scholarly journals Derivation of the Water Vapor Content from the GNSS Radio Occultations Observations

2006 ◽  
Vol 23 (7) ◽  
pp. 936-943 ◽  
Author(s):  
Francesco Vespe ◽  
Teresa Persia
Keyword(s):  
External Information ◽  
Mathematical Treatment ◽  
Low Latitude ◽  
Bending Angle ◽  
Ground Pressure ◽  
Pressure Profiles ◽  
Angle Data ◽  
The Relationship ◽  
Humidity Profiles ◽  
Bending Angles

Abstract The present work investigates the possibility of retrieving humidity using the bending angle data obtained from radio occultation of GPS signals without additional external information. In particular, with the proposed approach, the dry pressure profiles are obtained by fitting the bending angles of the outer-troposphere layers (from h = h250K up to the stratopause) using the Hopfield dry atmosphere model. The ground pressure and temperature are the parameters of the model to be estimated. In the second step the humidity profiles are extracted by subtracting the contribution resulting from the dry atmosphere from the measured bending angles. Such derivation implies a complex mathematical treatment of the relationship between the bending angle and the refractivity, which is fully explained herein. Furthermore, the method was applied on Challenging Minisatellite Payload (CHAMP) profiles. The CHAMP profiles are achieved by applying heuristic retrieval algorithms based on the canonical transform. The algorithms are applied to minimize the negative refractivity bias that is observed for low-latitude GNSS RO. Thus, the results are shown and discussed in the second part of the paper. Finally, it is widely discussed how the proposed method is able to retrieve refractivity profiles without using the Abel inversion.

Investigation on the relationship between bending angle of the overhanging surface and overhanging surface quality printed using selective laser melting

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Weipeng Duan ◽  
Jitai Han ◽  
Qingfneg Xia ◽  
Keqing Wang ◽  
Meiping Wu ◽  
...  
Keyword(s):  
Surface Quality ◽  
Molten Pool ◽  
Bending Angle ◽  
Content Type ◽  
Factors Affecting ◽  
Overall Performance ◽  
Increasing Demand ◽  
The Relationship ◽  
Bending Angles

Purpose With the increasing demand for lightweight parts, the quality of the inner structure gained growing attention from different kinds of fields. As the quality of the overhanging surface was one of the most important factors affecting inner structure formation, its quality still needs to improve. This paper aims to clarify the change of the overhanging surface quality caused by different bending angles. Design/methodology/approach The structure of the inner hole was redesigned according to the different performances of the overhanging and side inner surface. The experimental results revealed why different surface qualities can be seen under different bending angles. According to the experimental data, the inner structure was redesigned to increase its overall performance. Findings The results revealed that when the bending angle was small, the slope of the overhanging surface increased which lead to the decreasing length of the powder-supported layer. However, less space on bending angle resulted in the accumulation of unmelted powder which leads to the increasing of sinking distance. When the bending angle was too large, the slope of the overhanging surface decreased and the length of the molten pool which was supported by powder increased. It resulted in the sinking of the molten pool caused by the gravity of powder and its attachment. Originality/value This paper is the first work to study the relationship between bending angle and overhanging surface quality as far as the authors know. The different performances of left and right overhanging surfaces also have not been revealed in other research studies to the best of the knowledge.

scholarly journals Assimilation of GPSRO Bending Angle Profiles into the Brazilian Global Atmospheric Model

2019 ◽  
Vol 11 (3) ◽  
pp. 256 ◽  
Author(s):  
Ivette Banos ◽  
Luiz Sapucci ◽  
Lidia Cucurull ◽  
Carlos Bastarz ◽  
Bruna Silveira
Keyword(s):  
Data Assimilation ◽  
Weather Forecast ◽  
Atmospheric Model ◽  
Meridional Wind ◽  
Point Of View ◽  
Bending Angle ◽  
Global Atmospheric Model ◽  
Angle Data ◽  
Meteorological Systems ◽  
Bending Angles

