This paper synthesizes existing experimental research in the area of investor perceptions and offers directions for future research. Investor-related experimental research has…
Abstract
This paper synthesizes existing experimental research in the area of investor perceptions and offers directions for future research. Investor-related experimental research has grown substantially, especially in the last decade, as it has made valuable contributions in establishing causal links, examining underlying process measures, and examining areas with little available data. Within this review, I examine 121 papers and identify three broad categories that affect investor perceptions: information format, investor features, and disclosure credibility. Information format describes how investors are influenced by information salience, information labeling, reporting and accounting complexity, financial statement recognition, explanatory disclosures, and proposed disclosure changes. Investor features describes investors’ use of heuristics, investor preferences, and the effect of investor experience. Disclosure credibility is influenced by external and internal assurance, management credibility, disclosure characteristics, and management incentives. Using this framework, I summarize the existing research and identify areas that would benefit from additional research.
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A solution algorithm which enables various rheological models of combined one‐dimensional consolidation and creep to be accommodated in a unified approach, is used to solve three…
Abstract
A solution algorithm which enables various rheological models of combined one‐dimensional consolidation and creep to be accommodated in a unified approach, is used to solve three models which have appeared in the literature. The theories are those of Tan, Gibson and Lo, and Schiffman, Ladd and Chen. Comparisons between these hereditary rheological models are performed and assessments of the various features of the models presented.
The purpose of this paper is concerned with developing two-mode higher-order modified Korteweg-de Vries (KdV) equations. The study shows that multiple soliton solutions exist for…
Abstract
Purpose
The purpose of this paper is concerned with developing two-mode higher-order modified Korteweg-de Vries (KdV) equations. The study shows that multiple soliton solutions exist for essential conditions related to the nonlinearity and dispersion parameters.
Design/methodology/approach
The proposed technique for constructing a two-wave model, as presented in this work, has been shown to be very efficient. The employed approach formally derives the essential conditions for soliton solutions to exist.
Findings
The examined two-wave model features interesting results in propagation of waves and fluid flow.
Research limitations/implications
The paper presents a new and efficient algorithm for constructing and studying two-wave-mode higher-order modified KdV equations.
Practical implications
A two-wave model was constructed for higher-order modified KdV equations. The essential conditions for multiple soliton solutions to exist were derived.
Social implications
The work shows the distinct features of the standard equation and the newly developed equation.
Originality/value
The work is original and this is the first time for two-wave-mode higher-order modified KdV equations to be constructed and studied.
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Xiaogang Wang, Wutao Qin, Yuliang Bai and Naigang Cui
The time delay would occurs when the measurements of multiple unmanned aerial vehicles (UAVs) are transmitted to the date processing center during cooperative target localization…
Abstract
Purpose
The time delay would occurs when the measurements of multiple unmanned aerial vehicles (UAVs) are transmitted to the date processing center during cooperative target localization. This problem is often named as the out-of-sequence measurement (OOSM) problem. This paper aims to present a nonlinear filtering based on solving the Fokker–Planck equation to address the issue of OOSM.
Design/methodology/approach
According to the arrival time of measurement, the proposed nonlinear filtering can be divided into two parts. The non-delay measurement would be fused in the first part, in which the Fokker–Planck equation is utilized to propagate the conditional probability density function in the forward form. The time delay measurement is fused in the second part, in which the Fokker–Planck is used in the backward form approximately. The Bayes formula is applied in both parts during the measurement update.
Findings
Under the Bayesian filtering framework, this nonlinear filtering is not only suitable for the Gaussian noise assumption but also for the non-Gaussian noise assumption. The nonlinear filtering is applied to the cooperative target localization problem. Simulation results show that the proposed filtering algorithm is superior to the previous Y algorithm.
Practical implications
In this paper, the research shows that a better performance can be obtained by fusing multiple UAV measurements and treating time delay in measurement with the proposed algorithm.
