336 research outputs found

    Digital voice-of-customer processing by topic modelling algorithms: insights to validate empirical results

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    Purpose: Digital voice-of-customer (digital VoC) analysis is gaining much attention in the field of quality management. Digital VoC can be a great source of knowledge about customer needs, habits and expectations. To this end, the most popular approach is based on the application of text mining algorithms named topic modelling. These algorithms can identify latent topics discussed within digital VoC and categorise each source (e.g. each review) based on its content. This paper aims to propose a structured procedure for validating the results produced by topic modelling algorithms. Design/methodology/approach: The proposed procedure compares, on random samples, the results produced by topic modelling algorithms with those generated by human evaluators. The use of specific metrics allows to make a comparison between the two approaches and to provide a preliminary empirical validation. Findings: The proposed procedure can address users of topic modelling algorithms in validating the obtained results. An application case study related to some car-sharing services supports the description. Originality/value: Despite the vast success of topic modelling-based approaches, metrics and procedures to validate the obtained results are still lacking. This paper provides a first practical and structured validation procedure specifically employed for quality-related applications

    The Mobile Spatial coordinate Measuring System II (MScMS-II):system description and preliminary assessmentof the measurement uncertainty

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    According to the increasing interest in metrological systems for the dimensional measurements of large-size objects in a wide range of industrial sectors, several solutions based on different technologies, working principles, architectures, and functionalities have recently been developed. Among all, the most flexible and easily transportable solutions are those that have aroused most interest and have found greater success. In order to address the needs of Large-Scale Metrology (LSM) applications, a distributed flexible system based on a network of low-cost InfraRed (IR) sensors – the Mobile Spatial coordinate Measuring System II (MScMS-II) – has been developed at the Industrial Quality and Metrology Laboratory of Politecnico di Torino. This paper presents a preliminary uncertainty assessment of the system referring to the measured point coordinates in the 3D space, focusing on the sources of measurement uncertainty and the related propagation laws. A preliminary metrological characterization of MScMS-II architecture, experimentally evaluated through a system prototype, is also presented and discussed

    Cooperative diagnostics for distributed LSDM systems based on triangulation

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    In the field of large-scale dimensional metrology (LSDM), new distributed systems based on different technologies have blossomed over the last decade. They generally include (i) some targets to be localized and (ii) a network of portable devices, distributed around the object to be measured, which is often bulky and difficult to handle. The objective of this paper is to present some diagnostic tests for those distributed LSDM systems that perform the target localization by triangulation. Three are the tests presented: two global tests to detect the presence of potential anomalies in the system during measurements, and one local test aimed at isolating any faulty network device(s). This kind of diagnostics is based on the cooperation of different network devices that merge their local observations, not only for target localization, but also for detecting potential measurement anomalies. Tests can be implemented in real-time, without interrupting or slowing down the measurement process. After a detailed description of the tests, we present some practical applications on MSCMS-II, a distributed LSDM system based on infrared photogrammetric technology, recently developed at DIGEP-Politecnico di Torino

    Flexible aggregation operators to support hierarchization of Engineering Characteristics in QFD

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    Quality Function Deployment (QFD) is a management tool for organizing and conducting design activities of new products and/or services together with their relevant production and/or supply processes, starting from the requirements directly expressed by the end-users. It is organized in a series of operative steps which drive from the collection of the customer needs to the definition of the technical characteristics of the production/supply processes. The first step entails the construction of the House of Quality (HoQ), a planning matrix translating the Customer Requirements (CRs) into measurable product/service technical characteristics (Engineering Characteristics – ECs). One of the main goals of this step is to transform CR importances into an EC prioritization. A robust evaluation method should consider the relationships between CRs and ECs while determining the importance levels of ECs in the HoQ. In traditional approaches, such as for example Independent Scoring Method, ordinal information is arbitrarily converted in cardinal information introducing a series of controversial assumptions. Actually, the current scientific literature presents a number of possible solutions to this problem, but the question of attributing scalar properties to information collected on ordinal scales is far from being settled. This paper proposes a method based on ME-MCDM techniques (Multi Expert / Multiple Criteria Decision Making), which is able to compute EC prioritization without operating an artificial numerical codification of the information contained in the HoQ. After a general description of the theoretical principles of the method, a series of application examples are presented and discussed