The Global Positioning System (GPS) Radio Occultation (RO) technique allows valuable information to be obtained about the state of the atmosphere through vertical profiles obtained at various processing levels. From the point of view of data assimilation, there is a consensus that less processed data are preferable because of their lowest addition of uncertainties in the process. In the GPSRO context, bending angle data are better to assimilate than refractivity or atmospheric profiles; however, these data have not been properly explored by data assimilation at the CPTEC (acronym in Portuguese for Center for Weather Forecast and Climate Studies). In this study, the benefits and possible deficiencies of the CPTEC modeling system for this data source are investigated. Three numerical experiments were conducted, assimilating bending angles and refractivity profiles in the Gridpoint Statistical Interpolation (GSI) system coupled with the Brazilian Global Atmospheric Model (BAM). The results highlighted the need for further studies to explore the representation of meteorological systems at the higher levels of the BAM model. Nevertheless, more benefits were achieved using bending angle data compared with the results obtained assimilating refractivity profiles. The highest gain was in the data usage exploring 73.4% of the potential of the RO technique when bending angles are assimilated. Additionally, gains of 3.5% and 2.5% were found in the root mean square error values in the zonal and meridional wind components and geopotencial height at 250 hPa, respectively.

scholarly journals A Flexible Two-Sensor System for Temperature and Bending Angle Monitoring

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2962
Author(s):  
Yifeng Mu ◽  
Rou Feng ◽  
Qibei Gong ◽  
Yuxuan Liu ◽  
Xijun Jiang ◽  
...  
Keyword(s):  
Electronic System ◽  
Disease Diagnosis ◽  
Accurate Information ◽  
Polyimide Films ◽  
Bending Angle ◽  
Multiple Sensors ◽  
Constituent Material ◽  
Application Potential ◽  
Wearable Electronic ◽  
Bending Angles

A wearable electronic system constructed with multiple sensors with different functions to obtain multidimensional information is essential for making accurate assessments of a person’s condition, which is especially beneficial for applications in the areas of health monitoring, clinical diagnosis, and therapy. In this work, using polyimide films as substrates and Pt as the constituent material of serpentine structures, flexible temperature and angle sensors were designed that can be attached to the surface of an object or the human body for monitoring purposes. In these sensors, changes in temperature and bending angle are converted into variations in resistance through thermal resistance and strain effects with a sensitivity of 0.00204/°C for temperatures in the range of 25 to 100 °C and a sensitivity of 0.00015/° for bending angles in the range of 0° to 150°. With an appropriate layout design, two sensors were integrated to measure temperature and bending angles simultaneously in order to obtain decoupled, compensated, and more accurate information of temperature and angle. Finally, the system was tested by being attached to the surface of a knee joint, demonstrating its application potential in disease diagnosis, such as in arthritis assessment.

scholarly journals Intra-Articular Pressure in Osteoarthritis of the Knee

2020 ◽  
Author(s):  
kai niu ◽  
le hai Pan
Keyword(s):  
Joint Space Narrowing ◽  
Normal Subjects ◽  
Joint Space ◽  
Positive Pressure ◽  
Osteoarthritis Of The Knee ◽  
Research Subjects ◽  
Pressure Profiles ◽  
Control Knee ◽  
Group 2 ◽  
The Relationship

Abstract Background: IAP （intra-articular pressure）of the knee has been extensively studied in the knee of rheumatoid arthritis1.3 . the relationship between IAP and osteoarthrosis of knee rarely mentioned in the literature. The purpose of the study was to discover the pressure profiles observed in OA(Osteoarthritis ）. The characteristics of osteoarthritis are multiple osteophytes, unstable chondral flaps ,joint-space narrowing，sclerosis. Whether these factors effect of osteoarthritis intra-articular pressure.Methods: Fifty three research subjects were studied. They were divided into two subgroups, group 1: Forty osteoarthritis (OA). group 2: Thirteen control knee of healthy volunteer. IAP was measured using the hand held portable water manometer. before operation of arthroscopic procedures in OAgroup . Research data were analyzed to identify IAP between the two groups. Results: The main findingwasthat Resting IAP was positive pressure in all Osteoarthritis joints, otherwise subatmospheric or weakly atmospheric in normal subjects. Conclusions: The IAP rising is a feature of all patients with OAgroup. Therefore, These observations we recognize that significantly increased resting IAP is major influences by multiple osteophytes, joint-space narrowing，sclerosis , loose bodies and definite deformity of bony ends.

