In this paper, we consider a single-item periodic-review stochastic inventory system with both minimum order quantity (MOQ) and batch ordering requirements. In each time period, the firm can order either none or at least as much as the MOQ. At the same time, if an order is placed, the order quantity is required to be an integral multiple of a given specific batch size. We first adopt a heuristi...

Necessary conditions of optimality, in the form of a maximum principle, are derived for a class of optimal control problems, certain of whose controls are represented by measures and whose state trajectories are functions of bounded variation. State trajectories are interpreted as robust solutions of the dynamic equations, a concept of solutions which takes account of the interaction between th...

This paper accompanies a talk given at the Workshop on Mathematical Methods in Queueing Networks held at the Mathematical Sciences Institute at Cornell University in August 1988. In earlier work we had exhibited a threshold phenomenon in the transient behaviour of a closed network of . / M / 1 nodes: When there are N customers circulating, and the initial state is x, let d~(t ) denote the total...

Convex duality is a powerful framework for solving non-smooth optimal control problems. However, for problems set in non-reflexive Ba-nach spaces such as L 1 (Ω) or BV(Ω), the dual problem is formulated in a space which has difficult measure theoretic structure. The predual problem , on the other hand, can be formulated in a Hilbert space and entails the minimization of a smooth functional with...

Predicting real-time movement trace of remote objects or the control points of objects when delay-jitter occurs is a critical and challenging issue in most Internet-based collaborative graphics editing systems. This paper presents two novel algorithms: Machine Learning algorithm and Changeable Scale algorithm. Related experiments were carried out to test the effectiveness of the algorithms. Res...

An optimal control problem for semilinear parabolic partial differential equations is considered. The control variable appears in the leading term of the equation. Necessary conditions for optimal controls are established by the method of homogenizing spike variation. Results for problems with state constraints are also stated. Mathematics Subject Classification. 49K20, 35B27. Received August 7...

This paper shows the design and performance of an AQM (Active Queue Management) enabled router. The design is based on a classical proportional control system. The application of such a router is to enhance streaming media over IP performance by avoiding bursty packet drop situations, control the router queue delay, and balancing packet drop, delay, and link utilization. The selected AQM equili...

Delay jitter is the variation of the delays with which packets traveling on a network connection reach their destination. For good quality of reception, continuous-media (video, audio, image) streams require that jitter be kept below a sufficiently small upper bound. This paper proposes a distributed mechanism for controlling delay jitter in a packet-switching network. The mechanism can be appl...

The popular IEEE 802.11 WLAN today does not provide any quality-of-service (QoS) because of its contention-based channel access nature of the medium access control (MAC). Therefore, we proposed a simple software upgrade-based solution, called a dual queue scheme, to provide QoS to real-time services such as Voice-over-IP (VoIP) in our previous work [7]. The dual queue scheme operates on top of ...