Gravitational pose estimation

Problem of relative pose estimation between a camera and rigid object, given an object model with feature points and image(s) with respective image points (hence known correspondence) has been extensively studied in the literature. We propose a “correspondenceless” method called gravitational pose estimation (GPE), which is inspired by classical mechanics. GPE can handle occlusion and uses only one image (i.e., perspective projection of the object). GPE creates a simulated gravitational field from the image and lets the object model move and rotate in that force field, starting from an initial pose. Experiments were carried out with both real and synthetic images. Results show that GPE is robust, consistent, and fast (runs in less than a minute). On the average (including up to 30% occlusion cases) it finds the orientation within 6° and the position within 17% of the object’s diameter. SoftPOSIT was so far the best correspondenceless method in the literature that works with a single image and point-based object model like GPE. However, SoftPOSIT’s convergence to a result is sensitive to the choice of initial pose. Even “random start SoftPOSIT,” which performs multiple runs of SoftPOSIT with different initial poses, can often fail. However, SoftPOSIT finds the pose with great precision when it is able to converge. We have also integrated GPE and SoftPOSIT into a single method called GPEsoftPOSIT, which finds the orientation within 3° and the position within 10% of the object’s diameter even under occlusion. In GPEsoftPOSIT, GPE finds a pose that is very close to the true pose, and then SoftPOSIT is used to enhance accuracy of the result. Unlike SoftPOSIT, GPE also has the ability to work with three points as well as planar object models.     

Clinical Consequences of Intermittent Elevation of C-Reactive Protein Level in Hemodialysis Patients

The presence of persistently high C‐reactive protein (CRP) levels is well known to be associated with a state of inflammation, malnutrition, and erythropoietin resistance in hemodialysis (HD) population. Meanwhile, a substantial group of patients present with intermittent elevations of CRP levels, and its clinical consequences are unclear. We designed this study to compare the inflammatory and nutritional parameters and erythropoietin requirements in HD patients with persistent or intermittent CRP elevation and those with CRP levels in without. We included 100 HD patients [age: 48.4 ± 14.3 years; HD duration: 69.3 ± 49.0 months (minimum 12 months)]. The 6‐month retrospective clinical and laboratory data were retrieved from the patient records, and those with chronic inflammatory disease, malignancy, infectious complications, and surgery were excluded. The monthly determined CRP levels (at least 6 for each patient) were reviewed, and the patients were grouped according to their CRP levels as those with persistent (group 1), intermittent (at least one level of CRP 10 mg/L) (group 2), and those with CRP in normal ranges set by the laboratory (group 3). We compared the fibrinogen, ICAM‐1, VCAM‐1, albumin, prealbumin, normalized protein catabolic rate (nPCR), interdialytic weight gain (IDWG), and rHuEPO/kg/Hct results of the patient groups. The patient groups revealed significant differences in terms of fibrinogen (p < 0.001), albumin (p < 0.0001), prealbumin (p < 0.007), ICAM‐1 (p < 00.2) levels and nPCR (p < 0.03), IDWG (p < 0.02), and rHuEPO/kg/Hct (p < 0.03) values. Group 2 presented to be in risk of inflammation and malnutrition with a decrease in albumin levels and nPCR and presence of rHUEpo resistance when compared to patients in group 3. We conclude that, similar to HD patients with persistently high CRP levels, those with intermittent elevation of CRP must also be considered to be in a state of chronic inflammatory response associated with malnutrition and erythropoietin resistance. This signifies the importance of regulatory monitoring of CRP in HD population.     

Analysis of information leakage from encrypted Skype conversations

Voice over IP (VoIP) has experienced a tremendous growth over the last few years and is now widely used among the population and for business purposes. The security of such VoIP systems is often assumed, creating a false sense of privacy. This paper investigates in detail the leakage of information from Skype, a widely used and protected VoIP application. Experiments have shown that isolated phonemes can be classified and given sentences identified. By using the dynamic time warping (DTW) algorithm, frequently used in speech processing, an accuracy of 60% can be reached. The results can be further improved by choosing specific training data and reach an accuracy of 83% under specific conditions. The initial results being speaker dependent, an approach involving the Kalman filter is proposed to extract the kernel of all training signals.     