Evaluating the Impact of the COSMIC RO Bending Angle Data on Predicting the Heavy Precipitation Episode on 16 June 2008 during SoWMEX-IOP8

2014 ◽  
Vol 142 (11) ◽  
pp. 4139-4163 ◽  
Author(s):  
Shu-Chih Yang ◽  
Shu-Hua Chen ◽  
Shu-Ya Chen ◽  
Ching-Yuang Huang ◽  
Ching-Sen Chen
Keyword(s):  
Lower Troposphere ◽  
Heavy Precipitation ◽  
Southwest Monsoon ◽  
Weather Research And Forecasting ◽  
Heavy Rainfall Event ◽  
Bending Angle ◽  
Angle Data ◽  
Ensemble Transform Kalman Filter ◽  
The Impact ◽  
Better Than

Abstract Global positioning system (GPS) radio occultation (RO) data have been broadly used in global and regional numerical weather predictions. Assimilation with the bending angle often performs better than refractivity, which is inverted from the bending angle under spherical assumption and is sometimes associated with negative biases at the lower troposphere; however, the bending angle operator also requires a higher model top as used in global models. This study furnishes the feasibility of bending-angle assimilation in the prediction of heavy precipitation systems with a regional model. The local RO operators for simulating bending angle and refractivity are implemented in the Weather Research and Forecasting (WRF)–local ensemble transform Kalman filter (LETKF) framework. The impacts of assimilating RO data from the Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) using both operators are evaluated on the prediction of a heavy precipitation episode during Southwest Monsoon Experiment intensive observing period 8 (SoWMEX-IOP8) in 2008. Results show that both the refractivity and bending angle provide a favorable condition for generating this heavy rainfall event. In comparison with the refractivity data, the advantage of assimilating the bending angle is identified in the midtroposphere for deepening of the moist layer that leads to a rainfall forecast closer to the observations.

scholarly journals Three-dimensional oblique water-entry problems at small deadrise angles

2012 ◽  
Vol 711 ◽  
pp. 259-280 ◽  
Author(s):  
M. R. Moore ◽  
S. D. Howison ◽  
J. R. Ockendon ◽  
J. M. Oliver
Keyword(s):  
Three Dimensional ◽  
Oblique Impact ◽  
Water Entry ◽  
Rigid Bodies ◽  
Normal Impact ◽  
Displacement Potential ◽  
Pressure Profiles ◽  
The Relationship ◽  
Wagner Theory ◽  
The Ideal

AbstractThis paper extends Wagner theory for the ideal, incompressible normal impact of rigid bodies that are nearly parallel to the surface of a liquid half-space. The impactors considered are three-dimensional and have an oblique impact velocity. A formulation in terms of the displacement potential is used to reveal the relationship between the oblique and corresponding normal impact solutions. In the case of axisymmetric impactors, several geometries are considered in which singularities develop in the boundary of the effective wetted region. We present the corresponding pressure profiles and models for the splash sheets.

INNOVATION COLLABORATIONS IN LOW-TO-MEDIUM TECH SMEs: THE ROLE OF THE FIRM’S INNOVATION ORIENTATION AND USE OF EXTERNAL INFORMATION

2019 ◽  
Vol 23 (02) ◽  
pp. 1950011 ◽  
Author(s):  
OUAFA SAKKA ◽  
JOSÉE ST-PIERRE ◽  
MOUJIB BAHRI
Keyword(s):  
Management Control ◽  
Manufacturing Industries ◽  
External Information ◽  
Marketing Innovation ◽  
Research Organisation ◽  
Research Organisations ◽  
Medium Enterprises ◽  
Successful Innovation ◽  
The Relationship

This study articulates and tests the direct and indirect relationships between the company’s innovation orientation (IO), its collection and dissemination (C&D) of external information among the organisational members, and the level of success of its innovation collaborations involving customers, suppliers, and research organisations. Our conceptual framework is developed based on an integration of the literatures on organisational capabilities, marketing, innovation, and management control. We empirically test these relationships on a sample of 117 small-to-medium enterprises (SME) operating in Low-to-Medium-Tech (LMT) manufacturing industries. Partial Least Squares (PLS) results reveal that the relationship between the firm’s IO and the success of its customer collaborations is partially mediated by the C&D of external information. We also find that the relationship between the firm’s IO and the success of supplier collaborations is direct, and that the C&D of external information has no effect on the success of such collaborations. Finally the relationship between IO, C&D of external information and the success of research organisation collaborations is found to be indirect. Overall, these findings suggest that developing successful innovation collaborations in LMT sectors requires that SME managers start by building an internal culture that promotes innovation, learning and openness to the external environment.

