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41.
Order Acceptance (OA) is one of the main functions in business control. Accepting an order when capacity is available could
disable the system to accept more profitable orders in the future with opportunity losses as a consequence. Uncertain information
is also an important issue here. We use Markov decision models and learning methods from Artificial Intelligence to find decision
policies under uncertainty. Reinforcement Learning (RL) is quite a new approach in OA. It is shown here that RL works well
compared with heuristics. It is demonstrated that employing an RL trained agent is a robust, flexible approach that in addition
can be used to support the detection of good heuristics. 相似文献
42.
For a tandem line of finite, single-server queues operating under the production blocking mechanism, we study the effects
of pooling several adjacent stations and the associated servers into a single station with a single team of servers. We assume
that the servers are cross-trained (so that they can work at several different stations) and that two or more servers can
cooperate on the same job. For such a system, we provide sufficient conditions on the service times and sizes of the input
and output buffers at the pooled station under which pooling will decrease the departure time of each job from the system
(and hence increase the system throughput). We also show that pooling decreases the total number of jobs in the system at
any given time and the sojourn time of each job in the system if the departure time of each job from the system is decreased
by pooling and there is an arrival stream at the first station. Moreover, we provide sufficient conditions under which pooling
will improve the holding cost of each job in the system incurred before any given time, and extend our results to closed tandem
lines and to queueing networks with either a more general blocking mechanism or probabilistic routing. Finally, we present
a numerical study aimed at quantifying the improvements in system performance obtained through pooling and at understanding
which stations should be pooled to achieve the maximum benefit. Our results suggest that the improvements gained by pooling
may be substantial and that the bottleneck station should be among the pooled stations in order to obtain the greatest benefit.
AMS subject classification: 90B22 相似文献
43.
44.
Portfolio optimization under D.C. transaction costs and minimal transaction unit constraints 总被引:1,自引:0,他引:1
This paper addresses itself to a portfolio optimization problem under nonconvex transaction costs and minimal transaction unit constraints. Associated with portfolio construction is a fee for purchasing assets. Unit transaction fee is larger when the amount of transaction is smaller. Hence the transaction cost is usually a concave function up to certain point. When the amount of transaction increases, the unit price of assets increases due to illiquidity/market impact effects. Hence the transaction cost becomes convex beyond certain bound. Therefore, the net expected return becomes a general d.c. function (difference of two convex functions). We will propose a branch-and-bound algorithm for the resulting d.c. maximization problem subject to a constraint on the level of risk measured in terms of the absolute deviation of the rate of return of a portfolio. Also, we will show that the minimal transaction unit constraints can be incorporated without excessively increasing the amount of computation. 相似文献
45.
We show the existence ofaverage cost (AC-) optimal policy for an inventory system withuncountable state space; in fact, the AC-optimal cost and an AC-optimal stationary policy areexplicitly computed. In order to do this, we use a variant of thevanishing discount factor approach, which have been intensively studied in recent years but the available results not cover the inventory problem we are interested in.The work of the first author (OVA) was partially supported by Fondo del Sistema de Investigación del Mar de Cortéz under grant SIMAC/94/CT-005. The work of the second author (RMdO) was partially supported by Consejo Nacional de Ciencia y Tecnologia (CONACyT) under grant 0635P-E9506. 相似文献
46.
K.D. Glazebrook 《Stochastic Processes and their Applications》1982,13(2):171-187
A general model is proposed for the stochastic version of the single-machine allocation problem. Sufficient conditions are given to ensure that there is an optimal strategy given by a fixed permutation of the job set. Additional results are given for an important special case of the general model involving simple jobs. The paper concludes with material concerning the evaluation of fixed permutations as strategies under conditions more general than the sufficient conditions mentioned above. 相似文献
47.
48.
A model for option pricing of fractional version of the Merton model with ‘Hurst exponent’ H being in [1/2,1) is established with transaction costs. In particular, for H(1/2,1) the minimal price Cmin(t,St) of an option under transaction costs is obtained, which displays that the timestep δt and the ‘Hurst exponent’ H play an important role in option pricing with transaction costs. 相似文献
49.
Land rental problems describe situations where one tenant demands land from several lessors. The way lessors rent their land can be seen as equivalent to a bankruptcy problem. We extend the idea of self-duality in bankruptcy problems to land rental problems. We provide a complete characterization of the family of rules that satisfy self-duality. Moreover, self-duality is enough to assure the proportional land share among lessors. Adding other reasonable properties, we pick up a single rule. 相似文献
50.
《Operations Research Letters》2020,48(6):792-797
This study considers a multi-period two-region repositioning problem with setup repositioning costs involved for vehicle sharing systems. We find that incorporating such costs can influence the total cost significantly and complicate the structure of the optimal policy. Moreover, we manage to partially characterize the optimal policy, and then develop an easy-to-implement heuristic policy. The performance of the heuristic policy and the influence of setup repositioning costs on policies are assessed numerically. 相似文献