One-off or batch upgrading of complex products and systems: concepts,data model and analysis framework

One-off or Batch upgrading is the term given to the process of improving one or several operational instances of complex products or systems (e.g., trains, aircrafts, etc.) during their life span. Other products such as cars or personal computers are regularly improved through redesign, generation after generation; however, redesign never concerns only one or several instance(s). The main challenge presented in this paper is to provide a suitable framework to analyse one-off and batch upgrading processes. This framework targets at containing required concepts and drivers for upgrade problem posing. The axiom beneath this research is that the goal of upgradings is to improve the performances of products or systems. Upgrade-to-performance, UtP in short, represents this paradigm that will be defined and illustrated through examples. To reach this goal, necessary concepts are defined and linked together through a generic data model. The UtP data model can be used in a conceptual way clarifying the scope of the upgrading process. It can also be specialized to specific industrial domain and used as the main driver of the design of a database for a given upgrading projects. The use case reported concerns the conversion of a passenger train into an express freight where the focus is put on enlarging a coach’ door. The results are then discussed to figure out the links between the UtP problem-posing and problem-solving methods and the gaps to fill. Finally, further research niches are described.     

Designing transcranial magnetic stimulation systems

We explain the process of designing optimized transcranial magnetic stimulation systems and outline a method for identifying optimal system parameters such as the number of turns, the capacitor size, the working voltage, and the size of the stimulation coil. The method combines field analysis, linear and nonlinear circuit analysis, and neural strength-duration response parameters. The method uses boundary-element analysis to predict the electric field as a function of depth, frequency, current, and excitation coil size. It then uses the field analysis to determine the inductance as a function of size and, in general, current when a saturable core is used. Circuit analysis allows these electric field computations to be indexed against system parameters, and optimized for total system energy and stimulation coil size. System optimizations depend on desired stimulation depth. A distinguishing feature of the method is that it inherently treats excitation frequency as an unknown to be determined from optimization.     

Designing systems for new users

This paper discusses the relationship between a system and ‘noncaptive’ users and the qualities which make a good system. Various methods for designing systems are considered and the author's development of meeting design (shared experience events) is presented.     

Designing mechanical systems for optimum diagnosability

An analysis and modeling method of the diagnostic characteristics for electro-mechanical systems is presented. Diagnosability analysis is especially relevant given the complexities and functional interdependencies of modern-day systems, since improvements in diagnosability can lead to a reduction of a system’s life-cycle costs. Failure and diagnostic analysis leads to system diagnosability modeling with the failure modes and effects analysis (FMEA) and component-indication relationship analysis. Methods are then developed for translating the diagnosability model into mathematical methods for computing metrics such as distinguishability and No Fault Found. These methods involve the use of matrices to represent the failure and replacement characteristics of the system. Diagnosability metrics are extracted by matrix multiplication. These metrics are useful when comparing the diagnosability of proposed designs or predicting the life-cycle costs of fault isolation.     

Designing piezoelectric films for micro electromechanical systems

Piezoelectric thin films are of increasing interest in low-voltage micro electromechanical systems for sensing, actuation, and energy harvesting. They also serve as model systems to study fundamental behavior in piezoelectrics. Next-generation technologies such as ultrasound pill cameras, flexible ultrasound arrays, and energy harvesting systems for unattended wireless sensors will all benefit from improvements in the piezoelectric properties of the films. This paper describes tailoring the composition, microstructure, orientation of thin films, and substrate choice to optimize the response. It is shown that increases in the grain size of lead-based perovskite films from 75 to 300 nm results in 40 and 20% increases in the permittivity and piezoelectric coefficients, respectively. This is accompanied by an increase in the nonlinearity in the response. Band excitation piezoresponse force microscopy was used to interrogate the nonlinearity locally. It was found that chemical solution-derived PbZr(0.52)Ti(0.48)O(3) thin films show clusters of larger nonlinear response embedded in a more weakly nonlinear matrix. The scale of the clusters significantly exceeds that of the grain size, suggesting that collective motion of many domain walls contributes to the observed Rayleigh behavior in these films. Finally, it is shown that it is possible to increase the energy-harvesting figure of merit through appropriate materials choice, strong imprint, and composite connectivity patterns.     

Designing performance measurement systems for just-in-time operations

Results of a study conducted to understand how performance is evaluated in just-in-time (JIT) operations are reported in this paper. The purpose of the study was to develop a series of propositions concerning the performance criteria, standards, measurement techniques, and reporting methods that are appropriate in JIT environments. Ten propositions are provided.     

Designing of epoxy resin systems for cryogenic use

The mechanical and thermal properties of several types of epoxy systems were designed based on the chemical structure, network structure and morphology aiming at cryogenic application. In this research di-epoxies or multifunctional epoxies were cured by several kinds of hardeners such as anhydride, amine or phenol and were blended with polycarbonate, carboxyl-terminated butadiene acrylonitrile copolymer or phenoxy. The mechanical properties and thermal properties of these cured epoxies were measured at room and liquid nitrogen temperature. It was found that the two-dimensional network structured linear polymer shows high performance even at cryogenic temperature. It was concluded that the controls of the structures are very important to optimize epoxy systems for cryogenic application.     

