On the analogy between the evolution of thermodynamicand bibliometric systems: a breakthrough or justa bubble?

This paper presents an in depth study of an interesting analogy, recently proposed by Prathap (Scientometrics 87(3):515-524, 2011a), between the evolution of thermodynamic and bibliometric systems. The goal is to highlight some weaknesses and clarify some ‘‘dark sides'' in the conceptual framework of this analogy, discussing the formal validity and practical meaning of the concepts of Energy, Exergy and Entropy in bibliometrics. Specifically, this analogy highlights the following major criticalities: (1) the definitions of E and X are controversial, (2) the equivalence classes of E and X are questionable, (3) the parallel between the evolution of thermodynamic and bibliometric systems is forced, (4) X is a non-monotonic performance indicator, and (5) in bibliometrics the condition of ‘‘thermodynamic perfection'' is questionable. Argument is supported by many analytical demonstrations and practical example

A short survey on Air Quality Indicators: properties, use and (mis)use

Purpose - Analysis and comparison of three existing indicators of the air quality: the American air quality index, the French Atmo, and the Italian Indice di Qualita` dell'Aria. Design/methodology/approach - International general and organic regulations to control air quality do not exist yet. Consequently many countries have independently implemented specific indicators to monitor the air pollution and then alert people of resulting health risks. The paper focuses on three of them. Each one is independently presented showing the peculiarities. Therefore, these indicators are compared to identify the features they have in common, as well as those that set them apart, and to figure out which are either restrictive or permissive, and what are their qualities and drawbacks. Findings - The three mentioned indicators convert the real health risk due to air pollution into numerical information, in different ways. Doing this, they carry out some simplifications or assumptions, which can be questionable. The main difficulty is to understand if the indicators aggregate the different pollutant concentrations consistently with the real effects on human health. Research limitations/implications - This paper analyses only three specific indicators of the air quality, selected among the existing ones. Practical implications - Indicators should carefully be analysed to understand if they properly represents the real effects of pollutants on human health. The most critical aspect to consider is the aggregation of the different pollutant concentrations in one information. Originality/value - This paper analyses the efficacy of representation of some air quality indicators. It discusses if indicators aggregation is consistent with the real effects on human healt

Classification of Performance and Quality Indicators in Manufacturing

A critical aspect in operations management is to represent the firm goals properly. This is usually done by translating the organisational results and objectives in ‘performance measurements'. The scientific literature shows many applications in different fields such as quality, production, logistics, marketing, etc. Nevertheless, a general theory formalising basic and application concepts is still lacking. This paper shows a classification of ‘performance indicators' in manufacturing, providing a mathematical structure to the concept of ‘indicator'. This approach is based on the formalism of the Representation Theory. All the mentioned concepts are explained and discussed through practical example

Aggregating multiple ordinal rankings in engineering design: the best model according to the Kendall’s coefficient of concordance

Aggregating the preferences of a group of experts is a recurring problem in several fields, including engineering design; in a nutshell, each expert formulates an ordinal ranking of a set of alternatives and the resulting rankings should be aggregated into a collective one. Many aggregation models have been proposed in the literature, showing strengths and weaknesses, in line with the implications of Arrow's impossibility theorem. Furthermore, the coherence of the collective ranking with respect to the expert rankings may change depending on: (i) the expert rankings themselves and (ii) the aggregation model adopted. This paper assesses this coherence for a variety of aggregation models, through a recent test based on the Kendall's coefficient of concordance (W), and studies the characteristics of those models that are most likely to achieve higher coherence. Interestingly, the so-called Borda count model often provides best coherence, with some exceptions in the case of collective rankings with ties. The description is supported by practical examples

A novel multi-target modular probe for multiple Large-Volume Metrology systems

Recent studies show that the combined use of Large-Volume Metrology (LVM) systems (e.g., laser trackers, rotary-laser automatic theodolites (R-LATs), photogrammetric cameras, etc.) can lead to a systematic reduction in measurement uncertainty and a better exploitation of the available equipment. Unfortunately, the sensors of a specific LVM system are usually able to localize only specific targets (i.e., active/passive elements positioned in the measurement volume) and not necessarily those related to other systems (e.g., the reflective markers for photogrammetric cameras cannot be used for R-LATs or laser trackers); this represents an obstacle when using combinations of different LVM systems. This paper describes the design of a new modular probe, with different typologies of targets and integrated sensors, which allows to simplify the measurement process. The probe is versatile as the number of targets, their typology and spatial position can be customized depending on the combination of LVM systems in use. A detailed analysis of the technical and functional characteristics of the probe is followed by the presentation of a mathematical/statistical model for the real-time probe localization. Description is supported by realistic application examples

