Preview of evalution models of geodetic control measurements

In the contribution the classification of evaluation\ud models of geodetic control measurements is given.\ud Contemporary geodetic measurement systems offer\ud possibilities to measure movements and deformations\ud of object in all details. As such they give the opportunity\ud to fulfill the trends in engineering surveying which\ud intend to determine not only the geometrical changes\ud of an object but above all to describe the dynamic of\ud the changes in space and time as subject of influencing\ud forces. This procedure demands the use of dynamic\ud models, which consider the object, causative forces and\ud the resulting deformations as the entirety. By\ud simplification of dynamic models the static, kinematic\ud and (identity) models are derived

Use of Automatic Target Recognition System for the Displacement Measurements in a Small Diameter Tunnel Ahead of the Face of the Motorway Tunnel During Excavation

During construction of the Sentvid tunnel a unique opportunity arose to measure the 3D displacements ahead of the motorway tunnel excavation face, since the exploratory tunnel was already constructed in the axis of the main tunnel. According to reviewed literature such measurements had not been performed yet and several problems regarding equipment and complete scheme of the experiment needed to be overcome. The paper gives a brief description of the Sentvid tunnel project, presents significant factors that affected the choice of the geodetic equipment and describes the scheme of the experiment. A special attention is focused on the problems relating to the operation of the instrument in demanding environmental conditions (water, dust)

Have Your Cake and Eat It, Too: Engineering Measurements at Fabrication for Channel Design and Process Control

This paper demonstrates the acquisition of advanced circuit board performance parameters from breakaway test coupons measured right at the PCB fabricator. We show how to acquire S-parameter and TDR-based measurements up to 30 GHz using robust probes and test coupon fixtures. The measurements provide pass/fail tests for process control and they provide model parameters as feedback to improve channel design. By way of example, we demonstrate measurements of several representative test coupons, perform total loss tests, such as SET2DIL, and extract design parameters that can be used to improve EDA channel models. We also demonstrate measurement and tests of impedance uniformity and differential delay skew, both of which are influenced by glass weave position and copper fabrication variations. Archiving fundamental S-parameter and TDR measurements allows for further extraction of important design-to-fabrication feedback while in the process of tracking PCB process statistics

The Use of Kalman Filer for Kinematic Geodetic Ob- servations

Surveying of deformations and movements, which means measuring of processes and ana- lyzing of observations, today requires interdisciplinary work of experts from different disci- plines. The advantage of geodetic procedures in surveying of deformations and movements is their definition in space and time. In the case of deformations and movements regar- ded as kinematic, Kalman filter can be used for the processing of kinematic terrestrial observations. For the PhD thesis the concrete measurements of the kinematic process have been performed. Measurements were made with one of the most modern electronic tacheometers capable of automatic tracking of a moving reflector. Kinematic process was carried out based on the motion of the trolley with a reflector moving along a straight trajectory, given in a local coordinate system. To capture measurements a software was prepared to establish communication with the instrument, to automatically track the re- flector and to acquire and store the measurements. For the processing of measurements the discrete Wiener process acceleration model was used, with prior application of the law of propagation of variances and covariances. The dissertation focuses on the statistical evaluation of the developed model, which allows us to detect the presence of gross errors in measurements and provides adequacy of the given input values. Originality of the thesis is represented by independent control of mathematical stochastic model reliability based on an independent reference trajectory. The advantage of the reference trajectory is the possibility of simultaneous evaluation of the model and capabilities of the instrument. The contribution of the work is in giving several demands that need extra attention in the case of kinematic geodetic terrestrial processes

Geodetic measurements in tunnel Šentvid

This article describes the geodetic monitoring of the\ud impact that the tunnel excavations have on the rock\ud mass at the tunnel face in the Šentvid tunnel. In the\ud preliminary phase, an exploratory gallery was built\ud almost along the main tunnel axis to collect geological,\ud tectonic zone and other relevant data. The exploratory\ud gallery is now being used for geodetic and other\ud monitoring of the impact of tunnel excavations on the\ud surrounding rock mass. Before the beginning, methods\ud of point and station point stabilization, and a\ud measurement method were chosen. Thus, the chosen\ud methods are the method of 3D inner intersection with\ud adjustment of redundant observation for station point\ud determination, and the polar method for calculating\ud 3D coordinates of detail points. The method of\ud determination of station point was chosen because of\ud the far reaching influence that the tunnel excavations\ud have on rock mass behaviour at the tunnel face

Improved modelling of helium and tritium production for spallation targets

Reliable predictions of light charged particle production in spallation reactions are important to correctly assess gas production in spallation targets. In particular, the helium production yield is important for assessing damage in the window separating the accelerator vacuum from a spallation target, and tritium is a major contributor to the target radioactivity. Up to now, the models available in the MCNPX transport code, including the widely used default option Bertini-Dresner and the INCL4.2-ABLA combination of models, were not able to correctly predict light charged particle yields. The work done recently on both the intranuclear cascade model INCL4, in which cluster emission through a coalescence process has been introduced, and on the de-excitation model ABLA allows correcting these deficiencies. This paper shows that the coalescence emission plays an important role in the tritium and $^3He$ production and that the combination of the newly developed versions of the codes, INCL4.5-ABLA07, now lead to good predictions of both helium and tritium cross sections over a wide incident energy range. Comparisons with other available models are also presented.Comment: 6 pages, 9 figure

Break-up stage restoration in multifragmentation reactions

In the case of Xe+Sn at 32 MeV/nucleon multifragmentation reaction break-up fragments are built-up from the experimentally detected ones using evaluations of light particle evaporation multiplicities which thus settle fragment internal excitation. Freeze-out characteristics are extracted from experimental kinetic energy spectra under the assumption of full decoupling between fragment formation and energy dissipated in different degrees of freedom. Thermal kinetic energy is determined uniquely while for freeze-out volume - collective energy a multiple solution is obtained. Coherence between the solutions of the break-up restoration algorithm and the predictions of a multifragmentation model with identical definition of primary fragments is regarded as a way to select the true value. The broad kinetic energy spectrum of $^3$He is consistent with break-up genesis of this isotope.Comment: 17 pages, 5 figure

High Dielectric Permittivity in AFe1/2_{1 / 2}B1/2_{1 / 2}O3_{3} Nonferroelectric Perovskite Ceramics (A - Ba, Sr, Ca; B - Nb, Ta, Sb)

AFe$_{1 / 2}$B$_{1 / 2}$O$_{3}$(A- Ba, Sr, Ca; B-Nb, Ta, Sb) ceramics were synthesized and temperature dependencies of the dielectric permittivity were measured at different frequencies. The experimental data obtained show very high values of the dielectric permittivity in a wide temperature interval that is inherent to so-called high-k materials. The analyses of these data establish a Maxwell-Wagner mechanism as a main source for the phenomenon observed.Comment: 6 pages, 7 figure