过程变革中的自相似性

本文试图按照社会技术系统的概念来描述企业，这一概念包括将企业作为一个自相似系统进行建模，这类系统能够不断变化和发展以便达到完成其任务的所有要求，为此目的，有必要对结构和过程的自相似性加以并行考虑，拥有各部门和工作小组的企业结构的自相似性与过程变革的自相似性。     

Microsensor-aided measurements of cellular signalling and metabolism on tumor cells. The cell monitoring system (cms(R))

Microsensors provide instruments particularly suited for the rapid, noninvasive and on-line analysis of cell and tissue cultures. The microsensor system presented in this paper is a modular arrangement of various planar and nonplanar sensor elements for the measurement of physiological parameters of cell cultures. An optic access to the cultures (e.g. for light microscopy and spectrophotometric techniques) is also provided for a parallel and comparative data acquisition. The system was originally designed for biomedical research in chemotherapy (predicative chemotherapy assays) and pharmacology but it turned out to be also an effective tool for toxicological and environmental research.     

Computer aided engineering of automated guided vehicle systems

Automated Guided Vehicle Systems (AGVS) are becoming more and more the main material handling devices in flexible manufacturing systems. The design of an AGVS network is a complex, iterative process. It requires a sequence of geometrical layout drawings and an analytical and computational evaluations. The ability to analyze the AGVS design directly and interactively from the layout drawing would substantially increase the productivity of the design engineer.

A Computer Aided Engineering (CAE) design tool must provide the following three capabilities. First, it must allow the easy, interactive and graphical definition of the system by providing standard drawing symbols and the required operations on those symbols. Second, it must support direct, interactive analysis of the design from within the drafting package. Third, it must provide for the necessary output to interface with off line simulation, analysis and verification programs.

The possibility of extending the prominent CAD packages CADAM and AutoCad to perform CAE of AGVS is examined. A prototype of such a CAE tool has been developed based upon the Autocad package and implemented on a microcomputer. Design and implementation issues, as well as future research areas, will be reported on.     

Detecting evoked potentials with SVD- and ICA-based statistical models.

In the functional diagnostics of human sensor systems, the analysis of stimulus responses embedded in an electroencephalogram (EEG), e.g. evoked potentials (EPs), is of high relevance for an objective electrophysiological assessment. The aim of this work is to detect weak EPs from highly contaminated signal traces. In principle this can be done using methods of spatiotemporal signal processing, which simultaneously increase the weak SNR (signal-to-noise ratio). However, methods based on any a priori knowledge of spatial or temporal properties as well as the propagation speed and direction are not applicable. Models with adjustable signal properties similar to real cortical activity are necessary for the development and evaluation of new methods of spatiotemporal signal processing. A model is needed which can be used in forward- and inverse-projection calculations. This study aims to develop a signal generator of the background EEG activity with embedded EPs of fully adjustable signal parameters. The study also compares the results of modeled signal analysis by known methods for signal decomposition, SVD (singular value decomposition) and ICA (independent component analysis).     

Numerical investigations on premixed spherical flames for Lewis numbers larger than unity

We present numerical simulations of premixed spherical flames under μg conditions using the thermo-diffusive approximation. The employed numerical method is based on a finite volume discretization with explicit Runge-Kutta time integration, both of second order. A multiresolution technique is used to represent the solution on an adaptive, locally refined grid, which allows efficient and accurate computations at a reduced computational cost. We study the ignition limit, i.e. the critical radius for which the flame extinguishes, for varying Lewis numbers larger than unity. We also present fully three-dimensional simulations of initially stretched spherical flames and show their relaxation towards spherical flames, which justifies the one-dimensional spherically symmetric simulations.     

Green fluorescent protein tag for studies of drug-induced translocation of nucleolar protein RH-II/Gu

We have constructed a human osteogenic sarcoma cell line, U-2 OS/GFP-Gu, that expresses nucleolar RNA helicase RH-II/Gu tagged with green fluorescent protein (GFP). The presence of a GFP tag does not inhibit RNA helicase, RNA folding and ATPase activities of RH-II/Gu protein. The derived cell line responds to cytotoxic agents like the parental cell line U-2 OS. In the presence of either actinomycin D or toyocamycin, the GFP-RH-II/Gu fusion protein translocates from the nucleolus to the nucleoplasm in the same way as the translocation of endogenous RH-II/Gu. The drug-induced translocation of GFP-RH-II/Gu is easily monitored by direct observation of live cells in vivo. This cell line can be used to screen cytotoxic drugs and to study the mechanisms of drug-induced translocation of RH-II/Gu. The cellular localization of RH-II/Gu during the cell cycle-dependent formation of the nucleolus is readily monitored. Real-time results are obtained more quickly without the disadvantages associated with cell fixation and immunofluorescence-based staining.     

A periodogram-based method for the detection of steady-statevisually evoked potentials

The task of objective perimetry is to scan the visual field and find an answer about the function of the visual system. Flicker-burst stimulation-a physiological sensible combination of transient and steady-state stimulation-is used to generate deterministic sinusoidal responses or visually evoked potentials (VEPs) at the visual cortex, which are derived from the electroencephalogram by a suitable electrode array. Here, the authors develop a new method for the detection of VEPs. Based on the periodogram of a time-series, they test the data for the presence of hidden periodic components, which correspond to steady-state VEPs. The method is applied successfully to real data