We investigate the average Level Crossing Rate （LCR） and Average Fading Duration （AFD） of multiuser single relay co- operation wireless uplinks over independent and non-identically distributed （i.ni.d） Ray- leig...We investigate the average Level Crossing Rate （LCR） and Average Fading Duration （AFD） of multiuser single relay co- operation wireless uplinks over independent and non-identically distributed （i.ni.d） Ray- leigh fading channels. We first present the statistical analyses of the first-hop equivalent envelope. Then, we investigate the LCR and AFD of an equivalent end-to-end envelope, and present the closed-form solutions to LCR and AFD, which are given with integral forms. Finally, we derive the Laplace approximations of LCR and AFD as well as the upper and lower bounds. The numerical results of LCR show that the upper bound is tight. For multi user systems with different number of mobile users, the analyses indicate that the LCRs are approximately the same at the low level of the envelope. envelope However, there are at the high level of the reasonable differences among the curves of LCRs. Due to that fact that AFD is the inverse function of LCR, the results for AFD are the opposite.展开更多
The response statistics of a compliant offshore structure excited by slowly varying wave drift forces is calculated by use of a numerical path integral solution method. The path integral solution is based on the Ganss...The response statistics of a compliant offshore structure excited by slowly varying wave drift forces is calculated by use of a numerical path integral solution method. The path integral solution is based on the Ganss-Legendre interpolation scheme, and the values of the response probability density are obtained at the Gauss quadrature points in sub-intervals. It is demonstrated that a distinct advantage of the path integral solution is that the joint probability density of the response displacement and velocity is one of the by products of the calculations. This makes it possible to calculate the mean level up-crossing rates, which provides estimates of the exceedance probabilities of specified response levels for given time periods.展开更多
A model has been constructed to study water flow in a single clay crack, and a new concept of the critical rise rate of water level in the crack has been put forward. When the water level rises faster than this critic...A model has been constructed to study water flow in a single clay crack, and a new concept of the critical rise rate of water level in the crack has been put forward. When the water level rises faster than this critical rate, the flow in a crack will increase, and vice versa. The flow in a crack is not in proportion to the water level. The maximium water flow in clay is 30-40 times smaller than that in a rock fissure under the same condition. In the process of water discharge, the flow in a crack will lessen gradually, and the crack will grow narrower by 3.0-4.0cm, with its depth reducing by over 50%.展开更多
In this paper, the difference of income and consumption levels between Chinese and Japanese town dwellers＇ is compared, based on the purchasing power parity of each currency. The results using a historical series of ...In this paper, the difference of income and consumption levels between Chinese and Japanese town dwellers＇ is compared, based on the purchasing power parity of each currency. The results using a historical series of the data and cross section data of the two countries are shown. And whenever the classification of Chinese and Japanese data is inconsistent, we reclassify Chinese material according to the Japanese classification.展开更多
The near future of coastal life is threated by the claim of global warming alarmist that sea levels will rise by one to seven metres by 2100,destroying many coastal cities and habitats.This paper shows that sea levels...The near future of coastal life is threated by the claim of global warming alarmist that sea levels will rise by one to seven metres by 2100,destroying many coastal cities and habitats.This paper shows that sea levels will more likely rise no more than just a few centimetres during this century as the Earth defrosts from the Little Ice Age 500 years ago with a mild warming.展开更多
基金supported by the Natural Science Foundation of China under Grant No.61261015the 973 Project under Grant No.2013CB329104+4 种基金the National Natural Science Foundation of China under Grants No. 61071090,No. 61171093the Key Projects under GrantsNo. 2011ZX03005-004-003, No. BK2011027the China Postdoctoral Science Foundation under Grant No. 2012M521105Research Fund for the Doctoral Program of Higher Educationof China under Grant No. 20113223110001the project 11KJA510001 and PAPD
文摘We investigate the average Level Crossing Rate （LCR） and Average Fading Duration （AFD） of multiuser single relay co- operation wireless uplinks over independent and non-identically distributed （i.ni.d） Ray- leigh fading channels. We first present the statistical analyses of the first-hop equivalent envelope. Then, we investigate the LCR and AFD of an equivalent end-to-end envelope, and present the closed-form solutions to LCR and AFD, which are given with integral forms. Finally, we derive the Laplace approximations of LCR and AFD as well as the upper and lower bounds. The numerical results of LCR show that the upper bound is tight. For multi user systems with different number of mobile users, the analyses indicate that the LCRs are approximately the same at the low level of the envelope. envelope However, there are at the high level of the reasonable differences among the curves of LCRs. Due to that fact that AFD is the inverse function of LCR, the results for AFD are the opposite.
文摘The response statistics of a compliant offshore structure excited by slowly varying wave drift forces is calculated by use of a numerical path integral solution method. The path integral solution is based on the Ganss-Legendre interpolation scheme, and the values of the response probability density are obtained at the Gauss quadrature points in sub-intervals. It is demonstrated that a distinct advantage of the path integral solution is that the joint probability density of the response displacement and velocity is one of the by products of the calculations. This makes it possible to calculate the mean level up-crossing rates, which provides estimates of the exceedance probabilities of specified response levels for given time periods.
文摘A model has been constructed to study water flow in a single clay crack, and a new concept of the critical rise rate of water level in the crack has been put forward. When the water level rises faster than this critical rate, the flow in a crack will increase, and vice versa. The flow in a crack is not in proportion to the water level. The maximium water flow in clay is 30-40 times smaller than that in a rock fissure under the same condition. In the process of water discharge, the flow in a crack will lessen gradually, and the crack will grow narrower by 3.0-4.0cm, with its depth reducing by over 50%.
文摘In this paper, the difference of income and consumption levels between Chinese and Japanese town dwellers＇ is compared, based on the purchasing power parity of each currency. The results using a historical series of the data and cross section data of the two countries are shown. And whenever the classification of Chinese and Japanese data is inconsistent, we reclassify Chinese material according to the Japanese classification.
文摘The near future of coastal life is threated by the claim of global warming alarmist that sea levels will rise by one to seven metres by 2100,destroying many coastal cities and habitats.This paper shows that sea levels will more likely rise no more than just a few centimetres during this century as the Earth defrosts from the Little Ice Age 500 years ago with a mild warming.
