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1.
The DY Conjugate Gradient Method with Armijo-type Line Searches   总被引:1,自引:0,他引:1  
Two Armijo-type line searches are proposed in this paper for nonlinear conjugate gradient methods. The two Armijo-type line searches are shown to guarantee the global convergence of the DY method for the unconstrained minimization of nonconvex differentiable functions. Further, if the function is strictly convex, the two Armijo-type line searches and another Armijo-type line search are also shown to guarantee the convergence of the DY method.  相似文献   

2.
In technology-intensive markets,it is a common strategy for companies to develop long-term multiple generation product lines instead of releasing consecutive single products.Even though this strategy is more profitable than sequentially introducing single product generations,it can also result in inter-product line cannibalization.Cannibalization of multiple-generation product lines is a complex problem that needs to be taken into account at the early product line planning stage in order to sustain long-term profitability.In this paper,we propose an agent-based model that can simulate the potential cannibalization scenarios within a multiple-generation product line.We view a multiple-generation product line(MGPL) as complex adaptive system where each product generation in the MGPL adjusts its sales price over time based on the shifts in the market demand.The proposed model provides insights into how various pricing strategies impact the overall lifecycle profitability of MGPL and can be used to assist companies in developing appropriate dynamic pricing strategies at the early product line planning stages.  相似文献   

3.
In this paper we propose a COncurrent Production Engineering System (COPES) for the flexible transfer line (FTL) layout design in a restricted area. COPES first determines the buffer size in front of the bay of each machine tool in the FTL and then initializes a computer aided design (CAD) system to draw the FTL in a restricted area. We develop a set of modules systems which have been integrated into a single framework, in accordance with the practice of concurrent engineering. Concurrent engineering involves the cooperation of these activities. It's expected that the developed COPES can improve the cooperation between production engineers' and the plant designer. This can be done by enabling the production engineers' to make better decision regarding FTL buffer size.  相似文献   

4.
The authors propose an affine scaling modified gradient path method in association with reduced projective Hessian and nonmonotonic interior backtracking line search techniques for solving the linear equality constrained optimization subject to bounds on variables. By employing the QR decomposition of the constraint matrix and the eigensystem decomposition of reduced projective Hes- sian matrix in the subproblem, the authors form affine scaling modified gradient curvilinear path very easily. By using interior backtracking line search technique, each iterate switches to trial step of strict interior feasibility. The global convergence and fast local superlinear/quadratical convergence rates of the proposed algorithm are established under some reasonable conditions. A nonmonotonic criterion should bring about speeding up the convergence progress in some ill-conditioned cases. The results of numerical experiments are reported to show the effectiveness of the proposed algorithm.  相似文献   

5.
Motivated by the small world network research of Watts & Strogatz, this paper studies relationships between topology and cascading line outages in electric power grids. Cascading line outages are a type of cascading collapse that can occur in power grids when the transmission network is congested. It is characterized by a self-sustaining sequence of line outages followed by grid breakup, which generally leads to widespread blackout. The main findings of this work are twofold: On one hand, the work suggests that topologies with more disorder in their interconnection topology tend to be robust with respect to cascading line outages in the sense of being able to support greater generation and demand levels than more regularly interconnected topologies. On the other hand, the work suggests that topologies with more disorder tend to be more fragile in that should a cascade get started, they tend to break apart after fewer outages than more regularly interconnected topologies. Thus, as has been observed in other complex networks, there appears to be a tradeoff between robustness and fragility. These results were established using synthetically generated power grid topologies and verified using the IEEE 57 bus and 188 bus power grid test cases.  相似文献   

6.
This paper proposes an inexact SQP method in association with line search filter technique for solving nonlinear equality constrained optimization.For large-scale applications,it is expensive to get an exact search direction,and hence the authors use an inexact method that finds an approximate solution satisfying some appropriate conditions.The global convergence of the proposed algorithm is established by using line search filter technique.The second-order correction step is used to overcome the Maratos effect,while the line search filter inexact SQP method has q-superlinear local convergence rate.Finally,the results of numerical experiments indicate that the proposed method is efficient for the given test problems.  相似文献   

7.
The purpose of this paper is to develop a high speed detection scheme for moving and / or stationary point targets in a multitarget environment as registered in an IR image sequence. An iterative approximate 3-D line searching algorithm based upon the geometric representation of lines (for non-maneuvering targets in space) in a 3-D space is derived. The convergency of the algorithm is proved. An analysis is performed of the theoretical detection performance of the algorithm. The statistical experiment results show high effectiveness and computational efficiency of the algorithm in the case of low SNR. The idea may be employed to satisfy the real-time processing requirement of an IR system.  相似文献   

