014-01-01

Background: The presence of blood in the subarachnoid space is an acute pathology with a serious risk of death and complications. The most common etiology (approximately 80%) is intracranial aneurysm. Objectives: The aim of this study was to assess the role of bone subtracted computed tomographic angiography (BSCTA), a novel and noninvasive method for determining and characterizing intracranial aneurysms. Patients and Methods: Sixty consecutive patients with clinically suspected non-traumatic subarachnoid hemorrhage (SAH) were considered to enter the study. The subtraction quality was inadequate in ten patients; thus, they were excluded, leaving 50 patients (84.4%) in the study. Bone subtracted and non-subtracted 3D images were obtained from the BSCTA raw data sets. All images obtained by digital subtraction angiography (DSA), BSCTA, and computed tomographic angiography (CTA) were evaluated for the presence or absence of an aneurysm and the location, minimal sac diameter, and neck size ratio of the aneurysm. DSA was considered as the gold standard during the evaluation of the data. Results: Of the 50 patients who participated in this study, 11 had no aneurysms as determined by both CTA and DSA. Examination of the remaining 39 patients revealed the presence of 51 aneurysms. While 3D-CTA could not detect six aneurysms that were located in the base of the skull, 3D-BSCTA easily detected them. Moreover, five aneurysms were only partially detected by 3D-CTA. According to this data, the sensitivity of 3D-BSCTA and 3D-CTA was calculated as 98% and 86.3%, respectively; the specificity was calculated as 100% and 90.9%, respectively, per aneurysm; and the sensitivity of 100% for 3D-BSCTA and 98% for 3D-CTA was achieved by using combined images with multi-planar reconstruction (MPR) and maximum intensity projection (MIP). BSCTA detected and characterized the aneurysms as well as DSA, and BSCTA and DSA gave concordant results in detecting aneurysms. Conclusions: BSCTA is

NEI You Tube Videos: Amblyopia

Medline Plus

Full Text Available ... search for current job openings visit HHS USAJobs Home >> NEI YouTube Videos >> NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

Talking Video in 'Everyday Life'

DEFF Research Database (Denmark)

McIlvenny, Paul

For better or worse, video technologies have made their way into many domains of social life, for example in the domain of therapeutics. Techniques such as Marte Meo, Video Interaction Guidance (ViG), Video-Enhanced Reflection on Communication, Video Home Training and Video intervention....../prevention (VIP) all promote the use of video as a therapeutic tool. This paper focuses on media therapeutics and the various in situ uses of video technologies in the mass media for therapeutic purposes. Reality TV parenting programmes such as Supernanny, Little Angels, The House of Tiny Tearaways, Honey, We...... observation and instruction (directives) relayed across different spaces; 2) the use of recorded video by participants to visualise, spatialise and localise talk and action that is distant in time and/or space; 3) the translating, stretching and cutting of social experience in and through the situated use...

Video Classification and Adaptive QoP/QoS Control for Multiresolution Video Applications on IPTV

Directory of Open Access Journals (Sweden)

Huang Shyh-Fang

2012-01-01

Full Text Available With the development of heterogeneous networks and video coding standards, multiresolution video applications over networks become important. It is critical to ensure the service quality of the network for time-sensitive video services. Worldwide Interoperability for Microwave Access (WIMAX is a good candidate for delivering video signals because through WIMAX the delivery quality based on the quality-of-service (QoS setting can be guaranteed. The selection of suitable QoS parameters is, however, not trivial for service users. Instead, what a video service user really concerns with is the video quality of presentation (QoP which includes the video resolution, the fidelity, and the frame rate. In this paper, we present a quality control mechanism in multiresolution video coding structures over WIMAX networks and also investigate the relationship between QoP and QoS in end-to-end connections. Consequently, the video presentation quality can be simply mapped to the network requirements by a mapping table, and then the end-to-end QoS is achieved. We performed experiments with multiresolution MPEG coding over WIMAX networks. In addition to the QoP parameters, the video characteristics, such as, the picture activity and the video mobility, also affect the QoS significantly.

NEI You Tube Videos: Amblyopia

Medline Plus

Full Text Available ... search for current job openings visit HHS USAJobs Home » NEI YouTube Videos » NEI YouTube Videos: Amblyopia Listen NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia Animations Blindness Cataract ...

Airborne Video Surveillance

National Research Council Canada - National Science Library

Blask, Steven

2002-01-01

The DARPA Airborne Video Surveillance (AVS) program was established to develop and promote technologies to make airborne video more useful, providing capabilities that achieve a UAV force multiplier...

Reflections on academic video

Directory of Open Access Journals (Sweden)

Thommy Eriksson

2012-11-01

Full Text Available As academics we study, research and teach audiovisual media, yet rarely disseminate and mediate through it. Today, developments in production technologies have enabled academic researchers to create videos and mediate audiovisually. In academia it is taken for granted that everyone can write a text. Is it now time to assume that everyone can make a video essay? Using the online journal of academic videos Audiovisual Thinking and the videos published in it as a case study, this article seeks to reflect on the emergence and legacy of academic audiovisual dissemination. Anchoring academic video and audiovisual dissemination of knowledge in two critical traditions, documentary theory and semiotics, we will argue that academic video is in fact already present in a variety of academic disciplines, and that academic audiovisual essays are bringing trends and developments that have long been part of academic discourse to their logical conclusion.

Informal Physics Learning from Video Games: A Case Study Using Gameplay Videos

Science.gov (United States)

Croxton, DeVaughn; Kortemeyer, Gerd

2018-01-01

Researching informal gameplay can be challenging, since as soon as a formal study design is imposed, it becomes neither casual nor self-motivated. As a case study of a non-invasive design, we analyze publicly posted gameplay videos to assess the effectiveness of a physics educational video game on special relativity. These videos offer unique…

On the difference between additive and subtractive QM/MM calculations

Science.gov (United States)

Cao, Lili; Ryde, Ulf

2018-04-01

The combined quantum mechanical (QM) and molecular mechanical (MM) approach (QM/MM) is a popular method to study reactions in biochemical macromolecules. Even if the general procedure of using QM for a small, but interesting part of the system and MM for the rest is common to all approaches, the details of the implementations vary extensively, especially the treatment of the interface between the two systems. For example, QM/MM can use either additive or subtractive schemes, of which the former is often said to be preferable, although the two schemes are often mixed up with mechanical and electrostatic embedding. In this article, we clarify the similarities and differences of the two approaches. We show that inherently, the two approaches should be identical and in practice require the same sets of parameters. However, the subtractive scheme provides an opportunity to correct errors introduced by the truncation of the QM system, i.e. the link atoms, but such corrections require additional MM parameters for the QM system. We describe and test three types of link-atom correction, viz. for van der Waals, electrostatic and bonded interactions. The calculations show that electrostatic and bonded link-atom corrections often give rise to problems in the geometries and energies. The van der Waals link-atom corrections are quite small and give results similar to a pure additive QM/MM scheme. Therefore, both approaches can be recommended.

