The normalform of a space curve and its application to surface design

x )=0 with ∥▿h∥=1. The normalform function h is (unlike the latter cases) not differentiable at curve points. Despite of this disadvantage the normalform is a suitable tool for designing surfaces which can be treated as common implicit surfaces. Many examples (bisector surfaces, constant distance sum/product surfaces, metamorphoses, blending surfaces, smooth approximation surfaces) demonstrate applications of the normalform to surface design. Published online: 25 July 2001     

Characterization and oxidation behavior of MTCVD Ti–B–N coatings

In this work, Ti–B–N coatings have been prepared by moderate temperature chemical vapor deposition (MTCVD). The effect of a varying boron concentrations (9.6 and 55.4 at.%) on the chemical composition and the oxidation behavior was investigated by XRD, SEM, WDS, XPS and Raman spectroscopy. The results clearly demonstrate a good correlation between the different techniques. The same transition trends were observed in the examined Ti–B–N system in the progression from TiN to TiB₂ by the addition of boron. At boron concentrations ≥ 18 at.%, the coatings reveal a two phase structure comprising a nanocrystalline TiN phase embedded in an amorphous TiB₂ matrix. In Ti–B–N coatings with boron concentrations ≤ 18 at.%, the high sensitivity of Raman spectroscopy enabled the identification of an amorphous TiB phase.The oxidation behavior of Ti–B–N coatings was found to be affected by the boron concentration as well. Boron concentrations ≤ 18 at.% improve the thermal stability compared to TiN, most likely due to the TiB phase present in these coatings. Ti–B–N coatings with a high boron concentration show a higher degree of oxidation compared to TiN manifested in a higher oxide layer thickness. In addition, these coatings tend to form boron oxides on their surface, which lead to the formation of metastable anatase rather than the thermodynamically stable rutile.     

Evaluation of Product and Process Design Robustness

Critical design decisions are commonly made throughout the product development process assuming known material and process behavior. However, stochastic variation during manufacture can inadvertently result in inferior or unacceptable product performance and reduced production yields. Stochastic simulations have been developed to estimate the end-use performance distribution prior to the commitment of hard tooling. This article proposes a definition for integrated product and process robustness, and extends existing stochastic methods to model the important role of the manufacturing flexibility in elimination of defects and product optimization. The goal is to enable the designer to understand and account for not only the negative effects of manufacturing variation, but also the positive impact of manufacturing flexibility wherein instantaneous corrections in the manufacturing process can frequently improve the product quality and eliminate flaws in the product design. Then, a methodology is introduced and contrasted with conventional development methods in the evaluation of best practices for development of a molded plastic component.     

On the uplink SIR of a mobile in soft handoff with applications to BLER estimation

We focus on the uplink and derive the joint probability density function of the signal to interference (+noise) ratios (SIRs) at the base stations (BSs) for the general case of n BSs supporting a mobile in soft handoff, each using maximal ratio combining with m-fold diversity. We then calculate the correlations between the SIRs for some example cases. The insights gained here lead to a fresh approach to the estimation of the block error rate (BLER) at the output of the frame selector (FS), which is the usual measure of quality of service in UMTS. For low specified BLER (e.g., 0.1%), the method of counting cyclic redundancy code errors requires an impractically large number of data blocks for an accurate estimate of BLER. We propose to estimate the BLER at the FS output based on measurements performed by the individual BSs. The initial setting of the target SIR in the outer loop power control can then be selected in the same way in order to expedite BLER convergence to the desired setting.     

Datenschutzrechtliche Aspekte bei der weitergabe von IP-Adressen

Im Alltag eines Administrators werden rund um den Betrieb von Web- und E-Mail-Servern in vielerlei Hinsicht IP-Adressen gespeichert oder sogar an Dritte übermittelt. H?ufig übersehen oder gar wissentlich übergangen wird dabei die inzwischen kaum mehr umstrittene Tatsache, dass es sich bei IP-Adressen um personenbezogene Daten handelt, die unter die Regeln des Datenschutzes fallen. Aber welche konkreten technischen und rechtlichen Konsequenzen hat diese Einordnung, insbesondere wenn die Daten an Dritte weitergegeben werden?