We study a stochastic inventory model of a firm, that sources the product from a make-to-order manufacturer, and can ship orders by a combination of two freight modes. The two freight modes differ in lead-times, and each has a fixed and a quantity proportional cost for each use. The ordering decisions are made periodically; however, the inventory holding and back-order penalty costs are incurre...

The genesis of complex ventricular rhythms during atrial tachyarrhythmias in humans is not fully understood. To clarify the dynamics of atrioventricular (AV) conduction in response to a regular high-rate atrial activation, 29 episodes of spontaneous or pacing-induced atrial flutter (AFL), covering a wide range of atrial rates (cycle lengths from 145 to 270 ms), were analyzed in 10 patients. AV ...

This paper considers a multistage serial inventory system with Markov-modulated demand. Random demand arises at Stage 1, Stage 1 orders from Stage 2, etc., and Stage N orders from an outside supplier with unlimited stock. The demand distribution in each period is determined by the current state of an exogenous Markov chain. Excess demand is backlogged. Linear holding costs are incurred at every...

We study a perishable inventory system that requires to maintain a fresh and large quantity of inventory at all times. For example, certain pharmaceuticals are kept for emergency preparedness and response operations. We aim to maximize the profit by optimizing the joint problem of the ordering and issuing policies while maintaining a minimum amount of perishable inventory. First, we consider a ...

Introduction. We study a class of capacitated stochastic lot-sizing inventory control problems with stochastic, non-stationary and correlated demands that evolve over time. Economies of scale and capacity constraints exist in many practical scenarios. However, models with fixed ordering costs and capacity constraints are typically computationally intractable, and even the structure of the optim...

Multiple-input-multiple-output (MIMO) system has become one of the major focuses in the research community of wireless communication and information theory. Due to the channel characteristics, severe inter-symbol interference (ISI) may occur to the transmitted signals. Therefore it is necessary to use an equalizer to counter the effect of the channel. The effect of fading and interference effec...

We study a single-period inventory control problem with two independent suppliers. With the first supplier, the buyer incurs a high variable cost but negligible fixed cost; with the second supplier, the buyer incurs a lower variable cost but a positive fixed cost. At the same time, the ordering quantity is limited. We develop the optimal inventory control policy when the holding and shortage co...

This brief presents an improved layered space-time symbol detection algorithm for multiple-input multiple-output (MIMO) wireless systems. The proposed detection scheme utilizes a different layer ordering strategy than the so-called optimal ordering used in the conventional Bell Laboratories Layered Space-Time (BLAST) algorithm. To calculate the nulling vectors and their associated ordering, ins...

In this paper, an inverse nodal problem for a second-order differential equation having a chemical potential on a finite interval is investigated. First, we estimate the nodal points and nodal lengths of differential operator. Then, we show that the potential can be uniquely determined by a dense set of nodes of the eigenfunctions.

Many combinatorial optimization problems can be formulated as 0/1 integer programs (0/1 IPs). The investigation of the structure of these problems raises the following tasks: count or enumerate the feasible solutions and find an optimal solution according to a given linear objective function. All these tasks can be accomplished using binary decision diagrams (BDDs), a very popular and effective...