On the Difference Between Additive and Subtractive QM/MM Calculations

Directory of Open Access Journals (Sweden)

Lili Cao

2018-04-01

Full Text Available The combined quantum mechanical (QM and molecular mechanical (MM approach (QM/MM is a popular method to study reactions in biochemical macromolecules. Even if the general procedure of using QM for a small, but interesting part of the system and MM for the rest is common to all approaches, the details of the implementations vary extensively, especially the treatment of the interface between the two systems. For example, QM/MM can use either additive or subtractive schemes, of which the former is often said to be preferable, although the two schemes are often mixed up with mechanical and electrostatic embedding. In this article, we clarify the similarities and differences of the two approaches. We show that inherently, the two approaches should be identical and in practice require the same sets of parameters. However, the subtractive scheme provides an opportunity to correct errors introduced by the truncation of the QM system, i.e., the link atoms, but such corrections require additional MM parameters for the QM system. We describe and test three types of link-atom correction, viz. for van der Waals, electrostatic, and bonded interactions. The calculations show that electrostatic and bonded link-atom corrections often give rise to problems in the geometries and energies. The van der Waals link-atom corrections are quite small and give results similar to a pure additive QM/MM scheme. Therefore, both approaches can be recommended.

A new video programme

CERN Multimedia

CERN video productions

2011-01-01

"What's new @ CERN?", a new monthly video programme, will be broadcast on the Monday of every month on webcast.cern.ch. Aimed at the general public, the programme will cover the latest CERN news, with guests and explanatory features. Tune in on Monday 3 October at 4 pm (CET) to see the programme in English, and then at 4:20 pm (CET) for the French version.   var flash_video_player=get_video_player_path(); insert_player_for_external('Video/Public/Movies/2011/CERN-MOVIE-2011-129/CERN-MOVIE-2011-129-0753-kbps-640x360-25-fps-audio-64-kbps-44-kHz-stereo', 'mms://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2011/CERN-MOVIE-2011-129/CERN-MOVIE-2011-129-Multirate-200-to-753-kbps-640x360-25-fps.wmv', 'false', 480, 360, 'https://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2011/CERN-MOVIE-2011-129/CERN-MOVIE-2011-129-posterframe-640x360-at-10-percent.jpg', '1383406', true, 'Video/Public/Movies/2011/CERN-MOVIE-2011-129/CERN-MOVIE-2011-129-0600-kbps-maxH-360-25-fps-...

Self-Recognition in Live Videos by Young Children: Does Video Training Help?

Science.gov (United States)

Demir, Defne; Skouteris, Helen

2010-01-01

The overall aim of the experiment reported here was to establish whether self-recognition in live video can be facilitated when live video training is provided to children aged 2-2.5 years. While the majority of children failed the test of live self-recognition prior to video training, more than half exhibited live self-recognition post video…

The value of subtraction MRI in detection of amyloid-related imaging abnormalities with oedema or effusion in Alzheimer's patients. An interobserver study

International Nuclear Information System (INIS)

Martens, Roland M.; Bechten, Arianne; Ingala, Silvia; Schijndel, Ronald A. van; Machado, Vania B.; Jong, Marcus C. de; Sanchez, Esther; Wattjes, Mike P.; Purcell, Derk; Arrighi, Michael H.; Brashear, Robert H.; Barkhof, Frederik

2018-01-01

Immunotherapeutic treatments targeting amyloid-β plaques in Alzheimer's disease (AD) are associated with the presence of amyloid-related imaging abnormalities with oedema or effusion (ARIA-E), whose detection and classification is crucial to evaluate subjects enrolled in clinical trials. To investigate the applicability of subtraction MRI in the ARIA-E detection using an established ARIA-E-rating scale. We included 75 AD patients receiving bapineuzumab treatment, including 29 ARIA-E cases. Five neuroradiologists rated their brain MRI-scans with and without subtraction images. The accuracy of evaluating the presence of ARIA-E, intraclass correlation coefficient (ICC) and specific agreement was calculated. Subtraction resulted in higher sensitivity (0.966) and lower specificity (0.970) than native images (0.959, 0.991, respectively). Individual rater detection was excellent. ICC scores ranged from excellent to good, except for gyral swelling (moderate). Excellent negative and good positive specific agreement among all ARIA-E imaging features was reported in both groups. Combining sulcal hyperintensity and gyral swelling significantly increased positive agreement for subtraction images. Subtraction MRI has potential as a visual aid increasing the sensitivity of ARIA-E assessment. However, in order to improve its usefulness isotropic acquisition and enhanced training are required. The ARIA-E rating scale may benefit from combining sulcal hyperintensity and swelling. (orig.)

The value of subtraction MRI in detection of amyloid-related imaging abnormalities with oedema or effusion in Alzheimer's patients. An interobserver study

Energy Technology Data Exchange (ETDEWEB)

Martens, Roland M.; Bechten, Arianne; Ingala, Silvia; Schijndel, Ronald A. van; Machado, Vania B.; Jong, Marcus C. de; Sanchez, Esther; Wattjes, Mike P. [VU University Medical Center, Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam (Netherlands); Purcell, Derk [California Pacific Medical Center, Department of Radiology, San Francisco, CA (United States); BioClinica Inc, Newark, CA (United States); Arrighi, Michael H.; Brashear, Robert H. [Janssen Alzheimer Immunotherapy Research and Development, LLC, South San Francisco, CA (United States); Barkhof, Frederik [VU University Medical Center, Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam (Netherlands); University College London, Institutes of Neurology and Healthcare Engineering, London (United Kingdom)

2018-03-15

Immunotherapeutic treatments targeting amyloid-β plaques in Alzheimer's disease (AD) are associated with the presence of amyloid-related imaging abnormalities with oedema or effusion (ARIA-E), whose detection and classification is crucial to evaluate subjects enrolled in clinical trials. To investigate the applicability of subtraction MRI in the ARIA-E detection using an established ARIA-E-rating scale. We included 75 AD patients receiving bapineuzumab treatment, including 29 ARIA-E cases. Five neuroradiologists rated their brain MRI-scans with and without subtraction images. The accuracy of evaluating the presence of ARIA-E, intraclass correlation coefficient (ICC) and specific agreement was calculated. Subtraction resulted in higher sensitivity (0.966) and lower specificity (0.970) than native images (0.959, 0.991, respectively). Individual rater detection was excellent. ICC scores ranged from excellent to good, except for gyral swelling (moderate). Excellent negative and good positive specific agreement among all ARIA-E imaging features was reported in both groups. Combining sulcal hyperintensity and gyral swelling significantly increased positive agreement for subtraction images. Subtraction MRI has potential as a visual aid increasing the sensitivity of ARIA-E assessment. However, in order to improve its usefulness isotropic acquisition and enhanced training are required. The ARIA-E rating scale may benefit from combining sulcal hyperintensity and swelling. (orig.)

Thallium-201 chloride dynamic analysis using thallium-201 chloride and sodium iodide-131 thyroid subtraction scintigraphy

Energy Technology Data Exchange (ETDEWEB)

Morimoto, Setsuo; Hiraki, Yoshio; Togami, Izumi [Okayama Univ. (Japan). School of Medicine

1984-10-01

The mechanism of /sup 201/Tl chloride accumulation is unclear in thyroid gland and thyroid tumor. This report examines 108 patients that received thyroid scintigraphy examinations with both /sup 201/Tl chloride and sodium /sup 131/I. The patients were diagnosed clinically and histologically whenever possible. The ROI were obtained by subtraction imaging with both isotopes and by subtraction positive and negative areas of imaging. Dynamic curves were obtained for /sup 201/Tl chloride per square unit of each ROI. The dynamic curve in the radioiodide-accumulated area was examined. The data indicate that the clearance rate of /sup 201/Tl chloride (T/sub 15/) was correlated with the sodium /sup 131/I uptake rate at 24 h (r=0.70).

