Offset Method Research Articles

Метод снижения потерь энергии в импульсном преобразователе напряжения

A signal timing calculation method to control power switches of bidirectional switching converter (SC) with high efficiency is proposed. The method is applicable for MOSFET-based cascaded boost-buck converter, which has a negative offset current flow at the beginning of each conversion period. This current allows to perform turning on switches under zerovoltage and zero current switching condition to minimize switching losses. Meanwhile, the delay time between halfbridge transistors’ switching points is needed, when transistors’ output capacitances recharging takes place with following anti parallel body diode of transistor is being turned on unlocking. A proposed method is based on a switching delay time of input stage transistors valuation for the worst case of SC’s components’ parameters scatter, and provides guaranteed turning on of the upper transistor of the input stage under zero voltage and zero current condition. A clarified offset current calculation method is provided which introduces described time delays and SC’s input voltage.

An Intelligent IoT Sensing System for Rail Vehicle Running States Based on TinyML

Real-time identification of the running state is one of the key technologies for a smart rail vehicle. However, it is a challenge to accurately real-time sense the complex running states of the rail vehicle on an Internet-of-Things (IoT) edge device. Traditional systems usually upload a large amount of real-time data from the vehicle to the cloud for identification, which is laborious and inefficient. In this paper, an intelligent identification method for rail vehicle running state is proposed based on Tiny Machine Learning (TinyML) technology, and an IoT system is developed with small size and low energy consumption. The system uses a Micro-Electro-Mechanical System (MEMS) sensor to collect acceleration data for machine learning training. A neural network model for recognizing the running state of rail vehicles is built and trained by defining a machine learning running state classification model. The trained recognition model is deployed to the IoT edge device at the vehicle side, and an offset time window method is utilized for real-time state sensing. In addition, the sensing results are uploaded to the IoT server for visualization. The experiments on the subway vehicle showed that the system could identify six complex running states in real-time with over 99% accuracy using only one IoT microcontroller. The model with three axes converges faster than the model with one. The model recognition accuracy remained above 98% and 95%, under different installation positions on the rail vehicle and the zero-drift phenomenon of the MEMS acceleration sensor, respectively. The presented method and system can also be extended to edge-aware applications of equipment such as automobiles and ships.

THE MINIMIZATION METHOD OF THE THERMAL DRIFT INFLUENCE ON ANALOG INTEGRATED CIRCUITS

The existing offset cancellation methods are based on digital-to-converters (DAC) and the calibration paths. During thermal drift the parameters of transistors in calibration pa¬t¬h change, which increase the offset of the system. The proposed offset cancellation meth¬od includes current DAC which is directly connected to the output of the system. The absence of the calibration path makes the circuit more stable during temperature drifts without voltage-current-voltage conversion. The offset variation of the circuit during thermal drift is reduced 19 times (1.42 mV). The circuit occupies 43.2 % less area as in the current DAC, only transistors have been used instead of the resistor-transistor structure of voltage DAC. Power consumption increases 7 % as the branch of the current DAC is always on.

ONSHORE SEISMIC IMAGING USING DIFFERENT DATA DOMAIN IN NORTHERN NIGER DELTA, NIGERIA

Wide azimuth land acquisition, 3D data is spatially well sampled with a wide range of azimuth and the offsets distributed around those azimuths. This work examined how advance seismic processing technique has come onshore, using offset vector tile methods, high-fidelity, high-resolution is available for use on onshore data. Data were split into one hundred and twenty four vector tiles as a function of source-to-detector distance and azimuth relationship individual pre-trace is assigned an offset vector tiles number that is stored in the trace headers the number is based on the relative shot and receiver location for the trace. Data is regularized to maintain the necessary number of traces and the range of offset in each bin and allow to be filled then migration of the target lines and stacking. After regularization for both the common offset binning and the offset vector tiles (OVTs), it was observed that there is improved signal to noise ratio in the offset vector tiles as compare to the common offset binning, and there is overall improvement in event continuity on the OVTs result. Because onshore (land) data exhibit poor signal-to-noise ratios arising from irregular geometries and noise contamination a fundamental change in processing methods is required. The offset vector tiles (OVTs) have proven to be an effective and efficient tool for 3D wide azimuth acquisitions, the OVTs domain pre-processing, will yield a better imaging when compared to the common offset binning (COB) domain pre-processing.

