The effect of roll damping on the prediction of a ship＇s motion is significant. A method based on the 3-D CFD approach for calculating the roll damping of a ship is proposed in this paper. The free decay experiments ...The effect of roll damping on the prediction of a ship＇s motion is significant. A method based on the 3-D CFD approach for calculating the roll damping of a ship is proposed in this paper. The free decay experiments of 4 different types of ships at zero velocity are carried out. The roll damping coefficients are calculated and compared with the experiment results, with a good agreement. It is shown that the method adopted in this paper could be used to simulate the free rolling of a ship in the calm water at zero velocity very well and with good, stable accuracy for the prediction of the roll damping, and also with good applicability. This method may be further developed for the prediction of a full scale ship in the future.展开更多
The parametric rolling（PR） in the head or following waves has been considered as one of the main stability failure modes in the development of the 2nd generation Intact Stability criterion by the International Marit...The parametric rolling（PR） in the head or following waves has been considered as one of the main stability failure modes in the development of the 2nd generation Intact Stability criterion by the International Maritime Organization（IMO）.According to previous studies,the estimation methods of the roll damping affect the prediction of the PR significantly,and most of them are based on experiment data or Ikeda＇s empirical formula.The accuracy of the estimation method for the roll damping could be a key aspect for the validity of its prediction for the full scale ship.In this research,a hybrid prediction method is developed for the numerical prediction of the parametric rolling when experiment data are not available for the roll damping.Comparison study is also carried out between the hybrid method and a nonlinear dynamics method,where the roll damping is estimated by the simplified Ikeda＇s method and the direct CFD prediction method in a direct non-linear simulation based on the 3-D CFD approach in the model scale.It is shown that the results of the hybrid method are in satisfactory agreements with the model experiment results,and the method can be used for analysis especially at the early design stage where experiment data are often not available.展开更多
The aim of this paper is to characterize the （＊, ~）-good congruences on regular ortho-lc-monoids by making use of the compatible congruence systems on the semi-spined product components of regular ortho-lc-monoids.
Novel Coronavirus Disease(COVID-19)is a communicable disease that originated during December 2019,when China officially informed the World Health Organization(WHO)regarding the constellation of cases of the disease in...Novel Coronavirus Disease(COVID-19)is a communicable disease that originated during December 2019,when China officially informed the World Health Organization(WHO)regarding the constellation of cases of the disease in the city of Wuhan.Subsequently,the disease started spreading to the rest of the world.Until this point in time,no specific vaccine or medicine is available for the prevention and cure of the disease.Several research works are being carried out in the fields of medicinal and pharmaceutical sciences aided by data analytics and machine learning in the direction of treatment and early detection of this viral disease.The present report describes the use of machine learning algorithms[Linear and Logistic Regression,Decision Tree(DT),K-Nearest Neighbor(KNN),Support Vector Machine(SVM),and SVM with Grid Search]for the prediction and classification in relation to COVID-19.The data used for experimentation was the COVID-19 dataset acquired from the Center for Systems Science and Engineering(CSSE),Johns Hopkins University(JHU).The assimilated results indicated that the risk period for the patients is 12–14 days,beyond which the probability of survival of the patient may increase.In addition,it was also indicated that the probability of death in COVID cases increases with age.The death probability was found to be higher in males as compared to females.SVM with Grid search methods demonstrated the highest accuracy of approximately 95%,followed by the decision tree algorithm with an accuracy of approximately 94%.The present study and analysis pave a way in the direction of attribute correlation,estimation of survival days,and the prediction of death probability.The findings of the present study clearly indicate that machine learning algorithms have strong capabilities of prediction and classification in relation to COVID-19 as well.展开更多
We formulate a lattice Boltzmann model which simulates Korteweg-de Vries equation by using a method of higher moments of lattice Boltzmann equation.Using a series of lattice Boltzmann equations in different time scale...We formulate a lattice Boltzmann model which simulates Korteweg-de Vries equation by using a method of higher moments of lattice Boltzmann equation.Using a series of lattice Boltzmann equations in different time scales and the conservation law in time scale t0,we obtain equilibrium distribution function.The numerical examples show that the method can be used to simulate soliton.展开更多
