A bidding mechanism for Web-based agents involved in information classification

The impact of the World Wide Web on providing an easy information access is clearly evident in all aspects of today's life. As attractive as the information availability is, due to its sheer volume, it creates an information-overload on users. Agent-based collaborative filtering is a technique used to effectively counter this burden. For agents to collaborate successfully, and maintain an overall progress of the entire interconnected environment, a governing mechanism is necessary. In this article, we present an economic framework based on a bidding mechanism for agents to communicate and negotiate with each other, thereby achieving collaborative information classification. D-SIFTER, a system developed using this economic framework, is described along with various experiments and their results.     

Mechanical and thermal properties of acrylic fibers crosslinked with disulfonyl azides

A novel method for the crosslinking of acrylic fibers was devised, which uses disulfonyl azides as crosslinking agents. This is a fiber‐finishing process in which 1,6‐hexanedisulfonyl azide, 1,3‐benzenedisulfonyl azide, 4,4‐biphenyldisulfonyl azide, 1,5‐naphthalenedisulfonyl azide, and 2,6‐naphthalenedisulfonyl azide were applied to an acrylic fiber (Courtelle) and thermally treated to bring about crosslinking. A study was made of the mechanical and thermal properties of the crosslinked fibers and of the abrasion and pilling performance of the associated fabrics. Crosslinking brought about significant improvements in the initial modulus, resistance to abrasion, pilling performance, and thermal stability of the fibers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1309–1319, 2002; DOI 10.1002/app.2349     

Modified Hamiltonian chain: A graph theoretic approach to group technology

Graph theory can be effectively applied to the group technology configuration problem (GTCP). Earlier attempts were made to use graph theoretic algorithms, e.g. minimal spanning tree (MST), tree search, and branch & bound to solve the group technology (GT) problem. The proposed algorithm is based on modified Hamiltonian chain (MHC) and consists of two stages. Stage I forms the graph from the machine part incidence matrix. Stage II generates a modified Hamiltonian chain which is a subgraph of the main graph developed in Stage I, and it gives machine sequence and part sequence directly. Dummy edges are considered in MHC for better accessibility in order to arrive at a block diagonal solution to the problem. This paper presents a simple approach by designing a MHC in the graph theoretic method to solve the group technology configuration problem. Results obtained from testing the method are compared with the other well-known methods and found to be satisfactory.     

Understanding the mechanical reinforcement of uniformly dispersed multiwalled carbon nanotubes in alumino-borosilicate glass ceramic

The improvement of mechanical properties of carbon nanotube–reinforced polycrystalline ceramic or glass matrix composites was limited in earlier studies by the difficulties in producing a good dispersion of carbon nanotubes. Additionally, a proper understanding of the reinforcing mechanisms, if any, affecting the mechanical properties of ceramics containing carbon nanotubes is still lacking. We report here the effects of a good dispersion of as much as 10 wt.% multiwalled carbon nanotubes (MWCNTs) on the mechanical properties of dense alumino-borosilicate glass ceramics (ABS) prepared by an ultrasonication-assisted sol–gel technique followed by hot pressing (950 °C; 2 h; Ar atmosphere). The fracture toughness and flexural strength of the nanocomposites increased with increasing MWCNT content up to 10 wt.%. The ABS–10 wt.% MWCNT nanocomposite possessed nearly double the strength of the unreinforced ABS, accompanied by ～150% improvement in fracture toughness. However, a further increase in MWCNT content to 15 wt.% resulted in a modest deterioration of the mechanical properties due to agglomeration of the MWCNTs. The carbon nanotubes have been observed to bridge crack openings of the order of ～100 nm and the experimental evidence, along with theoretical analysis, showed that crack bridging provided the major contribution towards the improvement in fracture toughness. Debonding between the MWCNTs and the matrix appeared to occur in the matrix, away from the actual interface. However, the absence of significant pull-out of broken sections of the MWCNTs during fracture, due to failure of the bridging CNTs being predominantly at the crack plane, indicates that further toughening may be available if this mechanism can be activated.     

DESIGNING OPEN SYSTEMS WITH CASE

Abstract

CASE technology is now advanced enough for use in the design of open systems for distributed computing. Open systems can be accessed for operations by other systems through standard interfaces. This article includes a step-by-step approach for designing an open system architecture using CASE.     

Two-stage procedures for selecting the best exponential population when the scale parameters are unknown and unequal

In this paper, we discuss two-stage procedures for selecting the largest location parameter among k (≥ 2) negative exponential populations having unknown and unequal scale parameters. We compare this new two-stage procedure for k = 2 with that of Mukhopadhyay (1984), and Mukhopadhyay's (1984) procedure comes out as the inferior one. To facilitate this comparison, we need a specialized table (Table I) for the Studentized smaller Chi-squares, and we provide with an exact method to do just that. The Table I is also very useful for another related problem discussed in Mukhopadhyay and Hamdy (1963). In the end, we present a limited simulation study about the moderate sample-size performances of the two-stage procedures in Mukhopadhyay (1984), and Mukhopadhyay and Hamdy (1983) for k = 2. However, for a general k (≥ 3), our newly developed two-stage procedures as developed here are the only ones known to us at this time.     

Preparation of single crystal films of magnetic bubble materials—rare earth yttrium iron gallium garnets by liquid phase epitaxy and their physical properties

The liquid phase epitaxial growth of rare earth-substituted magnetic garnet films suitable for magnetic bubble domain application by both vertical and horizontal dipping using PbO and B₂O₃ as flux is reported. The dependence of various parameters on lead incorporation in the films present as inhomogeneity has been studied.