A Regional Zenith Tropospheric Correction Model Based on the Guangxi CORS Network

2013 ◽  
Vol 353-356 ◽  
pp. 3438-3443
Author(s):  
Li Long Liu ◽  
Liang Ke Huang ◽  
Teng Xu Zhang ◽  
Miao Zhou ◽  
Chao Long Yao
Keyword(s):  
Interpolation Method ◽  
Meteorological Data ◽  
Correction Model ◽  
New Model ◽  
Model Based ◽  
Proposed Model ◽  
New Models ◽  
Using Data ◽  
The Relationship ◽  
Tropospheric Delays

In this paper, the relationship between zenith tropospheric delays and the altitude of stations is analyzed using the EGNOS tropospheric correction model. The new model (EHT model) is proposed for estimating zenith tropospheric delays from regional CORS data without meteorological data. The proposed model is compared with the direct interpolation method and the remove-restore method using data from Guangxi CORS. The results show that the new models significantly improve the calculated precision.

A new underwater positioning model based on average sound speed

2021 ◽  
pp. 1-17
Author(s):  
Yixu Liu ◽  
Xiushan Lu ◽  
Shuqiang Xue ◽  
Shengli Wang
Keyword(s):  
Efficient Algorithm ◽  
Sound Speed ◽  
Incident Angle ◽  
Function Model ◽  
Positioning Accuracy ◽  
Correction Model ◽  
Model Based ◽  
Underwater Positioning ◽  
Speed Function ◽  
The Relationship

Abstract The layout of seafloor datum points is the key to constructing the seafloor geodetic datum network, and a reliable underwater positioning model is the prerequisite for achieving precise deployment of the datum points. The traditional average sound speed positioning model is generally adopted in underwater positioning due to its simple and efficient algorithm, but it is sensitive to incident angle related errors, which lead to unreliable positioning results. Based on the relationship between incident angle and sound speed, the sound speed function model considering the incident angle has been established. Results show that the accuracy of positioning is easily affected by errors related to the incident angle; the new average sound speed correction model based on the incident angle proposed in this paper is used to significantly improve the underwater positioning accuracy.

Examining Behavioral Intention Toward Mobile Services

2011 ◽  
Vol 3 (2) ◽  
pp. 1-19 ◽  
Author(s):  
Theodora Zarmpou ◽  
Vaggelis Saprikis ◽  
Maro Vlachopoulou
Keyword(s):  
Stepwise Regression ◽  
Mobile Services ◽  
Ease Of Use ◽  
Perceived Usefulness ◽  
Perceived Ease Of Use ◽  
Key Factors ◽  
Proposed Model ◽  
Using Data ◽  
The Relationship ◽  
Adoption Intention

This study presents a conceptual model that combines perceived ease of use, perceived usefulness, innovativeness, trust, demographic characteristics and relationship drivers in order to examine their influence on the mobile services’ adoption intention. The proposed model is empirically tested using data collected from a survey with questionnaires conducted in Greece. The results are analyzed through factor analysis, stepwise regression analysis, and ANOVAs. The findings show that individuals’ innovativeness, their educational level, and the relationship ties between the users and the mobile services are key factors to encourage m-services’ adoption. The results provide interesting insights and useful hints to practitioners and researchers.

scholarly journals Forecasting Realized Volatility Using a Nonnegative Semiparametric Model

2019 ◽  
Vol 12 (3) ◽  
pp. 139 ◽  
Author(s):  
Anders Eriksson ◽  
Daniel P. A. Preve ◽  
Jun Yu
Keyword(s):  
Predictive Accuracy ◽  
Estimation Method ◽  
Semiparametric Model ◽  
Error Component ◽  
New Model ◽  
Finite Samples ◽  
Proposed Model ◽  
Forecasting Performance ◽  
Out Of Sample ◽  
Using Data

This paper introduces a parsimonious and yet flexible semiparametric model to forecast financial volatility. The new model extends a related linear nonnegative autoregressive model previously used in the volatility literature by way of a power transformation. It is semiparametric in the sense that the distributional and functional form of its error component is partially unspecified. The statistical properties of the model are discussed and a novel estimation method is proposed. Simulation studies validate the new method and suggest that it works reasonably well in finite samples. The out-of-sample forecasting performance of the proposed model is evaluated against a number of standard models, using data on S&P 500 monthly realized volatilities. Some commonly used loss functions are employed to evaluate the predictive accuracy of the alternative models. It is found that the new model generally generates highly competitive forecasts.

