首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 10 毫秒
1.
Iron ore quality depends upon successive shipments being uniform in composition, not only in iron but also in several other minerals. The production process involves several stages of scheduling, from the mine face, through railing, stockpiling and ship loading. At each of these stages there is potential to improve the composition uniformity through appropriate scheduling procedures. This paper discusses a variety of algorithms and simulation models developed to aid these scheduling decisions.  相似文献   

2.
Patient no-show has long been a recognized problem in modern outpatient health-care delivery systems. The common impacts are reduced clinic efficiency and provider productivity, wasted medical resources, increased health-care cost and limited patient access to care. The main goal of this research is to develop an effective dynamic overbooking policy into any scheduling system that accounts for the predictive probability of no-shows for any given patient. This policy increases the quality of patient care in terms of wait time and access to care while minimizing the clinic's costs. This proposed model is also illustrated to be more cost-effective than overbooking patients evenly throughout a clinic session. This paper also suggests that overbooking should be performed at better patient flow and higher no-show rate so that the costs are minimized. Consequently, this research improves the outpatient experience for both patients and medical providers.  相似文献   

3.
The problem considered is that of the allocation of resources to activities according to a fractional measure given by the ratio of “return” to “cost”. The return is the sum of returns from the activities, each activity being described by a concave return function. There is a positive fixed cost and a variable cost that depend linearly on the allocations. Properties related to the uniqueness of optimal solutions and the number of non-zero allocations are derived. A method is given by which any set of feasible allocations can be used to derive an upper bound of the optimal value of the objective function: optimal and almost-optimal allocations can be recognized. Allocations can be generated by a fast incremental method that is described. The method utilizes data in sequential order and can be used to solve large problems.  相似文献   

4.
5.
ONTHECENTRALLIMITTHEOREMINPRODUCTSPACESSUZHONGGENAbstract:SupposethatEandFareseparableBanachspaces,XandYareindependentsymmetr...  相似文献   

6.
In this article we examine the minimaxity and admissibility of the product limit (PL) estimator under the loss function% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqaqpepeea0xe9qqVa0l% b9peea0lb9sq-JfrVkFHe9peea0dXdarVe0Fb9pgea0xa9pue9Fve9% Ffc8meGabaqaciGacaGaaeqabaWaaeaaeaaakeaacaWGmbGaaiikai% aadAeacaGGSaGabmOrayaajaGaaiykaiabg2da9maapeaabaGaaiik% aiaadAeacaGGOaGaamiDaiaacMcaaSqabeqaniabgUIiYdGccqGHsi% slceWGgbGbaKaacaGGOaGaamiDaiaacMcacaGGPaWaaWbaaSqabeaa% caaIYaaaaOGaamOramaaCaaaleqabaaccmGae8xSdegaaOGaaiikai% aadshacaGGPaGaaiikaiaaigdacqGHsislcaWGgbGaaiikaiaadsha% caGGPaGaaiykamaaCaaaleqabaGaeqOSdigaaOGaamizaiaadEfaca% GGOaGaamiDaiaacMcaaaa!5992!\[L(F,\hat F) = \int {(F(t)} - \hat F(t))^2 F^\alpha (t)(1 - F(t))^\beta dW(t)\].To avoid some pathological and uninteresting cases, we restrict the parameter space to ={F: F(ymin) }, where (0, 1) and y 1,...y,n are the censoring times. Under this set up, we obtain several interesting results. When y 1=···=y n, we prove the following results: the PL estimator is admissible under the above loss function for , {–1, 0}; if n=1, ==–1, the PL estimator is minimax iff dW ({y})=0; and if n2, , {–1, 0}, the PL estimator is not minimax for certain ranges of . For the general case of a random right censorship model it is shown that the PL estimator is neither admissible nor minimax. Some additional results are also indicated.Partially supported by the Governor's Challenge Grant.Part of the work was done while the author was visiting William Paterson College.  相似文献   

7.
A LIL type result for the product limit estimator   总被引:2,自引:0,他引:2  
Summary Let X 1,X 2,...,X n be i.i.d. r.v.'-s with P(X>u)=F(u) and Y 1,Y 2,...,Y n be i.i.d. P(Y>u)=G(u) where both F and G are unknown continuous survival functions. For i=1,2,...,n set i=1 if X i Y i and 0 if X i >y i , and Z i =min {itXi, Yi}. One way to estimate F from the observations (Z i , i ) i=l,...,n is by means of the product limit (P.L.) estimator F n * (Kaplan-Meier, 1958 [6]).In this paper it is shown that F n * is uniformly almost sure consistent with rate O(log logn/n), that is P(sup ¦F n * (u)– F(u)¦=0(log log n/n)=1 –<u<+ if G(T F )>0, where T F =sup{x F(x)>0}.A similar result is proved for the Bayesian estimator [9] of F. Moreover a sharpening of the exponential bound of [3] is given.  相似文献   