Subtraction radiography and computer assisted densitometric analyses of standardized radiographs. A comparison study with /sup 125/I absorptiometry

Energy Technology Data Exchange (ETDEWEB)

Ortmann, L.F.; Dunford, R.; McHenry, K.; Hausmann, E.

1985-01-01

A standardized radiographic series of incrementally increasing alveolar crestal defects in skulls were subjected to analyses by subtraction radiography and computer assisted quantitative densitometric analysis. Subjects were able to detect change using subtraction radiography in alveolar bone defects with bone loss in the range of 1-5 percent as measured by /sup 125/I absorptiometry. Quantitative densitometric analyses utilizing radiographic pairs adjusted for differences in contrast (gamma corrected) can be used to follow longitudinal changes at a particular alveolar bone site. Such measurements correlate with change observed by /sup 125/I absorptiometry (r=0.82-0.94). (author).

Video Toroid Cavity Imager

Energy Technology Data Exchange (ETDEWEB)

Gerald, Rex E. II; Sanchez, Jairo; Rathke, Jerome W.

2004-08-10

A video toroid cavity imager for in situ measurement of electrochemical properties of an electrolytic material sample includes a cylindrical toroid cavity resonator containing the sample and employs NMR and video imaging for providing high-resolution spectral and visual information of molecular characteristics of the sample on a real-time basis. A large magnetic field is applied to the sample under controlled temperature and pressure conditions to simultaneously provide NMR spectroscopy and video imaging capabilities for investigating electrochemical transformations of materials or the evolution of long-range molecular aggregation during cooling of hydrocarbon melts. The video toroid cavity imager includes a miniature commercial video camera with an adjustable lens, a modified compression coin cell imager with a fiat circular principal detector element, and a sample mounted on a transparent circular glass disk, and provides NMR information as well as a video image of a sample, such as a polymer film, with micrometer resolution.

Maximal Abelian and Curci-Ferrari gauges in momentum subtraction at three loops

Science.gov (United States)

Bell, J. M.; Gracey, J. A.

2015-12-01

The vertex structure of QCD fixed in the maximal Abelian gauge (MAG) and Curci-Ferrari gauge is analyzed at two loops at the fully symmetric point for the 3-point functions corresponding to the three momentum subtraction (MOM) renormalization schemes. Consequently, the three-loop renormalization group functions are determined for each of these three schemes in each gauge using properties of the renormalization group equation.

A Framework for Video Modeling

NARCIS (Netherlands)

Petkovic, M.; Jonker, Willem

In recent years, research in video databases has increased greatly, but relatively little work has been done in the area of semantic content-based retrieval. In this paper, we present a framework for video modelling with emphasis on semantic content of video data. The video data model presented

Video library for video imaging detection at intersection stop lines.

Science.gov (United States)

2010-04-01

The objective of this activity was to record video that could be used for controlled : evaluation of video image vehicle detection system (VIVDS) products and software upgrades to : existing products based on a list of conditions that might be diffic...

Deep video deblurring

KAUST Repository

Su, Shuochen

2016-11-25

Motion blur from camera shake is a major problem in videos captured by hand-held devices. Unlike single-image deblurring, video-based approaches can take advantage of the abundant information that exists across neighboring frames. As a result the best performing methods rely on aligning nearby frames. However, aligning images is a computationally expensive and fragile procedure, and methods that aggregate information must therefore be able to identify which regions have been accurately aligned and which have not, a task which requires high level scene understanding. In this work, we introduce a deep learning solution to video deblurring, where a CNN is trained end-to-end to learn how to accumulate information across frames. To train this network, we collected a dataset of real videos recorded with a high framerate camera, which we use to generate synthetic motion blur for supervision. We show that the features learned from this dataset extend to deblurring motion blur that arises due to camera shake in a wide range of videos, and compare the quality of results to a number of other baselines.

Pelvic digital subtraction catheter angiography-Are routine oblique projections necessary?

International Nuclear Information System (INIS)

Rane, Neil; Imam, Atique; Foley, Peter; Timmons, Grace; Uberoi, Raman

2011-01-01

The oblique projection is used widely in imaging of the lower vascular tree. Much of the evidence justifying the oblique projection is anecdotal. This study compares the sensitivity of the anteroposterior (AP) projection alone in lower limb vascular catheter angiography to that combined with the oblique projection. 110 digitally subtracted angiograms were analysed initially on AP and subsequently on oblique views. Oblique imaging increases confidence, demonstrates stenoses not seen on AP and changes the diagnosis. This supports the use of the oblique projection in lower limb vascular interventional imaging.

Multinuclide digital subtraction imaging in symptomatic prostnetic joints

International Nuclear Information System (INIS)

Chafetz, N.; Hattner, R.S.; Ruarke, W.C.; Helms, C.A.; Genant, H.K.; Murray, W.R.

1985-01-01

One hundred eleven patients with symptomatic prosthetic joints (86 hips, 23 knees, and two shoulders) were evaluated for prosthetic loosening and infection by combined technetium-99m-MDP/gallium-67 digital subtraction imaging. Clinical correlation was based on the assessment of loosening and bacterial cultures obtained at the time of surgery in 54 patients, joint aspiration cultures obtained in 37 patients, and long-term clinical follow-up for greater than 1.5 years in an additional 15 patients. Results revealed an 80-90% predictive value of a positive test for loosening, and a 95% predictive value of a negative test for infection. However, because of the low sensitivities and specificities observed, this approach to the evaluation of symptomatic prosthetic joints does not seem cost effective

The Children's Video Marketplace.

Science.gov (United States)

Ducey, Richard V.

This report examines a growing submarket, the children's video marketplace, which comprises broadcast, cable, and video programming for children 2 to 11 years old. A description of the tremendous growth in the availability and distribution of children's programming is presented, the economics of the children's video marketplace are briefly…

Toward enhancing the distributed video coder under a multiview video codec framework

Science.gov (United States)

Lee, Shih-Chieh; Chen, Jiann-Jone; Tsai, Yao-Hong; Chen, Chin-Hua

2016-11-01

The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.

THE APPLICATION OF CONTINUOUS WAVELET TRANSFORM BASED FOREGROUND SUBTRACTION METHOD IN 21 cm SKY SURVEYS

International Nuclear Information System (INIS)

Gu Junhua; Xu Haiguang; Wang Jingying; Chen Wen; An Tao

2013-01-01

We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra are smooth in frequency domain, while the 21 cm signal spectrum is full of saw-tooth-like structures, thus their characteristic scales are significantly different. We can distinguish them in the wavelet coefficient space easily and perform the foreground subtraction. Compared with the traditional spectral fitting based method, our method is more tolerant to complex foregrounds. Furthermore, we also find that when the instrument has uncorrected response error, our method can also work significantly better than the spectral fitting based method. Our method can obtain similar results with the Wp smoothing method, which is also a non-parametric method, but our method consumes much less computing time

NEI You Tube Videos: Amblyopia

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Camera network video summarization

Science.gov (United States)

Panda, Rameswar; Roy-Chowdhury, Amit K.