From creative process engagement to performance: bidirectional support

2016 ◽  
Vol 37 (7) ◽  
pp. 966-982 ◽  
Author(s):  
Yana Du ◽  
Li Zhang ◽  
Yanhong Chen
Keyword(s):  
Creative Process ◽  
Relative Effect ◽  
Hierarchical Regression ◽  
Role Performance ◽  
Content Type ◽  
Proposed Model ◽  
Using Data ◽  
Investment Process ◽  
The Relationship ◽  
Practical Implications

Purpose The purpose of this paper is to explore the effect of creative process engagement on employees’ in-role performance, and does so by considering the support that employees received from and given to their supervisors. Design/methodology/approach Using data from 540 questionnaires collected in China, this paper conducts a hierarchical regression analysis to test the proposed model. Findings Creative process engagement positively affects employees’ in-role performance. However, the moderating effect of receiving support on the above relationship is not significant. Instead, it is the interaction of receiving support from and giving it to supervisors that moderates the relationship between creative process engagement and in-role performance. Research limitations/implications The study has some contributions to the conservation of resource (COR) theory. The authors find that acquiring new resources such as receiving support from supervisors is not always effective. The acquisition process of resources should be considered with the investment process of resources. According to the COR theory, people invest resources to gain resources and protect themselves from losing resources or to recover from resource loss (Halbesleben et al., 2014). The findings of the study show that employees investing resources is not just for gaining resources. Sometimes, they invest resources such as giving support to supervisors to remain a relatively balanced relationship. Practical implications Companies can encourage employees to place more attention on creative process engagement to improve in-role performance. In addition, when offering support to employees, managers should consider whether the employees are able to give it back in response to the received support, and distribute their support to employees accordingly. Originality/value This paper explored employee’s engagement at creative process in a more novel way and clarified the relative effect of creative process engagement on in-role performance. Also, this paper was the first to pay attention to the bidirectional nature of supervisor support.

Flexible Interaction Model for Complex Interactions of Multiple Anesthetics

2006 ◽  
Vol 105 (2) ◽  
pp. 286-296 ◽  
Author(s):  
Matthew Fidler ◽  
Steven E. Kern
Keyword(s):  
Drug Interactions ◽  
Interaction Model ◽  
Data Sets ◽  
Additive Interaction ◽  
New Model ◽  
Complex Interactions ◽  
Anesthetic Drugs ◽  
Proposed Model ◽  
Quantitative Manner ◽  
Using Data

Background Minto et al. (Anesthesiology 2000) described a mathematical approach based on response surface methods for characterizing drug-drug interactions between several intravenous anesthetic drugs. To extend this effort, the authors developed a flexible interaction model based on the general Hill dose-response relation that includes a set of parameters that can be statistically assessed for interaction significance. Methods This new model was developed to identify pharmacologically meaningful interaction-related parameters and address mathematical limitations in previous models. The flexible interaction model and the model of Minto et al. were compared in their assessment of additivity using simulated sample data sets. The flexible interaction model was also compared with the Minto model in describing drug interactions using data from several other clinical studies of propofol, opioids, and benzodiazepines from Short et al. (Anesthesiology 2002) and Kern et al. (Anesthesiology 2004). Results The flexible interaction model was able to accurately classify an additive interaction based on the classic definition proposed by Loewe, with at most an 8% difference between the two surfaces. Also, the proposed model fit the clinical interaction data as well or slightly better than that of Minto et al. Conclusions The new model can accurately classify additive and synergistic drug interactions. It also can classify antagonistic interactions with biologically rational surfaces. This has been a problem for other interaction models in the past. The statistically assessable interaction parameters provide a quantitative manner to assess the interaction significance.

Dynamic Ship Domain Model Based on AIS Data for Inland Waterways

2020 ◽  
Author(s):  
Yankang He ◽  
Di Zhang ◽  
Jinfen Zhang ◽  
Bing Wu ◽  
Carlos Guedes Soares
Keyword(s):  
Open Water ◽  
Domain Model ◽  
Inland Waterways ◽  
Ship Traffic ◽  
Model Based ◽  
Proposed Model ◽  
Channel Boundary ◽  
Domain Models ◽  
Inland Rivers ◽  
Using Data

Abstract The existing ship domain models are mostly based on the navigation behavior of open water vessels, and they are not practicable to directly apply to inland rivers. Therefore, it is necessary to establish an inland ship safety domain model based on the ship traffic characteristic therein. Based on the AIS data in the Yangtze River, this paper establishes the functional relationship between these data through multiple regression analysis using data such as ship spacing, ship length, ship speed, and heading angle. Based on this, the safety distance between ships of different lengths in different situations and other ships is determined, so as to establish a dynamic ship domain model. At the same time, this paper explores the geographical relationship between ship and channel boundary and incorporates it into the ship domain model. Finally, a quantitative approach for ship collision risk is proposed, and the collision threat degree is calculated according to the relative heading of the ship and the position in the dynamic ship domain model. Two case studies, including crossing and overtaking situations, are performed to validate the proposed model.

scholarly journals Improving the complementary methods to estimate evapotranspiration under diverse climatic and physical conditions

