The internal representation of vowel spectra investigated using behavioral response-triggered averaging

Listeners presented with noise were asked to press a key 13 whenever they heard the vowels [a] or [i:]. The noise had a random spectrum, with levels in 60 frequency bins changing every 0.5 s. Reverse correlation was used to average the spectrum of the noise prior to each key press, thus estimating the features of the vowels for which the participants were listening. The formant frequencies of these reverse-correlated vowels were similar to those of their respective whispered vowels. The success of this response-triggered technique suggests that it may prove useful for estimating other internal representations, including perceptual phenomena like tinnitus

Kvantitativna i kvalitativna procena obrasca hoda kod bolesnika sa Parkinsonovom bolešću

Background/Aim. Postural impairments and gait disorders in Parkinson's disease (PD) affect limits of stability, impaire postural adjustment, and evoke poor responses to perturbation. In the later stage of the disease, some patients can suffer from episodic features such as freezing of gait (FOG). Objective gait assessment and monitoring progress of the disease can give clinicians and therapist important information about changes in gait pattern and potential gait deviations, in order to prevent concomitant falls. The aim of this study was to propose a method for identification of freezing episodes and gait disturbances in patients with PD. A wireless inertial sensor system can be used to provide follow-up of the treatment effects or progress of the disease. Methods. The system is simple for mounting a subject, comfortable, simple for installing and recording, reliable and provides high-quality sensor data. A total of 12 patients were recorded and tested. Software calculates various gait parameters that could be estimated. User friendly visual tool provides information about changes in gait characteristics, either in a form of spectrogram or by observing spatiotemporal parameters. Based on these parameters, the algorithm performs classification of strides and identification of FOG types. Results. The described stride classification was merged with an algorithm for stride reconstruction resulting in a useful graphical tool that allows clinicians to inspect and analyze subject's movements. Conclusion. The described gait assessment system can be used for detection and categorization of gait disturbances by applying rule-based classification based on stride length, stride time, and frequency of the shank segment movements. The method provides an valuable graphical interface which is easy to interpret and provides clinicians and therapists with valuable information regarding the temporal changes in gait.Uvod/Cilj. Poremećaji hoda i ravnoteže kod bolesnika sa Parkinsonovom bolešću (PD) uključuju i poremećaje stabilnosti, održavanja ravnoteže prilikom hoda i nemogućnost adekvatne reakcije na iznenadne perturbacije. U kasnijim fazama bolesti neki bolesnici razvijaju i epizode motornog bloka, odnosno 'frizing' tokom hoda. Objektivno praćenje i merenje karakteristika hoda i promena obrasca hoda tokom progresije bolesti mogu pomoći kliničarima jer ukazuju na promene koje bi dovele do padova i ugrozile bolesnika. Cilj rada bio je razvoj metode koja bi identifikovala ovakve epizode kod bolesnika sa Parkinsonovom bolesti. Razvijeni bežični sistem sa senzorima mogao bi se koristiti za posmatranje efekata terapije ili progresije bolesti. Metode. U radu je prikazan sistem za objektivnu procenu obrasca hoda. Korišćenjem bežičnog senzorskog sistema koji koristi akcelerometre, žiroskope i senzore sile, moguće je dobiti procenu parametara hoda, ali i identifikovati 'frizing' epizode karakteristične za PD. Uz pomoć ovog sistema snimljeno je 12 bolesnika, te je na osnovu snimljenih signala razvijen novi softverski alat koji omogućava praćenje parametara hoda. Rezultati. Na osnovu dužine koraka, trajanja koraka i frekvencije pokreta, razvijen je algoritam za klasifikaciju tipova koraka i uočavanje promena frekvencija pokreta tokom hoda. Prikaz rezultata ovog sistema je dat kroz primer jednog bolesnika. Zaključak. Opisani sistem za procenu hoda može biti korišćen za kategorizaciju poremećaja hoda kroz posmatranje promena u dužini i trajanju koraka, kao i frekvencija segmenata noge. Razvijeni metod omogućava iliustrativni prikaz i grafički interfejs koji je jednostavan za interpretaciju i omogućava dobijanje informacija koje kliničarima mogu ukazati na trenutne promene u obrascu hoda

Senzorski sistem za objektivnu motornu procenu na osnovu tapping-a prstima i stopalom