2017-05-01

Networks of vision sensors are deployed in many settings, ranging from security needs to disaster response to environmental monitoring. Many of these setups have hundreds of cameras and tens of thousands of hours of video. The difficulty of analyzing such a massive volume of video data is apparent whenever there is an incident that requires foraging through vast video archives to identify events of interest. As a result, video summarization, that automatically extract a brief yet informative summary of these videos, has attracted intense attention in the recent years. Much progress has been made in developing a variety of ways to summarize a single video in form of a key sequence or video skim. However, generating a summary from a set of videos captured in a multi-camera network still remains as a novel and largely under-addressed problem. In this paper, with the aim of summarizing videos in a camera network, we introduce a novel representative selection approach via joint embedding and capped l21-norm minimization. The objective function is two-fold. The first is to capture the structural relationships of data points in a camera network via an embedding, which helps in characterizing the outliers and also in extracting a diverse set of representatives. The second is to use a capped l21-norm to model the sparsity and to suppress the influence of data outliers in representative selection. We propose to jointly optimize both of the objectives, such that embedding can not only characterize the structure, but also indicate the requirements of sparse representative selection. Extensive experiments on standard multi-camera datasets well demonstrate the efficacy of our method over state-of-the-art methods.

A subtractive approach to interior intrusion detection system design

International Nuclear Information System (INIS)

Sons, R.J.; Graham, R.H. Jr.

1986-01-01

This paper discusses the subtractive approach to interior intrusion detection system design which assumes that all sensors are viable candidates until they are subjected to the constraints imposed by a particular facility. The constraints are determined by a sequence of questions concerning parameters such as threat definition, facility description and operation, environment, assets to be protected, security system capabilities, and cost. As a result of the questioning, some sensors will be eliminated from the candidate list, and the ''best'' set of sensors for the facility will remain. This form of questioning could be incorporated into an expert system aiding future intrusion detection system designs

Intra-arterial digital subtraction angiography of the carotid arteries

International Nuclear Information System (INIS)

Nakstad, P.; Bakke, S.J.; Kjartansson, O.; Nyhus, S.

1986-01-01

A cross-over test in intra-arterial digital subtraction angiography (IADSA) of the carotid arteries was performed in 50 patients to evaluate image quality and side-effects with iohexol and metrizoate injected at concentrations of 100 mg I/ml by hand. The image quality was excellent or good in all cases. Although the severity and the frequency of side-effects were higher with metrizoate, both contrast media were suitable for IADSA at this low concentration. No complications were seen. It was assumed that the risk with IADSA was less than that of conventional-selectivity and with small amounts of contrast media, as in this study. (orig.)

The energy expenditure of an activity-promoting video game compared to sedentary video games and TV watching.

Science.gov (United States)

Mitre, Naim; Foster, Randal C; Lanningham-Foster, Lorraine; Levine, James A

2011-01-01

In the present study we investigated the effect of television watching and the use of activity-promoting video games on energy expenditure in obese and lean children. Energy expenditure and physical activity were measured while participants were watching television, playing a video game on a traditional sedentary video game console, and while playing the same video game on an activity-promoting video game console. Energy expenditure was significantly greater than television watching and playing video games on a sedentary video game console when children played the video game on the activity-promoting console. When examining movement with accelerometry, children moved significantly more when playing the video game on the Nintendo Wii console. Activity-promoting video games have shown to increase movement, and be an important tool to raise energy expenditure by 50% when compared to sedentary activities of daily living.

Fast compressed domain motion detection in H.264 video streams for video surveillance applications

DEFF Research Database (Denmark)

Szczerba, Krzysztof; Forchhammer, Søren; Støttrup-Andersen, Jesper

2009-01-01

This paper presents a novel approach to fast motion detection in H.264/MPEG-4 advanced video coding (AVC) compressed video streams for IP video surveillance systems. The goal is to develop algorithms which may be useful in a real-life industrial perspective by facilitating the processing of large...... on motion vectors embedded in the video stream without requiring a full decoding and reconstruction of video frames. To improve the robustness to noise, a confidence measure based on temporal and spatial clues is introduced to increase the probability of correct detection. The algorithm was tested on indoor...

Digital subtraction angiography - a new approach to brain death determination in the newborn

International Nuclear Information System (INIS)

Albertini, A.; Schonfeld, S.; Hiatt, M.; Hegyi, T.

1993-01-01

The diagnosis of brain death in the newborn infants is elusive and often difficult. The lack of cerebral blood flow has become an identified criterion for loss of cerebral function. The diagnosis can be obtained by the technique of digital subtraction angiography, which is presented in two case reports demonstrating the utility of this technique. (orig.)

Sound for digital video

CERN Document Server

Holman, Tomlinson

2013-01-01

Achieve professional quality sound on a limited budget! Harness all new, Hollywood style audio techniques to bring your independent film and video productions to the next level.In Sound for Digital Video, Second Edition industry experts Tomlinson Holman and Arthur Baum give you the tools and knowledge to apply recent advances in audio capture, video recording, editing workflow, and mixing to your own film or video with stunning results. This fresh edition is chockfull of techniques, tricks, and workflow secrets that you can apply to your own projects from preproduction

Mobile Video in Everyday Social Interactions

Science.gov (United States)

Reponen, Erika; Lehikoinen, Jaakko; Impiö, Jussi

Video recording has become a spontaneous everyday activity for many people, thanks to the video capabilities of modern mobile phones. Internet connectivity of mobile phones enables fluent sharing of captured material even real-time, which makes video an up-and-coming everyday interaction medium. In this article we discuss the effect of the video camera in the social environment, everyday life situations, mainly based on a study where four groups of people used digital video cameras in their normal settings. We also reflect on another study of ours, relating to real-time mobile video communication and discuss future views. The aim of our research is to understand the possibilities in the domain of mobile video. Live and delayed sharing seem to have their special characteristics, live video being used as a virtual window between places whereas delayed video usage has more scope for good-quality content. While this novel way of interacting via mobile video enables new social patterns, it also raises new concerns for privacy and trust between participating persons in all roles, largely due to the widely spreading possibilities of videos. Video in a social situation affects cameramen (who record), targets (who are recorded), passers-by (who are unintentionally in the situation), and the audience (who follow the videos or recording situations) but also the other way around, the participants affect the video by their varying and evolving personal and communicational motivations for recording.

Gamifying Video Object Segmentation.

Science.gov (United States)

Spampinato, Concetto; Palazzo, Simone; Giordano, Daniela

2017-10-01

Video object segmentation can be considered as one of the most challenging computer vision problems. Indeed, so far, no existing solution is able to effectively deal with the peculiarities of real-world videos, especially in cases of articulated motion and object occlusions; limitations that appear more evident when we compare the performance of automated methods with the human one. However, manually segmenting objects in videos is largely impractical as it requires a lot of time and concentration. To address this problem, in this paper we propose an interactive video object segmentation method, which exploits, on one hand, the capability of humans to identify correctly objects in visual scenes, and on the other hand, the collective human brainpower to solve challenging and large-scale tasks. In particular, our method relies on a game with a purpose to collect human inputs on object locations, followed by an accurate segmentation phase achieved by optimizing an energy function encoding spatial and temporal constraints between object regions as well as human-provided location priors. Performance analysis carried out on complex video benchmarks, and exploiting data provided by over 60 users, demonstrated that our method shows a better trade-off between annotation times and segmentation accuracy than interactive video annotation and automated video object segmentation approaches.

