Relative Scale Factor Research Articles

Scaling of the linear viscoelasticity of entangled poly(ethylene oxide) aqueous solutions

The dynamic modulus of polymer solutions and melts can be expressed as a universal function of reduced frequency when the modulus is scaled by a characteristic value according to the scaling theory of polymer physics. Although the plot of the scaled modulus as a function of the scaled frequency supports the theory, it suffers from considerable scattered distribution of data points around the hypothetical master curve. Compared with the master curve of the time–temperature superposition (TTS) of polymer melts, the master curve of polymer solutions has poor quality. Furthermore, the scale factors of polymer solutions may not show a clear dependency on molecular weight and concentrations. Experimental errors and molecular weight distribution appear to enhance the inaccuracy of the master curve. Therefore, we apply a global optimization for the superposition of the viscoelastic data of polymer solutions with various molecular weights and concentrations. The global optimization resulted in the superposition of data as accurate as that of TTS. Furthermore, the numerically determined shift factors, which were relative scale factors, showed clear dependences on molecular weight and concentrations. We compared our global optimization with previous scaling methodologies.

From bench to bedside: 64Cu/177Lu 1C1m-Fc anti TEM-1: mice-to-human dosimetry extrapolations for future theranostic applications

The development of diagnostic and therapeutic radiopharmaceuticals is an hot topic in nuclear medicine. Several radiolabeled antibodies are under development necessitating both biokinetic and dosimetry extrapolations for effective human translation. The validation of different animal-to-human dosimetry extrapolation methods still is an open issue. This study reports the mice-to-human dosimetry extrapolation of 64Cu/177Lu 1C1m-Fc anti-TEM-1 for theranostic application in soft-tissue sarcomas. We adopt four methods; direct mice-to-human extrapolation (M1); dosimetry extrapolation considering a relative mass scaling factor (M2), application of a metabolic scaling factor (M3) and combination of M2 and M3 (M4). Predicted in-human dosimetry for the [64Cu]Cu-1C1m-Fc resulted in an effective dose of 0.05 mSv/MBq. Absorbed dose (AD) extrapolation for the [177Lu]Lu-1C1m-Fc indicated that the AD of 2 Gy and 4 Gy to the red-marrow and total-body can be reached with 5–10 GBq and 25–30 GBq of therapeutic activity administration respectively depending on applied dosimetry method. Dosimetry extrapolation methods provided significantly different absorbed doses in organs. Dosimetry properties for the [64Cu]Cu-1C1m-Fc are suitable for a diagnostic in-human use. The therapeutic application of [177Lu]Lu-1C1m-Fc presents challenges and would benefit from further assessments in animals’ models such as dogs before moving into the clinic.

Effects of sampling rate on multiscale entropy of electroencephalogram time series

A physiological system encompasses numerous components that function at various time scales. To characterize the scale-dependent feature, the multiscale entropy (MSE) analysis has been proposed to describe the complex processes on multiple time scales. However, MSE analysis uses the relative scale factors to reveal the time-related dynamics, which may cause in-comparability of results from diverse studies with inconsistent sampling rates. In this study, in addition to the conventional MSE with relative scale factors, we also expressed MSE with absolute time scales (MaSE). We compared the effects of sampling rates on MSE and MaSE of simulated and real EEG time series. The results show that the previously found phenomenon (down-sampling can increase sample entropy) is just the projection of the compressing effect of down-sampling on MSE. And we have also shown the compressing effect of down-sampling on MSE does not change MaSE’s profile, despite some minor right-sliding. In addition, by analyzing a public EEG dataset of emotional states, we have demonstrated improved classification rate after choosing appropriate sampling rate. We have finally proposed a working strategy to choose an appropriate sampling rate, and suggested using MaSE to avoid confusion caused by sampling rate inconsistency. This novel study may apply to a broad range of studies that would traditionally utilize sample entropy and MSE to analyze the complexity of an underlying dynamic process.

