Some Statistical Considerations on Window Width and Matching Stability of Images.

In stereo matching of images, sample cross-covariances are used commonly as a criterion for deciding whether matched points are truly conjugate. Hereupon window width is a serious parameters to dominate matching stability. This paper argues about relation of matching stability with window width in terms of statistical behavior of sample covariances. For simple circumstances of analysis auto-covariances of a single image are considered instead of cross-covariances of stereo ones. First the mean and variance of sample auto-covariances are derived with parameters, window width and positional lag. Secondly they are evaluated from the correlation function estimated on an aerial image under the assumption of ergodicity to observe how they vary according as two parameters vary. From this result a variation factor is proved usefull to estimate appropriate window width

Rectification of Digitized Aerial Photographic Image

A practical example of digital rectification of tilted photographs using a drum scanning micro densitometer and general purpose computers is depicted. The present research covers rectification of projective distorsions, occuring when the camera axis is not truly vertical, and affine distorsions due to curvature of a drum of a scanner. For this purpose, fundamental mathematical expressions were derived. And some pixel interpolation methods necessary for image reconstruction were compared experimentally. The examples revealed, however, that the film was deformed so complexly that they could not be corrected sufficiently only by affine transformation. Accuracy of rectification was checked by use of stereo aerial photographs in terms of residual y-parallaxes. The result showed residual y-parallaxes of ± 1 pixel (± 50 μm) and sometimes ± 2 pixels were observed. They seem to be caused mainly by film deformations which have not been eliminated, and their amount seems to exceed the photogrammetric tolerance

Off-Line Stereo Plotting by Means of Image Correlation

The algorithm of automatic stereo plotting by iterative image correlation from aerial photographs and the corresponding empirical tests are described. The algorithm is oriented to off-line process, using a image scanner and a general purpose computer, and consists of 3 hierarchical correlation steps, based on one-dimensional matching using usual correlation maximum. For the correlation calculation, the FFT is effectively used. Though some defects exist in the algorithm at present, close contour plotting to middle scale maps is available except in hilly regions, in which marked features in ground covers do not exist

Complexity of the Collision and Near-Collision Attack on SHA-0 with Different Message Schedules

SHA-0 employs a primitive polynomnial of degree 16 over GF(2) in its message schedule. There are 2048 primitive polynomials of degree 16 over GF(2). For each primitive polynomial, a SHA-0 variant can be constructed. In this paper, the security of 2048 variants is analyzed against the Chabaud-Joux attack proposed in CRYPTO\u2798. The analysis shows that all the variants could be collision-attacked by using near-collisions as a tool and thus the replacement of the primitive polynomial is not a proper way to make SHA-0 secure. However, it is shown that the selection of the variants highly affects the complexity of the attack. Furthermore, a collision in the most vulnerable variant is presented. It is obtained by the original Chabaud-Joux attack without any improvements

CAMERA CALIBRATION TECHNIQUE BY PAN-CLOSEUP EXPOSURES FOR INDUSTRIAL VISION METROLOGY

A high precision and easy-to-use CCD camera calibration technique for industrial vision metrology is discussed. A well-known method is self-calibration by convergent camera configuration of a two- or three-dimensional target field. Only with this technique the central part of a sensor area is precisely calibrated, but off the centre the precision rapidly deteriorates. The presented technique is a simultaneous adjustment of both pan and close exposures, which compensates the lack of distortion data in the fringe area of the sensor and offers both uniform and high-precision calibration. Some patterns of camera configuration are compared in an experiment in terms of the precision and its uniformity over the sensor. And the combination of convergent pan exposures and vertical close exposures is proved the best. 1

Visualization of Stent Lumen in MR Imaging: Relationship with Stent Design and RF Direction