Although Morison equation is often applied for simulating hydrodynamic force of marine structure, it may give poor results when non-linear behavior is severe or random wave is encountered. This leads to some modificat...Although Morison equation is often applied for simulating hydrodynamic force of marine structure, it may give poor results when non-linear behavior is severe or random wave is encountered. This leads to some modifications of Morison equation or other methods for predicting hydrodynamic force. One of them is the system identification technique. In this paper, NARMAX model theory is firstly used to identify the hydrodynamic system of heave damping plates, which are commonly installed on spar platform. Both linear and non-linear models are obtained. The comparisons between the predieted results and measured data indicate that NARMAX model can predict hydrodynamic force of a heave damping plate very well. The measured data for identification originate from forced oscillation tests, which are random records with given spectrum. The forced oscillation forms in experiment also contain simple harmonic, multi-frequency ones.展开更多
The project investigated the potential of building geometry to minimize energy consumption in office buildings.Five distinct geometries were modeled as mid-size office occupancies in the context of Toronto,Ontario,and...The project investigated the potential of building geometry to minimize energy consumption in office buildings.Five distinct geometries were modeled as mid-size office occupancies in the context of Toronto,Ontario,and examined with varied design parameters:window to wall ratio(WWR)and external static shading devices.IES VE software was used to predict the annual energy consumption of the five archetypes for 40 permutations.The outcome of this research showed that the variation of the total energy use from one shape to another was relatively small.WWR appeared to have a stronger impact on the energy pattern of a building than its shape.Overall,the energy performance of the archetypes were observed to conform to their individual building aspect ratios.The findings are thus expected to provide useful guidelines for architects on utilizing building geometry as an energy saving measure in the design of office buildings.展开更多
This paper relates to an advanced open mobile communication system and method of integrating the mobile communications, wireless access systems and wired communications into one common platform architecture for China&...This paper relates to an advanced open mobile communication system and method of integrating the mobile communications, wireless access systems and wired communications into one common platform architecture for China's 4th generation mobile communications, supporting costeffective broadband voice, data and video services in wireless, mobile and wired environment with one single integrated mobile terminal device. The paper includes new architecture in the integrated mobile device and converged network access, and minimum modifi cation in the existing mobile telecommunication infrastructures. This paper introduces the long-term evolution strategy for China's TDD system platform towards China's future 4G mobile communications.展开更多
基金Project supported by the Ministry of Industry and Infor-mation Technology of the China(Grant No.[2012]533)the Chinese Government Key Research Project KSHIP-Ⅱ Project(Knowledge-based Ship Design Hyper-Integrated Platform)(Grant No.201335)
文摘The effect of roll damping on the prediction of a ship＇s motion is significant. A method based on the 3-D CFD approach for calculating the roll damping of a ship is proposed in this paper. The free decay experiments of 4 different types of ships at zero velocity are carried out. The roll damping coefficients are calculated and compared with the experiment results, with a good agreement. It is shown that the method adopted in this paper could be used to simulate the free rolling of a ship in the calm water at zero velocity very well and with good, stable accuracy for the prediction of the roll damping, and also with good applicability. This method may be further developed for the prediction of a full scale ship in the future.
基金supported by the Ministry of Industry and Infor-mation Technology of China(Grant No.[2012]533)the Chinese Government Key Research Knowledge-based Ship Design Hyper-Integrated Platform(Grant No.201335)
文摘The parametric rolling（PR） in the head or following waves has been considered as one of the main stability failure modes in the development of the 2nd generation Intact Stability criterion by the International Maritime Organization（IMO）.According to previous studies,the estimation methods of the roll damping affect the prediction of the PR significantly,and most of them are based on experiment data or Ikeda＇s empirical formula.The accuracy of the estimation method for the roll damping could be a key aspect for the validity of its prediction for the full scale ship.In this research,a hybrid prediction method is developed for the numerical prediction of the parametric rolling when experiment data are not available for the roll damping.Comparison study is also carried out between the hybrid method and a nonlinear dynamics method,where the roll damping is estimated by the simplified Ikeda＇s method and the direct CFD prediction method in a direct non-linear simulation based on the 3-D CFD approach in the model scale.It is shown that the results of the hybrid method are in satisfactory agreements with the model experiment results,and the method can be used for analysis especially at the early design stage where experiment data are often not available.
