High-precision Work Research Articles

Application of High-Precision Magnetic Survey to the Investigation of Mineral Resources in Halaganlawusu Area, Inner Mongolia

In this paper 1:10 000 high-precision magnetic survey work has been done using GSM-19T proton magnetometer in Halaganlawusu area. There were data processing including gridding, filtering, reduction to the pole, continuation, derivation, and so on. By precise interpretation and inference with magnetic anomaly, the distribution characteristics of basic rock mass was found out. According to the magnetic survey data and geological research, fitting-inversion of measured magnetic section P1, P2 were done. It preliminarily concluded the distribution characteristics of underground ore rock mass and achieved the effect of the geophysical prospecting.

Design of Surface Contour Detection System Based on SCM

An automatic surface contour detection system was designed. The detection precision of two sensors and the transmission accuracy of screw were important factors influencing the characteristics of the detection system. A laser displacement sensor and cable-displacement sensor were chosen in this system, which both have high precision and easy work principles. Bluetooth module could realize interaction between SCM and PC reliably and quickly in close range. After programming interaction interface using LabView, the surface contour of measured part could be acquired in real-time.

High-precision work distributions for extreme nonequilibrium processes in large systems

The distributions of work for strongly nonequilibrium processes are studied using a very general form of a large-deviation approach, which allows one to study distributions down to extremely small probabilities of almost arbitrary quantities of interest for equilibrium, nonequilibrium stationary, and even nonstationary processes. The method is applied to quickly vary the external field in a wide range B = 3 ↔ 0 for a critical (T = 2.269) two-dimensional Ising system of size L × L = 128 × 128. To obtain free-energy differences from the work distributions, they must be studied in ranges where the probabilities are as small as 10^{-240}, which is not possible using direct simulation approaches. By comparison with the exact free energies, which are available for this model for the zero-field case, one sees that the present approach allows one to obtain the free energy with a very high relative precision of 10^{-4}. This works well also for a nonzero field, i.e., for a case where standard umbrella-sampling methods are not efficient to calculate free energies. Furthermore, for the present case it is verified that the resulting distributions of work for forward and backward processes fulfill Crooks theorem with high precision. Finally, the free energy for the Ising magnet as a function of the field strength is obtained.

191 高精度セラミックス部品の形状測定に関する研究(学生賞IV,一般講演)

191 高精度セラミックス部品の形状測定に関する研究(学生賞IV,一般講演)

Evaluation of and Compensation for Thermal Deformation in a Compact CNC Lathe

Because heat sources for compact Computer Numerically Controlled (CNC) lathes are likely to be closely arranged, they may cause large and complicated thermal deformation. Previously, we developed a CNC lathe with its heat sources arranged so as to reduce thermal deformation. This lathe achieved highprecision work under stable temperatures in continuous operation. However, in some cases, it could cause rapid thermal deformation. Previously, we proposed a simple method to compensate for the thermal deformation in CNC lathes by measuring temperatures at only a few points. By developing amodified compensation method capable of estimating minute and complicated thermal deformation and applying this method to the current lathe, processing accuracy will become more precise. Thus, we evaluated the thermal deformation of a compact CNC lathe. As a result, we found that the thermal deformation of the lathe was caused not only by movable parts, such as the spindle motor, but also by non-movable parts, such as the hydraulic unit. We therefore approximated the thermal deformation caused by the non-movable parts and estimated the change in the deformation caused only by the movable parts. This enabled us to express the thermal deformation by a simple linear equation, the form of which was same as that used for previous lathes. From these results, we were able to compensate for the thermal deformation using approximate equations for both movable and non-movable parts and we applied this method to the current lathe. We confirmed that the work error can be reduced under stable conditions using this method.

