[Objective] The purpose of this study is to judge the rationality of land use structure from new perspectives and method. [Method] The theory of data en- velopment analysis （DEA） has been employed in this article. A...[Objective] The purpose of this study is to judge the rationality of land use structure from new perspectives and method. [Method] The theory of data en- velopment analysis （DEA） has been employed in this article. A case study of evalu- ation of land use structure for Wujin district in 2012 is provided to illustrate the ap- plication of this research model. At the micro perspective, land use efficiency has been analyzed by use of data envelopment analysis model. The optimization and adjustment direction in land use structure has been pointed out from the view point of land use efficiency. [Result] The result has shown that the research method based on information entropy and data envelopment analysis model can effectively overcome the drawback of traditional evaluation techniques. Compared with the tra- ditional methods, the new optimization model based on a structure of the multi-crite- ria factors and objective weighting method can evaluate the rationality of land use structure more comprehensively.展开更多
The study examined the levels of resource-use efficiency of rice farmers unde,r irrigation method in Dadinkowa, Gombe state of Nigeria. Using questionnaire, data were collected during the year 2010 irrigation season f...The study examined the levels of resource-use efficiency of rice farmers unde,r irrigation method in Dadinkowa, Gombe state of Nigeria. Using questionnaire, data were collected during the year 2010 irrigation season from 120 randomly sampled rice irrigators and the data were analyzed using multiple regression and marginal analyses. Results showed that significant factors influencing irrigated rice production were labour （P 〈 0.001）, land and fertilizer （P 〈 0.01）. In addition, the coefficient of determination （R2）, the F-ratio and the standard error of the mean （S） were found to be 0.471, 16.37＊＊＊ and 8.908, respectively. The results also indicated that efficiency values of land, seeds, fertilizer and labour were 1.234, 0.498, 2.352 and 1.620, respectively. Finally, it was found that resource-use among the farmers were not efficient thus equipment, land, fertilizer and labour inputs shall be increased by 78.3%, 18.9%, 57.5% and 38.3%, respectively, while seed input shall be reduced by 50.2% for the farmers to attain optimal resource utilization.展开更多
This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a signifi...This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.展开更多
Purpose： The oil and gas gathering and processing facility of Kuwait Oil Company is built with a nameplate capacity of X MBOPD （thousand barrels oil per day） with 50% water cut. However, the facility was operating ...Purpose： The oil and gas gathering and processing facility of Kuwait Oil Company is built with a nameplate capacity of X MBOPD （thousand barrels oil per day） with 50% water cut. However, the facility was operating with a water cut of 35%. This comprehensive technical study was conducted to evaluate possibility of increasing oil processing capacity of this facility in line with current lower water cut and other operational flexibilities available in the facility without utilizing its design margin. Topic： This paper shares an innovative approach to increase name plate capacity of oil and gas processing facility utilizing available operational flexibility and operational margins with minor modification. It shares a case study where facility capacity is increased by around 19% without utilizing design margins of equipment or pipeline. Method： The study includes theoretical verification and analysis of all major equipment and piping to identify available capacity and limitation, in order to utilize available additional margin and to propose debottleneck options to overcome limitations. Achievement： The study confirmed that, facility name plate capacity can be revised from X MBOPD （with 50% w.c （water cut）） to X ＋ 32 MBOPD （with： 45% w.c） minor modification in separator and utilizing margin available in feed specification ofdesalter trains.展开更多
The authors employ the recent stochastic-control-based approach to financial mathematicsto solve a problem of determination of the risk premium for a stochastic interest rate model,andthe corresponding problem of equi...The authors employ the recent stochastic-control-based approach to financial mathematicsto solve a problem of determination of the risk premium for a stochastic interest rate model,andthe corresponding problem of equity valuation.The risk premium is determined explicitly,by meansof solving a corresponding partial differential equation (PDE),in two forms:one,time-dependent,corresponding to a finite time contract expiration,and the simpler version corresponding to perpetualcontracts.As stocks are perpetual contracts,when solving the problem of equity valuation,the latterform of the risk premium is used.By means of solving the general pricing PDE,an efficient equityvaluation method was developed that is a combination of some sophisticated explicit formulas,and anumerical procedure.展开更多
文摘[Objective] The purpose of this study is to judge the rationality of land use structure from new perspectives and method. [Method] The theory of data en- velopment analysis （DEA） has been employed in this article. A case study of evalu- ation of land use structure for Wujin district in 2012 is provided to illustrate the ap- plication of this research model. At the micro perspective, land use efficiency has been analyzed by use of data envelopment analysis model. The optimization and adjustment direction in land use structure has been pointed out from the view point of land use efficiency. [Result] The result has shown that the research method based on information entropy and data envelopment analysis model can effectively overcome the drawback of traditional evaluation techniques. Compared with the tra- ditional methods, the new optimization model based on a structure of the multi-crite- ria factors and objective weighting method can evaluate the rationality of land use structure more comprehensively.
