An exploration of the factors affecting the diffusion of advanced costing techniques: a comparative analysis of two surveys (1996-2005)

The issue of cost calculation has been largely debated in the last years under the pressure of the perceived lost of relevance of the so called "traditional cost accounting approaches". The enthusiasm for new management accounting techniques has often driven most of attention towards technical or theoretical aspects of the proposed new cost models. In particular, Activity-Based Costing (ABC) implementation literature pinpoints a large number of studies that have looked at technical and organizational/behavioral factors that influence effective implementation. Recently a great attention has been paid by researchers on the contingent factors affecting the adoption of advanced management accounting techniques and the influence of the variables that drive towards higher levels of cost system sophistication. The need is felt for insightful studies regarding processes and contingent variables working through time in relation with these changes. Improved analysis can be obtained by undertaking replication studies based on larger number of responses and/or across geographic and cultural borders. Whitin the boundaries of a contingent framework analysis, this paper has provided additional insights into areas relating to factors influencing the level of sophistication of product cost systems in Italy. The paper presents the comparison of two survey results carried on in a ten years distance on the same sample of Italian largest companies. These two long-distance surveys provide the opportunity to assess the changes occurred in the companies that in 1996 declared the adoption of (or the interest in adopting) ABC and Target costing (Cinquini et al., 1999).Moreover, the time elapsed could allow the perception about adopters’ behavior, along different stages of the diffusion process of advanced costing techniques. The research findings pinpoint that only “importance of cost information” and “cost structure”, among the contextual variables considered in the more recent survey responses, are positive and significant in relation with increasing in implementation of advanced costing techniques. This outcome could open to further studies to assess whether or not adopters are moving from a “fad and fashion” behavior of the early stages, to a more rational approach in which the matching between management needs and tools potentiality is maximized.Management accounting innovations, Activity-Based Costing, Target costing, Product costing design, Cost system sophistication, Contingent factors

An exploration of the factors affecting the diffusion of Advanced Costing techniques: a comparative analysis of two surveys (1996-2005)

The issue of cost calculation has been largely debated in the last years under the pressure of the perceived lost of relevance of the so called "traditional cost accounting approaches". The enthusiasm for new management accounting techniques has often driven most of attention towards technical or theoretical aspects of the proposed new cost models. In particular, Activity-Based Costing (ABC) implementation literature pinpoints a large number of studies that have looked at technical and organizational/behavioral factors that influence effective implementation. Recently a great attention has been paid by researchers on the contingent factors affecting the adoption of advanced management accounting techniques and the influence of the variables that drive towards higher levels of cost system sophistication. The need is felt for insightful studies regarding processes and contingent variables working through time in relation with these changes. Improved analysis can be obtained by undertaking replication studies based on larger number of responses and/or across geographic and cultural borders. Whitin the boundaries of a contingent framework analysis, this paper has provided additional insights into areas relating to factors influencing the level of sophistication of product cost systems in Italy. The paper presents the comparison of two survey results carried on in a ten years distance on the same sample of Italian largest companies. These two long-distance surveys provide the opportunity to assess the changes occurred in the companies that in 1996 declared the adoption of (or the interest in adopting) ABC and Target costing (Cinquini et al., 1999).Moreover, the time elapsed could allow the perception about adopters’ behavior, along different stages of the diffusion process of advanced costing techniques. The research findings pinpoint that only “importance of cost information” and “cost structure”, among the contextual variables considered in the more recent survey responses, are positive and significant in relation with increasing in implementation of advanced costing techniques. This outcome could open to further studies to assess whether or not adopters are moving from a “fad and fashion” behavior of the early stages, to a more rational approach in which the matching between management needs and tools potentiality is maximized.Management accounting innovations, Activity-Based Costing, Target costing, Product costing design, Cost system sophistication, Contingent factors

Fabrication of quencher-free liquid scintillator-based, high-activity 222^{222}Rn calibration sources for the Borexino detector

A reliable and consistently reproducible technique to fabricate $^{222}$Rn-loaded radioactive sources ($\sim$0.5-1 kBq just after fabrication) based on liquid scintillator (LS), with negligible amounts of LS quencher contaminants, was implemented. This work demonstrates the process that will be used during the Borexino detector's upcoming calibration campaign, with one or several $\sim$100 Bq such sources will be deployed at different positions in its fiducial volume, currently showing unprecedented levels of radiopurity. These sources need to fulfill stringent requirements of $^{222}$Rn activity, transparency to the radiations of interest and complete removability from the detector to ensure their impact on Borexino's radiopurity is negligible. Moreover, the need for a clean, undistorted spectral signal for the calibrations imposes a tight requirement to minimize quenching agents ("quenchers") to null or extremely low levels

