In this paper we present a linear time approximation scheme for the job shop scheduling problem with fixed number of machines and fixed number of operations per job. This improves on the previously best 2 + ǫ, ǫ > 0, approximation algorithm for the problem by Shmoys, Stein, and Wein. Our approximation scheme is very general and it can be extended to the case of job shop scheduling problems with...

Task compaction has been examined as a means of reducing fragmentation in par titionable machines based on multi stage hypercube mesh and linear array inter connection networks Ordered partial task compaction involves moving a subset of executing tasks without permuting their relative order to accommodate a request for a large submesh that would otherwise be blocked from entering the system In ...

Arguments are presented favouring the step-wise introduction of mechanisation into cane harvesting. The multi-pass "McConnel" system of whole stick harvesting offers such a phased introduction. Three machines are introduced in the following order as labour becomes scarcer a versatile loader, a reaping aid which leaves the cane in orderly swaths "inline", and a pickup cleaner-bundler which takes...

Securing automated teller machines (ATMs), as critical and complex infrastructure, requires a precise understanding of the associated threats. This paper reports on the application of attack-defense trees to model and analyze the security of ATMs. We capture the most dangerous multi-stage attack scenarios applicable to ATM structures, and establish a practical experience report, where we reflec...

This paper reviews a cyclic scheduling model of repetitive manufacturing environments consisting of exible machines and multi-stage jobs. We explicitly model two system performance measures, throughput and ow time, while incorporating variability arising from uncertainty in operation processing times. We present an iterative approximation scheme to estimate the two moment behavior of our perfor...

This paper presents a novel, multi-objective mixed-integer nonlinear programming (MINLP) model for a cell formation problem (CFP) with alternative means. Due to existing contradiction among objectives, three are considered: 1) Minimizing the total cost consisting of; intercellular movements, purchasing, operation, and maintenance; 2) maximizing the utilization of machines in the system; 3) mini...

Industry 5.0 aims at maximizing the collaboration between humans and machines. Machines are capable of automating repetitive jobs, while handle creative tasks. As a critical component Industrial Internet Things (IIoT) systems for service delivery, network data stream analytics often encounter concept drift issues due to dynamic IIoT environments, causing performance degradation automation diffi...

We define quantum multi-stack machines (abbr. QMSMs) by generalizing quantum pushdown automata (abbr. QPDAs) dealt with before from one-stack to multi-stack, and the well-formedness (abbr. W-F) conditions for characterizing the unitary evolution are presented. Afterwards, by means of QMSMs we define quantum multi-counter machines (abbr. QMCMs) that are somewhat different from the quantum counte...

Appropriate scheduling and sequencing of tasks on machines is one of the basic and significant problems that a shop or a factory manager encounters with it, this is why in recent decades extensive researches have been done on scheduling issues. A type of scheduling problems is just-in-time (JIT) scheduling and in this area, motivated by JIT manufacturing, this study investigates a mathematical ...