Originality/value
In this paper, the OOSM problem is settled based on solving the Fokker–Planck equation. Generally, the Fokker–Planck equation can be used to predict the probability density forward in time. However, to associate the current state with the state related to OOSM, it would be used to propagate the probability density backward either.
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Xiaogang Wang, Wutao Qin, Yu Wang and Naigang Cui
This paper aims to propose Bayesian filtering based on solving the Fokker–Planck equation, to improve the accuracy of filtering in non-Gauss case. Nonlinear filtering plays an…
Abstract
Purpose
This paper aims to propose Bayesian filtering based on solving the Fokker–Planck equation, to improve the accuracy of filtering in non-Gauss case. Nonlinear filtering plays an important role in many science and engineering fields for estimating the state of dynamic system, but the existing filtering algorithms are mainly used for solving the problem of Gauss system.
Design/methodology/approach
Under the Bayesian framework, the time update of this filtering is based on solving Fokker–Planck equation, while the measurement update uses the Bayes formula directly. Therefore, this novel algorithm can be applied to nonlinear, non-Gaussian estimation. To reduce the computational complexity due to standard meshing, an adaptive meshing algorithm proposed which includes the coarse meshing, significant domain determination that is generated using extended Kalman filtering and Chebyshev’s inequality theorem, and value assignment for significant domain. Simulations are conducted on a reentry body tracking problem to demonstrate the effectiveness of this novel algorithm.
Findings
In this way, finer grid points can be placed in the regions with high conditional probability density, while the grid points with low conditional probability density can be neglected. The simulation results indicate that the novel algorithm can reduce the computational burden significantly compared to the standard meshing, while achieving similar accuracy.
Practical implications
A novel Bayesian filtering based on solving the Fokker–Planck equation using adaptive meshing is proposed, and the simulations show that algorithm can reduce the computational burden significantly compared to the standard meshing, while achieving similar accuracy.
Originality/value
A novel nonlinear filtering based on solving the Fokker–Planck equation is proposed. The novel algorithm is suitable for non-Gauss system, and can achieve similar accuracy compared to the standard meshing with the significant reduction of computational burden.
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Tian Rong and ChenXu Wang
Island attack and defense, emergency rescue, scientific research, civilian fisheries and other fields are inseparable from timely, high-quality underwater communications. However…
Abstract
Purpose
Island attack and defense, emergency rescue, scientific research, civilian fisheries and other fields are inseparable from timely, high-quality underwater communications. However light and other electromagnetic waves are severely attenuated in water, acoustic is currently the only energy carrier that can transmit signals over long distances in water. However, the complex water environment and serious interference bring serious challenges to underwater activities using underwater acoustic sensors-hydroacoustic transducers. Thus, this paper aims to develop a class of high reception sensitivity hydroacoustic transducer structures to provide research and utilization ideas for related scholars.
Design/methodology/approach
The electromechanical coupling coefficient is improved by converting the thickness vibration mode of the piezoelectric ceramic into the longitudinal vibration mode of the piezoelectric pillars array, and no polymer is added between the piezoelectric pillars array to reduce lateral coupling as well as internal friction, which can thus reduce the energy losses. Radial stacking in parallel can also enhance the charge generated through the positive piezoelectric effect. The optimal parameters of the structure are determined by equivalent circuit method and finite element analysis, and a hydroacoustic transducer of this structure is fabricated finally.
Findings
According to the standard test procedure, the hydroacoustic transducer was tested in water. The tests show that the conductance curve of the stacked high-sensitivity hydroacoustic transducer tested in the air is in good agreement with the simulation results. The resonant frequency is about 118 kHz, and the receiver sensitivity is −166 dB. The stacked material hydroacoustic transducer is in the high-frequency range and has a much higher sensitivity (−166 dB) than many types of hydroacoustic transducers fabricated by piezoelectric ceramic (less than −200 dB).