基金The research was supported by the NSF （10871161, 11101336, 11371177, 11226044） of China, the Natural Science Foundation Project of CQ CSTC （2009BB2291）, and the Talents Technology Fund of Xi＇an University of Architecture and Technology （Grant No. RC1110）.
文摘The aim of this paper is to characterize the （＊, ~）-good congruences on regular ortho-lc-monoids by making use of the compatible congruence systems on the semi-spined product components of regular ortho-lc-monoids.
文摘Novel Coronavirus Disease(COVID-19)is a communicable disease that originated during December 2019,when China officially informed the World Health Organization(WHO)regarding the constellation of cases of the disease in the city of Wuhan.Subsequently,the disease started spreading to the rest of the world.Until this point in time,no specific vaccine or medicine is available for the prevention and cure of the disease.Several research works are being carried out in the fields of medicinal and pharmaceutical sciences aided by data analytics and machine learning in the direction of treatment and early detection of this viral disease.The present report describes the use of machine learning algorithms[Linear and Logistic Regression,Decision Tree(DT),K-Nearest Neighbor(KNN),Support Vector Machine(SVM),and SVM with Grid Search]for the prediction and classification in relation to COVID-19.The data used for experimentation was the COVID-19 dataset acquired from the Center for Systems Science and Engineering(CSSE),Johns Hopkins University(JHU).The assimilated results indicated that the risk period for the patients is 12–14 days,beyond which the probability of survival of the patient may increase.In addition,it was also indicated that the probability of death in COVID cases increases with age.The death probability was found to be higher in males as compared to females.SVM with Grid search methods demonstrated the highest accuracy of approximately 95%,followed by the decision tree algorithm with an accuracy of approximately 94%.The present study and analysis pave a way in the direction of attribute correlation,estimation of survival days,and the prediction of death probability.The findings of the present study clearly indicate that machine learning algorithms have strong capabilities of prediction and classification in relation to COVID-19 as well.
基金Supported by the Foundation of the Laboratory for Nonlinear Mechanics of Continuous Media,Institute of Mechanics,Chinese Academy of Sciences.
文摘We formulate a lattice Boltzmann model which simulates Korteweg-de Vries equation by using a method of higher moments of lattice Boltzmann equation.Using a series of lattice Boltzmann equations in different time scales and the conservation law in time scale t0,we obtain equilibrium distribution function.The numerical examples show that the method can be used to simulate soliton.
文摘Although Morison equation is often applied for simulating hydrodynamic force of marine structure, it may give poor results when non-linear behavior is severe or random wave is encountered. This leads to some modifications of Morison equation or other methods for predicting hydrodynamic force. One of them is the system identification technique. In this paper, NARMAX model theory is firstly used to identify the hydrodynamic system of heave damping plates, which are commonly installed on spar platform. Both linear and non-linear models are obtained. The comparisons between the predieted results and measured data indicate that NARMAX model can predict hydrodynamic force of a heave damping plate very well. The measured data for identification originate from forced oscillation tests, which are random records with given spectrum. The forced oscillation forms in experiment also contain simple harmonic, multi-frequency ones.
文摘The project investigated the potential of building geometry to minimize energy consumption in office buildings.Five distinct geometries were modeled as mid-size office occupancies in the context of Toronto,Ontario,and examined with varied design parameters:window to wall ratio(WWR)and external static shading devices.IES VE software was used to predict the annual energy consumption of the five archetypes for 40 permutations.The outcome of this research showed that the variation of the total energy use from one shape to another was relatively small.WWR appeared to have a stronger impact on the energy pattern of a building than its shape.Overall,the energy performance of the archetypes were observed to conform to their individual building aspect ratios.The findings are thus expected to provide useful guidelines for architects on utilizing building geometry as an energy saving measure in the design of office buildings.
文摘This paper relates to an advanced open mobile communication system and method of integrating the mobile communications, wireless access systems and wired communications into one common platform architecture for China's 4th generation mobile communications, supporting costeffective broadband voice, data and video services in wireless, mobile and wired environment with one single integrated mobile terminal device. The paper includes new architecture in the integrated mobile device and converged network access, and minimum modifi cation in the existing mobile telecommunication infrastructures. This paper introduces the long-term evolution strategy for China's TDD system platform towards China's future 4G mobile communications.
