Digital manufacturing market: a semantic web-based framework for agile supply chain deployment

Manufacturing Market is a market in which manufacturing process capacity is the object of trade. In a market, units of capacity, represented as manufacturing services, can be acquired as needed and when needed, thus making supply chains more responsive to fluctuations in supply and demand. Although Manufacturing Market can be built physically as a spot market, its benefits can be better realized in a web-based framework. We refer to the web-based version of Manufacturing Market as Digital Manufacturing Market (DMM). The major challenges in deployment of a virtual market for manufacturing services include standard representation of manufacturing needs and capabilities, incorporation of intelligent supplier search and evaluation mechanism, and automation of supply chain configuration process. This paper introduces DMM through its major components including a multi-agent framework, a formal ontology for representation of manufacturing services as well as a matchmaking methodology used for connecting buyers and sellers of manufacturing services based on their semantic similarities. The ultimate goal of the proposed framework is to enable autonomous deployment of manufacturing supply chains based on the specific technological requirements defined by particular work orders.     

Flood Intensification due to Changes in Land Use

The non-stationarity in runoff regime may be attributed to various causes such as climate change, land use change, and man-made runoff control structures. Degradation of land use can induce significant impact on infiltration and surface roughness leading to higher flood discharges. This study aims at quantifying possible effects of land use changes and identifying flood source areas for future flood control planning in the Golestan watershed located northeast of Iran. A preliminary trend analysis on the annual maximum flood record of three stations inside the watershed showed that two stations were subject to anthropogenic change. This is while no trend could be detected in the annual maximum rainfall records in the region. Using a calibrated event-based rainfall-runoff model, flood hydrographs corresponding to land use conditions in 1967 and 1996 were simulated and relative changes in the peak flow of the two subsequent conditions were determined for different return periods. The results showed that the impact of land use changes on the flood peak discharge is considerably greater in some subwatersheds. Two limiting land use scenarios were also considered to investigate the envelope of future flood peaks in the watershed. By successively eliminating subwatersheds from the simulation process in a method titled "unit flood response”, the contribution of each subwatershed to the outlet flood peak was quantified. Contribution, per unit area, to the outlet flood peak was the basis to rank the subwatersheds in terms of their flood potential.     

Properties of blends of linear and branched polypropylenes in film blowing

The effect of blending a long‐chain branched polypropylene (LCB‐PP) with a linear polypropylene (L‐PP) on the processability and properties of blown films was investigated. The rheological data revealed that blending an LCB‐PP with an L‐PP improved the elongational properties and the bubble stability, but a severe drop in the mechanical strength was observed for the blends. The most deteriorating effect was the reduction in the elongation at break in tensile tests carried out in the transverse direction (TD), where no yielding behaviour was observed for the blends.     

Large eddy simulation of heat and mass transport in turbulent flows. Part 2: Scalar field

Several subgrid-scale (SGS) scalar flux (τ_iA) and unmixedness (λ_AB) models are presented for large eddy simulation (LES) of heat and mass transport in turbulent flows. The models are similar to those considered in [Int. J. Heat Mass Transfer, in press] for SGS stresses and are based on the information residing at filtered or resolved field. All closures are implemented “locally” and are assessed a priori and a posteriori via data generated by direct numerical simulations of several nonreacting and reacting turbulent flows. A priori assessment indicates that the local values of τ_iA and λ_AB obtained by new “serial decomposition” closures are closer to “true” values than those obtained by dynamic-diffusivity and two-parameter mixed models. A posteriori assessment also indicates that the statistics of the scalar field in nonreacting and reacting flows are better predicted by LES when new SGS models are used.     