Carrier Phase-Based Synchronization and High-Accuracy Positioning in 5G New Radio Cellular Networks

Inspired by excellent precision of carrier phase positioning, this paper presents a new carrier phase positioning technique for 5G new radio cellular networks with a focus on clock synchronization and integer ambiguity resolution. A carrier-phase based clock offset estimation method is first proposed to achieve precise clock synchronization among base stations, and proved to achieve the Cramér–Rao Lower Bound (CRLB) asymptotically. A fusion method is developed to fuse the estimated positions of a mobile station (MS) based on time-difference-of-arrival, with the estimated position changes based on the temporal changes of carrier phase measurements. While circumventing the integer ambiguities of the carrier phase measurements, the fusion method provides quality interim estimates of the MS positions, at which the measurements can be linearized to resolve the integer ambiguities. As a result, precise MS positions can be obtained based on the disambiguated carrier phase measurements. Numerical simulations show that the proposed carrier phase positioning can achieve a centimeter-level accuracy in wireless cellular networks.

POI Detection of High-Rise Buildings Using Remote Sensing Images: A Semantic Segmentation Method Based on Multitask Attention Res-U-Net

A Point-Of-Interest (POI) represents a specific point location that may be useful or interesting for people, and therefore each and every building footprint in a topographic map can be recognized as a POI. Automatic extraction of building footprints using remote sensing images has become a challenging and important research topic which is in demand for urban planning and development. Extensive studies have explored a variety of semantic segmentation methods using deep learning algorithms to achieve better performance in building footprint extraction, however the existing algorithms were shown to have some limitations which lead to poor segmentation results. Building roofs were recognized as building footprints in the previous studies. This is prone to error especially for high-rise buildings due to different sensor view angles. In this paper, we propose a multi-task Res-U-Net model with attention mechanism for the extraction of the building roofs and the whole building shapes from remote sensing images, then use an offset vector method to detect the footprints of the high-rise buildings based on the boundaries of the corresponding building roofs and shapes. We also apply the online food delivery (OFD) data to parse the POI name of every building footprint. Several strategies are also developed in combination with the proposed model, including data augmentation and post-processing. We conduct numerical experiments using real data of remote sensing images and OFD historical order data. Results demonstrate that our proposed model achieves a total F1-score of 77.05% and intersection over union (IoU) of 63.55% in terms of the building roof segmentation, and an overall F1-score of 79.02% and IoU of 66.05% for the whole building shape segmentation, which both achieve the best performance among all baseline models.

A 0.56-mW 63.6-dB SNDR 250-MS/s Two-Step SAR ADC in 8-nm FinFET

This paper presents a two-step SAR ADC that uses coarse and fine comparators with dedicated SAR logics and asynchronous clock generators for each comparator to increase the energy efficiency by optimizing comparators and reduce output loading of the comparators and asynchronous clock generators. The relative offset of the two comparators is calibrated by redundancy based offset detection and input transistor transconductance controlled offset correction method without compromising the power. A constant impedance skewed inverter saves reference current with low short circuit current without additional CDAC settling time and logic. The ADC is fabricated in an 8 nm FinFET process, and achieves 63.6 dB SNDR at 250 MS/s while consuming 0.56 mW, resulting in Walden FoM of 1.81 fJ/conversion step.