How to correct relative voxel scale factors for calculations of vector-difference Fourier maps in cryo-EM

The atomic coordinates derived from cryo-electron microscopy (cryo-EM) maps can be inaccurate when the voxel scaling factors are not properly calibrated. Here, we describe a method for correcting relative voxel scaling factors between pairs of cryo-EM maps for the same or similar structures that are expanded or contracted relative to each other. We find that the correction of scaling factors reduces the amplitude differences of Fourier-inverted structure factors from voxel-rescaled maps by up to 20–30%, as shown by two cryo-EM maps of the SARS-CoV-2 spike protein measured at pH 4.0 and pH 8.0. This allows for the calculation of the difference map after properly scaling, revealing differences between the two structures for individual amino acid residues. Unexpectedly, the analysis uncovers two previously overlooked differences of amino acid residues in structures and their local structural changes. Furthermore, we demonstrate the method as applied to two cryo-EM maps of monomeric apo-photosystem II from the cyanobacteria Synechocystis sp. PCC 6803 and Thermosynechococcus elongatus. The resulting difference maps reveal many changes in the peripheral transmembrane PsbX subunit between the two species.

Three-position characterization for the adjustment of MEMS accelerometer scale factor

Up/down static and the six-position least squares calibration methods are commonly used in research conducted on adjustment of the micro-electromechanical systems (MEMS) accelerometer scale factor (or sensitivity). When applying these methods, it is difficult to adjust the accelerometer measuring axis parallel to the gravity direction, causing an error in the accelerometer scale factor. In this paper, a three-position scale factor characterization that does not require corrections of the precise coincident of the measuring axis with the direction of gravity is studied. The method uses the up/down calibration method to obtain the coarse scale factor and bias. The coarse adjustment coefficient is then used to convert the accelerometer output data in the horizontal, up, and down positions into acceleration. The horizontal acceleration is used to estimate the scale factor error. Next, the estimated scale factor error is used to modify the coarse scale factor, producing a more accurate scale factor. The adjustment results from simulation and experiments on triaxial MEMS accelerometers show that the proposed method can effectively correct the scale factor error caused by inability to align the accelerometer measurement axis parallel to the gravity line, with a relative scale factor error of 0.07%, improving the accuracy of the accelerometer scale factor.

Effective Method for Identifying Student Learning Ability During Classroom Focused on Cognitive Performance

Cognitive performance is associated with learning ability and academic success of a student. Since an individual student may lose attention during class, a study on cognitive performance and focus sustainability can improve their academic performance. Moreover, cognitive performance is influenced by various factors called cognitive factors including gender, body mass index, and alcohol drinking state. These factors encourage performance to improve or decline eSense meters, attention, and relaxation. Therefore, this study proposes an effective method to identify brain cognitive performance of a student by using a decision tree algorithm with relative scale and cognitive factors. Brainwaves of students are recorded by electroencephalography during 45 min class with separated four periods of detection, 10 min per period. The detected data are calculated to cognitive performance value via relative scale equation. It is compiled into a decision tree with mentioned factors for accurate classification. The accuracy results of the decision tree model for four periods of cognitive performance are 100%, 100%, 94%, and 98%; which are strongly acceptable. In addition, there are different levels of cognitive performance including low, neutral, good, and high. It indicates that some students have a lower level of performance during the class. In conclusion, the proposed method can identify cognitive performance level of individual students accurately. Classified results can improve learning performance of student along with enhancing class management.

Quantification of Hepatic Organic Anion Transport Proteins OAT2 and OAT7 in Human Liver Tissue and Primary Hepatocytes.

Organic anion transporter (OAT) 2 and OAT7 were recently shown to be involved in the hepatic uptake of drugs; however, there is limited understanding of the population variability in the expression of these transporters in liver. There is also a need to derive relative expression-based scaling factors (REFs) that can be used to bridge in vitro functional data to the in vivo drug disposition. To this end, we quantified OAT2 and OAT7 surrogate peptide abundance in a large number of human liver tissue samples ( n = 52), as well as several single-donor cryopreserved human hepatocyte lots ( n = 30) by a novel, validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The average surrogate peptide expression of OAT2 and OAT7 in the liver samples was 1.52 ± 0.57 and 4.63 ± 1.58 fmol/μg membrane protein, respectively. While we noted statistically significant differences ( p < 0.05) in hepatocyte and liver tissue abundances for both OAT2 and OAT7, the differences were relatively small (1.8- and 1.5-fold difference in median values, respectively). Large interindividual variability was noted in the hepatic expression of OAT2 (16-fold in liver tissue and 23-fold in hepatocytes). OAT7, on the other hand, showed less interindividual variability (4-fold) in the livers, but high variability for the hepatocyte lots (27-fold). A significant positive correlation in OAT2 and OAT7 expression was observed, but expression levels were neither associated with age nor sex. In conclusion, our data suggest marked interindividual variability in the hepatic expression of OAT2/7, which may contribute to the pharmacokinetic variability of their substrates. Because both transporters were less abundant in hepatocytes than livers, a REF-based approach is recommended when scaling in vitro hepatocyte transport data to predict hepatic drug clearance and liver exposure of OAT2/7 substrates.

