scholarly journals A Heterodyne Interferometer with Separated Beam Paths for High-Precision Displacement and Angular Measurements

Author(s):  
Guido Straube ◽  
Juan Sebastian Fischer Calderón ◽  
Ingo Ortlepp ◽  
Roland Füßl ◽  
Eberhard Manske

AbstractAs standard concepts for precision positioning within a machine reach their limits with increasing measurement volumes, inverse concepts are a promising approach for addressing this problem. The inverse principle entails other limitations, as for high-precision positioning of a sensor head within a large measurement volume, three four-beam interferometers are required in order to measure all necessary translations and rotations of the sensor head and reconstruct the topography of the reference system consisting of fixed mirrors in the x-, y-, and z-directions. We present the principle of a passive heterodyne laser interferometer with consequently separated beam paths for the individual heterodyne frequencies. The beam path design is illustrated and described, as well as the design of the signal-processing and evaluation algorithm, which is implemented using a System-On-a-Chip with an integrated FPGA, CPU, and A/D converters. A streamlined bench-top optical assembly was set up and measurements were carried out to investigate the remaining non-linearities. Additionally, reference measurements with a commercial homodyne interferometer were executed.

1977 ◽  
Vol 16 (02) ◽  
pp. 112-115 ◽  
Author(s):  
C. O. Köhler ◽  
G. Wagner ◽  
U. Wolber

The entire field of information processing in medicine is today already spread out and branched to such an extent that it is no longer possible to set up a survey on relevant literature as a whole. But even in narrow parts of medical informatics it is hardly possible for the individual scientist to keep up to date with new literature. Strictly defined special bibliographies on certain topics are most helpful.In our days, problems of optimal patient scheduling and exploitation of resources are gaining more and more importance. Scientists are working on the solution of these problems in many places.The bibliography on »Patient Scheduling« presented here contains but a few basic theoretical papers on the problem of waiting queues which are of importance in the area of medical care. Most of the papers cited are concerned with practical approaches to a solution and describe current systems in medicine.In listing the literature, we were assisted by Mrs. Wieland, Mr. Dusberger and Mr. Henn, in data acquisition and computer handling by Mrs. Gieß and Mr. Schlaefer. We wish to thank all those mentioned for their assistance.


2011 ◽  
Vol 131 (3) ◽  
pp. 275-282
Author(s):  
Kenta Seki ◽  
Hiroaki Matsuura ◽  
Makoto Iwasaki ◽  
Hiromu Hirai ◽  
Soichi Tohyama

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.


2019 ◽  
Vol 130 (629) ◽  
pp. 1384-1415 ◽  
Author(s):  
Ralph Hertwig ◽  
Michael D Ryall

ABSTRACT Thaler and Sunstein (2008) advance the concept of ‘nudge’ policies—non-regulatory and non-fiscal mechanisms designed to enlist people's cognitive biases or motivational deficits so as to guide their behaviour in a desired direction. A core assumption of this approach is that policymakers make artful use of people's cognitive biases and motivational deficits in ways that serve the ultimate interests of the nudged individual. We analyse a model of dynamic policymaking in which the policymaker's preferences are not always aligned with those of the individual. One novelty of our set-up is that the policymaker has the option to implement a ‘boost’ policy, equipping the individual with the competence to overcome the nudge-enabling bias once and for all. Our main result identifies conditions under which the policymaker chooses not to boost in order to preserve the option of using the nudge (and its associated bias) in the future—even though boosting is in the immediate best interests of both the policymaker and the individual. We extend our analysis to situations in which the policymaker can be removed (e.g., through an election) and in which the policymaker is similarly prone to bias. We conclude with a discussion of some policy implications of these findings.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1830
Author(s):  
Yiheng Zhou ◽  
Baoquan Kou ◽  
He Zhang ◽  
Lu Zhang ◽  
Likun Wang

The multi-degree-of-freedom high-precision positioning system (MHPS) is one of the key technologies in many advanced industrial applications. In this paper, a novel hyperbolic magnetic field voice coil actuator using a rhombus magnet array (HMF-VCA) for MHPS is proposed. Benefiting from the especially designed rhombus magnet array, the proposed HMF-VCA has the advantage of excellent force uniformity, which makes it suitable for multi-degree-of-freedom high-precision positioning applications. First, the basic structure and operation principles of the HMF-VCA are presented. Second, the six-degree-of-freedom force and torque characteristic of the HMF-VCA is studied by three-dimensional finite element analysis (3-D FEA). Third, the influence of structural parameters on force density and force uniformity is investigated, which is conducive to the design and optimization of the HMF-VCA. Finally, a prototype is constructed, and the comparison between the HMF-VCA and conventional VCAs proves the advantage of the proposed topology.


2019 ◽  
Vol 1 (1) ◽  
pp. 179-195 ◽  
Author(s):  
Tina Besley

This article explores concepts of teacher responsibility, accountability, being in loco parentis, and responsibilization as many advanced capitalist societies have dropped policies and practices that were set up in the mid 19th century after the Great Depression in the welfare state under Keynesian economics. Since the early 1980s most of these states have adopted neoliberal policies and market rationality for all aspects of social policy including education. Under neoliberalism, the subject theorised by Homo economicus, is one that is theorised as a rational autonomous individual, with its responsibilized behavior underpinning much of how not only teachers but students now are compleed to behace and perform. These have resulted in major shifts in attitudes to professionalism of teachers, in responsibilising individuals and so have impacted on subjectivity as the state has pulled back from all manner of social provision and has responsibilized the individual to be a consumer-citizen, a prudential and entrepreneurial self even in terms of education. The upshot is increasing use of audits, checklists and accountability regimes for teachers who are becoming increasingly a de-professionalised in a low-trust managerialist environment with students as consumers.


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