资源均衡是重复性项目中的经典调度问题,本文提出一种新的基于平衡线法(line of balance,LOB)的资源均衡方法。首先,本文提出LOB中关键路线的确定方法,确定关键路线及关键工序类型。而后,本文分析项目总工期的决定因素,对不同类型关键...资源均衡是重复性项目中的经典调度问题,本文提出一种新的基于平衡线法(line of balance,LOB)的资源均衡方法。首先,本文提出LOB中关键路线的确定方法,确定关键路线及关键工序类型。而后,本文分析项目总工期的决定因素,对不同类型关键工序的特性及其与总工期、资源调整之间的关系进行了研究,论证了在LOB的资源均衡问题中,由于逆关键工序、点关键工序这些特殊工序的存在,可以在保证项目总工期不变的前提下,通过同时调整关键工序和非关键工序实现资源优化。按照这一思路,论文设计了LOB中资源均衡的遗传算法。算例分析表明该资源均衡算法的优化性能。本文提出的资源均衡思路和算法能帮助项目计划人员拓展资源优化空间,达到更好的资源均衡效果。展开更多
Using extended homogeneous balance method and variable separation hypothesis, we found new variable separation solutions with three arbitrary functions of the （2＋1）-dimensional dispersive long-wave equations, Based...Using extended homogeneous balance method and variable separation hypothesis, we found new variable separation solutions with three arbitrary functions of the （2＋1）-dimensional dispersive long-wave equations, Based on derived solutions, we revealed abundant oscillating solitons such as dromion, multi-dromion, solitoff, solitary waves, and so on, by selecting appropriate functions.展开更多
A modified homogeneous balance method is proposed by improving some key steps in the homogeneousbalance method.Bilinear equations of some nonlinear evolution equations are derived by using the modified homogeneousbala...A modified homogeneous balance method is proposed by improving some key steps in the homogeneousbalance method.Bilinear equations of some nonlinear evolution equations are derived by using the modified homogeneousbalance method.Generalized Boussinesq equation,KP equation,and mKdV equation are chosen as examples to illustrateour method.This approach is also applicable to a large variety of nonlinear evolution equations.展开更多
In order to investigate the nonlinear characteristics of structural joint,the experimental setup with a jointed mass system is established for dynamic characterization analysis and vibration prediction,and a correspon...In order to investigate the nonlinear characteristics of structural joint,the experimental setup with a jointed mass system is established for dynamic characterization analysis and vibration prediction,and a corresponding nonlinearity identification method is studied.First,the sine-sweep vibration test with different baseexcitation levels areapplied to the structural joint system to study the dominant modal of mass rigid motion.Then,based on t e harmonic balance method principle,t e measured vibration transmissibilities a e utilized for nonlinearity identification using different excitation levels.Experimental results show that nonlinear spring and damping force can be represented by a polynomial order approximation.The identified nonlinear stiffness and damping force can predict the system’s response,and they can reveal t e shifts of resonant frequency or damping due to discontinuity of contact mechanisms within a certain range.展开更多
Based on homogeneous balance method, sofiton solutions to a generalized nonlinear Sehr6dinger equation （NLSE） with varying coefficients have been gotten. Our results indicate that a new family of vortex or petal-lik...Based on homogeneous balance method, sofiton solutions to a generalized nonlinear Sehr6dinger equation （NLSE） with varying coefficients have been gotten. Our results indicate that a new family of vortex or petal-like spatial solitons can be formed in the Kerr nonlinear media in the cylindrical symmetric geometry. It is shown by numerical simulation that these soliton profiles are stable.展开更多
A two-sided assembly line is typically found in plants producing large-sized products. Its advantages over a one-sided line and the difficulties faced in two-sided line balancing problems were discussed. A mathematica...A two-sided assembly line is typically found in plants producing large-sized products. Its advantages over a one-sided line and the difficulties faced in two-sided line balancing problems were discussed. A mathematical model for two-ALB problem was suggested. A modification of the “ranked positional weight” method, namely two-ALB RPW for two-ALB problems was developed. Experiments were carried out to verify the performance of the proposed method and the results show that it is effective in solving two-sided assembly line balancing problems.展开更多