车载激光系统光束控制反射镜角位移测量装置

To control of a Fast Steering Mirror(FSM) stably and precisely in the circumstances of vehicles and ships,a high precision device for angle displacement measurement was designed to provide the mirror sway angle information as a feedback signal to realize the servo closed loop control.As traditional detectors for the FSM are disadvantageous to high-precision work in the mobile circumstance,a precision grating based on the Moire fringe counting measurement principle was designed by using the Chinese characters Tian' splitting phase method.At the same time,the absolute zero point signal against jamming and temperature changing was designed through computer simulation and its contrast ratio was 0.25.Furthermore,in order to realize the miniature,the signal processing circuit was highly integrated.Experimental results indicate that the resolution of the measurement device is 0.15″and the angle precision is higher than 0.4″.This device satisfies the requirements of angle measurement precision in the mobile condition for the high-energy laser projecting systems.

Nuclear size effects in rotational spectra: A tale with a twist

We report a 4-component relativistic benchmark study of the isotopic field shift in the rotational spectrum of three diatomic molecules: TlI, PbTe and PtSi. A central quantity in the theory is the derivative with respect to internuclear distance of an effective electron density associated with a given nucleus, calculated at the equilibrium distance. The effective density, which is related to the mean electron density within the nuclear volume, is usually replaced with the contact density, that is, the electron density at the origin of the nucleus. Our computational study shows that for the chosen systems this induces errors on the order of 10%, which is not acceptable for high-precision work. On the other hand, the systematic nature of the error suggests that it can be handled by an atom-specific correction factor. Our calibration study reveals that relativistic effects increase the contact density gradient by about an order of magnitude, and that the proper transformation of the associated property operator is mandatory in 1- and 2-component relativistic calculations. Our results show very good agreement with the experimental data presented by Schlembach and Tiemann [Chem. Phys. 68 (1982) 21], but disagree completely with the revised results given by the same group in a later paper [Chem. Phys. 93 (1985) 349]. We have carefully re-derived the relevant formulas and cannot see that the rescaling of results is justified. Curiously previous DFT calculations agree quite well with the revised results for TlI and PbTe, but we demonstrate that this is because the authors inadvertently employed a non-relativistic Hamiltonian, which by chance induces an error of the same magnitude as the suggested scaling. For the PtSi molecule our results for the correction term due to nuclear volume disagree with experiment by a factor five, and we recommend a re-examination of the experimental data.

The Laguerre inequalities and the zeros of the Riemann ξ-function

The main result of this article shows that some finite Fourier cosine transform of the Jacobi θ-function, the ‘truncated’ Riemann ξ-function, has at least two non-real zeros. The proof is based on the Laguerre inequality and some high-precision numerical work. Infinite Fourier cosine transforms of kernels related to the Jacobi θ-function are also discussed.

Cosmological perturbation theory for baryons and dark matter: One-loop corrections in the renormalized perturbation theory framework

We generalize the `renormalized' perturbation theory (RPT) formalism of Crocce & Scoccimarro (2006a) to deal with multiple fluids in the Universe and here we present calculations up to the one-loop level. We apply the approach to the non-linear evolution of baryon and cold dark matter (CDM) perturbations, evolving from distinct sets of initial conditions. In current models of structure formation, it is standard practice to treat baryons and CDM as an effective single component fluid. In this approximation, one uses a weighed sum of late-time baryon and CDM transfer functions to set initial conditions. Here, we explore whether this approach can be used for high precision work. We show that, even for a pure linear treatment, there is a large-scale scale-dependent bias between baryons and CDM for WMAP5 cosmology. This bias is >1% until the present day, when it is driven towards unity through gravitational relaxation. Using the RPT formalism we test this approximation in the non-linear regime, and show that the CDM power spectrum in the 2-component fluid differs from that obtained from a 1-component fluid by ~3% on scales of order k~0.05 h/Mpc at z=10, and by ~0.5% at z=0. However, for the case of baryons the situation is worse and we find that the power spectrum is suppressed by ~15% on scales k~0.05 h/Mpc at z=10, and by ~3-5% at z=0, relative to the total matter. Importantly, besides the suppression of the spectrum, baryonic acoustic oscillations (BAO) are amplified for baryon and damped for CDM spectra. Thus, high precision modeling of baryons can not be probed through CDM only simulations; detection significance of BAO will be amplified in probes that study baryonic matter. Total mass can be modeled accurately using a 1-component fluid approach at all times. (Abridged)