Thallium-technetium-subtraction scintigraphy in secondary hyperparathyroidism

International Nuclear Information System (INIS)

Adalet, I.; Hawkins, T.; Clark, F.; Wilkinson, R.

1994-01-01

Between 1983 and 1992 thallium-technetium subtraction scintigraphy (TTS) was performed on 74 patients with clinical and biochemical evidence of hyperparathyroidism. Twenty-five of the 53 investigations since 1988 were conducted on patients with renal failure with a suspicion of secondary hyperparathyroidism. In a retrospective study we have evaluated radioisotope scintigraphy for patients with adenoma and for renal failure patients with possible parathyroid hyperplasia. Thirty of 74 patients underwent neck exploration. Scintigraphy detected 17 of 24 parathyroid adenomas (sensitivity 71%). In contrast, in six renal patients who came to operation, scintigraphy localised only 5 of 20 hyperplastic parathyroid glands (sensitivity 25%) and in one renal patient we localised a parathyroid adenoma. A review of the literature shows low detection rates for hyperplasia by TTS to be a common observation. Based on these findings a rational approach is offered for parathyroid localisation in renal patients prior to neck exploration. (orig.)

N -jettiness subtractions for g g →H at subleading power

Science.gov (United States)

Moult, Ian; Rothen, Lorena; Stewart, Iain W.; Tackmann, Frank J.; Zhu, Hua Xing

2018-01-01

N -jettiness subtractions provide a general approach for performing fully-differential next-to-next-to-leading order (NNLO) calculations. Since they are based on the physical resolution variable N -jettiness, TN , subleading power corrections in τ =TN/Q , with Q a hard interaction scale, can also be systematically computed. We study the structure of power corrections for 0-jettiness, T0, for the g g →H process. Using the soft-collinear effective theory we analytically compute the leading power corrections αsτ ln τ and αs2τ ln3τ (finding partial agreement with a previous result in the literature), and perform a detailed numerical study of the power corrections in the g g , g q , and q q ¯ channels. This includes a numerical extraction of the αsτ and αs2τ ln2τ corrections, and a study of the dependence on the T0 definition. Including such power suppressed logarithms significantly reduces the size of missing power corrections, and hence improves the numerical efficiency of the subtraction method. Having a more detailed understanding of the power corrections for both q q ¯ and g g initiated processes also provides insight into their universality, and hence their behavior in more complicated processes where they have not yet been analytically calculated.

Use of signal subtraction methods in ESR dating of burned flint

International Nuclear Information System (INIS)

Porat, Naomi; Schwarcz, H.P.

1991-01-01

Geological samples of chert display some of the characteristics of electron spin resonance (ESR) signals of quartz. When chert is heated in a fireplace, most of these signals are annealed. The signals grow again in fire-heated chert buried in archaeological sites, as a result of internal and external radiation doses. The date of the heating event can be determined from the acquired dose (AD) and the dose rate. The E' and Al signals are best suited for dating. Although many cherts, when heated to a sufficient temperature, acquire a carbon radical (C) signal that largely obscures the E' signal, it can be subtracted from digitized spectra. The E' signal also appears to saturate at relatively low doses, restricting the time range of dating to between 200 and 600 ka, depending on the dose rates. The Al signal shows no saturation, but is also interfered with by organic signals, present in burnt and unburned flint. These can also be subtracted to reveal the ''pure'' Al signal. Applying the E' signal to date flint from Yabroud, we obtain an age between 100 and 125 ka, while both thermoluminescence (TL) dating of the flint and ESR dating of tooth enamel give 195 and 225 ka, respectively; the discrepancy may be due to an overestimate of the α-efficiency. At Nahr Ibrahim, the age (c. 80 ka) is consistent with archaeological estimates. (author)

The parallel-sequential field subtraction technique for coherent nonlinear ultrasonic imaging

Science.gov (United States)

Cheng, Jingwei; Potter, Jack N.; Drinkwater, Bruce W.

2018-06-01

Nonlinear imaging techniques have recently emerged which have the potential to detect cracks at a much earlier stage than was previously possible and have sensitivity to partially closed defects. This study explores a coherent imaging technique based on the subtraction of two modes of focusing: parallel, in which the elements are fired together with a delay law and sequential, in which elements are fired independently. In the parallel focusing a high intensity ultrasonic beam is formed in the specimen at the focal point. However, in sequential focusing only low intensity signals from individual elements enter the sample and the full matrix of transmit-receive signals is recorded and post-processed to form an image. Under linear elastic assumptions, both parallel and sequential images are expected to be identical. Here we measure the difference between these images and use this to characterise the nonlinearity of small closed fatigue cracks. In particular we monitor the change in relative phase and amplitude at the fundamental frequencies for each focal point and use this nonlinear coherent imaging metric to form images of the spatial distribution of nonlinearity. The results suggest the subtracted image can suppress linear features (e.g. back wall or large scatters) effectively when instrumentation noise compensation in applied, thereby allowing damage to be detected at an early stage (c. 15% of fatigue life) and reliably quantified in later fatigue life.

Crowded Field Photometry and Moving Object Detection with Optimal Image Subtraction

Science.gov (United States)

Lee, Austin A. T.; Scheulen, F.; Sauro, C. M.; McMahon, C. T.; Berry, S. J.; Robinson, C. H.; Buie, M. W.; Little, P.

2010-05-01

High precision photometry and moving object detection are essential in the study of Pluto and the Kuiper Belt. In particular, the New Horizons mission would benefit from an accurate and fast method of performing image subtraction to locate faint Kuiper Belt Objects (KBO) among large data sets. The optimal image subtraction (OIS) algorithm was optimized for IDL to decrease execution time by a factor of about 140 from a previous implementation (Miller 2008, PASP, 120, 449). In addition, a powerful image transformation and interpolation routine was written to provide OIS with well-aligned input images using astrometric fit data. The first half of this project is complete including the code optimization and the alignment routine. The second half of the project is focused on using these tools to search a 5 x 10 degree search area to find KBOs for possible targets for the New Horizons mission. We will present examples of how these tools work and along with resulting Pluto photometry and KBO target lists. The optimized OIS and transformation routines are available in Marc Buie's IDL library at http://www.boulder.swri.edu/ buie/idl/ as ois.pro and dewarp.pro. This project was conducted for Harvey Mudd College's Clinic Program with financial support from the NASA Planetary Astronomy Program grant number NNX09AB43G.

Place of digital X-ray tomography in improving the diagnosis of pulmonary tuberculosis, lung cancer and mediastinal abnormality

International Nuclear Information System (INIS)

Portnoj, L.M.; Vyatkina, E.I.; Petukhova, N.Yu.; Stashuk, G.A.

1999-01-01

To assess the role of current digital X-ray fluorography in the diagnosis of various diseases of the lung (primarily its tuberculosis and cancer, and abnormalities of the mediastinum). 2500 cases from different patient groups (those registered at dispensary or identified at screening, those with a previously verified pathology). In addition to a particularly diagnostic section organizational and methodological problems in the introduction of digital X-ray fluorography into practical public health of Russia are discussed [ru

The quality assurance program data analysis for diagnostic radiology in government hospitals in southern provinces of Syria

International Nuclear Information System (INIS)

Kharita, M. H.; Khedr, M. S.; Wannus, K. M.

