Offset Coefficient Research Articles

Study of pedestrian flow on stairs with a cellular transmission model

The aim of this study is to address the following issues: 1) revealing the typical behaviors and properties of pedestrian movement when going upstairs and downstairs; 2) constructing a pedestrian evacuation model to formulate the walking process of pedestrians in stair area; 3) verifying that the cell transmission model widely used in the two-dimensional walking space can also be applied to the three-dimensional staircase area. Firstly, an observation experiment is carried out to gain the pedestrian movement data in the process of going upstairs and downstairs. By collating the data, the relation between density and flow in the unidirectional process of going upstairs or going downstairs, and in the bi-directional process of going upstairs and downstairs, are drawn respectively. Then, by analyzing the fundamental diagrams, several characteristics of pedestrian movement in stair area are revealed. Based on these characteristics, an extended cell transmission model is proposed. In this model, a potential correction coefficient is introduced to change the route choice of pedestrians by using the influence of different directional pedestrians on the potential; a flow modification coefficient is introduced to describe the effect of physical parameters on the maximum flow at the boundary between two neighboring cells; and an offset coefficient is introduced to correct movement rules and strengthen the influence of preferential direction on pedestrian route choice. Further, simulations relied on the proposed model are conducted. By comparing the simulation results with the experimental data, the model is calibrated. Then the calibrated model is employed to formulate the pedestrian movement in stair area, and the sensitivity of the potential correction parameter is also discussed. The simulation results indicate that the proposed model can successfully reproduce the movement of pedestrians on stair. Moreover, the route-choice behaviors of pedestrians can be directed by varying the values of the potential correction coefficient, which can present important information about optimizing the evacuation process of pedestrians on stair, thereby reducing the risk of an accident, such as congesting and treading.

Energy-Balanced Routing Algorithm Based on Ant Colony Optimization for Mobile Ad Hoc Networks

The mobile ad hoc network (MANET) is a multi-hop, non-central network composed of mobile terminals with self-organizing features. Aiming at the problem of extra energy consumption caused by node motion in MANETs, this paper proposes an improved energy and mobility ant colony optimization (IEMACO) routing algorithm. Firstly, the algorithm accelerates the convergence speed of the routing algorithm and reduces the number of route discovery packets by introducing an offset coefficient of the transition probability. Then, based on the energy consumption rate, the remaining lifetime of nodes (RLTn) is considered. The position and velocity information predicts the remaining lifetime of the link (RLTl). The algorithm combines RLTn and RLTl to design the pheromone generation method, which selects the better quality path according to the transition probability to ensure continuous data transmission. As a result, the energy consumption in the network is balanced. The simulation results show that compared to the Ad Hoc on-demand multipath distance vector (AOMDV) algorithm with multipath routing and the Ant Hoc Max-Min-Path (AntHocMMP) algorithm in consideration of node energy consumption and mobility, the IEMACO algorithm can reduce the frequency of route discovery and has lower end-to-end delay as well as packet loss rate especially when nodes move, and can extend the network lifetime.

Modeling of grasping force for a soft robotic gripper with variable stiffness

The purpose of this research is to present a grasping force model for a soft robotic gripper with variable stiffness. The soft robotic gripper was made of shape memory alloys (SMAs) with contraction and variable stiffness properties. A variable stiffness mechanism with embedded sets of SMA fibers was developed; however, the response characteristics of its backbone did not comply with the constant-curvature model when it was subjected to complex forces/torques, such as gravity, grasping forces and driving torques. In this case, the Cosserat theory was used to implement real-time computations of the grasping force of the soft robotic gripper that was subjected to complex forces. Finally, a series of tests were conducted on the grasping force of the soft finger and the gripper. The elicited results showed that the grasping force is related to the stiffness and to the object's offset and friction coefficient. Moreover, experimental results showed that the grasping force of the soft robotic gripper increased by 48.7% when the Young's modulus of the SMA-2 wires increased from 25 GPa to 48 GPa.

A 4 mm² Double Differential Torsional MEMS Accelerometer Based on a Double-Beam Configuration.