Robust Registration Algorithm for Optical and SAR Images Based on Adjacent Self-Similarity Feature

Because optical and synthetic aperture radar (SAR) images are complementary, their registration has received extensive attention in joint applications. However, robust optical and SAR image registration is challenging due to substantial geometric and radiometric differences. To address this problem, we propose a fast and robust registration algorithm for optical and SAR images based on a novel feature type known as the adjacent self-similarity (ASS). The ASS feature of the pixelwise feature representation is defined to quickly and finely capture the structural features of the image. The ASS feature is extracted by using an optimized offset mean filtering method in a neighborhood of the unit pixel radius to accelerate and refine calculations and the local statistics weighted difference operation to suppress coherent speckles. Based on the ASS feature, we extract the minimum self-similarity map (SSM) and the index map, which are robust against radiometric differences and speckles. Then, based on the excellent characteristics of the two maps, we propose a feature detector based on suppressing the local nonmaximum on the minimum SSM and a novel feature descriptor based on calculating the distribution histogram of the index map in a log-polar grid. In addition, we design a rotation invariance enhancement method for the descriptor to improve the rotation invariance robustness of the algorithm. We conduct experiments with both synthetic and real image pairs. The registration results demonstrate that the proposed algorithm has good scale and rotation invariance, as well as good antinoise ability, and that the algorithm performs better than existing state-of-the-art algorithms in terms of registration robustness, accuracy, and efficiency. The registration results on two real optical and SAR image pairs with complex image scenes show the adaptability of the proposed algorithm. The source code of ASS is publicly available¹.

Paper] Improvement of Internal Compensation by Differential Offset Method for OLED Display Using High Mobility Oxide TFT

Paper] Improvement of Internal Compensation by Differential Offset Method for OLED Display Using High Mobility Oxide TFT

Change of Direction Speed in Youth Male Soccer Players: The Predictive Value of Anthropometrics and Biological Maturity.

This study aimed to develop the optimal allometric body size/shape and a biological maturity model that predicted the change of direction (CoD) mean speed performance in youth male soccer players. One-hundred and fifteen youth soccer players (age: 12.4 [1.3]y) participated in this study. The 505 test was used to assess CoD mean speed performance. Anthropometric measurements comprised body height (cm), sitting height (cm), body mass (kg), fat mass (kg), lower limb length (cm), thigh length (cm), leg length (cm), foot length (cm), thigh girth (cm), and calf girth (cm). The maturity status was determined based on the maturity offset method. To identify size/shape and maturity characteristics associated with CoD speed performance, we computed a multiplicative allometric log-linear regression model, which was refined using backward elimination. The multiplicative allometric model exploring the association between 505 CoD mean speed performance and the different anthropometric characteristics in youth soccer players estimated that fat mass (P < .001), sitting height (P = .02), and maturity offset (P = .004) are the key predictors. More specifically, youths who are more mature and have a lower fat mass and a shorter trunk length, are likely to achieve a better CoD mean speed performance. These findings highlight the relevance of considering anthropometric and maturity characteristics in youth soccer players to support talent identification.

Review on the thickness measurement of ultrathin oxide films by mutual calibration method

Mutual calibration was suggested as a method to determine the absolute thickness of ultrathin oxide films. It was motivated from the large offset values in the reported thicknesses in the Consultative Committee for Amount of Substance (CCQM) pilot study P‐38 for the thickness measurement of SiO2 films on Si(100) and Si(111) substrates in 2004. Large offset values from 0.5 to 1.0 nm were reported in the thicknesses by ellipsometry, X‐ray reflectometry (XRR), medium‐energy ion scattering spectrometry (MEIS), Rutherford backscattering spectroscopy (RBS), nuclear reaction analysis (NRA), and transmission electron microscopy (TEM). However, the offset value for the thicknesses by X‐ray photoelectron spectroscopy (XPS) was close to zero (−0.013 nm). From these results, the mutual calibration method was reported for the thickness measurement of SiO2 films on Si(100) by combination of TEM and XPS. The mutual calibration method has been applied for the thickness measurements of hetero oxide films such as Al2O3 and HfO2. Recently, the effect of surface contamination was reported to be critical to the thickness measurement of HfO2 films by XPS. On the other hand, MEIS was proved to be a powerful zero offset method which is not affected by the surface contamination. As a result, the reference thicknesses in the CCQM pilot study P‐190 for the thickness measurement of HfO2 films on Si(100) substrate were determined by mutual calibration method from the average XRR data and MEIS analysis. Conclusively, the thicknesses of ultrathin oxide films can be traceably certified by mutual calibration method and most thickness measurement methods can be calibrated from the certified thicknesses.

