The paper discusses the problem of designing attribute sampling plans by means of closed-form approximate formulae. A methodology is developed to fully characterize the formulae, in terms of design error, i.e. difference between "estimated" and "true" parameters of the sampling plan for given requirements. The focus is on the quality control of isolated lots, but the proposed methodology is applicable to any attribute single sampling plan. The cases in which the design formulae are "exact", and the cases in which they are not, are identified.

There are two well-known and different approaches to statistical inference and hypothesis testing, i.e. the frequentist (or orthodox) and the Bayesian one. Consequently, there are also (if one stays in the framework of probability theory) two rival approaches to uncertainty. The present work is partly a tutorial, aimed at explaining the basic aspects of the two approaches, and their relationship with the GUM; and partly a demonstration that the implementation of the Bayesian approach in the GUM Supplement 1 is too rigid. In particular, objective Bayesianism is incompatible with the propagation of distributions prescribed in Supplement 1.

The paper discuss the computation of the worst case uncertainty (WCU) in common measurement problems. The usefulness of computing the WCU besides the standard uncertainty is illustrated. A set of equations to compute the WCU in almost all practical situations is presented. The application of the equations to real-world cases is shown.

Ring; image segmentation; non-invasive diagnosis

This paper describes an original numerical procedure for the recognition of images applied to the case of individuals’ authentication by using biometric patterns, like the retinal vascular one. Because of the statistical nature of the recognition procedure, the 2x2 confusion matrix, typical of decision tests for binary lassification models, is here considered in order to evaluate the performances of the proposed matching algorithm. An ad hoc procedure is then performed both to build the templates of reference database and to evaluate the threshold for the final decision test.

In the present paper, the authors propose a thermal energy balance model in order to prevent accidents in hemodialysis. Hemodialysis is the most common treatment for renal failure. It performs an extracorporeal blood wastes filtration taking the place of the malfunctioning kidney. Nevertheless this replacement therapy is cause of several side effects affecting the hemodynamic stability of patient. The authors focus attention on the hypotension accident. Thermal energy/heat exchanges between extracorporeal system and body might be cause of hypotension occurrence. Nevertheless, today poor importance is given to such aspects. A careful analysis of these issues has allowed authors to define a model for optimizing treatment procedures nowadays used in medical practice. In fact, most of the hemodialysis machines control automatically the dialysate solution temperature starting from peripheral body temperature measurements. Differently, the proposed approach is based on two control parameters: the predialysis patient core temperature and heat exchanges. Non-invasive temperature measurements of arterial and venous blood are obtained by estimating the thermal energy exchange. The aim of the present model is to guarantee a constant patient core temperature preventing intradialytic hypotension.

The cognitive event-related measurements of the human brain are performed by measuring electrical signals and electromagnetic fields (electroencephalography, EEG, and magnetoencephalography, MEG) and hemodynamic responses (measured by fMRI and PET). The EEG and MEG reflect synchronized electrical activity of neurons, and then show the same timescale as neurocognitive processes. The fMRI is related to the power consumption of groups of neurons and registers a signal on a timescale of several seconds. Unlike fMRI, MEG and EEG are not imaging methods. It is opinion of the authors that the combination of MEG or EEG with the fMRI therefore would be very useful to reach a high resolution, both in time and space, of brain functions. It is not assured however that all measured events during an EEG acquisition and cognitive process-related produce measurable changes of the BOLD signal – and vice versa. In this paper, a new strategy of combining signals (electric and hemodynamic responses) simultaneously acquired from different clinical methodologies is performed and tested in order to produce more reliable information about brain activity. Two different algorithms are explored and compared via repeatability standard deviation estimations of fMRI images.

Obiettivo del lavoro è la proposta di una procedura semplificata per la valutazione della portata volumetrica di un fluido che scorre in una condotta a sezione quadrata. Questa si basa sulla misura diretta, effettuata in un punto stabilito della sezione della condotta, della velocità media del fluido. Dati sperimentali mostrano che il metodo proposto, oltre a semplificare notevolmente la procedura di misura suggerita dalla norma EN 12599, permette la stima della portata con minore incertezza.

The main purpose of the paper is to assess the reliability of particular configuration of Laser Doppler Vibrometry intended to be suitable for the analysis of vibrations affecting rotating components of machines. In the paper an analysis of uncertainty has been carried out due to the possible static misalignments of the mirrors utilized in the experimental apparatus set up for the estimation of the out of plane vibrations of moving (rotating) objects. Those misalignments have to be distinguished from the so called dynamic ones due instead to dynamic effects induced by the movement of the object itself. That is in order to give a better characterization of the self-tracking technique employed with the use of a 1D LDV and of the measurements done by means of it, whose uncertainties are mostly linked to the interaction between environment and instrumentation.

Aim of the paper is to evaluate the reliability of a novel configuration of a Laser Doppler Vibrometer (LDV) for the measurement of vibrations affecting rotating components of machines. In the paper an analysis of errors due to the possible static misalignments of the mirrors utilized in an experimental apparatus has been carried out. This instrument was set up for the estimation of the out of plane vibrations of moving (rotating) objects, in order to give a better characterization of the self-tracking technique employed with the use of a 1D single point LDV and its measurements. The accuracies of the measures are mostly linked to the interaction between environment and instrumentation.