This paper reports the design and simulation of a 4 mm2 double differential torsional MEMS accelerometer based on a double-beam configuration. Based on the structure of conventional torsional accelerometers, normally composed of one pair of proof masses and one torsional beam, this work explores the double differential configuration: a torsional accelerometer with two pairs of unbalanced proof masses rotating in reverse. Also, the torsional beam is designed as a double-beam structure, which is a symmetrical structure formed by two torsional beams separated by a certain distance. The device area of the novel accelerometer is more than 50 times smaller than that of a traditional double differential torsional MEMS accelerometer. The FEM simulation results demonstrate that the smaller device does not sacrifice other specifications, such as mechanical sensitivity, nonlinearity and temperature robustness. The mechanical sensitivity and nonlinearity of a ±15 g measuring range is 59.4 fF/g and 0.88%, respectively. Compared with traditional single-beam silicon structures, the novel structure can achieve lower maximum principle stress in critical regions and reduce the possibility of failure when high-g acceleration loading is applied along all three axes. The mechanical noise equivalent acceleration is about in the theoretical calculations and the offset temperature coefficient is 0.25 mg/ in the full temperature range of to .

A TWO-STEPS RADIOMETRIC CORRECTION OF SPOT-4 MULTISPECTRAL AND MULTITEMPORAL FOR SEAMLESS MOSAIC IN CENTRAL KALIMANTAN

This research analyzed the radiometric correction method using SPOT-4 imageries to produce the same reflectance for the same land cover. Top of Atmosphere (TOA) method was applied in previous radiometric correction approach, this TOA approach was upgraded with the reflectance effect from difference satellite viewing angle. The 250 scene of Central Kalimantan SPOT-4 imageries from 2006 until 2012 with varies viewing angle was used. This research applied two-step approaches, the first step is TOA correction, and the second step is normalization using a linear function of reflectance and satellite viewing angle. Gain and offset coefficient of this linear function was calculated using an iterative approach to producing the same reflectance in the forest area. The target of iterative processed is to minimize the standard deviation of a digital number from a forest area in the selected region. The result shows that the standard deviation of a digital number from a forest area in the two steps approach are 8.6, 16.5, and 16.8 for band 1, band 3 and band 4. These values are smaller compared with the standard deviation of digital number result from TOA approach are 15.0, 28,3 and 34.7 for band 1, band 3 and band 4. Decreasing the standard deviation shows the homogeneity of forest reflectance that could be seen in the seamless result. This algorithm can be applied for making seamless SPOT-4 mosaic whole of Indonesia.

A double differential torsional micro-accelerometer based on V-shape beam

This paper reports the design, simulation, fabrication and measurement of a double differential torsional micro-accelerometer based on V-shape beam. The structure of conventional torsional micro-accelerometers is typically composed of two unbalanced proof masses and a torsional beam. This work develops a torsional micro-accelerometer with an optimized structure, which is composed of four proof masses splitting into two pairs. The two pairs of unbalanced masses have the opposite sensitivity to acceleration but the same sensitivity to off-acceleration input, and by using double differential arithmetic the sensitivity, environment robustness and bias stability can be improved. The accelerometer prototype is fabricated with the pre-buried mask wet-etching method and tested. The resonant frequency and quality factor are about 1485Hz and 28.02 respectively. The sensitivity and nonlinearity of the measuring range ±15g is 0.14mV/g and 0.22% respectively. The x-axis and y-axis cross-axis errors are 0.04% and 0.69% respectively. The 1g bias stability of the accelerometer is 0.11mg for 1h and the Allan deviation is 8.7μg. In the full temperature range of −40°C to +60°C,the temperature sensitivity of the scale factor is 49.9ppm/°C while the offset temperature coefficient is 0.22mg/°C after temperature compensation.

Modeling thermal emissive bands radiometric calibration impact with application to AVHRR

AbstractA novel analytical model of the calibration error impact on the Earth radiance measurement from thermal emissive bands of sensors is developed. The goal is to assess the impact of calibration errors, to evaluate those errors and to perform correction. This model is applied in the correction of bias in Advanced Very High Resolution Radiometer (AVHRR) channels 4 and 5 observed from the intercomparison with Infrared Atmospheric Sounding Interferometer measurements. A two‐step regression is used to separate the effects of calibration radiance errors from calibration coefficient errors. In the first step, the calibration radiance error, primarily due to internal calibration target (ICT) imperfections and temperature measurement error, is evaluated using the bias from selected Earth scenes with brightness temperatures close to the ICT temperature. The effects from the ICT imperfections and temperature measurement errors are analyzed collectively. The resulting estimation of the calibration radiance error is 0.30% for channel 4 and 0.33% for channel 5. After correcting the Earth scene radiance for these effects, the errors in the offset and nonlinear coefficient of instrument response are evaluated through the second step of the regression. A weighting function is used to account for the nonuniformity in the data distribution over the Earth radiance range. After the evaluation of the errors, removal of their effects can be achieved either through corrections of the calibration coefficients or correction of the measured radiance. The results are useful for the improvement of the AVHRR IR channel calibration algorithm. This model and two‐step regression approach can also be applied to other similar broadband thermal infrared radiometric sensors.