8.
Design of good QC-LDPC codes without small girth in the p-plane   总被引:2,自引:0,他引:2       下载免费PDF全文
A construction method based on the p-plane to design high-girth quasi-cyclic low-density parity-check (QC-LDPC) codes is proposed. Firstly the good points in every line of the p-plane can be ascertained through filtering the bad points, because the designed parity-check matrixes using these points have the short cycles in Tanner graph of codes. Then one of the best points from the residual good points of every line in the p-plane will be found, respectively. The optimal point is also singled out according to the bit error rate (BER) performance of the QC-LDPC codes at last. Explicit necessary and sufficient conditions for the QC-LDPC codes to have no short cycles are presented which are in favor of removing the bad points in the p-plane. Since preventing the short cycles also prevents the small stopping sets, the proposed construction method also leads to QC-LDPC codes with a higher stopping distance.  相似文献   

9.
The shrinking of cell-size brings significant changes to the wireless uplink of densely small cells (DSCs). A codebook design is proposed that utilizes the strong line of sight (LOS) chan- nel component existing in a DSC system for uplink of the DSC system. To further improve the uplink performance, the high-rank codebook is designed based on singular value decomposition (SVD) due to the unnecessary preservation of strict constant modulus in the DSC system. And according to the simulation result, the proposed codebook leads to significant sum-rate gain and appreciable block error rate (BLER) performance improvement in the DSC system.  相似文献   

10.
This paper presents a methodology which determines the allocation of power demand among the committed generating units while minimizes number of objectives as well as meets physical and technological system constraints. The procedure considers two decoupled problems based upon the dependency of their goals on either active power or reactive power generation. Both the problems have been solved sequentially to achieve optimal allocation of active and reactive power generation while minimizes operating cost, gaseous pollutants emission objectives and active power transmission loss with consideration of system operating constraints along with generators prohibited operating zones and transmission line flow limits. The active and reactive power line flows are obtained with the help of generalized generation shift distribution factors (GGDF) and generalized Z-bus distribution factors (GZBDF), respectively. First problem is solved in multi-objective framework in which the best weights assigned to objectives are determined while employing weighting method and in second problem, active power loss of the system is minimized subject to system constraints. The validity of the proposed method is demonstrated on 30-bus IEEE power system.  相似文献   

11.
In Myanmar,the formal financial institution does not provide uncollateralized credits.The rural unbanked under the poverty line is depending on the informal money-lenders with high interest rate.Private Agency Collaboration Together is only one microfinance institution providing the credits without collateral and with low interest rate to the unbanked in Myanmar.Half of the unbanked are unable to borrow the loans from the microfinance institution because of the weakness of the information contribution and the strict legal policies of the microfinance institution.Therefore,the objective of this study is to construct a system to improve the relationship between the microfinance institution and the unbanked by reducing the obstacles in the current system of microfinance institution.The legal policy is studied from the vision of the local unbanked as the originality of this research and the /-System methodology is applied to accomplish the research.The current system comprises the information contribution,loans and legal policies.The current system is only one relationship between the microfinance institution and unbanked.When the ten obstacles occurred in the current system,the unbanked cannot approach to the microfinance institution.An access system including four sub-systems is developed depending on the collected ideas to solve these obstacles and intend to improve the relationship between microfinance institution and the unbanked.  相似文献   

12.
This paper presents a new nonmonotone filter line search technique in association with the MBFGS method for solving unconstrained minimization. The filter method, which is traditionally used for constrained nonlinear programming (NLP), is extended to solve unconstrained NLP by converting the latter to an equality constrained minimization. The nonmonotone idea is employed to the filter method so that the restoration phrase, a common feature of most filter methods, is not needed. The global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions. The results of numerical experiments indicate that the proposed method is efficient,  相似文献   

13.
Automatic process control (APC) based on design of experiment (DOE) is a cost-efficient approach for variation reduction. The process changes both in mean and variance owing to online parameter adjustment make it hard to apply traditional SPC charts in such DOE-based APC applied process. An adaptive SPC scheme is developed, which can better track the process transitions and achieve the possible SPC run cost reduction when the process is stable. The control law of SPC parameters is designed by fully utilizing the estimation properties of the process model instead of traditionally using the data collected from the production line. An example is provided to illustrate the proposed adaptive SPC design approach.  相似文献   