A nonlinear transformation and some multi-solition solutions for the (2+1 )-dimensional generalized Broer-Kaup (GBK) system is first given by using the homogeneous balance method. Then starting from the nonlinear tran...A nonlinear transformation and some multi-solition solutions for the (2+1 )-dimensional generalized Broer-Kaup (GBK) system is first given by using the homogeneous balance method. Then starting from the nonlinear transformation, we reduce the (2+ 1)-dimensional GBK system to a simple linear evolution equation. Solving this equation,we can obtain some new explicit exact solutions of the original equations by means of the extended hyperbola function method.展开更多
By means of extended homogeneous balance method and variable separationapproach, quite a general variable separation solution of the (2+l)-dimensionalBroer-Kaup-Kupershmidt equation is derived. From the variable separ...By means of extended homogeneous balance method and variable separationapproach, quite a general variable separation solution of the (2+l)-dimensionalBroer-Kaup-Kupershmidt equation is derived. From the variable separation solution and by selectingappropriate functions, a new class of (2+1)-dimensional nonpropagating solitary waves are found. Thenovel features exhibited by these new structures are first revealed.展开更多
In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. T...In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).展开更多
Isoplethic VLE data for the systems benzene-hexane at 9 different compositions in the temperature range from 298 K to 331K, chloroform-benzene at 11 different compositions in the temperature range from 308 K to 350 K ...Isoplethic VLE data for the systems benzene-hexane at 9 different compositions in the temperature range from 298 K to 331K, chloroform-benzene at 11 different compositions in the temperature range from 308 K to 350 K and chloroform-hexane at 9 different compositions in the temperature range from 311 K to 337 K were determined by using an inclined ebulliometer with a pump-like stirrer. Isothermal and isobaric VLE were calculated from the isoplethic results with a extended UNIQUAC equation and these data agree well with the literature data.展开更多
In order to obtain the solubility data of propylene in 2-propanol-water solutions, gas-liquid equilibrium (GLE) experiments were carried out at 303.15-333.15 K, 0.27-0.98 MPa in a static equilibrium still. The origina...In order to obtain the solubility data of propylene in 2-propanol-water solutions, gas-liquid equilibrium (GLE) experiments were carried out at 303.15-333.15 K, 0.27-0.98 MPa in a static equilibrium still. The original mass ratio of 2-propanol to water was 9∶1,8∶2,7∶3,1∶0, respectively. The equilibrium data were correlated with an empirical model and the regression of model parameters was completed by Gauss-Newton nonlinear least square (NLS). The average relative deviation (ARD) between the experimental and calculated value is 1.570 0, and the maximum relative deviation (MRD) is 4.820 0. In addition, a simple approach that correlated the model parameters with the system composition was also provided.展开更多
文摘资源均衡是重复性项目中的经典调度问题,本文提出一种新的基于平衡线法(line of balance,LOB)的资源均衡方法。首先,本文提出LOB中关键路线的确定方法,确定关键路线及关键工序类型。而后,本文分析项目总工期的决定因素,对不同类型关键工序的特性及其与总工期、资源调整之间的关系进行了研究,论证了在LOB的资源均衡问题中,由于逆关键工序、点关键工序这些特殊工序的存在,可以在保证项目总工期不变的前提下,通过同时调整关键工序和非关键工序实现资源优化。按照这一思路,论文设计了LOB中资源均衡的遗传算法。算例分析表明该资源均衡算法的优化性能。本文提出的资源均衡思路和算法能帮助项目计划人员拓展资源优化空间,达到更好的资源均衡效果。
基金The project supported by the Natural Science Foundation of Inner Mongolia under Grant No. 200408020113 and National Natural Science Foundation of China under Grant No. 40564001
文摘Using extended homogeneous balance method and variable separation hypothesis, we found new variable separation solutions with three arbitrary functions of the （2＋1）-dimensional dispersive long-wave equations, Based on derived solutions, we revealed abundant oscillating solitons such as dromion, multi-dromion, solitoff, solitary waves, and so on, by selecting appropriate functions.
