We describe all possible asymptotic behavior of bucket brigade production lines with two or three workers, each characterized by a constant work velocity. The results suggest wariness in interpreting simulation results. They also suggest a strategy for partitioning a workforce into e ective teams to sta the lines.

The increasing ease of producing nucleic acids and proteins to specification offers potential for design and fabrication of artificial synthetic "organisms" with a myriad of possible capabilities. The prospects for these synthetic organisms are significant, with potential applications in diverse fields including synthesis of pharmaceuticals, sources of renewable fuel and environmental cleanup. ...

Continuous cultures of T cells reactive to the hapten 4-ethoxymethylene-2-phenyloxazolone were tested for interferon production after antigenic stimulation in vitro. Induction of interferon was antigen-specific and also restricted by the I region of the major histocompatibility complex. Kinetics of antigen induced interferon production were different from those reported for mitogen induced synt...

The allocation of buffers between workstations is a major optimization problem faced by manufacturing systems designers. It entails the determination of optimal buffer allocation plans in production lines with the objective of maximizing their throughput. We present and compare two stochastic approaches for solving the buffer allocation problem in large reliable production lines. The allocation...

This work introduces a new evolutionary approach to search for a global solution to multiobjective optimisation problem in the Pareto sense. Novelty of the proposed method consists in application of an evolutionary multi-agent system (EMAS) instead of classical evolutionary algorithms. Decentralisation of the evolution process in EMAS allows for intensive exploration of the search space and eff...

P. Fernandes , M.E.J. O’Kelly , C.T. Papadopoulos ∗(3), and A. Sales (1) Pontif́ıcia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga, 6681 Porto Alegre, Brazil. Phone: +55 51 3320 3611. Fax: +55 51 3320 3621. Emails: [email protected], [email protected] Waterford Institute of Technology, Cork Road, Waterford, Ireland. Phone: +353 51 302 000. Fax: +353 51 378 292. Email: m...

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The bottleneck (BN) of a production system is a machine with the strongest effect on the system’s throughput. In this paper, a method for BN identification in serial lines with rework and Bernoulli machines is developed. In addition, the paper provides two system-theoretic results: First, it demonstrates that BNs may be shifting not only because of changes in machine and buffer parameters but a...

Conditioned media collected under serum-free conditions over 24 to 48 h from 18 human colon adenocarcinoma cell lines were analyzed for transforming growth factor, types alpha and beta (TGF-alpha and -beta), and platelet-derived growth factor in assays for anchorage-independent growth and radioreceptor competition. Detectable levels of TGF-alpha, TGF-beta, and platelet-derived growth factor wer...

Three human colon cancer lines (SW 480, SW 620, WIDR) were characterized as to their production of molecules with transforming growth factor (TGF)-like activity. Production of both TGF alpha-like and TGF beta-like activity was quantitated, as were cellular receptors for these molecules, and growth response in soft agar to exogenous epidermal growth factor (EGF) (as a substitute for TGF alpha) a...