Spherical gearing with intermediate ball elements: parameter ranges with a high contact ratio

The paper presents analytical research of the geometry and kinematical parameters of spherical gearing with ball intermediate elements. The main attention is paid to the influence of the offset coefficient on the tooth geometry generation, the contact ratio and the motion transmission angle. Intermediate ball element racetracks on the gear are trochoidal curves on a spherical surface. Two areas for the offset coefficient values providing a high value of the contact ratio – basic trochoid (without offset) and prolate trochoid with abutting racetracks of adjacent ball elements ― were revealed. Analysis of the investigated parameters showed that for power transmission, it is preferable to use spherical gearing without an offset, and for kinematic transmission, it is possible to use profiles with a large offset. The present study allows making a rational choice of geometrical parameters depending on the transmission predestination.

Effects of Pectus Excavatum on the Spine of Pectus Excavatum Patients with Scoliosis.

Background There is high risk in the correction surgery of pectus excavatum with scoliosis because of the lack of the correction mechanism of pectus excavatum with scoliosis. This study performed a comprehensive analysis about the impact that pectus excavatum had on scoliosis and elaborated its biomechanical mechanism in pectus excavatum patients with scoliosis. Methods 37 pectus excavatum patients were selected. According to age, Haller index of pectus excavatum, offset coefficient, vertical position, sternal torsion angle, and asymmetric index, 37 patients were, respectively, divided into 2 compared groups. The result was statistically calculated. Results The scoliosis incidence and severity did not correlate with Haller index, offset coefficient, vertical position, sternal torsion angle, and asymmetric index of pectus excavatum, and there was no statistical significance between the two compared groups. Conclusions The incidence and severity of scoliosis in PE patients with scoliosis have nothing to do with the geometric parameters of pectus excavatum but correlate with age. The scoliosis will aggravate with the increase of age. The heart may provide an asymmetric horizontal force to push the spines to the right. The mechanism of how the biomechanical factors exert influences on spines needs to be further investigated to keep the spine stable.

The Risk Premium, Interest Rate Determination, and Monetary Independence Under a Fixed, but Adjustable, Exchange Rate

AbstractThis paper examines interest rate determination and monetary independence in a small economy with a fixed exchange rate. The risk premium is determined endogenously in the stochastic, general‐equilibrium model. The sign of the risk premium and the magnitude of the interest rate depend on the specification of the policy rule for the future exchange rate. Increases in domestic credit can decrease, increase or have no effect on the interest rate. The offset coefficient can differ from −1 (the ‘trilemma’ may not hold), but numerical calculations indicate that the offset is close to −1. Under certain conditions, empirical analyses overestimate monetary independence. Copyright © 2016 John Wiley & Sons, Ltd.

Reliability process methodology of the centrifugal rotary machining in the medium of steel balls

The research results on improving reliability of the finishing-strengthening centrifugal rotary processing are presented. The research subject is the formation of the finishing and strengthening centrifugal rotary processing (FS CRP) reliability provided by a reasonable coupling of the technological modes and operating environment characteristics. The research objective is to improve efficiency and reliability of the finishing-hardening centrifugal rotary processing with studying the arising failures based on the development of a set of the adequate theoretical processing patterns. The refined theoretical patterns of the finished part surface layer indices forming - the extent and depth of hardening, are obtained. The analytical forecasting methodology of the finishing-hardening centrifugal rotary processing reliability with the following parameters: the coefficient of the instantaneous scattering of the controlled variable, the offset coefficient of the controlled variable, and the coefficient of the process marginal accuracy, is developed. It is established that the FS CRP process provides obtaining the required parameters of the workpiece surface quality under the processing within the tolerance values in a certain range of the technological mode change and the operating environment characteristics. The design technique for the FS CRP processes with allowance for their reliability is developed.

