Shop-scheduling problems with fixed and non-fixed machine orders of the jobs

The paper deals with the determination of an optimal schedule for the so-called mixed shop problem when the makespan has to be minimized. In such a problem, some jobs have fixed machine orders (as in the job-shop), while the operations of the other jobs may be processed in arbitrary order (as in the open-shop). We prove binary NP-hardness of the preemptive problem with three machines and three jobs (two jobs have fixed machine orders and one may have an arbitrary machine order). We answer all other remaining open questions on the complexity status of mixed-shop problems with the makespan criterion by presenting different polynomial and pseudopolynomial algorithms.

[Book review] Rights of the Accused, Crime Control and Protection of Victims

Review of: Rights of the Accused, Crime Control and Protection of Victims. Edited by Eliahu Harnon & Alex Stein. A special volume of the Israel Law Review, Vol. 31, Nos. 1-3, Winter-Summer 1997. Published by the Faculty of Law, Hebrew University, Jerusalem.

Occupational health regulations and health workers: protection or vulnerability?

Several trade agreements include occupational health and safety regulations but there are many barriers to implementation. Mechanisms for sanctions are often weak but the lack of political will is the biggest barrier.