Rescheduling to Minimize the Maximum Lateness Under the Sequence Disruptions of Original Jobs

2017 ◽  
Vol 34 (05) ◽  
pp. 1750024 ◽  
Author(s):  
Qiulan Zhao ◽  
Jinjiang Yuan

We introduce and study the rescheduling on a single machine to minimize the maximum lateness under the sequence disruptions of original jobs. In the problem, each original job [Formula: see text] has a constraint disruption on its sequence respect to an original optimal schedule [Formula: see text], i.e., [Formula: see text]. That is, if [Formula: see text] is the [Formula: see text]th job in [Formula: see text], then it is required that the position index [Formula: see text] of [Formula: see text] in a schedule for all jobs satisfies [Formula: see text]. By introducing the positive sequence disruption [Formula: see text] and the negative sequence disruption [Formula: see text], three problems are considered in this paper: problem (P1) is [Formula: see text], problem (P2) is [Formula: see text], and problem (P3) is [Formula: see text]. We show that the three problems are equivalent and can be solved in [Formula: see text] time. Then we study an extension of problem (P2): [Formula: see text]. We show that the extended problem can be solved in [Formula: see text] time.

1985 ◽  
Vol 17 (3) ◽  
pp. 252-260 ◽  
Author(s):  
R. E. Larson ◽  
M. I. Dessouky ◽  
R. E. Devor

2017 ◽  
Vol 1 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Tomasz Drabek

The paper discusses the effects of the presence of subharmonics (i.e. frequencies lower than the basic 50 Hz) in the voltage supplying the induction machine. Subharmonics in a three-phase grid are the result of the oscillations of peak values of the voltages. In induction machines, this results in the subharmonic and interharmonic currents, the generation of alternating moments, the increase in the rms value of the current of the fundamental harmonic and the oscillations of the rotor speed. In the paper is derived expression on the thermally acceptable load of the motor (by torque and power), in the case of supplying it by three-phase voltage containing a positive sequence of subharmonics. It presented the obstacles to derive the analogical expression for power supply containing a negative sequence of subharmonics.


2018 ◽  
Vol 2 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Tomasz Drabek

The paper discusses the effects of interharmonics, i.e. frequencies higher than the fundamental frequency, not being its total multiplicity, in the voltage supplying the induction motor. The emergence of interharmonics in a three-phase grid is mainly the result of the swinging of peak mains voltages. In induction machines, this results in the occurrence of currents with interharmonic and subharmonic frequencies, the generation of alternating moments, the swinging of the rotor speed and the change in the RMS value of the current of the fundamental frequency. The paper explores these phenomena simulation, taking into account the skin effect of currents in the rotor cage. The research was carried out both for interharmonics with a positive sequence of phases as well as for the negative sequence. The paper is a continuation of work [1].


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