Detailed modeling of oxalic acid degradation by UV-TiO2 nanoparticles: Importance of light scattering and photoreactor scale-up

A detailed computational fluid dynamics model is presented that integrates reactor hydrodynamics with advanced light models and UV-TiO2 advanced oxidation kinetics to yield the degradation of oxalic acid in a dispersed-phase photoreactor. Model predictions were first compared against experimental data obtained from the literature and subsequently used in a parametric study for investigating scale-up effects associated with both process and photoreactor variables. Investigated variables included: TiO2 concentration (5–400 mg L−1), initial oxalic acid concentration (0.9–32 mg L−1), lamp irradiance (100–10,000 W m−2), background fluid absorbance (0-30 m−1), reactor size (1/4-4 as relative scaling factor), lamp orientation (0-360°) and flowrate (2.5–10 m3 h−1). The analysis revealed that an optimum in oxalic acid degradation is observed when the TiO2 concentration was controlled in the 20–40 mg L−1 range (depending on lamp irradiance). While lamp orientation showed minimal impact, reactor size and flowrate emerged as key variables for photoreactor design. Moreover, an increase in initial oxalic acid concentration substantially reduced oxalic acid degradation performance observed at high loadings. Also, TiO2 activation and photoreactor degradation performance were impacted negatively by light competition with background fluid absorbance.

A rapid and robust gradient measurement technique using dynamic single-point imaging.

We propose a new gradient measurement technique based on dynamic single-point imaging (SPI), which allows simple, rapid, and robust measurement of k-space trajectory. To enable gradient measurement, we utilize the variable field-of-view (FOV) property of dynamic SPI, which is dependent on gradient shape. First, one-dimensional (1D) dynamic SPI data are acquired from a targeted gradient axis, and then relative FOV scaling factors between 1D images or k-spaces at varying encoding times are found. These relative scaling factors are the relative k-space position that can be used for image reconstruction. The gradient measurement technique also can be used to estimate the gradient impulse response function for reproducible gradient estimation as a linear time invariant system. The proposed measurement technique was used to improve reconstructed image quality in 3D ultrashort echo, 2D spiral, and multi-echo bipolar gradient-echo imaging. In multi-echo bipolar gradient-echo imaging, measurement of the k-space trajectory allowed the use of a ramp-sampled trajectory for improved acquisition speed (approximately 30%) and more accurate quantitative fat and water separation in a phantom. The proposed dynamic SPI-based method allows fast k-space trajectory measurement with a simple implementation and no additional hardware for improved image quality. Magn Reson Med 78:950-962, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Young’s modulus, thermal conductivity, electrical resistivity and coefficient of thermal expansion of mesophase pitch-based carbon fibers

Although there are several reported correlations among structural parameters, Young’s modulus (E), thermal conductivity, electrical resistivity and coefficient of thermal expansion of carbon fibers in the longitudinal direction, a single physical model has not yet been established to explain quantitatively these properties. Here a model of continuous defective graphene nanoribbons (dGNR), which are arranged in stacks, is presented to predict a number of properties of mesophase pitch (MPP)-based carbon fibers in a single physical framework. Reported in situ tensile tests and other works support the assumption that, for MPP-based carbon fibers with E>350GPa, slightly misaligned perfect graphene regions of the dGNR are longitudinally in series with defective regions of an approximately constant length δ=3nm. The longitudinal properties of the dGNR depend strongly on the average longitudinal concentration of defective regions (x) of length δ, which can be estimated from the X-ray diffraction in-plane longitudinal coherence length (La‖). The model was applied with success to high- and ultra-high-modulus commercial MPP-based carbon fibers; other fibers were also discussed. The values for the properties of the defective regions were determined and are consistent with the proposed model structure; relative values and scaling factors between properties were discussed.