Studies on the Synthesis and Activity of Three Tripalladium Complexes Containing Planaramine Ligands

The present study deals with the synthesis, characterization and activity against human cancer cell lines: A2780, A2780^cisR and A2780^ZD0473R of three tripalladium complexes, MH3, MH4 and MH5, that each have two planaramine ligands bound to the central metal ion. Cellular uptake levels, extent of DNA binding, and nature of interaction with salmon sperm and pBR322 plasmid DNA were determined for each complex. Palladium compounds are much more reactive than their corresponding platinum derivatives, which makes them therapeutically inactive but toxic. However, the results of the present study suggest that significant antitumour activity can be introduced in palladium complexes by lessening their reactivity by the introduction of sterically hindered ligands such as 2‐hydroxypyridine, 3‐hydroxypyridine and 4‐hydroxypyridine. When bound to the central palladium ion, 4‐hydroxypyridine appears to be more activating than 2‐hydroxypyridine and 3‐hydroxypyridine, suggesting that noncovalent interactions, such as hydrogen bonding, may also be key determinants of antitumour activity in addition to the steric effect. While cisplatin binds with DNA to form intrastrand GG adducts that causes local bending of a DNA strand, these planaramine‐derived palladium complexes are expected to bind with DNA and form a number of long‐range interstrand GG adducts that would cause a global change in DNA conformation, provided the tripalladium cations in MH3, MH4 and MH5 persist under physiological conditions.     

Trajectory Tracking with Parallel Robots Using Low Chattering,Fuzzy Sliding Mode Controller

This paper proposes a trajectory tracking scheme which belongs to the sliding mode control (SMC) for the 4-degree-of-freedom (DOF) parallel robots. Two fuzzy logic systems (FLS) are first put forward to replace the constant switching control gain and the width of the boundary layer. The fuzzy adaptive supervisory controller (FASC) is combined with the fuzzy sliding mode control (FSMC) to further reduce the chattering. The design is simple and less fuzzy rules are required. The simulation results demonstrate that the chattering of the SMC is reduced greatly and the parallel robot realizes the trajectory tracking with very good robustness to the parameter uncertainties and external disturbances.     

Author Index,Volume 10 (2003)

Authors Index

Author Index, Volume 10 (2003)     

Spatial resolution enhancement of fiber-optic scanning white-light interferometer by use of a Vernier principle

A Vernier principle is employed to improve the spatial resolution of a fiber-optic white-light interferometer to the accuracy of 0.2 microm. The Vernier principle is implemented by combination of interference fringes itself and a virtual fringe that is generated by means of software tracing the scanning mirror. Two rulers are read with respect to each other. This design is insensitive to intensity fluctuation of the interference fringe. The applications, submicrometer estimation for the quadrature-locking selection and the tolerance of the relative measurement, demonstrate its effectiveness.     

The Role of Fuzzy Awareness Modelling in Cooperative Management

Cooperative management is concerned with the management of networks and services involving the cooperation of a number of human/organizational entities. One of the prerequisites for efficient management of these complex systems is related to understanding of the roles of humans and the ways hey interact with each other. Cooperative management Methodology for Enterprise Networks (CoMEN) achieves these objectives by defining an abstract measure of cooperation called Awareness level that is based on Computer Supported Cooperative Work (CSCW) concepts and techniques. In view of the abstract nature of the awareness level definitions, it is not clear how abstract awareness levels can be accurately translated into equivalent cooperative management design parameters. This paper explores the notion of fuzzy sets that enables the use of linguistic values for awareness levels. This is aimed at unveiling of the deficiencies in the existing collaborative support tools with a view to developing more effective cooperative applications. We also model the CSCW tools in terms of repositories and communication mechanisms using fuzzy notions with a view to arrive at a formal design methodology for cooperative management systems. The idea has been illustrated with a case study in a large telecom organization.     

Heuristic rules for tardiness problem in flow shop with intermediate due dates

In this paper, the tardiness flow shop models with intermediate due date were considered. The flow shop models consist of a set of jobs each having a number of operations, while each operation is performed in a single machine. All the jobs are considered having the same unidirectional precedence order. In the tardiness flow shop models with intermediate due date, which we call the generalized tardiness flow shop models, there exist a due date associated with the completion of each operation, and we want to find a schedule which minimizes the total tardiness of the jobs. This is a more general version of tardiness flow shop in the sense that, by assigning a large value to each of the intermediate due dates, we can obtain the traditional flow shop models. Considering the generalized tardiness flow shop models as the NP-hard problems, a set heuristic sequencing rules for finding the best permutation schedule for such problems is proposed. We conducted an extensive computational experiment using randomly generated test problems for evaluating the efficiency of the proposed rules in obtaining a near-optimal solution. The efficiency of the rules was evaluated, and those rules with better solutions were designated and reported.