Research limitations/implications
Although the stacked high-sensitivity hydroacoustic transducer that the authors have fabricated has a performance improvement, it has a limitation. The hollow design of the pillar arrays increases the reception stress on each pillar, and the imposed pressure comes from water also increases simultaneously, so the depth of water that the stacked high-sensitivity hydroacoustic transducer can operate in may be slightly shallower than that made of a pure piezoelectric ceramic block or a piezoelectric ceramic material with polymer added. This will be a problem to be solved in a future deployment.
Practical implications
Whether it is marine scientific research or in various fields such as civil recreation and fishing, hydroacoustic communication and necessary underwater exploration are indispensable for acoustic waves. The hydroacoustic transducer is the sensor that sends and receives sound waves, so a lot of water equipment, such as yachts, sonar buoys, and so on, cannot be separated from the hydroacoustic transducer. In addition, the complexity of the water environment also requires a good performance of the hydroacoustic transducer to facilitate the convenience and effectiveness of subsequent signal processing. Therefore, hydroacoustic transducers have great market and commercial value.
Social implications
Hydroacoustic transducers are not only of great commercial value but also have a significant impact on the military as well as on people’s livelihood. As we all know, in the area of submarine communication and underwater exploration, sonar is the main force. The performance of the hydroacoustic transducer directly affects the performance of the hydroacoustic signal processing system, and ultimately directly determines the success or failure of the mission. In addition, the large-scale replacement of hydroacoustic transducers on equipment requires the concerted efforts of a large number of practitioners, such as material scientists, structural scientists, mathematicians and so on. Therefore, the rise of hydroacoustic transducers has given rise to a large number of learning positions as well as employment positions.
Originality/value
To enhance the reception sensitivity of the hydroacoustic transducer, the authors have optimized the existing hydroacoustic transducer materials and structures to propose a stacked sensitive element, which can effectively enhance the electromechanical conversion coefficient of the piezoelectric material. Furthermore, the authors have manufactured a hydroacoustic transducer using the proposed stacked sensitive element. The test results of the hydroacoustic transducer also show that the designed stacked sensitive element is of great help to enhance the reception sensitivity of the hydroacoustic transducer.
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L.J. Crampon and K.T. Tan
A wide variety of factors influence international tourism; the number of trips taken, the distance traveled, the destinations selected for visits, and so forth. An understanding…
Abstract
A wide variety of factors influence international tourism; the number of trips taken, the distance traveled, the destinations selected for visits, and so forth. An understanding of these factors and their impacts is essential for the optimum development of tourism. The objective of this paper is, however, not to analyze or even identify all such influencing factors but rather to provide a framework for quantitatively examining the major elements or factor‐groups that influence travel in order to facilitate an identification and understanding of the various factors. The paper seeks to present a model or a tool that can be used for this needed analysis; the Pacific basin is used as en example.
Behrooz Yousefi, Mohammad Reza Esfahani and Mohammadreza Tavakkolizadeh
This paper aims to develop a new multi-fiber element for predicting the structural behavior of planar-reinforced concrete (RC) members.
Abstract
Purpose
This paper aims to develop a new multi-fiber element for predicting the structural behavior of planar-reinforced concrete (RC) members.
Design/methodology/approach
In this work, an exact multi-directional stiffness matrix is analytically derived based on the post-cracking bond-slip interaction between concrete and steel bars. The approach is also extended for large displacement analysis using Green–Lagrange finite strain tensor. In the proposed formulation, the weak form of governed differential equations is approximated by a trial-function expansion based on a finite strain-description and an additional degree of freedom for steel bars.
Findings
The findings provide a realistic description of cracking in the concrete structure. Numerical studies are conducted to examine the accuracy of the suggested approach and its capability to predict fairly complex responses of RC models. The findings prove that the proposed element can evaluate local and global responses of RC members, and it can be used as a reliable tool to reflect bond-slip effects in large displacement level. This leads to a robust and precise model for non-linear analysis of RC structures.
Originality/value
The methodology is capable of simulating coupled inelastic shear-flexural behavior of RC members through local stress field theory and Timoshenko beam model.