    New developments in high performance cylinder heads: application of LHIP and SPLIT cylinder head concept

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    Since specific power output of new engines is increasing, many engine components are facing new challenges. Among these, cylinder heads have to withstand tougher operating conditions in terms of temperatures and loads, which are approaching the limits of present aluminum alloys and of the manufacturing processes currently applied. The paper discusses two approaches to possibly extend the application of Aluminum alloy heads beyond their present limits: the first is the application of the Liquid Hot Isostatic Pressing (LHIP®) process aimed to improve the quality of the castings; the second is a novel design concept, split cylinder head, based on the application of different materials in different parts of the head, in order to achieve locally the required material properties

    Pharmacokinetics of single domain antibodies and conjugated nanoparticles using a hybrid near infrared method

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    Iron oxide nanoparticles and single domain antibodies from camelids (VHHs) have been increasingly recognized for their potential uses for medical diagnosis and treatment. However, there have been relatively few detailed characterizations of their pharmacokinetics (PK). The aim of this study was to develop imaging methods and pharmacokinetic models to aid the future development of a novel family of brain MRI molecular contrast agents. An efficient near-infrared (NIR) imaging method was established to monitor VHH and VHH conjugated nanoparticle kinetics in mice using a hybrid approach: kinetics in blood were assessed by direct sampling, and kinetics in kidney, liver, and brain were assessed by serial in vivo NIR imaging. These studies were performed under basal circumstances in which the VHH constructs and VHH-conjugated nanoparticles do not substantially interact with targets nor cross the blood brain barrier. Using this approach, we constructed a five-compartment PK model that fits the data well for single VHHs, engineered VHH trimers, and iron oxide nanoparticles conjugated to VHH trimers. The establishment of the feasibility of these methods lays a foundation for future PK studies of candidate brain MRI molecular contrast agents

    The success-index: an alternative approach to the h-index for evaluating an individual's research output

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    Among the most recent bibliometric indicators for normalizing the differences among fields of science in terms of citation behaviour, Kosmulski (J Informetr 5(3):481-485, 2011) proposed the NSP (number of successful paper) index. According to the authors, NSP deserves much attention for its great simplicity and immediate meaning— equivalent to those of the h-index—while it has the disadvantage of being prone to manipulation and not very efficient in terms of statistical significance. In the first part of the paper, we introduce the success-index, aimed at reducing the NSP-index's limitations, although requiring more computing effort. Next, we present a detailed analysis of the success-index from the point of view of its operational properties and a comparison with the h-index's ones. Particularly interesting is the examination of the success-index scale of measurement, which is much richer than the h-index's. This makes success-index much more versatile for different types of analysis—e.g., (cross-field) comparisons of the scientific output of (1) individual researchers, (2) researchers with different seniority, (3) research institutions of different size, (4) scientific journals, etc

    Hand rehabilitation with sonification techniques in the subacute stage of stroke

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    After a stroke event, most survivors suffer from arm paresis, poor motor control and other disabilities that make activities of daily living difficult, severely affecting quality of life and personal independence. This randomized controlled trial aimed at evaluating the efficacy of a music-based sonification approach on upper limbs motor functions, quality of life and pain perceived during rehabilitation. The study involved 65 subacute stroke individuals during inpatient rehabilitation allocated into 2 groups which underwent usual care dayweek) respectively of standard upper extremity motor rehabilitation or upper extremity treatment with sonification techniques. The Fugl-Meyer Upper Extremity Scale, Box and Block Test and the Modified Ashworth Scale were used to perform motor assessment and the McGill Quality of Life-it and the Numerical Pain Rating Scale to assess quality of life and pain. The assessment was performed at baseline, after 2 weeks, at the end of treatment and at follow-up (1 month after the end of treatment). Total scores of the Fugl-Meyer Upper Extremity Scale (primary outcome measure) and hand and wrist sub scores, manual dexterity scores of the affected and unaffected limb in the Box and Block Test, pain scores of the Numerical Pain Rating Scale (secondary outcomes measures) significantly improved in the sonification group compared to the standard of care group (time*group interaction < 0.05). Our findings suggest that music-based sonification sessions can be considered an effective standardized intervention for the upper limb in subacute stroke rehabilitation
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