Confidence and Accuracy in Determination of the Critical State Friction Angle

ABSTRACT The critical state friction angle, φc, is a parameter of interest in many geotechnical analyses dealing with cohesionless soils. However, despite the triaxial test being widely used to estimate this parameter, the accuracy achievable from a limited number of triaxial tests is unknown. Accuracy is of particular interest in industry, where typically only a few soil tests are possible due to budget limitations. Statistical analysis of an extensive high quality triaxial testing program from the literature is used here to obtain guidance on the number, density range, and pressure range of triaxial tests required to reach a specified level of confidence in the critical state friction angle. The adequacy of the estimating methodology is then tested against a smaller and independent set of triaxial tests on the same sand, performed in a commercial testing laboratory. The results suggest about six drained triaxial tests are needed for routine engineering where a precision of ±1.0° may suffice. However, for research or high precision work, more than twenty drained triaxial tests may be needed to determine φc to an accuracy of ±0.5° at 90% confidence. In all cases, tested samples should be uniformly distributed across the range of the soil's relative density.

Earth's Oldest Rocks.: MARTIN J. VAN KRANENDONK, R. HUGH SMITHIES, and VICKIE C. BENNETT, Editors. Pp. 1307. 2007. Developments in Precambrian Geology. 15. El-sevier. Amsterdam. ISBN-13: 978-0-444-52810-0, ISBN-10: 0-444-52810-5. Price: USD150.

I fondly remember a graduate class in the early 1980s on Archean geology at Queen’s University in Kingston, Canada, run by Herb Helmsteadt, Dugald Carmichael, Ed Ferrar, and John Haynes, with most other members of staff chipping in with talks and discussions. It was a very holistic, integrated way of teaching students about greenstone belts and shear zone-hosted gold deposits, komatiites, stromatolites, and so forth. This cross-disciplinary teaching was a “trademark” of the earth sciences at Queen’s, then way ahead of its time. The class had interesting and enthusiastic students, many eager to map and analyze Archean rocks of the Canadian Shield and, in particular, the Slave craton and the Superior province. Some are now leaders in Archean studies (and authors of chapters in this book; the principal editor of this book, too, completed his Ph.D. in this department). The most interesting aspect of the geology graduates from Queen’s University (and from others throughout Canada) is the sustained collegiate manner in which they set about their tasks to study the ancient real estate of Canada, including the Acasta gneisses, now recognized as the oldest preserved rocks on our planet (described in chapter 3.1). Their systematic collaboration has yielded the most comprehensive “open source” inventory of ancient lithosphere available anywhere in the world. Field-mapping has remained a prime objective, well supported today by a number of excellent geochronology laboratories that have sprung up all over the place, rooted in the superb high-precision work at the Ontario Museum and the mentorship of Tom Krogh. In the mid-1980s, the geologists also joined forces with an emerging geophysics consortium, culminating in the Lithoprobe program that systematically paved geotransects across Canada, producing seismic images of its crust (www.lithoprobe.ca). Other geophysical methods such as teleseismic and magnetotelluric probing joined in to look deeper into the lithosphere …

605 高精度加工実現のためのパラレルメカニズム式工作機械とその加工経路生成法の研究(OS9-1,オーガナイズドセッション:9 ロボット技術とメカトロ制御技術)

605 高精度加工実現のためのパラレルメカニズム式工作機械とその加工経路生成法の研究(OS9-1,オーガナイズドセッション:9 ロボット技術とメカトロ制御技術)

Project of ultrahigh-vacuum double-crystal monochromator

The project is aimed at the development of ultrahigh-vacuum mechanics and construction of devices with features allowing high-precision work in a warmed-up volume. The fundamental part of projected monochromator is a precise linear motion mechanism, linear stage, which can bear a warming-up in vacuum up to t=400°C without any change in its parameters. It is the tense friction wave transmission that serves to transfer the motion to the stage in the vacuum volume. The mechanism for precision tuning of the second crystal also has an original design and its compactness allows an easier solution of many design issues concerning the whole monochromator.