基于空间相机时间延迟积分传感器拼接区图像的像移测量

In order to measure the wide-frequency-range image motion caused by spacecraft attitude instability or residual vibration of the vibration isolation devices, image motion measurement method using images taken from time delayed integration (TDI) sensors, overlapped area is proposed. Offset coefficient is defined to measure the mismatch between image motion velocity and integration time. The relationship between mismatch and image quality using modulation transfer function (MTF) as image quality evaluation index is analyzed. The image motion measuring accuracy range is determined. By taking full advantage of features of the images taken from TDI sensors, overlapped area that have the same content but are taken at the different time, the theory of image motion measurement method based on images taken from TDI sensors, overlapped area is elaborated. Experimental results show that the measurement precision can reach 0.2377 pixel, and the measurement bandwidth can reach 228 Hz, proving that this method can effectively achieve wide-frequency-range, high-precision measurement of image motion.

English

The issue of whether public savings offset private savings, and visa vice, has important implications for the effectiveness of fiscal policy. This study examines long-run relationship between public and private savings rates using annual Turkish data for the period 1975-2005. The result of Engle-Granger cointegration test has shown that there is no long-run relationship between private and public savings ratios. However,once endogenously determined structural break is allowed, the test results confirm the existence of the cointegration relationship between private and public savings. Econometric estimation of the offset coefficients using both FMOLS and DOLS yields values of between -0.11 and -0.82. The results also indicate that the potency of fiscal policy significantly reduced with the liberalization of financial markets.Keywords: Savings, Offset coefficient, Ricardian Equivalence, DOLS, FMOLS. JEL Classificiation: E6, H6, E21

Hoarding of International Reserves and Sterilization in Dollarized and Indebted Countries: An Effective Monetary Policy?

The primary aim of this paper is to explore the effectiveness of Hoarding International Reserves and Sterilization in dollarized and indebted countries such as Turkey and Lebanon, by measuring the sterilization coefficient, and the offset coefficient. It also focuses on exploring the link between the sources of Reserves and the external debt. Using monthly data collected from the International Monetary Fund and from the Central Banks of Turkey and Lebanon between January 1994 and February 2011, we applied a 2SLS regression models and we identified explanatory variables that enabled us to estimate the aforementioned coefficients. Our results showed that despite their theoretical practice of sterilization policy, economic constrains of these countries contribute to weaken the efficacy expected from monetary policies.

Validation of MODIS and Deep Blue aerosol optical depth retrievals in an arid/semi-arid region of northwest China

The global aerosol optical depth (AOD or τ) has been retrieved using the Dark Target algorithm (the C004 and C005 products) and the Deep Blue algorithm (DB product). Few validations have thus far been performed in arid/semi-arid regions, especially in northwest China. The ground-based remote sensing of AOD from sun photometers at four sites in Xinjiang during the years 2002–2003 is used to validate aerosol products, including C004, C005 and DB of the Moderate Resolution Imaging Spectroradiometer (MODIS). The results show substantial improvement in the C005 aerosol product over the C004 product. The average correlation coefficient of regression with ground measurements increased from 0.59 to 0.69, and the average offset decreased from 0.28 to 0.13. The slopes of the linear regressions tended to be close to unity. The percentage of AODs falling within the retrieval errors of 30% (or △τ=±0.1±0.2τ) increased from 16.1% to 45.6%. The best retrievals are obtained over an oasis region, whereas the worst are obtained over urban areas. Both the MODIS C004 and C005 products overestimate AOD, which is likely related to improper assumptions of the aerosol model and of the estimation of surface reflectance. An encouraging result has been derived with regard to validation of the DB AOD. Overall, the average offset, slope and correlation coefficient of regression with sun-photometer measurements are −0.04, 0.88 and 0.85, respectively. Approximately 73% of the DB AOD retrievals fall within the expected error of 30%. Underestimation of the AOD by the DB products is observed. The aerosol model and estimations of surface reflectance in this region require further improvements.

How Potent is Fiscal Policy in Australia?