Bis(ethyleneglycolato-κ2O,O′)tellurium(IV)

The title compound, C4H8O4Te, crystallized from a solution of Te4+ in ethyl­ene glycol. The TeIV atom is in a distorted seesaw coordination defined by four O atoms from two different ethyl­eneglycate ligands. The C atoms of the ethyl­eneglycate ligands are disorderd over two positions, with population parameters of 50.3 (6) and 49.7 (6)% indicating a statistical distribution. Due to the possibility to transform the primitive monoclinic unit cell into a metrically ortho­rhom­bic C unit cell, the data are twinned and were refined with the twin law -100/0-10/101 with the relative scale factor refining to 1.82 (4)% for the minor component.

Membrane Protein Quantification by Peptide-Based Mass Spectrometry Approaches: Studies on the Organic Anion-Transporting Polypeptide Family

The reliable quantification of drug transport proteins is a key element that is necessary to establish relative scaling factors for human pharmacokinetic predictions and to account for pharmacokinetic variations across populations. Herein, we report a detailed evaluation of targeted mass spectrometry-based quantification methods from the perspective of sample preparation for three major organic anion-transporting polypeptide (OATP) membrane proteins. We also demonstrate the first implementation of stable isotope labeling by amino acids in cell culture (SILAC) into the OATP quantification scheme, which hinges on label incorporation at the protein level to allow for a substantially accelerated sample preparation process with precise results. These methods will enable comparable quantifications to provide individual scaling factors as well as address potential inter-individual variability in OATP proteins that are central to transporter-mediated hepatic drug clearance. The evaluation procedures can also serve as a model for other proteolytically resistant transporters that have not been adequately detected by higher-throughput quantifications. In addition, results derived from various sample preparation conditions explicitly illustrate how the conditions have a differential impact on the quantification of different proteins. Consequently, the ratio between different proteins can be an artifact of the conditions rather than a reflection of the endogenous ratio for typical peptide-based quantifications where a stoichiometrical relationship between the proteolytic peptide and the protein is not established. To the extent that ratios determined under different sets of conditions can underlie different conclusions, our results highlight important limitations that have been underappreciated in recent drug transporter quantifications that extend peptide-based mass spectrometry tools beyond relative quantifications in order to directly compare the abundance of multiple drug transporters.

In situstudies into the formation kinetics of potassium jarosite

This paper reports the results of time-resolved synchrotron powder diffraction and small-angle scattering experiments designed to investigate the kinetics of formation of potassium jarosite by co-precipitation at 353, 368 and 393 K. Only jarosite was produced in these syntheses, and the particles that formed nucleated on the walls of the capillary reaction vessels with a disc-like shape. Relative Rietveld scale factors indicating jarosite abundance have been used as the basis for kinetic modelling of the nucleation and growth stages using a modified form of the Avrami kinetic equation. The results show that jarosite forms by a single nucleation event followed by two distinct stages of growth, each characterized by a different Avrami exponent. The value of this exponent is initially between 1 and 2, and then reduces to around 1. This suggests that jarosite growth after nucleation is controlled by effects at the solution–boundary interface, with the first stage best described by two-dimensional growth which transitions to one-dimensional growth later in the reaction. An activation energy of 89 kJ mol−1was estimated for the first stage of growth, in good agreement with previous work.

Quality evaluation of virtual slides using methods based on comparing common image areas

BackgroundThere are many scanners of glass slides on the market now. Quality of digital images produced by them may be different and pathologists who examine virtual slides on a monitor may subjectively evaluate it. However, objective comparison of quality of digital slides captured by various devices requires assessment algorithms, which will be automatically executed.MethodsIn this work such an algorithm is proposed and implemented. It is dedicated for comparing quality of virtual slides which show the same glass slide captured by two or more scanners. In the first step this method looks for the largest corresponding areas in the slides. This task is realized by defining boundaries of tissues and providing the relative scale factor. Then, a certain number of smaller areas, which show the same fragments of both slides, is selected. The chosen fragments are analyzed using Gray Level Co-occurrence Matrix (GLCM). For GLCM matrices some of the Haralick features are calculated, like contrast or entropy. Basing on results for some sample images, features appropriate for quality assessment are chosen. Aggregation of values from all selected fragments allows to compare the quality of images captured by tested devices.ResultsDescribed method was tested on two sets of ten virtual slides, acquired by scanning the same set of ten glass slides by two different devices. First set was scanned and digitized using the robotic microscope Axioscope2 (Zeiss) equipped with AxioCam Hrc CCD camera. Second set was scanned by DeskScan (Zeiss) with standard equipment. Before analyzing captured virtual slides, images were stitched and converted using software which utilizes advances in aerial and satellite imaging.The results of the experiment show that calculated quality factors are higher for virtual slides acquired using first mentioned device (Axioscope2 with AxioCam).ConclusionsResults of the tests are consistent with opinion of the pathologists who assessed quality of virtual slides captured by these devices. This shows that the method has potential in automatic evaluation of virtual slides’ quality.