Experimental muscle pain modulates muscle activity and work performance differently during high and low precision use of a computer mouse

The aim was to investigate the influence of experimental muscle pain on performance and upper extremity muscle activity during occupational work requiring different levels of precision. Experimental muscle pain was induced by infusing hypertonic saline (0.3 ml, 5% NaCl) into the extensor carpi ulnaris (ECU) muscle. The same amount of isotonic saline was infused on a separate day to act as a control. Tasks requiring use of a computer mouse with high and low levels of precision were performed during the two sessions. Electromyographic (EMG) activity was measured from the ECU, the flexor carpi radialis (FCR) and the trapezius muscles. A group of 13 men participated in the study. Performance measured as work cycle time, cursor movements on the screen, and velocity of cursor movement were unaffected by muscle pain. The ECU muscle pain did not modulate EMG profiles of either the trapezius or FCR muscles either during high or during low precision work. During the low precision work the painful ECU muscle showed lower EMG activity in specific phases of the work cycle (highest activity phases) compared to the control session (P<0.05), whereas during the high precision work, experimental pain had no effect on the activity of the ECU muscle. In conclusion experimental muscle pain seems to modulate motor control differently depending on the precision level of the task. This may be of importance for our understanding of why some tasks lead to chronic musculoskeletal disorders.

Inverse Compton Scattering in Mildly Relativistic Plasma

We investigated the effect of inverse Compton scattering in mildly relativistic static and moving plasmas with low optical depth using Monte Carlo simulations, and calculated the Sunyaev-Zel'dovich effect in the cosmic background radiation. Our semi-analytic method is based on a separation of photon diffusion in frequency and real space. We use Monte Carlo simulation to derive the intensity and frequency of the scattered photons for a monochromatic incoming radiation. The outgoing spectrum is determined by integrating over the spectrum of the incoming radiation using the intensity to determine the correct weight. This method makes it possible to study the emerging radiation as a function of frequency and direction. As a first application we have studied the effects of finite optical depth and gas infall on the Sunyaev-Zel'dovich effect (not possible with the extended Kompaneets equation) and discuss the parameter range in which the Boltzmann equation and its expansions can be used. For high temperature clusters ($k_B T_e \gtrsim 15$ keV) relativistic corrections based on a fifth order expansion of the extended Kompaneets equation seriously underestimate the Sunyaev-Zel'dovich effect at high frequencies. The contribution from plasma infall is less important for reasonable velocities. We give a convenient analytical expression for the dependence of the cross-over frequency on temperature, optical depth, and gas infall speed. Optical depth effects are often more important than relativistic corrections, and should be taken into account for high-precision work, but are smaller than the typical kinematic effect from cluster radial velocities.

Measurement and assessment of geometric imperfections in thin-walled panels

Thin-walled members may be subject to performance limitations arising through local or distortional buckling of slender elements comprising the cross-section of the member, or overall buckling of the member. The effects of structural instability may be aggravated by the presence of geometric imperfections in these elements. An investigation is presented into methods of measuring and assessing geometric imperfections in cold-rolled thin-walled steel panels. These methods can be used to characterise the geometry of prismatic thin-walled members that exhibit performance sensitivity due to geometric imperfections. The measurement procedures investigated include close-range photogrammetry, precise optical levelling, and the use of a co-ordinate measurement machine. The assessment procedure comprises a least-squares spectral decomposition of the measurements to characterise the imperfections existent in the panels under investigation, and estimates of the precision of the derived Fourier coefficients are used to inter-compare the three measurement procedures. The investigation has demonstrated that statistically significant imperfections may exist in thin-walled members at short and medium wavelengths, leading to a reduction in the load carrying capacity. Both optical levelling and the co-ordinate measurement machine technique can yield desirable results, but for high precision work, use of the co-ordinate measurement machine is recommended.