Diaphragm design improvement for a metering pump

Since the membrane has to separate the process fluid from the oil circuit in metering diaphragm pumps, it is the critical component of these machines. Sometimes, depending on the operating conditions, the membrane may crack and it is necessary to disassemble the pump and replace this component part. Therefore it is important to improve the design of the membrane to avoid this. In this paper, the behaviour of a membrane mounted in a metering diaphragm pump has been simulated by using f.e.m. An accurate analysis of the results has allowed the membrane to be redesigned in a more rational way and to improve its performance

Multiple Fault Identification Method in the Frequency Domain for Rotor Systems

Fault identification in rotor systems has been studied by many authors, but the considered malfunction is one single fault only, generally an unbalance. Real machines can be affected by several different types of faults; moreover sometimes also two different faults may develop simultaneously. A model based method for identifying multiple faults acting simultaneously on a rotor system in the frequency domain is briefly described and its robustness with regards to measuring and modelling errors is evaluated, by means of numerical simulations performed on the models of two typical power plant machines: a steam turbogenerator and a gas turbogenerator

Analysis of the Instability Phenomena Caused by Steam in High-pressure Turbines

Instability phenomena in steam turbines may happen as a consequence of certain characteristics of the steam flow as well as of the mechanical and geometrical properties of the seals. This phenomenon can be modeled and the raise of the steam flow and pressure causes the increase of the cross coupled coefficients used to model the seal stiffness. As a consequence, the eigenvalues and eigenmodes of the mathematical model of the machine change. The real part of the eigenvalue associated with the first flexural normal mode of the turbine shaft may become positive causing the conditions for unstable vibrations. The original contribution of the paper is the application of a model-based analysis of the dynamic behavior of a large power unit, affected by steam-whirl instability phenomena. The model proposed by the authors allows studying successfully the experimental case. The threshold level of the steam flow that causes instability conditions is analyzed and used to define the stability margin of the power unit

Accuracy in the Identification of a Generator Thermal Bow

Model-based diagnostic techniques can be used to identify the faults that affect rotating machines. In general, the most important faults and malfunctions can be modelled by means of a suitable set of equivalent excitations that are applied to the nodes of a finite element model of the machine rotor train. Weighted least-squares error methods can be used to identify the set of forces and moments that minimize the error between experimental transient vibrations and the rotor system response obtained with the simulating model. However, the accuracy of the fault identification can be significantly influenced by the adequacy of the fault model as well as by the accuracy of the rotating machine model. This paper shows some methods, based on basic statistics, which enable the accuracy of the fault identification to be evaluated. The capabilities of the proposed methods have been proved by the results of the identification of the shaft thermalbow of a power unit generator that exhibited abnormal vibrations during machine coastdowns. The accuracy with which the location and the severity of the fault have been estimated is analyzed. In addition to this, the results obtained by the identification of the actual faults have been compared with those provided by the identification of false faults that cause similar symptoms

Some remarks on breathing mechanism, on non linear effects and on slant and helicoidal cracks

The breathingmechanism of cracks in rotating shafts is accurately investigated by means of 3D non-linear models. The behaviour is then modelled by means of a much simpler approximated approach, which allows also to calculate the stiffness variation of the cracked shaft. This simple model has then been used for analysing non-linear dynamic behaviour of cracked rotating shafts, which occurs when breathing is governed by the vibration itself. Finally, also the effects of cracks which have developed according a helix, instead of developing on a cross section, due to the combined action of bending and torsion, are investigated. The breathing behaviour and still more the deflections are then influenced by the torsion. The aim of these investigations is mainly to present behaviours of full size industrial machinery, computed numerically with finite element models of the shaft

Thermally Induced Vibrations due to Rub in Real Rotors

The analysis of the effects of the rotor-to-stator rub in the rotor dynamics field has produced many models, often nonlinear or with particular attention to chaotic behaviour, but with scarce correspondence with real rotors since Jeffcott-like rotors are mainly used without thermal transients, or sometimes real rotors are used but with very simple thermal modelling. One of the most remarkable aspects of the rotor-to-stator rub at operating speed is the possibility of observing spiral vibration phenomena in the synchronous vibration, i.e. the vibration vector changes its amplitude and rotates even at the rated speed. This is due to the combined effect of the contact forces which introduce heat and of the resulting thermal bow. The phenomenon is also called vector turning or thermally induced vibrations. It is interesting to analyse the dynamical behaviour of the machine: the spirals can have a self-propagating trend or conversely a self-correcting trend. The model presented in the paper for the analysis of the spiral vibration has a unique characteristic in that it allows real machines to be analysed, since it uses a fully assembled machine model (rotor, bearings and foundation) and implements a rather sophisticated thermal and contact model. The experimental validation of the proposed model is performed on data coming from a real machine: the generator of a 50 MW combined cycle power plant, in which unstable spiral vibrations were observed at the operating speed during a power increase