Cross-Range Scaling Algorithm for ISAR Images Using 2-D Fourier Transform and Polar Mapping

This paper proposes a new method that solves the problem of inverse synthetic aperture radar image cross-range scaling by estimating the rotational velocity (RV) using the expansion-rotation-scale relationship between two range-Doppler (RD) images. This method is composed of three steps. The first step is preprocessing to construct 2-D Fourier transform images and initial polar-mapped images. In this step, two RD images are 2-D Fourier transformed to avoid the necessity of finding the rotation center; then, the transformed images are polar mapped with identical polar grids to convert rotation into translation in the θ-direction only. The second step is a coarse search that finds the angular shift that provides the maximum correlation between two polar images. The angular shift found is used as the initial relative rotation angle (RA), and the initial relative scaling factor (RSF) is calculated using the RV which is equal to the angular shift divided by the time delay between the images. The third step is the optimization of the relative RA using the Nelder-Mead approach, with the RSF updated using the relative RA derived during each iteration. In simulations using a Mig-25 aircraft, composed of ideal point scatterers, and the measured data from a Boeing 747-400, the targets were properly rescaled in the range-cross-range domain due to the accurate estimation of the RV.

Scale factors and hypothetical referenda: A clarifying note

In this note we explore in detail the importance of, and problems associated with, correcting for variance differences between data sets obtained from hypothetical and real referenda. We show that a previous discussion in the literature rests on a problematic estimation of the relative scale factor. The implications are illustrated with data from Cummings et al. (1997) [5], as well as with simulated data. Moreover, we propose a concrete methodology for how to analyze cases where it is difficult, or even impossible, to estimate the relative scale factor due to informational limitations, such as when there is no variation of the bid. We conclude that it is valuable to be able to separate behavioral differences into variance differences and parameter differences in the underlying objective function. Yet, we argue that when using the results to interpret the results of other hypothetical referenda, it is sometimes the net effect, i.e., without correction for scale differences, that matters.

Joint seismic, geodynamic and mineral physical constraints on three-dimensional mantle heterogeneity: Implications for the relative importance of thermal versus compositional heterogeneity

SUMMARY The joint interpretation of seismic and geodynamic data requires mineral physical parameters linking seismic velocity to density perturbations in the Earth’s mantle. The most common approach is to link velocity and density through relative scaling or conversion factors: R ρ/s = dlnρ/dlnV S. However, the range of possible R ρ/s values remains large even when only considering thermal effects. We directly test the validity of several proposed depthdependent conversion profiles developed from mineral physics studies for thermally-varying properties of mantle materials. The tests are conducted by simultaneously inverting shear wave traveltime data and a diverse suite of convection-related constraints interpreted with viscous-flow response functions of the mantle. These geodynamic constraints are represented by surface spherical harmonic basis functions (up to harmonic degree 16) and they consist of the global free-air gravity field, tectonic plate divergences, dynamic surface topography and the excess ellipticity of the core-mantle boundary (CMB). The tests yield an optimum 1-D thermal R ρ/s profile that is generally compatible with all considered data, with the exception of the dynamic surface topography that is most sensitive to the shallow upper mantle. This result is not surprising given that cratonic roots are known to be compositionally-distinct from the surrounding ambient mantle. Moreover, it is expected that the temperature-dependence of the thermal R ρ/s in the upper mantle is significant due to the temperature-dependence of seismic attenuation or Q. Therefore, a simple 1-D density–velocity relationship is insufficient. To address this problem, we obtained independent estimates of the first-order correction factors to the selected R ρ/s profile within the cratonic roots and in the ambient (thermal) upper mantle. These correction factors, defined as ∂R ρ/s/∂lnV S, are highly negative within the cratons signifying considerable compositional buoyancy. This result confirms that the negative buoyancy associated with the low temperatures in the cratons is significantly counteracted by the composition-induced positive buoyancy resulting in near-neutral buoyancy of the cratonic roots. Within the ambient upper mantle, the correction factors are found to be positive which is consistent with the expected behaviour of the R ρ/s relationship in thermally-varying upper-mantle material. We obtain a significantly greater reconciliation of the global gravity anomalies and dynamic surface topography when applying these laterally-varying corrections compared to a simple 1-D R ρ/s relationship. Inversion for a fully 3-D R ρ/s relationship reveals secondary effects including additional compositional variation within the cratonic roots and the deep-mantle superplume structures. We estimate the relative magnitude of the thermal and compositional (non-thermal) contributions to mantle density anomalies and conclude that thermal effects dominate shear wave and density heterogeneity throughout the non-cratonic mantle. We also demonstrate the potential pitfalls of scaling a purely seismically-derived model to obtain density rather than performing a true joint inversion to obtain velocity and density simultaneously.