Designing integrated cellular manufacturing systems with tactical decisions

In this paper, we aim to design cellular manufacturing systems that optimize the performance of a manufacturing system subject to the optimization aspects of production planning. Consequently, the demand for each part – one of the production planning features – plays a vital role in determining the part families and the formation of machine cells in each period. In our study, holding and backorder costs follow a probabilistic structure, and they are described by a set of stochastic scenarios. In this model, five objective functions are employed: one of them minimizes the expected total holding and backorder costs in order to evaluate the risk in the model. The aim of this model is to select and optimize the assignment of parts and machines to different cells as well as the number of each produced part in each period. A new heuristic algorithm based on the optimization method is established to yield the best solution for this complicated mathematical formulation. Further, the performance of the proposed algorithm is verified using certain test problems in which the obtained results are compared with those obtained using the branch-and-bound algorithm and heuristic procedures.     

Designing cellular manufacturing systems with dynamic part populations

The effectiveness of a cellular manufacturing system is sensitive to fluctuations in the demand for products and the product mix. This paper presents a new formulation of the part family/machine cell formation problem that addresses the dynamic nature of the production environment by considering a multi-period forecast of product mix and demand during the formation of part families and machine cells. The goal of the multi-period formulation is to obtain a cellular design that continues to perform well with respect to the design objectives as the part population changes with time.     

Designing null detectors for analog-digital converters of scanning test systems

Conclusions A method for designing a pulsed null detector comprising an ac amplifier with forced discharging of its input and interstate capacitances was suggested.The restoration of zero by means of a pulsed feedback and the periodic zero-drift elimination reduces zero instability due to signals and stray effects down to values below the noise level of the ac input amplifier.Additional pulse correction reduces this noise level over a wider frequency range (from zero to 1/10 of the chopping frequency) than in other similar circuits.Thus, the suggested principle of forcibly discharging the capacitors serves to produce at a relatively low cost a highly-sensitive and high-speed null detector whose noise characteristics are superior to those of its constituent wide-band amplifier.Translated from Izmeritel'naya Tekhnika, No. 7, pp. 53–56, July, 1969.     

Designing multi-product lines: job routing in cellular manufacturing systems

An operation sequence-based method which integrates intra-cell layout cost with cell formation to minimize the total cost of the materials flow and machine investment is developed here for designing a cellular manufacturing system. The method comprises three distinct approaches: part-family formation, cell-formation, and layout configuration. In the first phase, an operation sequence-based similarity coefficient is applied in a p-median model to group the parts to form part families with similar operation sequences. In the second phase, machine assignment to part families is determined where a trade-off between potential inter-cell movement cost due to the. bottleneck machine and the potential benefit of assigning bottleneck machines to certain part-family is considered. In the third phase, intra-cell layout is determined for each cell so as to refine the initial layout of the cell further. Numerical examples are employed to demonstrate the mechanism of the procedure throughout all phases. A comparative study is also performed to support the present method     

Susceptibility and structure of metallo-proteins and model systems

The interest in the study of the diamagnetic properties of the whole molecule and/or the magnetic moment of metal ions bound in relation to the structure and function of proteins is briefly outlined. The advantages in using high-resolution superconducting magnetometers are described together with the main features of the experimental technique and its foreseen advancement. A few examples, as representative of classes of problems, are discussed in more detail with reference to recent experimental studies.     

Increases in patient doses need to be avoided when upgrading interventional cardiology systems to flat detectors

The aim of this study was to evaluate patient doses in two interventional cardiology laboratories over a period of 1 y in which the imaging devices were changed from image intensifier (II) to flat detector (FD). Dosimetric data from a total of 1040 coronary angiography (CA) procedures and 1087 percutaneous transluminal coronary angioplasty (PTCA) procedures were gathered. During the period studied with II imaging, median values of dose area product were 28 Gy cm(2) for CA and 57 Gy cm(2) for PTCA. In the first half of the year with FD imaging, median values were 37 Gy cm(2) for CA and 89 Gy cm(2) for PTCA. A significant increase in patient doses was noticed in the early stages of use of FD technology for imaging IC procedures, while fluoroscopy time and number of images remained similar. A careful setting of the X-ray systems, after upgrading the imaging system, is essential to avoid unjustified increases in patient doses.     

A stochastic model of disperse systems

We suggest a model of the structure of a disperse system that reflects the random character of the topology. We evaluate the effect of the stochastic nature of the topology on the effective conductivity. An asymptotic decrease in the conductivity with increase in the scale of the heat and mass transfer is established and explained.     

Designing thekmostatic devices. Part 1. A basic thermostat model

General principles are considered for one of the first stages in designing a thermostatic devices: choosing the basic model.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 3, pp. 504–508, September, 1986.