2008-01-01

This study covered comprehensive evaluation for diagnostic radiography and fluorography equipment used in medicine by applying SAEC quality control rules. The results showed that most of considered x-ray equipment have an acceptable performance but few reached 21.6% in radiography and 36.8% in fluorography need repair and recalibration. Also recommendations and guidance for repair and preventative maintenance are required and quality assurance program should be applied in all diagnostic radiology institutions in Syria.(author)

Use of subvoxel registration and subtraction to improve demonstration of contrast enhancement in MRI of the brain

International Nuclear Information System (INIS)

Curati, W.L.; Williams, E.J.; Oatridge, A.; Hajnal, J.V.; Saeed, N.; Bydder, G.M.

1996-01-01

To assess the potential of registration of images before and after contrast medium for improving the demonstration of contrast enhancement, we compared conventional 2 D T 1-weighted spin-echo images with precisely registered 3 D volume images and subtraction images derived from them in 2 normal subjects and 30 patients with a variety of brain disease. The volume images were registered to subvoxel accuracy using a rigid body translation and rotation, sinc interpolation and a least-squares fit; subtraction images were obtained from these. Normal contrast enhancement was demonstrated better with positionally registered volume and subtraction images than with conventional images in the meninges, ependyma, diploic veins, scalp, skin, orbit and sinuses. Abnormal enhancement was seen better in meningeal disease, multiple sclerosis and tumours as well as on follow-up studies. Subvoxel registration of images before and after contrast medium may be of considerable value in the recognition of contrast enhancement where there are small changes, or where the changes affect tissues with high or low baseline signal values. The technique also appears likely to be of value in demonstrating contrast enhancement in tissues at inferfaces and at other areas of complex anatomy, and in follow-up studies. (orig.). With 4 figs., 4 tabs

A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: a simulation study

International Nuclear Information System (INIS)

Choi, Sunghoon; Lee, Seungwan; Choi, Yuna; Kim, Heejoung

2014-01-01

Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05 - 1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: a simulation study

Energy Technology Data Exchange (ETDEWEB)

Choi, Sunghoon; Lee, Seungwan; Choi, Yuna; Kim, Heejoung [Yonsei University, Wonju (Korea, Republic of)

2014-06-15

Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05 - 1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

Addition Table of Colours: Additive and Subtractive Mixtures Described Using a Single Reasoning Model

Science.gov (United States)

Mota, A. R.; Lopes dos Santos, J. M. B.

2014-01-01

Students' misconceptions concerning colour phenomena and the apparent complexity of the underlying concepts--due to the different domains of knowledge involved--make its teaching very difficult. We have developed and tested a teaching device, the addition table of colours (ATC), that encompasses additive and subtractive mixtures in a single…

SIRSALE: integrated video database management tools

Science.gov (United States)

Brunie, Lionel; Favory, Loic; Gelas, J. P.; Lefevre, Laurent; Mostefaoui, Ahmed; Nait-Abdesselam, F.

2002-07-01

Video databases became an active field of research during the last decade. The main objective in such systems is to provide users with capabilities to friendly search, access and playback distributed stored video data in the same way as they do for traditional distributed databases. Hence, such systems need to deal with hard issues : (a) video documents generate huge volumes of data and are time sensitive (streams must be delivered at a specific bitrate), (b) contents of video data are very hard to be automatically extracted and need to be humanly annotated. To cope with these issues, many approaches have been proposed in the literature including data models, query languages, video indexing etc. In this paper, we present SIRSALE : a set of video databases management tools that allow users to manipulate video documents and streams stored in large distributed repositories. All the proposed tools are based on generic models that can be customized for specific applications using ad-hoc adaptation modules. More precisely, SIRSALE allows users to : (a) browse video documents by structures (sequences, scenes, shots) and (b) query the video database content by using a graphical tool, adapted to the nature of the target video documents. This paper also presents an annotating interface which allows archivists to describe the content of video documents. All these tools are coupled to a video player integrating remote VCR functionalities and are based on active network technology. So, we present how dedicated active services allow an optimized video transport for video streams (with Tamanoir active nodes). We then describe experiments of using SIRSALE on an archive of news video and soccer matches. The system has been demonstrated to professionals with a positive feedback. Finally, we discuss open issues and present some perspectives.

Medical video server construction.

Science.gov (United States)

Dańda, Jacek; Juszkiewicz, Krzysztof; Leszczuk, Mikołaj; Loziak, Krzysztof; Papir, Zdzisław; Sikora, Marek; Watza, Rafal

2003-01-01

The paper discusses two implementation options for a Digital Video Library, a repository used for archiving, accessing, and browsing of video medical records. Two crucial issues to be decided on are a video compression format and a video streaming platform. The paper presents numerous decision factors that have to be taken into account. The compression formats being compared are DICOM as a format representative for medical applications, both MPEGs, and several new formats targeted for an IP networking. The comparison includes transmission rates supported, compression rates, and at least options for controlling a compression process. The second part of the paper presents the ISDN technique as a solution for provisioning of tele-consultation services between medical parties that are accessing resources uploaded to a digital video library. There are several backbone techniques (like corporate LANs/WANs, leased lines or even radio/satellite links) available, however, the availability of network resources for hospitals was the prevailing choice criterion pointing to ISDN solutions. Another way to provide access to the Digital Video Library is based on radio frequency domain solutions. The paper describes possibilities of both, wireless and cellular network's data transmission service to be used as a medical video server transport layer. For the cellular net-work based solution two communication techniques are used: Circuit Switched Data and Packet Switched Data.

Image processing of integrated video image obtained with a charged-particle imaging video monitor system

International Nuclear Information System (INIS)

Iida, Takao; Nakajima, Takehiro

1988-01-01

A new type of charged-particle imaging video monitor system was constructed for video imaging of the distributions of alpha-emitting and low-energy beta-emitting nuclides. The system can display not only the scintillation image due to radiation on the video monitor but also the integrated video image becoming gradually clearer on another video monitor. The distortion of the image is about 5% and the spatial resolution is about 2 line pairs (lp)mm -1 . The integrated image is transferred to a personal computer and image processing is performed qualitatively and quantitatively. (author)

NEI You Tube Videos: Amblyopia

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Full Text Available ... YouTube Videos: Amblyopia Embedded video for NEI YouTube Videos: Amblyopia ... *PDF files require the free Adobe® Reader® software for viewing. This website is maintained by the ...

