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This paper aims to present a method for calculating the top event probability of a fault tree with priority AND gates.

The paper makes use of Merle's temporal operators for obtaining the minimal cut sequence set of a dynamic fault tree. Although Merle's expression is based on the occurrence time of an event sequence, the paper treats the expression as an event containing the order of events. This enables the authors to treat the minimal cut sequence set by using the static fault tree techniques. The proposed method is based on the sum of disjoint products. The method for a static FT is extended to a more applicable one that can deal with the order operators proposed by Merle et al.

First, an algorithm to obtain the minimal cut sequence set of dynamic fault trees is proposed. This algorithm enables the authors to analyze reasonably large scale dynamic fault trees. Second, the proposed method of obtaining the top event probability of a dynamic fault tree is efficient compared with an inclusion‐exclusion based method proposed by Merle et al. and a conventional Markov chain approach. Furthermore, the paper shows the top event probability is derived easily when all the basic events have exponential failure rates.

The methodology presented shows a new solution for calculating the top event probability of dynamic fault trees.

This paper aims to present two methods for calculating the steady state probability of a repairable fault tree with priority AND gates and repeated basic events when the minimal cut sets are given.

The authors consider a situation that the occurrence of an operational demand and its disappearance occur alternately. We assume that both the occurrence and the restoration of the basic event are statistically independent and exponentially distributed. Here, restoration means the disappearance of the occurring event as a result of a restoration action. First, we obtain the steady state probability of an output event of a single‐priority AND gate by Markov analysis. Then, we propose two methods of obtaining the top event probability based on an Inclusion‐Exclusion method and by considering the sum of disjoint probabilities.

The closed form expression of steady state probability of a priority AND gate is derived. The proposed methods for obtaining the top event probability are compared numerically with conventional Markov analysis and Monte Carlo simulation to verify the effectiveness. The result shows the effectiveness of the authors’ methods.

The methodology presented shows a new solution for calculating the top event probability of repairable dynamic fault trees.

Presents a new qualitative fault tree evaluation algorithm based on bit manipulation techniques for the identification of the largest independent sub‐trees and the subsequent determination of all minimal cut sets of large and complex fault trees. The methodology developed is validated by direct application to a complex fault tree taken from the literature. Results obtained are compared with those available in the literature. Shows that the use of the algorithm (FTABMT) developed results in significant savings in both computer time and storage requirements.

A major factor to the success of flexible manufacturing systems (FMSs) is their ability to transport work pieces between different workstations. FMS have now become more advanced and material‐handling systems have become progressively more sophisticated, it is not exceptional to have automated steering of tools to workstations as well. Such system design will improve the tool‐handling capability and the system productivity while holding tool cost to a minimum. Tool cost could represent as much as 25 percent of the operating cost. The purpose of this paper is to propose a new colored Petri net (CPN)‐based approach to the design and development of a tool sharing control system that is intended to help use of the proper and minimal number of tools for a manufacturing system.

A new black token timed PN model is first developed, to reduce the complexity of the graphical representation a new CPN model is developed. The new CPN model also allows to find the optimal sequence. The optimal sequence has no effect on the work in process (WIP) but it influences the number of tools used in the system. The main input to the PN model for a manufacturing system is the process plan. Next, all the invariants and total number of possible elementary circuits are determined using the Integrated Net Analyzer (INA) software. Output from the INA software is exported to the Excel spreadsheet. The Excel spreadsheet can be designed to calculate the total number of tokens, processing time, cycle time, etc. of each elementary circuit. Subsequently, the constraints used in Lingo will be created according to critical circuit rules. Finally, linear programming (LP) technique is used to optimize the WIP and tool inventory. Lingo software is used for the LP, the constraints from the Excel sheet will be the input data to the Lingo program, and based on those constraints the Lingo will provide the optimal values for the desired parameters. The output from Lingo will be used to recalculate the cycle time of each elementary circuit in the Excel sheet. The system is then analyzed before and after the implementation of the CPN model.

A new CPN model based on tool‐sharing philosophy for an FMS with N part types and M stations is proposed.

The paper presents a new CPN‐based approach to the design and development of a tool sharing control system, that is, intended to help use of the proper and minimal number of tools for a manufacturing system. The new CPN model also allows to find the optimal sequence. The idea is new and pure and has not been presented before using the methodology adopted in this paper.

As a first example of the application of the cut‐out procedure to fuselage problems and the selection of appropriate cut systems, the elimination of a complete ring is discussed in detail. ‘Minimal’, ‘maximal’ and ‘dismembering’ techniques are all applied to singly and doubly connected rings, and attention is drawn to some inadmissible and critical combinations of cuts in order to guide the most effective choice. The second fuselage example treats similarly the removal of a portion only of the ring.

A hybrid flowshop (HFS) problem on the pre‐sewing o perations and a master production scheduling (MPS) problem of apparel manufacture are solved by a proposed two‐tier scheduling model. The first objective of this paper is to plan a MPS for the factory so that the costs are minimized when the production orders are completed before and after the delivery dates required by the customers. The second objective is to minimize the completion time of the pre‐sewing operations in the cutting department while the production quantities required by the sewing department at several predetermined times can be fulfilled by the cutting department. Experimentation is conducted and the results show the excellent performance of the proposed scheduling model for the apparel industry.

A general concept of a structure function is proposed by considering a general order topology, where possible degrees of performance for the system and its components are going to be represented. Finite multistate structure functions and continuum structures can therefore be viewed as particular cases. Gives general definitions of minimal path and minimal cut, allowing general reliability bounds based on them. These are applied to some multivalued structures.

Drawing on the ideas of conversation analysis (CA), the purpose of this paper is to elaborate the picture of dialogical information seeking and sharing. To this end, information seeking and sharing are approached as interactive online talk occurring in an asynchronous discussion forum.

The conceptual framework is based on the elaboration of Schegloff’s model for sequence organisation in spoken conversation. As a result, ten categories constitutive of asynchronous online talk were identified. It was further examined how online talk of this type is structured by expanded question – answers adjacency pairs and how such pairs are constitutive of dialogical information seeking and sharing. This question was explored by scrutinising 20 discussion threads downloaded from a do-it-yourself related online forum.

Four ideal typical patterns of asynchronous online talk were identified. Answering the question is a basic pattern of online talk, based on the provision of responses to an individual request. Specifying the answer, broadening the discussion topic and challenging the answer represent more sophisticated patterns incorporating post-expansions of diverse kind.

As the study focusses on four patterns constitutive of online talk occurring in a particular domain, the findings cannot be generalised to depict the phenomena of dialogical information interaction as a whole. Further research is needed to scrutiny the particular features of asynchronous online talk in the context of dialogical information interaction.

The paper pioneers by examining the potential of CA in the micro-level study of dialogical information seeking and sharing structured by expanded adjacency pairs. The findings also identify the limitations of the conversation analytic methodology in the study of asynchronous online discourse.

The series of illustrations to the elimination procedures is concluded with two examples in which the various techniques are again examined critically. The first application considers the important problem of a major cut‐out in a fuselage, extending over a number of panels and bays, and including the attached ring segments. Here the dismembering process appears in its straightforward simplicity and generality a particularly effective choice. The final example investigates the removal of a major substructure from a system in the form of an ‘open’ or ‘closed chain’ of substructures. The discussion on cut‐outs is rounded off with a synopsis of the techniques used and a description of the automatic programme for checking an elimination scheme for any hidden singularities.