Swelling and dye adsorption properties of radiation induced N-vinyl-2-pyrrolidone/acrylonitrile hydrogels

Summary Swollen hydrogels were prepared by γ-radiation copolymerization of N-vinyl-2-pyrrolidone and acrylonitrile. The influence of radiation dose and feed composition on the swelling properties, diffusional behavior of water and diffusion coefficients of the hydrogel systems were examined. N-vinyl-2-pyrrolidone/acrylonitrile hydrogels were swollen in the range 50–850%. Water diffusion to the hydrogels generally was a non-Fickian type diffusion. The hydrogel were used in the studies of adsorption of some water soluble dye such as basic blue 9, tetraethyl rhodamine, xylidine ponceau 2R, indigo carmine, helianthin and erythrosine, and of a vitamin riboflavin (Vitamin B₂). Received: 9 June 1998/Revised version: 23 July 1998/Accepted: 23 July 1998     

Utilization of a very high lime fly ash for improvement of Izmir clay

This paper presents an investigation into the stabilization of a soft clay subgrade of a military zone in Izmir, Turkey with a very high lime fly ash. Zero%, 5%, 10%, 15% and 20% (m/m) of the soil was replaced with fly ash. In addition to the control specimen, four different stabilized soil samples were prepared mixing fly ash with soil at optimum water contents determined by standard proctor test. Experiments lasted for 3 months and the unconfined compressive strength and shear strength parameters, cohesion and internal friction angle, were determined after 1, 7, 28 and 90 days. It was found that, inclusion of fly ash improved the properties of the soil. The improvements, appearing with increasing fly-ash content, were attributed to the pozzolanic reaction and pore refinement effect of fly ash as well as its high free-lime content.     

Twin gas jet-assisted laser drilling through thermal barrier-coated nickel alloy substrates

Laser fabrication of cooling holes in certain parts of the aero-engine components involves percussion or trepan drilling at acute angles to the surface. These parts are often covered with plasma sprayed ceramic thermal barrier coatings (TBC) to protect them from reaching excessive temperatures in hot engine environments. Delamination of the TBC is the main problem of laser drilling acute angled holes in the coated components. The present study investigates a novel technique enabling to drill through thermal barrier-coated materials without delamination. The technique is based on the control of the melt flow trajectories and impact angle on the hole walls utilizing a secondary gas jet. Delamination-free laser-drilled holes inclined at 30° to the workpiece surface have been demonstrated. Finite volume-based numerical modelling of melt flow during the drilling process was developed to understand the effect of secondary jet in the prevention of delamination.     

关联大系统的分散自适应控制：孤立子系统动力学已知情况

本文研究了一类关联大系统的分散自适应控制问题，拓广了分散自适应控制的应用范围，在孤立子系统（ＭＩＭＯ）动力学信息已知，关联强度未知的情况下，论文提出了结构相当简单的分散自适应控制策略，它可保证闭环的分散自适应控制系统具有良好的动力学行为；系统的所有信号都全局有界，进一步，在状态调节情况下，关联大系统状态趋向于零；在模型跟踪情况下，跟踪误差可以通过控制器的设计使之任意小。     

On state reduction of incompletely specified finite state machines

State reduction of incompletely specified finite state machines (ISFSMs) is an important task in optimization of sequential circuit design and known as an NP-complete problem. Removal of redundant states reduces the logic, because of this, chip area decreases. In addition, test generation is easier when the sequential circuit is irredundant. In this paper, we present a heuristic for state reduction of ISFSMs. The proposed heuristic is based on a branch-and-bound search technique and identification of sets of compatible states of a given ISFSM specification. We have obtained results as good as the best exact method in the literature but with significantly better run-times.     

Using perceptual relation of regularity and anisotropy in the texture with independent component model for defect detection

This paper addresses the raw textile defect detection problem using independent components approach with insights from human vision system. Human vision system is known to have specialized receptive fields that respond to certain type of input signals. Orientation-selective bar cells and grating cells are examples of receptive fields in the primary visual cortex that are selective to periodic- and aperiodic-patterns, respectively. Regularity and anisotropy are two high-level features of texture perception, and we can say that disruption in regularity and/or orientation field of the texture pattern causes structural defects. In our research, we observed that independent components extracted from texture images give bar or grating cell like results depending on the structure of the texture. For those textures having lower regularity and dominant local anisotropy (orientation or directionality), independent components look similar to bar cells whereas textures with high regularity and lower anisotropy have independent components acting like grating cells. Thus, we will expect different bar or grating cell like independent components to respond to defective and defect-free regions. With this motivation, statistical analysis of the structure of the texture by means of independent components and then extraction of the disturbance in the structure can be a promising approach to understand perception of local disorder of texture in human vision system. In this paper, we will show how to detect regions of structural defects in raw textile data that have certain regularity and local orientation characteristics with the application of independent component analysis (ICA), and we will present results on real textile images with detailed discussions.