An electromyographic study of dental work

Musculoskeletal disorders are common among dentists, and have been ascribed to the demands of high precision work and sustained static loading in the neck-shoulder region, combined with a flexed and rotated cervical spine. In order to determine muscular load levels during dentistry, activity in neck, shoulder, and arm muscles was recorded using an electromyography technique (EMG). Normalized mean, median, 10th and 90th percentile EMG amplitude levels (% maximal reference contraction, %max-RVC) were calculated during ordinary dental work. Among the muscles investigated, the trapezius muscle on both sides had the highest mean (the right trapezius 9.0% and the left 7.6% of max-RVC) and 10th percentile amplitude levels (both about 2% of max-RVC). The trapezius muscles showed similar myoelectric activity on the right and left side, probably because of similar muscular static load on the both sides. The right extensor carpi radialis muscle had a significantly higher muscular load level than the left one, possibly due to stabilization demands on the dominant wrist during demanding precision work. The infraspinatus muscle had low activity level on both sides, reflecting that the dentists worked with a small degree of arm elevation and external rotation. The dentistry work thus seems to generate relatively high muscular load on both trapezius and dominant extensor-carpi-radialis, and relatively low load on the infraspinatus muscle.

The Construction of 4 Dense Astrometric Standard Areas With the Carlsberg Automatic Meridian Circle

High precision work in photographic astrometry requires accurate monitoring of the telescope+filter+emulsion system being used.

A computer controlled potentiometric titrator for quantitative determination of uranium

The modified Davies and Gray method is frequently used for the potentiometric titration of uranium. It is based upon the reduction of U(VI) to U(IV) with a reductant (e.g. Fe + +) followed by a selective oxidation of the excess of reductant and subsequent titration of U(IV) with potassium dichromate (K 2Cr 2O 7). Interference from other elements is low, but the method is rather cumbersome due to the number of reactants to be added before the titration is started. The timing of these additions also plays a role. In order to render the titration less dependent on human factors and with the aim of reaching high reproducibility, a computer controlled system has been designed and set-up. Reagents are added by five computer controlled burettes. A program allows the choice of volumes and waiting times, and commands the start of the final titration which is followed by the microprocessor of the automatic potentiometric titrator. In this way a routine uranium titration can be completed in about twelve minutes. Reproducibilities of the order of ± 0.15% are achievable in routine operation. For high precision work, the titrator is used as an end-point detector. Titrant is added manually by mass, so as to react with > 99% of the uranium. The residual uranium is then titrated automatically by volume with diluted titrant. The precision can be improved by a factor of approximately ten.

Cylindrical Penning traps with orthogonalized anharmonicity compensation

Compensated Penning traps with cylindrical ring and compensation electrodes and flat endcaps are considered as alternatives to high precision traps with hyperbolic ring and endcap electrodes. Cylindrical and flat electrodes can be more easily and precisely constructed, especially for the very small traps which are desirable for ion trapping. They are easily studied since Laplace's equation can be solved by a series expansion which is discussed in most electricity and magnetism textbooks. A central new result is that a judicious choice of the height-to-diameter ratio for a cylindrical trap makes the axial oscillation frequency of a trapped particle independent of adjustments in the compensation potential, just as has been recently proposed for hyperbolic traps. Other properties of such orthogonalized cylindrical traps appear to be adequate for particle trapping so that properly designed cylindrical traps are promising alternatives for high precision work, ready for laboratory testing. Whether or not cylindrical traps will be able to replace hyperbolic traps entirely for the highest precision work, a major point of this paper is that orthogonalized traps can be built with any reasonable electrode geometry. Special access traps with orthogonalized anharmonicity compensation are thus completely feasible, though numerical calculations will be generally required for their design.