Design decisions: concordance of designers and effects of the Arrow’s theorem on the collective preference ranking

The problem of collective decision by design teams has received considerable attention in the scientific literature of engineering design. A much debated problem is that in which multiple designers formulate their individual preference rankings of different design alternatives and these rankings should be aggregated into a collective one. This paper focuses the attention on three basic research questions: (i) “How can the degree of concordance of designer rankings be measured?”, (ii) “For a given set of designer rankings, which aggregation model provides the most coherent solution?”, and (iii) “To what extent is the collective ranking influenced by the aggregation model in use?”. The aim of this paper is to present a novel approach that addresses the above questions in a relatively simple and agile way. A detailed description of the methodology is supported by a practical application to a real-life case study

Prioritization of QFD Customer Requirements Based on the Law of Comparative Judgments

Quality function deployment (QFD) is a useful tool to improve the design/development process of products and services. The initial phases of the QFD process—that is, those concerning the collection and analysis of the so-called voice of the customer—are probably the most critical, because any distortion can propagate to the whole process results, making it ineffective or even misleading. The focus of this article is on the phase of prioritization of customer requirements (CRs). There are numerous techniques for this task; however, (1) the simplest often introduce questionable or unrealistic assumptions, whereas (2) the most sophisticated often require too much elaborate and repetitious information from customers, which may lead to inconsistencies. This article introduces a new prioritization technique based on the Thurstone’s law of comparative judgment. This technique makes it possible to aggregate the evaluations by multiple respondents and transform them into an interval scale, which depicts the relative importance of CRs. The greatest strength of this technique is combining a refined theoretical model with a simple and user-friendly data collection process. The description is supported by a realistic application example concerning the prioritization of QFD’s CRs in the design of an aircraft seat

Decision concordance with incomplete expert rankings in manufacturing applications

The manufacturing field encompasses a number of problems in which some experts formulate their rankings of a set of objects, which should be aggregated into a collective judgment. E.g., consider the aggregation of (i) the opinions of designers on alternative design concepts, (ii) the opinions of reliability/safety engineers on the criticality of a set of failures, (iii) the perceptions of a panel of customers on alternative aesthetic features of a product, etc.. For these problems, the Kendall’s concordance coefficient (W) can be used to express the degree of agreement between experts in a simple and practical way. Unfortunately, this indicator is applicable to complete rankings only, while experts often find it more practical to formulate incomplete rankings, e.g., identifying only the most/less relevant objects and/or deliberately excluding some of them, if they are not sufficiently relevant or well known. This research aims at extending the use of the traditional W to incomplete rankings, preserving its practical meaning and simplicity. In a nutshell, the proposed methodological approach associates a so-called “midrank” to all objects, even the ones that are not easily comparable with the other ones; subsequently, W can be applied to these midranks. The description is supported by several pedagogical examples

A proposal of a new paradigm for national quality certification systems

The goal of this paper is to suggest a new incentive model that is capable of creating the conditions for the autonomous growth of diffusion and credibility of the ISO 9000 national quality certification syste

Determining the extrinsic parameters of a network of Large-Volume Metrology sensors of different types

Large-Volume Metrology (LVM) instruments – such as laser trackers, photogrammetric systems, rotary-laser automatic theodolites, etc. – generally include several sensors, which measure the distances and/or angles subtended by some targets. This measurements, combined with the spatial position/orientation of sensors (i.e., the so-called extrinsic parameters), can be used to locate targets in the measurement volume. Extrinsic parameters of sensors are generally determined through dedicated sensor calibration methods, which are based on repeated measurements of specific artefacts. The combined use of multiple LVM instruments enables exploitation of available equipment but may require multiple instrument-dedicated sensor calibrations, which inevitably increase set-up time/cost. This document presents a novel calibration method – called global calibration – which allows the extrinsic parameters of all sensors to be determined in a single process. The proposed method uses a special artefact – i.e., a hand-held probe with assorted types of targets and inertial sensors – and includes a data-acquisition stage, in which the probe is repositioned in different areas of the measurement volume, followed by a data-processing stage, in which an ad hoc mathematical/statistical model is used to determine the extrinsic parameters of sensors. Additionally, the proposed method includes the formulation of a system of linearized equations, which are weighed considering the uncertainty of input variables