Internal Compensation by Offset Method for QHD OLED Display Using High Mobility Oxide TFT

Internal Compensation by Offset Method for QHD OLED Display Using High Mobility Oxide TFT

GBAZ segregation thickness and solute concentration effect on the mechanical properties in polycrystalline Ag‐doped Cu alloy

Utilising molecular dynamics simulation, the effect of segregation thickness and solute concentration on the mechanical properties of poly-crystalline Ag-doped Cu alloy are explored. The alloying atoms are dispersed randomly nearby grain boundaries with equidistant offset method. The dispersed domains are restricted in grain boundary affect zone. The uniaxial tensile simulation results indicate that dispersed alloying atoms exert a negative effect on the tensile behaviours of Ag-doped Cu alloy and its peak stress decreases as the increasing of segregation thickness and solute concentration. Moreover, the corresponding tensile deformation mechanisms are analysed according to the observed dislocation activities and structure evolutions.

Anelastic Behaviour of Commercial Die-Cast Magnesium Alloys: Effect of Temperature and Alloy Composition.

The anelastic deformation, resulting from partial reversal of {102} twinning, is studied at room temperature to 150 °C on several commercial die-cast magnesium alloys for the first time. The magnitude of anelastic strain decreases with increasing temperature. For inter-alloy comparison, AZ91 shows the largest maximum anelastic strain, while AM40 and AM60 show similar maximum anelastic strain. The phenomenon is discussed in terms of solid solution softening and hardening of slip planes and how they influence twinning. T5-aged AE44 consistently shows smaller magnitude of anelasticity compared to as-cast AE44, suggesting that the precipitates formed during ageing may decrease the twin-boundary mobility and further suppress untwinning. Presence of anelasticity poses a challenge to yield strength measurement using the conventional 0.2% offset method, and a more accurate and consistent method of using a higher offset strain or a lower modulus is proposed in this study.

Hitting Net-Zero Without Stopping Flying: Increasing Air Travelers’ Likelihood to Opt-in to Voluntary Carbon Offsetting

Voluntary carbon offset (VCO) programs give air travelers opportunities to neutralize their carbon footprint. Despite its potential, few existing studies have explained how to present VCOs that can effectively appeal to the sensibilities of travelers in different conditions. We designed three online experiments with strategies to motivate travelers to opt-in. We found travelers who receive concrete messages that emphasize specific actions are more likely to opt-in to VCOs when flying in the near future. In contrast, travelers receiving abstract messages that emphasize general initiatives are more likely to opt-in to VCOs when flying in the distant future. When travelers are allowed to choose their preferred carbon offset method, they are more likely to opt in, especially when they receive concrete messages that indicate specific actions but not general initiatives. These findings contribute to the aviation carbon offset literature and offer useful new insights for airline companies.

Study of the moving offset characteristics of multi-loop moving coil linear compressor

In this paper, a novel Multi-loop Moving Coil Large Output Volume Linear Compressors (M-MC-l-LC, Max 381.3cc) is proposed. A Co-core Bilateral Reverse Coil(CBRC) and a new Halbach permanent magnet ring array structure are proposed for the first time and applied to the development of prototype. The M-MC-l-LC electromagnetic force calculation equation is derived, the moving offset characteristics under different pressure ratios are studied, and a mathematical model that can reflect the moving offset law is established. Introduction the DC offset control method to solve the moving offset problem. Development the M-MC-l-LC prototype and construction a dynamic test rig for compressors. Experimental results show that increasing DC voltage countervails the moving offset and significantly increases the discharge pressure. The theoretical error of moving offset is within 8% and the mechanical efficiency of prototype is approximately 11.4% higher than that of the conventional compressor. The results of study have theoretical and practical implications for other linear compression moving offset analysis and accurate regulation of refrigeration capacity.

