Coalbed methane(CBM) commercial development requires choosing the arrangement of the wells.This should be done by considering the corresponding input-output(investment-profit) efficiencies.Simulations were obtained fr...Coalbed methane(CBM) commercial development requires choosing the arrangement of the wells.This should be done by considering the corresponding input-output(investment-profit) efficiencies.Simulations were obtained from the computer modeling group(CMG) given the reservoir conditions of the Panzhuang block in the southern part of the Qinshui Basin.This is a demonstration region for CBM development located in Shanxi province of northern China.The sensitivity of gas production from a single vertical well to the primary reservoir parameters was estimated first.Then multi-well gas production from three different well patterns was simulated to estimate the most appropriate well spacing.Combining the investment requirements then gave investment-profit efficiencies for these well patterns.A data envelopment analysis(DEA) model was used to optimize the efficiency.The results show that the permeability,the reservoir pressure,and the gas content have an evident impact on single well gas production.The desorption time has little or no affect on production.The equilateral triangular well pattern(ETWP) in a 400 m well spacing is,for multi-well development,the optimal pattern.It has a better input-output ratio,a longer stable yield time,and provides for greater CBM recovery than does either the rectangular well pattern(RWP) or the five point well pattern(FPWP).展开更多
In this paper, the authors study the association between firms＇ specific characteristics and performances for a sample of 320 American firms using a governance efficiency index, calculated by the stochastic frontier ...In this paper, the authors study the association between firms＇ specific characteristics and performances for a sample of 320 American firms using a governance efficiency index, calculated by the stochastic frontier analysis. The use of a latent class in the specification of the model, allowed detecting two groups of firms according to their specific characteristics： the firm size, the leverage, the dividend yield, and the return on equity （ROE）. The results of affectation equation show that the probability to be in the second group （the most efficient） is more important when the firm size, the dividend yield, and the ROE are high, while a high leverage level decreases the chance to be in the first group （the less efficient）.展开更多
Today cooperative banks belong to the most significant financial institution in the world. Moreover, they can compete with commercial banks. The own funds of the cooperative bank are important in their activity. The m...Today cooperative banks belong to the most significant financial institution in the world. Moreover, they can compete with commercial banks. The own funds of the cooperative bank are important in their activity. The main goal of this paper is to investigate how much the level of the own funds of the Polish cooperative banks influenced their efficiency. The research pertained to operating cooperative banks in Poland. The following measures of the efficiency were used in the research： return on Equity （ROE）, net profit, index C/I, and financial margin. The results of the study indicate that banks from the Quartile III （highest aggregate own funds）, had the highest net profits, the highest ROE, the lowest C/I value, the lowest ROE, and the lowest financial markups. On this basis, it remains to be recommended that banks of highest aggregate own funds continue expansion of own funds which will increase lending capacity and subsequently contribute to higher effectiveness.展开更多
基金supported by the National Natural Science Foundation of China (No. 40972207)the National Science and Technology Major Projects (No. 2011ZX05034-005)the PAPD of Jiangsu Higher Education Institutions
文摘Coalbed methane(CBM) commercial development requires choosing the arrangement of the wells.This should be done by considering the corresponding input-output(investment-profit) efficiencies.Simulations were obtained from the computer modeling group(CMG) given the reservoir conditions of the Panzhuang block in the southern part of the Qinshui Basin.This is a demonstration region for CBM development located in Shanxi province of northern China.The sensitivity of gas production from a single vertical well to the primary reservoir parameters was estimated first.Then multi-well gas production from three different well patterns was simulated to estimate the most appropriate well spacing.Combining the investment requirements then gave investment-profit efficiencies for these well patterns.A data envelopment analysis(DEA) model was used to optimize the efficiency.The results show that the permeability,the reservoir pressure,and the gas content have an evident impact on single well gas production.The desorption time has little or no affect on production.The equilateral triangular well pattern(ETWP) in a 400 m well spacing is,for multi-well development,the optimal pattern.It has a better input-output ratio,a longer stable yield time,and provides for greater CBM recovery than does either the rectangular well pattern(RWP) or the five point well pattern(FPWP).
文摘In this paper, the authors study the association between firms＇ specific characteristics and performances for a sample of 320 American firms using a governance efficiency index, calculated by the stochastic frontier analysis. The use of a latent class in the specification of the model, allowed detecting two groups of firms according to their specific characteristics： the firm size, the leverage, the dividend yield, and the return on equity （ROE）. The results of affectation equation show that the probability to be in the second group （the most efficient） is more important when the firm size, the dividend yield, and the ROE are high, while a high leverage level decreases the chance to be in the first group （the less efficient）.
文摘Today cooperative banks belong to the most significant financial institution in the world. Moreover, they can compete with commercial banks. The own funds of the cooperative bank are important in their activity. The main goal of this paper is to investigate how much the level of the own funds of the Polish cooperative banks influenced their efficiency. The research pertained to operating cooperative banks in Poland. The following measures of the efficiency were used in the research： return on Equity （ROE）, net profit, index C/I, and financial margin. The results of the study indicate that banks from the Quartile III （highest aggregate own funds）, had the highest net profits, the highest ROE, the lowest C/I value, the lowest ROE, and the lowest financial markups. On this basis, it remains to be recommended that banks of highest aggregate own funds continue expansion of own funds which will increase lending capacity and subsequently contribute to higher effectiveness.