The present paper describes a procedure improving the measurement of fluid flow rates in pipes through the measurement of vibrations. The authors show, via experimental tests for water system, that for a given pipe in terms of width, diameter and material, the first harmonic amplitude of the vibration signal transmitted from the flow to the pipe walls is linearly proportional to the flow rate at a given revolution of the pump. Then, accelerometer mini/micro-transducers can be used for non intrusive, low-cost and reliable flow rate measurements without load errors.

Wilson disease is a pathology due to a gene mutation causing malfunction in the copper excretion from the organism. Consequently, copper accumulation in the body gives rise to oxidative processes. So, this rare disease is responsible of several disorders affecting tissues and organs. Neurological disorders are common consequence of copper accumulation in the brain. About 95% of individuals with neurological/psychiatric disorders show a visible symptom in their eyes known as Kayser-Fleischer ring. It is a golden-brown, sometimes orange or greyish, ring due to copper deposit in the cornea. In medical screening, it is considered a diagnostic sign of Wilson disease more than ever in individuals with neurological problems. The authors propose an innovative technique based on ocular biometric measurements to diagnose the pathology and the origin of neurological disorder. An image processing algorithm detects the Kayser-Fleischer ring in eye cornea by segmentation. Subsequently, biometric measurements provide further information on the severity level of pathology. The aim is to provide a non-invasive diagnostic technique improving the accuracy of the current methods used in practice and reducing possible interpretation errors.

The purpose of the paper is to provide an analysis of the attitude exhibited by demodulation algorithms of Fiber Bragg Gratings (FBG) based on Cross Correlation methods. The Cross Correlation technique here considered is based on calculations performed in spectral domain. Its behavior against the peak-locking phenomenon has been analyzed and a way for attenuating it has been devised. The new Iterative Cross Correlation algorithm improves the FBG demodulation accuracy and precision, giving remarkably attenuated peak-locking amplitude.

Focus of the present work is the evaluation of the air flow rate in a pipe of squared cross section through the direct measurement of the mean velocity at a fixed location of the section. To this aim, an extension of the methodology already utilized for circular section pipes is here proposed. The method simplifies and improves the procedure suggested by the technical standard EN 12599. Specifically, it has been possible to state a geometrical position in the cross section where to straight measure the mean flow velocity in order to evaluate the flow rate. Here, it is shown that the proposed methodology allows the estimation of the flow rate with higher accuracy than the normed one does, estimating errors less than those accepted in common practice.

Hemodialysis treatment is biased by some complications during its operative phases. One of these potential accidents consists in intradialytic hypotension, that certainly causes discomfort to the patient but may even increase death risk. Therefore, it is very suitable, for reasons of prevention, predicting such events in the clinical routine procedures. As a cause of hypotension occurrence might be found in thermal energy/heat exchanges between extracorporeal system and the surrounding environment because of the operating temperatures during the clinical therapy. In the present work, a model for evaluating such heat losses is proposed and improved in order to maintain constant patient’s blood temperature as much as possible. By means of a deep investigation on these issues, the authors have defined a convenient procedure to improve and optimize the clinical treatment process. Differently from most of the hemodialysis machines used nowadays which control automatically the dialysate solution temperature starting from peripheral body temperature measurements, the proposed method is based on the control of only two important parameters: i) the pre-dialysis core temperature of the patient, and ii) the temperature of the blood entering the artery from the extracorporeal circuit after the treatment in the dialyzer. Measurements of arterial and venous blood temperatures are obtained in a non-invasive way by means of a suitable estimation of thermal energy exchanges between the blood and the environment during the extracorporeal recirculation. The suggested model guarantees a constant core temperature of the patient, improving prevention from intradialytic hypotension.

The paper describes an innovative, more accurate and reliable method for calibrating an S-type Pitot tubes (SPT) by means of Laser Doppler Anemometry technique (LDA). Due to its coarse structure (since it is used in chemically aggressive environments), it requires periodic calibrations, which are carried out by means of a more accurate standard L-type Pitot tube (LPT). The use of LDA as standard allows overcoming the drawbacks inherent in the usual calibration technique.

Kayser-Fleischer ring is a visible golden-brown, sometimes orange or greyish, pigmentation in the cornea. This is a common symptom of a rare genetic disorder known as Wilson Disease. This pathology is cause of a malfunction in the copper excretion from the organism. Copper accumulates in tissues and consequently is responsible of oxidative processes in the organs affected. Kayser-Fleischer ring is direct consequence of the copper deposit in the cornea. It is considered a basic diagnostic sign of Wilson disease more than ever in individuals with neurological disorders due to copper accumulation in brain. However, few ophthalmologists are experienced in identifying Kayser-Fleischer ring. In the manuscript, a mobile application (app) is proposed to detect automatically the Kayser-Fleischer ring. The smartphone takes a photograph of patient’s eye and sends it to a web-service. The latter performs the image processing by using a segmentation algorithm. Once that Kayser-Fleischer ring has been detected, biometric measurements provide the percentage extent of the corneal region affected by the symptom. This parameter allows the system to get information on the severity of the oxidative process such as an indirect measure of the pathology stage. Subsequently, further medical examinations support the physician to diagnose the Wilson disease. The proposed diagnostic measurement system is non-invasive and fully automated. At the moment the detection of the Kayser-Fleischer ring is made by ophthalmologist with a visual examination. However the symptom is not always recognised. Therefore interpretation errors and false-negative diagnoses are possible. In this sight, the proposed diagnostic tool could improve accuracy of actual methods used in practice and resolve the physician suspicion about the pathology occurrence.