This article examines the efficacy of fiscal policy in Australia, focusing on the relationship between changes in the economy’s consolidated fiscal imbalance and private sector saving over recent decades. We first examine the macroeconomic significance of the offset coefficient between public and private savings, whose size effectively determines the effectiveness of fiscal activism. The approach innovatively suggests that these estimates simultaneously reflect Ricardian and other non-Keynesian explanations of private consumption, such as the lifecycle and permanent income theories. Econometric estimation of the offset coefficient for Australia over the period 1980–2008 yields values between 0.75 and near unity, which imply a small or near-zero fiscal multiplier, and that running budget surpluses to lift national saving is ineffective.

A reprocessing for climate of sea surface temperature from the along-track scanning radiometers: A new retrieval scheme

We present a new coefficient-based retrieval scheme for estimation of sea surface temperature (SST) from the Along Track Scanning Radiometer (ATSR) instruments. The new coefficients are banded by total column water vapour (TCWV), obtained from numerical weather prediction analyses. TCWV banding reduces simulated regional retrieval biases to <0.1K compared to biases ~0.2K for global coefficients. Further, detailed treatment of the instrumental viewing geometry reduces simulated view-angle related biases from ~0.1K down to <0.005K for dual-view retrievals using channels at 11 and 12μm. A novel analysis of trade-offs related to the assumed noise level when defining coefficients is undertaken, and we conclude that adding a small nominal level of noise (0.01K) is optimal for our purposes.When applied to ATSR observations, some inter-algorithm biases appear as TCWV-related differences in SSTs estimated from different channel combinations. The final step in coefficient determination is to adjust the offset coefficient in each TCWV band to match results from a reference algorithm. This reference uses the dual-view observations of 3.7 and 11μm. The adjustment is independent of in situ measurements, preserving independence of the retrievals. The choice of reference is partly motivated by uncertainty in the calibration of the 12μm of Advanced ATSR.Lastly, we model the sensitivities of the new retrievals to changes to TCWV and changes in true SST, confirming that dual-view SSTs are most appropriate for climatological applications.

The Intrinsic Nature of Fatigue Heterogeneity Behavior Observed in Bulk Lead Zirconate Titanate Ceramics

Spatial heterogeneity of ferroelectric properties was observed in bulk lead zirconate titanate ceramics in fatigued states after long-term cyclic switching. The local piezoelectric hysteresis loops were measured at different locations after different switching cycle numbers. Measured parameters became essentially nonuniform with increasing of the cycle number. A linear correlation was found between the offset piezoelectric coefficient and the bias field. Nonuniform imprint model was utilized for explanation of the observed effects. A good qualitative agreement was found between the experimental data and computer simulation based on the proposed model. Observed facts clearly demonstrate the domain related nature of fatigue effects.

A non-uniform expansion mechanical safety model of the stent

Stents have a serial unstable structure that readily leads to non-uniform expansion. Non-uniform expansion in turn creates a stent safety problem. We explain how a stent may be simplified to a serial unstable structure, and present a method to calculate the non-uniform expansion of the stent on the basis of the serial unstable structure. We propose a safety criterion based on the expansion displacement instead of the strain, and explain that the parameter Rd, the ratio of the maximum displacement of the elements to normal displacement, is meaningful to assess the safety level of the stent. We also examine how laser cutting influences non-uniform expansion. The examples illustrate how to calculate the parameter Rd to assess non-uniform expansion of the stent, and demonstrate how the laser cutting offset and strengthening coefficient of the material influence the stent expansion behaviour. The methods are valuable for assessing stent safety due to non-uniform expansion.

Central Bank Intervention, Sterilization and Monetary Independence: The Case of Pakistan

This paper analyzes the response of the State bank of Pakistan—the central bank, to foreign exchange inflows for the period of 2001:1 to 2006:8. In this context, we estimated sterilization and offset coefficients using vector autoregression (VAR) model to account for the issue of endogeneity of domestic credit with the foreign exchange interventions. In addition, the paper also analyzes the role of foreign and domestic interest rate differentials in pulling in or pushing out of these foreign exchange flows. We found that the offset coefficient is very small and insignificant (0.16) implying that changes in credit resulted in very minimal offsetting reserve flows. The study found out that for the sample period, SBP only partially sterilized the inflows with magnitude of coefficient at (0.50) confirming the stylized facts. Results also indicate that inflows were neither pulled into the country due to high domestic interest rates due to some domestic policy nor they are pushed into Pakistan owing to low interest rates abroad.