Updated GNSS velocity solution in the Nordic and Baltic countries with a semi-automatic offset detection method

In Fennoscandia, the Glacial Isostatic Adjustment (GIA) causes intraplate deformations that affect the national static reference frames. The GNSS-determined velocities are important data for constraining the GIA models, which are necessary for maintaining the national reference frames. The Nordic Geodetic Commission (NKG) has published a dense and consistent GNSS station velocity solution in 2019, and we present now an update of the solution covering additional 3.5 years of data. Undetected positional offsets are the main factor decreasing the accuracy of the velocity estimates. We developed a method for the semi-automatic offset detection to improve the quality of our solution. The results show that we could correctly detect 74% of the manually determined offsets, and the undetected offsets would have caused a median 0.1 mm/y bias in trend. The method pointed out some otherwise unnoticed offsets and will decrease the need for manual analysis in the future. The updated velocity solution especially improves the velocity estimates of the newly established stations and the quality of the velocity estimates in Baltic countries. The formal uncertainties estimated using the power-law plus white noise model were at a median of 0.06 and 0.15 mm/y for horizontal and vertical velocities, respectively. However, we concluded that the systematic velocity uncertainties due to the reference frame alignment were approximately at the same level.

A method for suppressing disorderly scheduling in multipath transmission scenarios using time delay offset

Multipath transmission enables packets to be distributed over different paths for transmission, andthis method has made full use of individual link resources. However, most existing multipath transmissionschemes lack suitable scheduling mechanisms and suffer from high disorder and packet loss.To address the disorder problem, this paper designs a delay offset method combined with link rejectionor adaptive delay adjustment mechanism to suppress the packet disorder problem in multipathtransmission scenarios based on an in-depth study of the background related to multipath transmission.Finally, a multipath link topology is built on the P4 simulation platform to implement the abovemethod in code simulation, and the experimental results are compared and analyzed with other twoscheduling mechanisms. The experimental results show that this method maintains the disorder levelwithin 5% compared with the single-path transmission and the equivalent multipath method, but thetransmission bandwidth is increased by nearly two times.

Spectral Characteristics of Rail Surface by Measuring the Growth of Rail Corrugation

Continuous interaction between wheels and rails during train operation results in rail wear and tear. Corrugation of the rail surface is particularly caused by the contact mechanism between train wheel and rail and increases the vibration and dynamic wheel load, and if continued, leads to various defects and breakage of the track. Many devices are used to measure corrugation accurately, but measurement deviation varies greatly by measuring device. The most common corrugation measurement system measures surface roughness with a vibration acceleration sensor or displacement sensor. Corrugation with different pitches can be calculated by assuming the longitudinal rail surface as a chord with variable wavelength. Recent systems use a measurement model applying multiple sensors for more accurate measurement. This study investigated spectral characteristics of rail surface roughness based on long time measurement results. In particular, spectral changes upon the growth of rail surface wear and corrugation were analyzed when using the measurement system applying the chord offset method with multiple sensors. The results of analysis were verified through the field subway section, a running track undergoing corrugation, three months after initial measurement, and compared the measurement results according to the number of sensors. Additionally, the rail surface wavelength bands that affected measurement value according to the number of sensors were analyzed.

Using Ground Penetrating Radar for Permafrost Monitoring from 2015–2017 at CALM Sites in the Pechora River Delta

This paper describes the results of ground penetrating radar (GPR) research combined with geocryological data collected from the Circumpolar Active Layer Monitoring (CALM) testing sites in Kashin and Kumzha in August 2015, 2016, and 2017. The study area was located on the Pechora River delta. Both sites were composed of sandy ground and the permafrost depth at the different sites ranged from 20 cm to 8–9 m. The combination of optimum offset and multifold GPR methods showed promising results in these investigations of sandy permafrost geological profiles. According to direct and indirect observations after the abnormally warm conditions in 2016, the thickness and water content of the active layer in 2017 almost returned to the values in 2015 in the Kashin area. In contrast, the lowering of the permafrost table continued at Kumzha, and lenses of thin frozen rocks that were observed in the thawed layer in August of 2015 and 2017 were absent in 2016. According to recent geocryological and geophysical observations, increasing permafrost degradation might be occurring in the Pechora River delta due to the instability of the thermal state of the permafrost.