Magnetic resonance imaging (MRI) visualization of metallic stent lumens is possible if the stent structure counteracts eddy currents in the lumen induced by the radio frequency magnetic field, B1. To examine the effectiveness of various stent designs in counteracting eddy currents, we anchored eight copper stent models and 2 commercially available nickel-titanium alloy (Nitinol) stents in a gel phantom, perpendicular or parallel to the direction of B1. A mesh stent lumen showed hypointensity irrespective of its alignment relative to B1. A solenoid stent lumen showed hypointensity with the stent axis parallel to B1, but it had the same signal intensity as outside the lumen when perpendicular to B1. A Moebius stent lumen showed no signal reduction, irrespective of alignment relative to B1. Lumens of the commercially available stents showed hypointensity regardless of alignment relative to B1. Computer simulation revealed that the signal intensities of the stents corresponded to magnetic flux densities of B1 in the stents, which are modified by the structure of the stent. While in vivo MRI viewing of a Moebius stent lumen is likely possible regardless of axis alignment, inherent structural weakness may be problematic. As a more practical choice, the solenoid stent is easier to manufacture and generates no hypointensive signal when the axis is parallel to B0

Noninvasive Demonstration of Dual Coronary Artery Fistulas to Main Pulmonary Artery with 64-Slice Multidetector-Computed Tomography: A Case Report

Coronary artery fistulas, including coronary pulmonary fistulas, are usually discovered accidently among the adult population when undergoing invasive coronary angiographies. We report here a 58-year-old woman with dual fistulas originating from the left anterior descending coronary artery and right coronary sinus to the main pulmonary artery, demonstrating noninvasively with multidetector-computed tomography (MDCT) and transthoracic echocardiography (TTE)

A RUNX-targeted gene switch-off approach modulates the BIRC5/PIF1-p21 pathway and reduces glioblastoma growth in mice

Glioblastoma is the most common adult brain tumour, representing a high degree of malignancy. Transcription factors such as RUNX1 are believed to be involved in the malignancy of glioblastoma. RUNX1 functions as an oncogene or tumour suppressor gene with diverse target genes. Details of the effects of RUNX1 on the acquisition of malignancy in glioblastoma remain unclear. Here, we show that RUNX1 downregulates p21 by enhancing expressions of BIRC5 and PIF1, conferring anti-apoptotic properties on glioblastoma. A gene switch-off therapy using alkylating agent-conjugated pyrrole-imidazole polyamides, designed to fit the RUNX1 DNA groove, decreased expression levels of BIRC5 and PIF1 and induced apoptosis and cell cycle arrest via p21. The RUNX1-BIRC5/PIF1-p21 pathway appears to reflect refractory characteristics of glioblastoma and thus holds promise as a therapeutic target. RUNX gene switch-off therapy may represent a novel treatment for glioblastoma

The Pavlik harness in the treatment of developmentally dislocated hips: results of Japanese multicenter studies in 1994 and 2008

AbstractBackgroundIt has already been more than 50years since the Pavlik harness was introduced in Japan, and today the Pavlik harness is widely recognized as the standard initial treatment modality for developmental dysplasia of the hip. We performed a multicenter nationwide questionnaire study concerning the results of Pavlik harness treatment twice in 1994 and 2008.MethodsIn 1994 and in 2008, we sent questionnaires to 12 institutes in Japan specializing mainly in pediatric orthopedics. We compare the results of these two studies and discuss differences in reduction rates, incidence of avascular necrosis in the femoral epiphysis and the percentage of joints with acceptable morphology (Severin grade I+II/total) at skeletal maturity. We statistically assessed these results to see whether there were changes in the treatment outcomes over this 14-year period.ResultsReduction of the dislocated hips was obtained by the Pavlik harness in 80.2% (1990/2481 hips; 1994) and 81.9% (1248/1523 hips; 2008). The incidences of avascular necrosis of the proximal femoral epiphysis in the dysplastic hips were 14.3% (119/835 hips; 1994) and 11.5% (76/663 hips; 2008). The type of avascular necrosis in hips from the 2008 study was determined according to the classification of Kalamchi and MacEwen: 24/69 hips (34.8%) were classified as group I; 20/69 hips (29.0%) as group II; 11/69 hips (15.9%) as group Ill; 14/69 hips (20.3%) as group IV. The percentages of hips with acceptable outcomes at skeletal maturity discerned from Severin X-ray changes (grade I+II/total) were 72.3% (604/835 hips; 1994) and 77.7% (488/628 hips; 2008).ConclusionReduction rates and the incidence of avascular necrosis in 2008 were statistically similar to the results in 1994. The rate of acceptable outcome (Severin grade I+II/total) in 2008 was statistically higher than that of 1994