Automated model generation for performance engineering of building automation networks

Large technical systems need to be designed both reliable and efficient. Specialized design tools offer therefore a simplified, abstract design and extend details autonomously in the background. Analytic and simulation based models could improve the quality by testing and dimensioning the design before implementation, but setting up the necessary models is time-consuming and expensive. Therefore many developers ask for analysis tools which are able to create their models from the available information in the design tools. This paper presents such an automated modeling approach basing on an existing design database at the example of a network analysis for building automation fieldbuses. The process of automated modeling is unfolded, and the potentials and limitations are discussed.     

SPC: Fast and Efficient Scalable Predictive Coding of Animated Meshes

Animated meshes are often represented by a sequence of static meshes with constant connectivity. Due to their frame-based representation they usually occupy a vast amount of bandwidth or disk space. We present a fast and efficient scalable predictive coding (SPC) scheme for frame-based representations of animated meshes. SPC decomposes animated meshes in spatial and temporal layers which are efficiently encoded in one pass through the animation. Coding is performed in a streamable and scalable fashion. Dependencies between neighbouring spatial and temporal layers are predictively exploited using the already encoded spatio-temporal neighbourhood. Prediction is performed in the space of rotation-invariant coordinates compensating local rigid motion. SPC supports spatial and temporal scalability, and it enables efficient compression as well as fast encoding and decoding. Parts of SPC were adopted in the MPEG-4 FAMC standard. However, SPC significantly outperforms the streaming mode of FAMC with coding gains of over 33%, while in comparison to the scalable FAMC, SPC achieves coding gains of up to 15%. SPC has the additional advantage over FAMC of achieving real-time encoding and decoding rates while having only low memory requirements. Compared to some other non-scalable state-of-the-art approaches, SPC shows superior compression performance with gains of over 16% in bit-rate.     

On aspectualizing component models

Server‐side component models such as Enterprise JavaBeans (EJB) add powerful abstractions to the bare ‘business objects’ layer in order to support a clean separation of server‐side application logic from other concerns such as distribution, security, transaction management and persistence. An improved separation of concerns is also the main goal of aspect‐oriented programming (AOP). This paper compares the two approaches and reasons about the possibility of substituting (parts of) component models using AOP mechanisms. We conclude that AOP is a promising approach to eliminate important shortcomings of the container‐based component approach. However, our analysis of concrete aspect‐oriented languages shows that current AOP technology is not yet mature enough to supersede component models. Copyright © 2003 John Wiley & Sons, Ltd.     

Vapor- and liquid-phase adsorption of alcohol and water in silicalite-1 synthesized in fluoride media

In this work, batch-adsorption experiments and molecular simulations are employed to probe the adsorption of binary mixtures containing ethanol or a linear alkane-1,n-diol solvated in water or ethanol onto silicalite-1. Since the batch-adsorption experiments require an additional relationship to determine the amount of solute (and solvent) adsorbed, as only the bulk liquid reservoir can be probed directly, molecular simulations are used to provide a relationship between solute and solvent adsorption for input to the experimental bulk measurements. The combination of bulk experimental measurements and simulated solute–solvent relationship yields solvent and solute loadings that are self-consistent with simulation alone, and allow for an assessment of the various assumptions made in the literature. At low solution concentrations, the solute loading calculated is independent of the assumption made. At high concentrations, a negligent choice of assumption can lead to systematic overestimation or underestimation of calculated solute loading.     

Psychological predictors of college students’ cell phone use while driving

Despite the known risk, many people talk on a phone while driving. This study explored psychological predictors of cell phone use while driving. College students (final N = 69) completed a survey and predicted their driving performance both with and without a simultaneous phone conversation. Their actual performance on a driving simulator was then assessed. Cell phone use reduced performance on the simulation task. Further, perceiving oneself as good at compensating for driving distractions, overestimating one's performance on the driving simulator, and high illusory control predicted more frequent cell phone use while driving in everyday life. Finally, those who talked more frequently on a phone while driving had poorer real-world driving records. These findings suggest illusory control and positive illusions partly explain driver's decisions of whether to use cell phones while driving.     