Evaluation of left ventricular function by digital subtraction angiography

International Nuclear Information System (INIS)

Kuribayashi, Sachio; Ootaki, Makoto; Matsuyama, Seiya; Kanemoto, Nariaki; Furuya, Hideo

1985-01-01

Effects of contrast medium doses on left ventriculographic images using intravenous digital subtraction angiography (IVDSA-LVG) were assessed. The validity of IVDSA-LVG in evaluating ejection fraction (FF) and left ventricular regional wall motion was determined by comparison with conventional left ventriculography using direct injection (direct LVG). The advantages of left ventriculography using intraarterial subtraction angiography (IADSA-LVG) performed by injecting small doses of contrast media directly into the left ventricle were stressed. 1. To assess the effects of doses of contrast media on IVDSA-LVG, 10, 20, and 30 ml Urografin-76 were injected into the superior vena cava in 16 patients, and the resulting images were compared in each patient. With only 10 ml contrast medium, left ventricular opacification was fairly good, and regional wall motion was evaluated in many cases, but 30 ml were needed to calculate ventricular volume and EF. 2. To determine the validity of IVDSA-LVG in evaluating EF and regional wall motion, we compared IVDSA-LVG using 30 ml of contrast medium with direct LVG in 18 patients. There was a good correlation between the two methods in determining EF (r = 0.877), and 90 % of the interpretations of regional wall motion were in agreement by the two methods. IVDSA-LVG was useful and accurate in evaluating EF and regional wall motion of the left ventricle. 3. IADSA-LVG was performed for five patients, and good quality images were obtained in many cases, even with relatively small doses (10 ml) of contrast media. These results suggested that this method may be used in cases with impaired LV function, to avoid hemodynamic derangement induced by conventional direct LVG using large doses of contrast medium. (author)

Smart Streaming for Online Video Services

OpenAIRE

Chen, Liang; Zhou, Yipeng; Chiu, Dah Ming

2013-01-01

Bandwidth consumption is a significant concern for online video service providers. Practical video streaming systems usually use some form of HTTP streaming (progressive download) to let users download the video at a faster rate than the video bitrate. Since users may quit before viewing the complete video, however, much of the downloaded video will be "wasted". To the extent that users' departure behavior can be predicted, we develop smart streaming that can be used to improve user QoE with ...

Video outside versus video inside the web: do media setting and image size have an impact on the emotion-evoking potential of video?

NARCIS (Netherlands)

Verleur, R.; Verhagen, Pleunes Willem; Crawford, Margaret; Simonson, Michael; Lamboy, Carmen

2001-01-01

To explore the educational potential of video-evoked affective responses in a Web-based environment, the question was raised whether video in a Web-based environment is experienced differently from video in a traditional context. An experiment was conducted that studied the affect-evoking power of

Video games: good, bad, or other?

Science.gov (United States)

Prot, Sara; McDonald, Katelyn A; Anderson, Craig A; Gentile, Douglas A

2012-06-01

Video games are a pervasive pastime among children and adolescents. The growing popularity of video games has instigated a debate among parents, researchers, video game producers, and policymakers concerning potential harmful and helpful effects of video games on children. This article provides an overview of research findings on the positive and negative effects of video games, thus providing an empirical answer to the question, are video games good or bad? The article also provides some guidelines to help pediatricians, parents, and other caregivers protect children from negative effects and to maximize positive effects of video games. Copyright © 2012 Elsevier Inc. All rights reserved.

Blind prediction of natural video quality.

Science.gov (United States)

Saad, Michele A; Bovik, Alan C; Charrier, Christophe

2014-03-01

We propose a blind (no reference or NR) video quality evaluation model that is nondistortion specific. The approach relies on a spatio-temporal model of video scenes in the discrete cosine transform domain, and on a model that characterizes the type of motion occurring in the scenes, to predict video quality. We use the models to define video statistics and perceptual features that are the basis of a video quality assessment (VQA) algorithm that does not require the presence of a pristine video to compare against in order to predict a perceptual quality score. The contributions of this paper are threefold. 1) We propose a spatio-temporal natural scene statistics (NSS) model for videos. 2) We propose a motion model that quantifies motion coherency in video scenes. 3) We show that the proposed NSS and motion coherency models are appropriate for quality assessment of videos, and we utilize them to design a blind VQA algorithm that correlates highly with human judgments of quality. The proposed algorithm, called video BLIINDS, is tested on the LIVE VQA database and on the EPFL-PoliMi video database and shown to perform close to the level of top performing reduced and full reference VQA algorithms.

Hierarchical event selection for video storyboards with a case study on snooker video visualization.

Science.gov (United States)

Parry, Matthew L; Legg, Philip A; Chung, David H S; Griffiths, Iwan W; Chen, Min

2011-12-01

Video storyboard, which is a form of video visualization, summarizes the major events in a video using illustrative visualization. There are three main technical challenges in creating a video storyboard, (a) event classification, (b) event selection and (c) event illustration. Among these challenges, (a) is highly application-dependent and requires a significant amount of application specific semantics to be encoded in a system or manually specified by users. This paper focuses on challenges (b) and (c). In particular, we present a framework for hierarchical event representation, and an importance-based selection algorithm for supporting the creation of a video storyboard from a video. We consider the storyboard to be an event summarization for the whole video, whilst each individual illustration on the board is also an event summarization but for a smaller time window. We utilized a 3D visualization template for depicting and annotating events in illustrations. To demonstrate the concepts and algorithms developed, we use Snooker video visualization as a case study, because it has a concrete and agreeable set of semantic definitions for events and can make use of existing techniques of event detection and 3D reconstruction in a reliable manner. Nevertheless, most of our concepts and algorithms developed for challenges (b) and (c) can be applied to other application areas. © 2010 IEEE

Intelligent keyframe extraction for video printing

Science.gov (United States)

Zhang, Tong

2004-10-01

Nowadays most digital cameras have the functionality of taking short video clips, with the length of video ranging from several seconds to a couple of minutes. The purpose of this research is to develop an algorithm which extracts an optimal set of keyframes from each short video clip so that the user could obtain proper video frames to print out. In current video printing systems, keyframes are normally obtained by evenly sampling the video clip over time. Such an approach, however, may not reflect highlights or regions of interest in the video. Keyframes derived in this way may also be improper for video printing in terms of either content or image quality. In this paper, we present an intelligent keyframe extraction approach to derive an improved keyframe set by performing semantic analysis of the video content. For a video clip, a number of video and audio features are analyzed to first generate a candidate keyframe set. These features include accumulative color histogram and color layout differences, camera motion estimation, moving object tracking, face detection and audio event detection. Then, the candidate keyframes are clustered and evaluated to obtain a final keyframe set. The objective is to automatically generate a limited number of keyframes to show different views of the scene; to show different people and their actions in the scene; and to tell the story in the video shot. Moreover, frame extraction for video printing, which is a rather subjective problem, is considered in this work for the first time, and a semi-automatic approach is proposed.

Improved MDCT monitoring of pelvic myeloma bone disease through the use of a novel longitudinal bone subtraction post-processing algorithm

Energy Technology Data Exchange (ETDEWEB)

Horger, Marius; Thaiss, Wolfgang M.; Nikolaou, Konstantin; Kloth, Christopher [Eberhard-Karls-University Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Ditt, Hendrik [Sector Imaging and Interventional Radiology, Siemens AG Healthcare, Forchheim (Germany); Weisel, Katja [Eberhard-Karls-University Tuebingen, Department of Internal Medicine II, Tuebingen (Germany); Fritz, Jan [Johns Hopkins University School of Medcine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Liao, Shu [Siemens Medical Solutions, Malvern, PA (United States)

2017-07-15

To evaluate the diagnostic performance of a novel CT post-processing software that generates subtraction maps of baseline and follow-up CT examinations in the course of myeloma bone lesions. This study included 61 consecutive myeloma patients who underwent repeated whole-body reduced-dose MDCT at our institution between November 2013 and June 2015. CT subtraction maps classified a progressive disease (PD) vs. stable disease (SD)/remission. Bone subtraction maps (BSMs) only and in combination with 1-mm (BSM+) source images were compared with 5-mm axial/MPR scans. Haematological response categories at follow-up were: complete remission (n = 9), very good partial remission (n = 2), partial remission (n = 17) and SDh (n = 19) vs. PDh (n = 14). Five-millimetre CT scan yielded PD (n = 14) and SD/remission (n = 47) whereas bone subtraction + 1-mm axial scans (BSM+) reading resulted in PD (n = 18) and SD/remission (n = 43). Sensitivity/ specificity/accuracy for 5-mm/1-mm/BSM(alone)/BSM + in ''lesion-by-lesion'' reading was 89.4 %/98.9 %/98.3 %/ 99.5 %; 69.1 %/96.9 %/72 %/92.1 % and 83.8 %/98.4 %/92.1 %/98.3 %, respectively. The use of BSM+ resulted in a change of response classification in 9.8 % patients (n = 6) from SD to PD. BSM reading is more accurate for monitoring myeloma compared to axial scans whereas BSM+ yields similar results with 1-mm reading (gold standard) but by significantly reduced reading time. (orig.)