scholarly journals Simultaneous VHF radar backscatter and ionosonde observations of low-latitude E region

2005 ◽  
Vol 23 (3) ◽  
pp. 773-779 ◽  
Author(s):  
A. K. Patra ◽  
S. Sripathi ◽  
P. B. Rao ◽  
K. S. V. Subbarao
Keyword(s):  
Low Latitude ◽  
Vhf Radar ◽  
Radar Echoes ◽  
First Results ◽  
E Region ◽  
Gradient Drift ◽  
Drift Instability ◽  
Relationship Of ◽  
The Relationship ◽  
Field Aligned Irregularities

Abstract. The first results of simultaneous observations made on the low-latitude field-aligned irregularities (FAI) using the MST radar located at Gadanki (13.5° N, 79.2° E, dip 12.5°) and the Es parameters using an ionosonde at a nearby station Sriharikota (13.7° N, 80.1° E, dip 12.6°) are presented. The observations show that while the height of the most intense radar echoes is below the virtual height of Es (h'Es) during daytime, it is found to be either below or above during nighttime. The strength of the FAI is better correlated with the top penetration frequency (ftEs) and the blanketing frequency (fbEs) during the night (r=0.4 in both cases) as compared to the day (r=0.35 and -0.04, respectively). Furthermore, the signal strength of FAI is reasonably correlated with (ftEs-fbEs) during daytime (r=0.59) while very poorly correlated during nighttime (r=0.18). While the radar observations in general appear to have characteristics close to that of mid-latitudes, the relationship of these with the Es parameters are poorer than that of mid-latitudes. The observations reported here, nevertheless, are quite consistent with the expectations based on the gradient drift instability mechanism.

scholarly journals Analysis of ionospheric structure influences on residual ionospheric errors in GNSS radio occultation bending angles based on ray tracing simulations

2018 ◽  
Vol 11 (4) ◽  
pp. 2427-2440 ◽  
Author(s):  
Congliang Liu ◽  
Gottfried Kirchengast ◽  
Yueqiang Sun ◽  
Kefei Zhang ◽  
Robert Norman ◽  
...  
Keyword(s):  
Impact Parameter ◽  
Radio Occultation ◽  
Global Climate ◽  
Weather Prediction ◽  
Signal Propagation ◽  
Satellite System ◽  
Primary Role ◽  
Dual Frequency ◽  
Bending Angle ◽  
Bending Angles

Abstract. The Global Navigation Satellite System (GNSS) radio occultation (RO) technique is widely used to observe the atmosphere for applications such as numerical weather prediction and global climate monitoring. The ionosphere is a major error source to RO at upper stratospheric altitudes, and a linear dual-frequency bending angle correction is commonly used to remove the first-order ionospheric effect. However, the higher-order residual ionospheric error (RIE) can still be significant, so it needs to be further mitigated for high-accuracy applications, especially from 35 km altitude upward, where the RIE is most relevant compared to the decreasing magnitude of the atmospheric bending angle. In a previous study we quantified RIEs using an ensemble of about 700 quasi-realistic end-to-end simulated RO events, finding typical RIEs at the 0.1 to 0.5 µrad noise level, but were left with 26 exceptional events with anomalous RIEs at the 1 to 10 µrad level that remained unexplained. In this study, we focused on investigating the causes of the high RIE of these exceptional events, employing detailed along-ray-path analyses of atmospheric and ionospheric refractivities, impact parameter changes, and bending angles and RIEs under asymmetric and symmetric ionospheric structures. We found that the main causes of the high RIEs are a combination of physics-based effects – where asymmetric ionospheric conditions play the primary role, more than the ionization level driven by solar activity – and technical ray tracer effects due to occasions of imperfect smoothness in ionospheric refractivity model derivatives. We also found that along-ray impact parameter variations of more than 10 to 20 m are possible due to ionospheric asymmetries and, depending on prevailing horizontal refractivity gradients, are positive or negative relative to the initial impact parameter at the GNSS transmitter. Furthermore, mesospheric RIEs are found generally higher than upper-stratospheric ones, likely due to being closer in tangent point heights to the ionospheric E layer peaking near 105 km, which increases RIE vulnerability. In the future we will further improve the along-ray modeling system to fully isolate technical from physics-based effects and to use it beyond this work for additional GNSS RO signal propagation studies.

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