8.
The existence of the limit as ε→0 exp[(A+B/ε)t] exp[-Bt/ε]is studied for n×n matrices A,B. Necessary and sufficient conditions on B that the limit exist for all A are given.  相似文献   

9.
The employment of external resources to supplement available internal resources can improve a feasible schedule or make an infeasible schedule feasible. Based upon a well-known integer linear programming approach to the general multiproject scheduling problem, this paper provides an extension to account for the minimum cost usage of external resources. We modify an example from the literature to illustrate the solution of the revised model. Another approach using Lagrange multipliers is also discussed.
Zusammenfassung Es wird gezeigt, wie bei Problemen der Ablaufplanung durch zusätzliche externe Ressourcen, z.B. vorübergehend beschäftigte Arbeitnehmer, ein zulässiger Ablaufplan bezüglich einer gegebenen Zielfunktion verbessert werden kann bzw. überhaupt erst ein zulässiger Ablaufplan ermöglicht wird. Unter diesem Aspekt werden zwei Entscheidungsmodelle der Ablaufplanung, und zwar vonPritsker/Watters/Wolfe undFisher, modifiziert.
  相似文献   

10.
Translated from Statisticheskie Metody Otsenivaniya i Proverki Gipotez, PP. 77–83, 1984.  相似文献   

11.
In this paper, we give the central limit theorem and almost sure central limit theorem for products of some partial sums of independent identically distributed random variables.  相似文献   

12.
Several efficient lower bounds and time-bound adjustment methods for the resource constrained project scheduling problem (RCPSP) have recently been proposed. Some of them are based on redundant resources. In this paper we define redundant functions which are very useful for computing redundant resources. We also describe an algorithm for computing all maximal redundant functions. Once all these redundant functions have been determined, we have to identify those that are useful for bounding. Surprisingly, their number is reasonable even for large resource capacities, so a representative subset of them can be tabulated to be used efficiently. Computational results on classical RCPSP instances confirm their usefulness.  相似文献   

13.
A modified flow-shop scheduling problem for a production system, characterized by parts machining followed by their subsequent assembly (joining) operation, is studied. Several products of different kinds are ordered. Each part for the products is processed on machine M1 (the first stage) and then processed on machine M2 (the second stage). Each product is processed (e.g., joined) with the parts by one assembly operation on assembly stage MA (the third stage). The objective function to be minimized is the weighted sum of product completion times. The decision variables are the sequence of products to be assembled and the sequence of parts to be processed. In this paper, we assume that if product h is assembled before product h, then, on each machine, processing of any part for product h is done after processing of all parts for product h is completed. We call this assumption “Assumption B(2)” and call this problem “SPconstrained”. An efficient solution procedure using a branch and bound method is developed based on this assumption, where Johnson's algorithm is used as a part of the solution procedure. Computational experiments are provided to evaluate the performance of the solution procedure. It has been found that the proposed solution procedure is effective to obtain an optimal or ε-optimal solution for larger-scaled problems. We further compare the optimal value for SPconstrained with the optimal value for another problem SPunconstrained defined without Assumption B(2); the optimal solution for SPunconstrained being significantly more difficult to obtain. We offer three propositions to analyze some special cases in which the difference between the optimal value of SPconstrained and the optimal value of SPunconstrained is zero. For general cases, we make some computational experiments to evaluate the difference between the optimal value of SPconstrained and the optimal value of SPunconstrained. It has been found that the difference is very small.  相似文献   

14.
15.
For three coadjoint orbits \(\mathcal {O}_1, \mathcal {O}_2\) and \(\mathcal {O}_3\) in \(\mathfrak {g}^*\) , the Corwin–Greenleaf function \(n(\mathcal {O}_1 \times \mathcal {O}_2, \mathcal {O}_3)\) is given by the number of \(G\) -orbits in \(\{(\lambda , \mu ) \in \mathcal {O}_1 \times \mathcal {O}_2 \, : \, \lambda + \mu \in \mathcal {O}_3 \}\) under the diagonal action. In the case where \(G\) is a simple Lie group of Hermitian type, we give an explicit formula of \(n(\mathcal {O}_1 \times \mathcal {O}_2, \mathcal {O}_3)\) for coadjoint orbits \(\mathcal {O}_1\) and \(\mathcal {O}_2\) that meet \(\left( [\mathfrak {k}, \mathfrak {k}] + \mathfrak {p}\right) ^{\perp }\) , and show that the formula is regarded as the ‘classical limit’ of a special case of Kobayashi’s multiplicity-free theorem (Progr. Math. 2007) in the branching law to symmetric pairs.  相似文献   

16.
17.
Given two self-adjoint, positive, compact operators A,B on a separable Hilbert space, we show that there exists a self-adjoint, positive, compact operator C commuting with B such that
.  相似文献   

18.
The existence of limiting spectral distribution (LSD) of the product of two random matrices is proved. One of the random matrices is a sample covariance matrix and the other is an arbitrary Hermitian matrix. Specially, the density function of LSD of SnWn is established, where Sn is a sample covariance matrix and Wn is Wigner matrix.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号