14.
<正> This paper studies a class of forward-backward stochastic differential equations (FBSDE)in a general Markovian framework.The forward SDE represents a large class of strong Markov semimartingales,and the backward generator requires only mild regularity assumptions.The authors showthat the Four Step Scheme introduced by Ma,et al.(1994) is still effective in this case.Namely,the authors show that the adapted solution of the FBSDE exists and is unique over any prescribedtime duration;and the backward components can be determined explicitly by the forward componentvia the classical solution to a system of parabolic integro-partial differential equations.An importantconsequence the authors would like to draw from this fact is that,contrary to the general belief,in aMarkovian set-up the martingale representation theorem is no longer the reason for the well-posednessof the FBSDE,but rather a consequence of the existence of the solution of the decoupling integralpartialdifferential equation.Finally,the authors briefly discuss the possibility of reducing the regularityrequirements of the coefficients by using a scheme proposed by F.Delarue (2002) to the current case.  相似文献   

15.
Two pairs of approximation operators, which are the scale lower and upper approximations as well as the real line lower and upper approximations, are defined. Their properties and antithesis characteristics are analyzed. The rough function model is generalized based on rough set theory, and the scheme of rough function theory is made more distinct and complete. Therefore, the transformation of the real function analysis from real line to scale is achieved. A series of basic concepts in rough function model including rough numbers, rough intervals, and rough membership functions are defined in the new scheme of the rough function model. Operating properties of rough intervals similar to rough sets are obtained. The relationship of rough inclusion and rough equality of rough intervals is defined by two kinds of tools, known as the lower (upper) approximation operator in real numbers domain and rough membership functions. Their relative properties are analyzed and proved strictly, which provides necessary theoretical foundation and technical support for the further discussion of properties and practical application of the rough function model.  相似文献   

16.
17.
Beam Measurement System in NSRL   总被引:4,自引:0,他引:4  
1. INTRODUCTIOnThe accelerator of the NSRL consists of a 200MeV linac and transport line and an 88MeVelectronic storage ring. To measure the beam parameters and help to understand the machinebehavior during the commissioning phase and operation, the beam measurement system isbuilt [11. The system includes the part for the linac and transport line and the part for thestorage ring.The beam measuxemellt system on the linac and transport line includes 13 beam currentmonitors, 13 fluorescen…  相似文献   

18.
<正> This paper formulates and analyzes a line search method for general nonlinear equalityconstrained optimization based on filter methods for step acceptance and secant methods for searchdirection.The feature of the new algorithm is that the secant algorithm is used to produce a searchdirection,a backtracking line search procedure is used to generate step size,some filtered rules areused to determine step acceptance,second order correction technique is used to reduce infeasibility andovercome the Maratos effect.Global convergence properties of this method are analyzed:under mildassumptions it is showed that every limit point of the sequence of iterates generated by the algorithmis feasible,and that there exists at least one limit point that is a stationary point for the problem.Moreover,it is also established that the Maratos effect can be overcome in our new approach by addingsecond order correction steps so that fast local superlinear convergence to a second order sufficient localsolution is achieved.Finally,the results of numerical experiments are reported to show the effectivenessof the line search filter secant method.  相似文献   

19.
This paper presents an approach to the challenging is- sue of passive source localization in shallow water using a mobile short horizontal linear array with length less than ten meters. The short array can be conveniently placed on autonomous underwa- ter vehicles and deployed for adaptive spatial sampling. However, the use of such small aperture passive sonar systems makes it difficult to acquire sufficient spatial gain for localizing long-range sources. To meet the requirement, a localization approach that employs matched-field based techniques that enable the short ho- rizontal linear array is used to passively localize acoustic sources in shallow water. Furthermore, the broadband processing and inter-position processing provide robustness against ocean en- vironmental mismatch and enhance the stability of the estimation process. The proposed approach's ability to localize acoustic sources in shallow water at different signal-to-noise ratios is examined through the synthetic test cases where the sources are located at the endfire and some other bearing of the mobile short horizontal linear array. The presented results demonstrate that the positional parameters of the estimated source build up over time as the array moves at a low speed along a straight line at a constant depth.  相似文献   

20.
Carrier frequency and symbol rate estimation are the main contents of parameter estimation,which is the basis of modulation recognition and further processing of signals especially in non-cooperative communication.With the development of wireless communication,the signal transmission environment has become increasingly bad,causing more difficulties in parameter estimation.It is well known that the signal cycle spectrum is robust to noises and signal parameters are closely related.In practice,it is impossible to calculate the cyclic spectrum of infinite length data signals.When using finite length data to obtain a cycle spectrum,the truncation noise is induced,resulting in interference.It is necessary to overcome the influence of noises in order to improve the detection ability of discrete spectral lines.An improved method of the discrete spectral line extraction algorithm is proposed by reflecting the amplitude advantage of discrete spectral lines through salient features of continuous noises in discrete spectral line neighborhood.  相似文献   

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