Improved MDCT monitoring of pelvic myeloma bone disease through the use of a novel longitudinal bone subtraction post-processing algorithm

International Nuclear Information System (INIS)

Horger, Marius; Thaiss, Wolfgang M.; Nikolaou, Konstantin; Kloth, Christopher; Ditt, Hendrik; Weisel, Katja; Fritz, Jan; Liao, Shu

2017-01-01

To evaluate the diagnostic performance of a novel CT post-processing software that generates subtraction maps of baseline and follow-up CT examinations in the course of myeloma bone lesions. This study included 61 consecutive myeloma patients who underwent repeated whole-body reduced-dose MDCT at our institution between November 2013 and June 2015. CT subtraction maps classified a progressive disease (PD) vs. stable disease (SD)/remission. Bone subtraction maps (BSMs) only and in combination with 1-mm (BSM+) source images were compared with 5-mm axial/MPR scans. Haematological response categories at follow-up were: complete remission (n = 9), very good partial remission (n = 2), partial remission (n = 17) and SDh (n = 19) vs. PDh (n = 14). Five-millimetre CT scan yielded PD (n = 14) and SD/remission (n = 47) whereas bone subtraction + 1-mm axial scans (BSM+) reading resulted in PD (n = 18) and SD/remission (n = 43). Sensitivity/ specificity/accuracy for 5-mm/1-mm/BSM(alone)/BSM + in ''lesion-by-lesion'' reading was 89.4 %/98.9 %/98.3 %/ 99.5 %; 69.1 %/96.9 %/72 %/92.1 % and 83.8 %/98.4 %/92.1 %/98.3 %, respectively. The use of BSM+ resulted in a change of response classification in 9.8 % patients (n = 6) from SD to PD. BSM reading is more accurate for monitoring myeloma compared to axial scans whereas BSM+ yields similar results with 1-mm reading (gold standard) but by significantly reduced reading time. (orig.)

Diffraction, chopping, and background subtraction for LDR

Science.gov (United States)

Wright, Edward L.

1988-01-01

The Large Deployable Reflector (LDR) will be an extremely sensitive infrared telescope if the noise due to the photons in the large thermal background is the only limiting factor. For observations with a 3 arcsec aperture in a broadband at 100 micrometers, a 20-meter LDR will emit 10(exp 12) per second, while the photon noise limited sensitivity in a deep survey observation will be 3,000 photons per second. Thus the background subtraction has to work at the 1 part per billion level. Very small amounts of scattered or diffracted energy can be significant if they are modulated by the chopper. The results are presented for 1-D and 2-D diffraction calculations for the lightweight, low-cost LDR concept that uses an active chopping quaternary to correct the wavefront errors introduced by the primary. Fourier transforms were used to evaluate the diffraction of 1 mm waves through this system. Unbalanced signals due to dust and thermal gradients were also studied.

Alpha efficiency under TL and OSL - A subtraction technique using OSL and TL to detect artificial irradiation

International Nuclear Information System (INIS)

Zink, A.J.C.; Dabis, S.; Porto, E.; Castaing, J.

2010-01-01

With the development of thermoluminescence (TL) and optically stimulated luminescence (OSL) to determine the authenticity of old ceramics, forgers use artificial irradiation by gamma ray to age modern productions. Besides fraudulent action, objects can be exposed to various sources of X-rays (e.g. radiography, security control at airports). For all these reasons, the determination of artificial irradiation is an important topic for dating art objects. The main technique to identify artificial irradiations is the subtraction technique. It is based on the fact that alpha efficiency varies according to the luminescence technique (fine grain, coarse grains, predose, OSL). Having observed a rather significant difference of alpha efficiency for TL and OSL, we propose a new subtraction technique using OSL and TL of fine grains.

Despina Hatzifotiadou: ALICE Master Class 4 - Demonstration of the software for the 2nd part of the exercise - invariant mass spectra - background subtraction and calculation of number of Kaons, Lambdas, antiLambdas.

CERN Multimedia

CERN. Geneva

2016-01-01

This is the 4th of 4 short online videos. It contains a demonstration of the software for the 2nd part of the exercise, related to invariant mass spectra - background subtraction and calculation of number of Kaons, Lambdas, antiLambdas. More details and related links on this indico event page. In more detail: What is Physics Master Classes Students after morning lectures, run programmes in the afternoon to do measurements. These tutorials are about how to use the software required to do these measurements. Background info and examples  Looking for strange particles with ALICE http://aliceinfo.cern.ch/Public/MasterCL/MasterClassWebpage.html Introduction to first part of the exercise : what are strange particles, V0 decays, invariant mass. Demonstration of the software for the 1st part of the exercise - visual identification of V0s Introduction to second part of the exercise : strangeness enhancement; centrality of lead-lead collisions; explanation of efficiency, yield, background etc Demonstr...

A simple proof of renormalization group equation in the minimal subtraction scheme

International Nuclear Information System (INIS)

Chetyrkin, K.G.

1989-04-01

We give a simple combinatorial proof of the renormalization group equation in the minimal subtraction scheme. Being mathematically rigorous, the proof avoids both the notorious complexity of techniques using parametric representations of Feynman diagrams and heuristic arguments of usual ''proofs'' calling up bare fields living in the space-time of complex dimension. It also copes easily with the general case of Green functions of arbitrary number of composite fields. (author). 24 refs

Intraarterial digital subtraction angiography in bronchogenic carcinoma treated with bronchial artery infusion

International Nuclear Information System (INIS)

Gao-Jun Teng; Xi-Lei Chai; Guang-Ru Gao; Cheng-Fong Chu; Xian-Guang Zhou; Zhu-Yi Zhang; Ru-Li Xiang

1991-01-01

Intra-arterial digital subtraction angiography (IADSA) has been used with advantage for control of the results of bronchial artery infusion of drugs for primarily unresectable bronchogenic carcinoma. The IADSA has been performed as road mapping prior to therapy. Drug treatment has been performed with 4 different regimes, depending on tumour type. Debulking and in some cases complete healing are the results, which are superior to other reported treatments. (author). 7 refs.; 4 figs.; 3 tabs

Rheumatoid Arthritis Educational Video Series

Medline Plus

Full Text Available ... Patient Webcasts / Rheumatoid Arthritis Educational Video Series Rheumatoid Arthritis Educational Video Series This series of five videos ... member of our patient care team. Managing Your Arthritis Managing Your Arthritis Managing Chronic Pain and Depression ...