The lot-sizing and production scheduling problem in a real-life multi-product yoghurt production line is addressed. A new discrete/continuous time representation mixedinteger linear programming model, based on the definition of families of products, is presented. It is mainly optimized the packaging stage while timing and capacity constraints are imposed with respect to the pasteurization/homog...

In this paper, we study the lower semilattice of NP-subspaces of both the standard polynomial time representation and the tally polynomial time representation of a countably infinite dimensional vector space V, over a finite field F. We show that for both the standard and tally representation of V, , there exists polynomial time subspaces U and FV such that U + V is not recursive. We also study...

Time is crucially involved in most of the activities of humans and animals. However, the cognitive mechanisms that support experiencing and processing time remain largely unknown. In the present work we follow a self-organized connectionist modeling approach to study how time may be encoded in a neural network based cognitive system in order to provide suggestions for possible time processing m...

Design of sampled-data control systems is considered, where the closed-loop poles of the discretized system are shifted in a successive manner, in order to achieve a desired overall pole allocation. Modal extraction and the linear quadratic optimal regulator for sampled-data systems are employed in each step of the pole shifting operation, using both continuous-time and discrete-time representa...

The implementation of a pseudo text-independent Speaker Verification system is described. This system was designed to use only information extracted directly from the coded parameters embedded in the ITU-T G.729 bitstream. Experiments were performed over the YOHO database [1]. The feature vector as a short-time representation of speech consists of 16 LPC-Cepstral coefficients, as well as residu...

This paper proceeds to develop models for representing time and reasoning about time from the perspective of nonstandard analysis. It sets out a non-standard first-order theory and a non-standard qualitative approach for hyperreals. This first-order theory and this qualitative approach are based on the fact that any hyperreal is either infinitesimal, unlimited or appreciable. Within the first-o...

The qualitative time representation formalisms are considered from the viewpoint of category theory. The representation of a temporal situation can be expressed as a graph and the relationship holding between that graph and others (imprecise or coarser) views of the same situation are expressed as morphisms. These categorical structures are expected to be combinable with other aspects of knowle...

The efficiency of an algorithm depends greatly on the data structure adopted in practice, while the processing of useless data can cause not only much waste of memory but also much waste of time. Hence to eliminate redundant information is one of the main focuses in the research of algorithms, and the issue has received extensive attention in real-time field (especially those based on dense/con...

Template update allows to modify the biometric reference of a user while he uses the biometric system. With such kind of mechanism we expect the biometric system uses always an up to date representation of the user, by capturing his intra-class (temporary or permanent) variability. Although several studies exist in the literature, there is no commonly adopted evaluation scheme. This does not ea...

During the last 15 years, many mathematical models have been developed in order to solve process operation scheduling problems, using discrete or continuous time representations. In this paper, we present a unified representation and modeling approach for process scheduling problems. Four different time representations are presented, compared, and applied to single-stage and multi-stage batch s...