It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in Iran. Acer velutinum, an e...It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in Iran. Acer velutinum, an endemic species in Iran, is often planted in monocultures or in a mixture with other endemic species. Our study was conducted on A. velutinum planted in Berenjestanak(control plots) and Chaibagh(thinned plots) in northern Iran in 1991. A randomized sampling method with circular sampling plots of 100 m2was used to measure diameter and height of trees. The results show that the diameter of trees in thinned stands was 19.98 cm and in the control stands 13.84 cm, while the mean heights were 18.33 and 17.46 m, respectively. The mean basal area in thinned stands was 30.74 m2and in the control 15.70 m2per ha. The results of Student’s t tests indicate that there are significant differences at a probability level of 99.9% between the two variously treated stands in diameter(d), height(h), basal area, volume growth and the stability coefficient. We conclude that tending operations with suitable intensity in different time periods are recommended to obtain stable stands.展开更多
In this paper,the authors consider the empirical likelihood method for a first-order generalized random coefficient integer-valued autoregressive process.The authors establish the log empirical likelihood ratio statis...In this paper,the authors consider the empirical likelihood method for a first-order generalized random coefficient integer-valued autoregressive process.The authors establish the log empirical likelihood ratio statistic and obtain its limiting distribution.Furthermore,the authors investigate the point estimation,confidence regions and hypothesis testing for the parameters of interest.The performance of empirical likelihood method is illustrated by a simulation study and a real data example.展开更多
文摘It has become necessary to develop stands of fast growing endemic species in the Caspian forests because of their reduction in area and the domestic demand of timber processing industries in Iran. Acer velutinum, an endemic species in Iran, is often planted in monocultures or in a mixture with other endemic species. Our study was conducted on A. velutinum planted in Berenjestanak(control plots) and Chaibagh(thinned plots) in northern Iran in 1991. A randomized sampling method with circular sampling plots of 100 m2was used to measure diameter and height of trees. The results show that the diameter of trees in thinned stands was 19.98 cm and in the control stands 13.84 cm, while the mean heights were 18.33 and 17.46 m, respectively. The mean basal area in thinned stands was 30.74 m2and in the control 15.70 m2per ha. The results of Student’s t tests indicate that there are significant differences at a probability level of 99.9% between the two variously treated stands in diameter(d), height(h), basal area, volume growth and the stability coefficient. We conclude that tending operations with suitable intensity in different time periods are recommended to obtain stable stands.
基金supported by the National Natural Science Foundation of China under Grant Nos.11871028 and 11731015。
文摘In this paper,the authors consider the empirical likelihood method for a first-order generalized random coefficient integer-valued autoregressive process.The authors establish the log empirical likelihood ratio statistic and obtain its limiting distribution.Furthermore,the authors investigate the point estimation,confidence regions and hypothesis testing for the parameters of interest.The performance of empirical likelihood method is illustrated by a simulation study and a real data example.