文摘The study examined the levels of resource-use efficiency of rice farmers unde,r irrigation method in Dadinkowa, Gombe state of Nigeria. Using questionnaire, data were collected during the year 2010 irrigation season from 120 randomly sampled rice irrigators and the data were analyzed using multiple regression and marginal analyses. Results showed that significant factors influencing irrigated rice production were labour （P 〈 0.001）, land and fertilizer （P 〈 0.01）. In addition, the coefficient of determination （R2）, the F-ratio and the standard error of the mean （S） were found to be 0.471, 16.37＊＊＊ and 8.908, respectively. The results also indicated that efficiency values of land, seeds, fertilizer and labour were 1.234, 0.498, 2.352 and 1.620, respectively. Finally, it was found that resource-use among the farmers were not efficient thus equipment, land, fertilizer and labour inputs shall be increased by 78.3%, 18.9%, 57.5% and 38.3%, respectively, while seed input shall be reduced by 50.2% for the farmers to attain optimal resource utilization.
文摘This paper describes the field tests carried out to evaluate the new Vicon RS-EDW centrifugal fertilizer spreader, to be used in Precision Agriculture. The results of initial dynamic calibration tests showed a significant and systematic difference between the application rates of the two discs （about 20%）. This difference had to be corrected by the manufacturer that carried out the necessary changes to the electric actuators. The fertilizer spreader had good distribution homogeneity, considering different working velocities and different positions in the parcel. The pattern distribution curve for 18% super phosphate fertilizer led to an effective working width of 28 meters, with a coefficient of variation of 15%. The longitudinal test, under experimental working conditions led to a machine delay time of 6-7 seconds. The results show an actual fertilization application density between 74%-90% of that determined for each location. These results confirm that the spreader can be used to spread fertilizer differentially in the field.
文摘Purpose： The oil and gas gathering and processing facility of Kuwait Oil Company is built with a nameplate capacity of X MBOPD （thousand barrels oil per day） with 50% water cut. However, the facility was operating with a water cut of 35%. This comprehensive technical study was conducted to evaluate possibility of increasing oil processing capacity of this facility in line with current lower water cut and other operational flexibilities available in the facility without utilizing its design margin. Topic： This paper shares an innovative approach to increase name plate capacity of oil and gas processing facility utilizing available operational flexibility and operational margins with minor modification. It shares a case study where facility capacity is increased by around 19% without utilizing design margins of equipment or pipeline. Method： The study includes theoretical verification and analysis of all major equipment and piping to identify available capacity and limitation, in order to utilize available additional margin and to propose debottleneck options to overcome limitations. Achievement： The study confirmed that, facility name plate capacity can be revised from X MBOPD （with 50% w.c （water cut）） to X ＋ 32 MBOPD （with： 45% w.c） minor modification in separator and utilizing margin available in feed specification ofdesalter trains.
基金supported in part by the Center for Financial Engineering at the Suzhou University, Chinathe Taft Research Center at the University of Cincinnati, USA
文摘The authors employ the recent stochastic-control-based approach to financial mathematicsto solve a problem of determination of the risk premium for a stochastic interest rate model,andthe corresponding problem of equity valuation.The risk premium is determined explicitly,by meansof solving a corresponding partial differential equation (PDE),in two forms:one,time-dependent,corresponding to a finite time contract expiration,and the simpler version corresponding to perpetualcontracts.As stocks are perpetual contracts,when solving the problem of equity valuation,the latterform of the risk premium is used.By means of solving the general pricing PDE,an efficient equityvaluation method was developed that is a combination of some sophisticated explicit formulas,and anumerical procedure.