基金Supported by the National Natural Science Foundation of China under Grant No. 11071209the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province under Grant No. 10KJBll0011
文摘A modified homogeneous balance method is proposed by improving some key steps in the homogeneousbalance method.Bilinear equations of some nonlinear evolution equations are derived by using the modified homogeneousbalance method.Generalized Boussinesq equation,KP equation,and mKdV equation are chosen as examples to illustrateour method.This approach is also applicable to a large variety of nonlinear evolution equations.
基金The Major National Science and Technology Project(No.2012ZX04002032,2013ZX04012032)Graduate Scientific Research Innovation Project of Jiangsu Province(No.KYLX-0096)
文摘In order to investigate the nonlinear characteristics of structural joint,the experimental setup with a jointed mass system is established for dynamic characterization analysis and vibration prediction,and a corresponding nonlinearity identification method is studied.First,the sine-sweep vibration test with different baseexcitation levels areapplied to the structural joint system to study the dominant modal of mass rigid motion.Then,based on t e harmonic balance method principle,t e measured vibration transmissibilities a e utilized for nonlinearity identification using different excitation levels.Experimental results show that nonlinear spring and damping force can be represented by a polynomial order approximation.The identified nonlinear stiffness and damping force can predict the system’s response,and they can reveal t e shifts of resonant frequency or damping due to discontinuity of contact mechanisms within a certain range.
基金Supported by the Xianning University Foundation of Hubei Province under Grant No.2010CDB05103Xianning University Foundation under Grant No.BK001
文摘Based on homogeneous balance method, sofiton solutions to a generalized nonlinear Sehr6dinger equation （NLSE） with varying coefficients have been gotten. Our results indicate that a new family of vortex or petal-like spatial solitons can be formed in the Kerr nonlinear media in the cylindrical symmetric geometry. It is shown by numerical simulation that these soliton profiles are stable.
基金Key Projectof Scientific and TechnologicalCommittee of Shanghai(No.0 3 11110 0 5 )
文摘A two-sided assembly line is typically found in plants producing large-sized products. Its advantages over a one-sided line and the difficulties faced in two-sided line balancing problems were discussed. A mathematical model for two-ALB problem was suggested. A modification of the “ranked positional weight” method, namely two-ALB RPW for two-ALB problems was developed. Experiments were carried out to verify the performance of the proposed method and the results show that it is effective in solving two-sided assembly line balancing problems.
文摘A nonlinear transformation and some multi-solition solutions for the (2+1 )-dimensional generalized Broer-Kaup (GBK) system is first given by using the homogeneous balance method. Then starting from the nonlinear transformation, we reduce the (2+ 1)-dimensional GBK system to a simple linear evolution equation. Solving this equation,we can obtain some new explicit exact solutions of the original equations by means of the extended hyperbola function method.
文摘By means of extended homogeneous balance method and variable separationapproach, quite a general variable separation solution of the (2+l)-dimensionalBroer-Kaup-Kupershmidt equation is derived. From the variable separation solution and by selectingappropriate functions, a new class of (2+1)-dimensional nonpropagating solitary waves are found. Thenovel features exhibited by these new structures are first revealed.
基金support and help of many individuals in the SASTRA University
文摘In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).
基金Supported by Zhejiang Provincial Natural Science Foundation of China.
文摘Isoplethic VLE data for the systems benzene-hexane at 9 different compositions in the temperature range from 298 K to 331K, chloroform-benzene at 11 different compositions in the temperature range from 308 K to 350 K and chloroform-hexane at 9 different compositions in the temperature range from 311 K to 337 K were determined by using an inclined ebulliometer with a pump-like stirrer. Isothermal and isobaric VLE were calculated from the isoplethic results with a extended UNIQUAC equation and these data agree well with the literature data.
文摘In order to obtain the solubility data of propylene in 2-propanol-water solutions, gas-liquid equilibrium (GLE) experiments were carried out at 303.15-333.15 K, 0.27-0.98 MPa in a static equilibrium still. The original mass ratio of 2-propanol to water was 9∶1,8∶2,7∶3,1∶0, respectively. The equilibrium data were correlated with an empirical model and the regression of model parameters was completed by Gauss-Newton nonlinear least square (NLS). The average relative deviation (ARD) between the experimental and calculated value is 1.570 0, and the maximum relative deviation (MRD) is 4.820 0. In addition, a simple approach that correlated the model parameters with the system composition was also provided.