2014 ◽  
Vol 18 (6) ◽  
pp. 2049-2064 ◽  
Author(s):  
F. M. Anayah ◽  
J. J. Kaluarachchi
Keyword(s):  
Meteorological Data ◽  
Large River ◽  
Single Step ◽  
Coefficient Of Determination ◽  
Universal Method ◽  
Complementary Methods ◽  
Data Intensive ◽  
Physical Conditions ◽  
Proposed Model ◽  
Using Data

Abstract. Reliable estimation of evapotranspiration (ET) is important for the purpose of water resources planning and management. Complementary methods, including complementary relationship areal evapotranspiration (CRAE), advection aridity (AA) and Granger and Gray (GG), have been used to estimate ET because these methods are simple and practical in estimating regional ET using meteorological data only. However, prior studies have found limitations in these methods especially in contrasting climates. This study aims to develop a calibration-free universal method using the complementary relationships to compute regional ET in contrasting climatic and physical conditions with meteorological data only. The proposed methodology consists of a systematic sensitivity analysis using the existing complementary methods. This work used 34 global FLUXNET sites where eddy covariance (EC) fluxes of ET are available for validation. A total of 33 alternative model variations from the original complementary methods were proposed. Further analysis using statistical methods and simplified climatic class definitions produced one distinctly improved GG-model-based alternative. The proposed model produced a single-step ET formulation with results equal to or better than the recent studies using data-intensive, classical methods. Average root mean square error (RMSE), mean absolute bias (BIAS) and R2 (coefficient of determination) across 34 global sites were 20.57 mm month−1, 10.55 mm month−1 and 0.64, respectively. The proposed model showed a step forward toward predicting ET in large river basins with limited data and requiring no calibration.

A Regional Zenith Tropospheric Correction Model over Southern California Area

2014 ◽  
Vol 568-570 ◽  
pp. 292-296
Author(s):  
Li Long Liu ◽  
Miao Zhou ◽  
Teng Xu Zhang ◽  
Liang Ke Huang
Keyword(s):  
Southern California ◽  
Meteorological Data ◽  
Tropospheric Delay ◽  
Correction Model ◽  
New Model ◽  
Zenith Tropospheric Delay ◽  
The Stability ◽  
Better Than

In this paper, a new zenith tropospheric delay (ZTD) correction model is established by using 4 years of ZTD over Southern California, which not require any meteorological data and only related to the site’s elevation and the day of year. The results show that the stability and precision of the new model are better than Saastamoinen model using ECMWF date, and the precision increases along with increasing site’s elevation. The overall accuracy of the new model is about 3.86cm when used to predict zenith troposhperic delays in 2012 over Southern California area.

scholarly journals Mediating Effects of Place Attachment and Satisfaction on the Relationship between Tourists’ Emotions and Intention to Recommend

2016 ◽  
Vol 56 (8) ◽  
pp. 1079-1093 ◽  
Author(s):  
Sameer Hosany ◽  
Girish Prayag ◽  
Robert Van Der Veen ◽  
Songshan (Sam) Huang ◽  
Siripan Deesilatham
Keyword(s):  
Place Attachment ◽  
Positive Emotions ◽  
Positive Relationship ◽  
Negative Emotions ◽  
Developmental Theory ◽  
Mediating Effects ◽  
Tourist Destination ◽  
Model Based ◽  
Using Data ◽  
The Relationship

This study develops a model based on the developmental theory of place attachment. The model considers the influence of tourists’ emotions on place attachment and the mediating effects of satisfaction and place attachment on the relationship between tourists’ emotions and intention to recommend. The model was tested using data collected from 464 international tourists at the end of their trip to Thailand. Results show that positive emotions, negative emotions and satisfaction are significant determinants of place attachment. In particular, negative emotions display a positive relationship with place attachment. In addition, only satisfaction mediates the relationship between tourists’ emotions and intention to recommend. Findings highlight the need for researchers to incorporate emotions in modeling place attachment and offer implications for marketers promoting Thailand as a tourist destination.

scholarly journals A Novel E-Commerce Negotiation Optimization Model Based on Improved Genetic Algorithm

2012 ◽  
Vol 6-7 ◽  
pp. 566-570
Author(s):  
Yang Liu
Keyword(s):  
Genetic Algorithm ◽  
Electronic Commerce ◽  
Value Creation ◽  
Optimization Model ◽  
Improved Genetic Algorithm ◽  
Model Based ◽  
Proposed Model ◽  
Business Market ◽  
Major Player ◽  
The Relationship

Electronic commerce has rapidly become a major player in the business market .This paper proposes a new electronic commerce negotiation optimization model based on improved genetic algorithm which depends on not only price, but also other factors of commodity. The proposed model illustrates the relationship between the business components required to support the e-commerce processes with the value creation factor and the controlling complexity. The experiment results show that the proposed algorithm can gain the optimal negotiation result more efficiently than other three kinds of negotiation algorithms in competitive bilateral multi-issue negotiation.

Sign in / Sign up

Export Citation Format

Share Document