Polarization-stable oxide-confined VCSELs with enhanced single-mode output power via monolithically integrated inverted grating reliefs

It has been proven experimentally that the single-mode output power of vertical-cavity surface-emitting lasers (VCSELs) can be increased significantly with an inverted surface relief and that a reliable polarization control can be achieved by a monolithically integrated surface grating for even highly multimode VCSELs. In this paper, for the first time we report on a combination of these two techniques, namely, an inverted grating relief to realize VCSELs with a stable polarization and an increased single-mode output power. A statistically relevant number of monolithic, oxide-confined 850-nm VCSELs is investigated. All devices with a grating relief have a stable polarization with its orientation defined by the grating grooves. On the other hand, 64% of the reference devices exhibit polarization switches. Concurrently, the maximum single-mode output power is enhanced by more than a factor of three. Within the entire range of implemented grating parameters, the worst grating relief device still delivers higher single-mode output power than the best reference device.     

Reliable polarization control of VCSELs through monolithically integrated surface gratings: a comparative theoretical and experimental study

Vertical cavity surface-emitting lasers (VCSELs) with a well-defined and predictable polarization of the emitted light are sought for a number of applications. In this paper, we show that one can define and stabilize the polarization of single- and multimode oxide-confined VCSELs with a monolithically integrated dielectric surface grating. In recent years, we have developed a three-dimensional, fully vectorial model for VCSELs, which proved to nicely reproduce the experimental results of quite complex structures, such as noncircular devices and phase-coupled VCSEL arrays. This software allows for the first time to analyze the effects of a dielectric grating in the output facet cap layer and its capability to fix the polarization of the emitted light. It is here employed as a design tool, yielding excellent agreement with the experimental data. Since the simulations predict the polarization behavior to be sensitively dependent on the grating parameters, hundreds of VCSELs with 99 different parameter sets, two grating orientations and active diameters of 4 and 7 /spl mu/m have been analyzed. Even VCSELs with eight or more coexisting modes turned out to be linearly polarized with an orthogonal polarization suppression ratio in excess of 15 dB. Theoretical and experimental emission far-fields are compared, and it is shown that diffraction side lobes can be prevented with properly chosen grating parameters which simultaneously ensure full polarization stability.     

Sexuality in head and neck cancer patients

We describe a patient with Hirschsprung disease and autism. High-resolution karyotyping indicated that the patient has an interstitial deletion of 20p11.22-p11.23. Microsatellite analysis showed a deletion involving a 5-6 cM region from the maternally derived chromosome 20. The deleted region is proximal to, and does not overlap, the recently characterized Alagille syndrome region. This region of 20p has not yet been implicated in Hirschsprung disease or autism. However, this region contains several genes that could plausibly contribute to any phenotype that includes abnormal neural development.     

Pediatric forearm fractures. Diagnosis, therapy and possible complications

Nonoperative management of forearm fractures in children has a good outcome in over 90% of all cases. In our own series (n = 102) there were only six children (6.1%) with significant limitation (> 25 degrees) of forearm rotation. In these cases two out of four (50%) were located in the proximal third but only two out of 68 in the distal third. Indications for operative stabilization are the following: compound fractures, fractures associated with vessel and nerve injuries, joint fractures, dislocated fractures of the middle and proximal third, and Monteggia/Galeazzi injuries. As implants intramedullary devices are preferred. Twenty children were managed with elastic IM rods between 1994 and 1995 at our institution. At final follow-up all had a free ROM and a maximal axial malalignment of less than 5 degrees. In the region of the distal forearm K-wires are useful. Plates play a dominant role for corrections and nonunions; external skeletal stabilization is indicated for temporary fixation in compound fractures.