Parametric Design and Power-Flow Analysis of Parallel Force∕Velocity Actuators

In this paper we introduce a dual-input actuator, based on an epicyclic gear train, called parallel force∕velocity actuator (PFVA) designed for variable response manipulation. The focus of this work is to formulate a parametric representation for internal and external power flows, and effective inertia in this actuator. Dimensionless criteria have been developed to judge the design of a PFVA, based on the above phenomena. These criteria are then related to two fundamental dimensionless parameters of a PFVA: (i) a design parameter called the relative scale factor that describes the relative kinematic scaling between the two inputs of the PFVA and (b) an operational parameter called the velocity mixing ratio that represents the velocities of the inputs relative to each other. Some numerical examples have been considered using PFVA designs based on positive-ratio drives to convey the practical implication of our parametric models. Based on this study a set of design and operational guidelines has been suggested, which we believe will be useful to the designer in evaluating PFVA designs and operational scenarios on the basis of power-flow and effective inertias. As a representative result, it was observed that the efficiency of a PFVA decreases approximately 19% from the basic efficiency when the relative scale factor was increased approximately 6.5 times (from 4.7 to 25.27) and the velocity mixing ratio was increased 10 times (from 4.16 to 41.6).

Semiquantitative fast flow velocity measurements using catheter coils with a limited sensitivity profile.

Flow measurements can be used to quantify blood flow during MR-guided intravascular interventional procedures. In this study, a fast flow measurement technique is proposed that quantifies flow velocities in the vicinity of a small RF coil attached to an intravascular catheter. Since the small RF coil receives signal from only a limited volume around the catheter, a spatially nonselective signal reception is employed. To enhance signal from flowing blood, and suppress unwanted signal contributions from static material, a slice-selective RF excitation is used. At a velocity sensitivity of 150 cm/s, a temporal resolution of 2 x TR = 10.2 ms can be achieved. The flow measurement is combined with an automatic slice positioning to facilitate measurements during interventional procedures. The influence of the catheter position in the blood vessel on the velocity measurement was analyzed in simulations. For blood vessels with laminar flow, the simulation showed a systematic deviation between catheter measurement and true flow between -15% and 80%. In four animal experiments, the catheter velocity measurement was compared with results from a conventional ECG-triggered 2D phase-contrast (PC) technique. The shapes of the velocity time curves in the abdominal aorta were nearly identical to the conventional measurements. A relative scaling factor of 0.69-1.19 was found between the catheter velocity measurement and the reference measurement, which could be partly explained by the simulation results.

Scale factor calibration of a superconducting gravimeter at Esashi Station, Japan, using absolute gravity measurements

The scale factor of a superconducting gravimeter (SG) at the Esashi Earth Tides Station, Japan, was revised by repeating co-located absolute gravity measurements with an FG5 gravimeter. Although the calibration results from the absolute gravimeter (AG) show an apparent secular change in the scale factor of the SG (0.4% for the period 1993–2002), the relative scale factors, which are determined by tidal analysis with the response method, indicate that it has changed by no more than 0.01% during the above period. If the mean scale factor over the 10 years is adopted, a value of −56.082±0.029 μGal/V (1 μGal =10−8 m s−2) is obtained, which is about 0.4% smaller than that used in the global geodynamics project (GGP) database. Based on this newly determined scale factor, the tidal gravity factors at Esashi have been re-estimated. The observed tidal factors, corrected for the ocean tide effects with recent models, indicate that the theoretical gravity factors for an inelastic Earth model are more consistent with the observations than are those for an elastic model.