Crystal structure and charge distribution of pyrazine: effects of extinction, thermal diffuse scattering and series termination

The crystal structure and electronic charge distribution of pyrazine (1,4-diazabenzene) has been determined at 184 K by X-ray methods. The structural results of Wheatley [Acta Cryst. (1957), 10, 182-187] have been confirmed. A clear indication of bonding effects is obtained. Neither positional and thermal parameters nor difference-Fourier maps are affected by extinction. The effect of thermal diffuse scattering (TDS) on positional parameters is also negligible. However, after correction for TDS, thermal parameters increase significantly. The difference-Fourier map is influenced by TDS as well as the inclusion of high-order Fourier terms

Quality improving techniques in DIBR for free-viewpoint video

This paper evaluates our 3D view interpolation rendering algorithm and proposes a few performance improving techniques. We aim at developing a rendering method for free-viewpoint 3DTV, based on depth image warping from surrounding cameras. The key feature of our approach is warping texture and depth in the first stage simultaneously and postpone blending the new view to a later stage, thereby avoiding errors in the virtual depth map. We evaluate the rendering quality in two ways. Firstly, it is measured by varying the distance between the two nearest cameras. We have obtained a PSNR gain of 3 dB and 4.5 dB for the 'Breakdancers' and 'Ballet' sequences, respectively, compared to the performance of a recent algorithm. A second series of tests in measuring the rendering quality were performed using compressed video or images from surrounding cameras. The overall quality of the system is dominated by rendering quality and not by coding

Evolution of a Software Maintenance Organization from Cost Center to Service Center

The paper describes experiences with the evolution of a software maintenance organization for digital set-top boxes of a leading electronics company from a cost center towards a service center. Several years ago a dedicated software maintenance group was constituted. As the costs for software maintenance were not recovered from the customers, the software maintenance group was merely considered a cost center. Through starting a metrics program for software maintenance and defining a service strategy with various service levels, the software maintenance group generated sufficient revenues to become self-supporting. An important conclusion is that the use of ITIL (IT infrastructure library) service support has helped to develop a better customer focused approach, which is considered as the most important critical success factor for a professional, self-supporting maintenance organization

Behavioral state detection of newborns based on facial expression analysis

Prematurely born infants are observed at a Neonatal Intensive Care Unit (NICU) for medical treatment. Whereas vital body functions are continuously monitored, their incubator is covered by a blanket for medical reasons. This prevents visual observation of the newborns during most time of the day, while it is known that the facial expression can give valuable information about the presence of discomfort. This prompted the authors to develop a prototype of an automated video survey system for the detection of discomfort in newborn babies by analysis of their facial expression. Since only a reliable and situation-independent system is useful, we focus at robustness against non-ideal viewpoints and lighting conditions. Our proposed algorithm automatically segments the face from the background and localizes the eye, eyebrow and mouth regions. Based upon measurements in these regions, a hierarchical classifier is employed to discriminate between the behavioral states sleep, awake and cry. We have evaluated the described prototype system on recordings of three healthy newborns, and we show that our algorithm operates with approximately 95% accuracy. Small changes in viewpoint and lighting conditions are allowed, but when there is a major reduction in light, or when the viewpoint is far from frontal, the algorithm fails. © 2009 Springer Berlin Heidelberg

Grain size effect on the switching current in soft ferroelectric lead zirconate titanate

Recently, we reported on the appearance of a double peak in the switching current during the reverse poling. In the present paper, the switching current measurements have been carried out on a soft lead zirconate titanate as a function of grain size. While in small grains only a small single switching peak is observed, large grains, however, showed double peak switching, as commonly observed in this material. The pyroelectric coefficient curves show a consistent trend with the switching curves. This behavior is attributed to non-180° domain switching during the reversed poling case as a result of residual stresses developed during forward poling. ©2007 American Institute of Physic

Performance-efficient architecture for free-viewpoint 3DTV receiver

This paper presents algorithmic and architectural solutions for a free-viewpoint 3DTV receiver system. We describe our rendering algorithm and evaluate performance-related challenges in mapping of the algorithm on a receiver board of which the architecture is outlined. It is found that the required processing load exceeds the provisioning of dual Virtex5 FPGAs. We develop several mapping optimizations to fit the rendering algorithm into a platform

Prediction of transient tumor enlargement using MRI tumor texture after radiosurgery on vestibular schwannoma

Purpose: Vestibular schwannomas (VSs) are uncommon benign brain tumors, generally treated using Gamma Knife radiosurgery (GKRS). However, due to the possible adverse effect of transient tumor enlargement (TTE), large VS tumors are often surgically removed instead of treated radiosurgically. Since microsurgery is highly invasive and results in a significant increased risk of complications, GKRS is generally preferred. Therefore, prediction of TTE for large VS tumors can improve overall VS treatment and enable physicians to select the most optimal treatment strategy on an individual basis. Currently, there are no clinical factors known to be predictive for TTE. In this research, we aim at predicting TTE following GKRS using texture features extracted from MRI scans. Methods: We analyzed clinical data of patients with VSs treated at our