Background/Aim. Finger tapping test is commonly used in neurological examinations as a test of motor performance. The new system comprising inertial and force sensors and custom proprietary software was developed for quantitative estimation and assessment of finger and foot tapping tests. The aim of this system was to provide diagnosis support and objective assessment of motor function. Methods. Miniature inertial sensors were placed on fingertips and used for measuring finger movements. A force sensor was placed on the fingertip of one finger, in order to measure the force during tapping. For foot tapping assessment, an inertial sensor was mounted on the subject's foot, which was placed above a force platform. By using this system, various parameters such as a number of taps, tapping duration, rhythm, open and close speed, the applied force and tapping angle, can be extracted for detailed analysis of a patient's motor performance. The system was tested on 13 patients with Parkinson's disease and 14 healthy controls. Results. The system allowed easy measurement of listed parameters, and additional graphical representation showed quantitative differences in these parameters between neurological patient and healthy subjects. Conclusion. The novel system for finger and foot tapping test is compact, simple to use and efficiently collects patient data. Parameters measured in patients can be compared to those measured in healthy subjects, or among groups of patients, or used to monitor progress of the disease, or therapy effects. Created data and scores could be used together with the scores from clinical tests, providing the possibility for better insight into the diagnosis.Uvod/Cilj. Tapping tj. tapkanje prstiju šake i stopala se uobičajeno koristi u neurološkim ispitivanjima kao test motorike. Prikazan je novi sistem koji sadrži inercijalne senzore i senzore sile, kao i odgovarajući softver za kvantitativnu procenu dijagnostičkog motornog testa na osnovu tapping-a prstima i stopalima. Uz pomoć ovog sistema moguća je objektivna evaluacija motornog obrasca bolesnika, a samim tim i lakše postavljanje određenih dijagnoza i praćenje progresa bolesti ili terapije. Metode. Minijaturni inercijalni senzori su bili postavljeni na vrhove prstiju u cilju kvantifikovanja pokreta prstiju. Senzor sile postavljen je na jagodicu jednog prsta i merio je silu primenjenu u toku tapping-a - tapkanja kažiprsta o palac. Za ocenu tapping-a stopalom, inercijalni senzor je postavljen na gornji deo stopala ispitanika koje je bilo postavljeno na platformu za merenje sile. Pomoću ovog sistema mogu se posmatrati brojni parametri poput broja i trajanja svakog pokreta, ritma i promena ritma, brzine otvaranja i brzine zatvaranja prstiju, primenjene sile, promene ugla između prstiju, i na osnovu ovih parametara može se vršiti detaljna analiza motornog stanja bolesnika. Sistem je testiran na 13 bolesnika sa Parkinsonovom bolešću i 14 zdravih ispitanika. Rezultati. Sistem je omogućio jednostavno merenje navedenih parametara i grafički prikaz kvantitativnih razlika u ovim parametrima između zdravih ispitanika i bolesnika sa neurološkim oboljenjem. Zaključak. Novi sistem za tapping prstima i stopalima je kompaktan, jednostavan za upotrebu i efikasan za prikupljanje podataka o bolesniku. Izmereni parametri mogu se koristi za poređenje bolesnika sa zdravim ispitanicima, ili sa drugim grupama bolesnika, ali i za praćenje progresa bolesti ili efekata terapije. Dobijeni podaci mogu se koristiti zajedno sa rezultatima drugih kliničkih testova, dajući tako mogućnost za bolji uvid u dijagnozu

Residual life estimation of a thermal power plant component: The high-pressure turbine housing case

This study focuses on the estimation of residual life of damaged thermal power plant components. The high-pressure turbine housing was chosen as an example of thermal power plant component where, during the years of exploitation, damage appeared in the form of dominant crack. Residual life estimation procedure, based upon experimental and numerical methods has been introduced and applied. Material properties were determined experimentally both at room and operating temperature, while all necessary calculations were performed by the special finite element method, so-called X-FEM. The residual life estimation of the damaged high-pressure turbine housing was performed by applying the Paris's law for crack growth analysis

Casting Process Improvement by the Application of Artificial Intelligence

On the way to building smart factories as the vision of Industry 4.0, the casting process stands out as a specific manufacturing process due to its diversity and complexity. One of the segments of smart foundry design is the application of artificial intelligence in the improvement of the casting process. This paper presents an overview of the conducted research studies, which deal with the application of artificial intelligence in the improvement of the casting process. In the review, 37 studies were analyzed over the last 15 years, with a clear indication of the type of casting process, the field of application of artificial intelligence techniques, and the benefits that artificial intelligence brought. The goals of this paper are to bring to attention the great possibilities of the application of artificial intelligence for the improvement of manufacturing processes in foundries, and to encourage new ideas among researchers and engineers

Application of Machine Learning in the Control of Metal Melting Production Process

Abstract This paper presents the application of machine learning in the control of the metal melting process. Metal melting is a dynamic production process characterized by nonlinear relations between process parameters. In this particular case, the subject of research is the production of white cast iron. Two supervised machine learning algorithms have been applied: the neural network and the support vector regression. The goal of their application is the prediction of the amount of alloying additives in order to obtain the desired chemical composition of white cast iron. The neural network model provided better results than the support vector regression model in the training and testing phases, which qualifies it to be used in the control of the white cast iron production

Effects of Trace Elements on the Fatty Acid Composition in Danubian Fish Species

Anthropogenic pollution poses a major threat to aquatic ecosystems, which can lead to their degradation. The accumulation and toxicity of metals and trace elements in fish leads to physiological and chemical changes in the fish body. In this study, we investigated the effects of bioaccumulation of metals and trace elements on freshwater fish fatty acid profiles at two different sites before and after the discharge of untreated municipal wastewater in two fish species with different diet habits. Although the concentrations of toxic elements were below the maximum levels proposed by the EU and the Republic of Serbia, this study showed statistically significant correlations between the presence of certain elements and the fatty acid (FA) profile in fish muscle. Lower concentrations of polyunsaturated FA in fish sampled after the discharge of untreated municipal wastewater were detected.In this study, the concentrations of metals and trace elements (As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn) were determined in the muscle tissue of adult roach and white bream at two different sites in the Belgrade section of the Danube. Twenty-six fatty acids, consisting of nine saturated FA (SFAs), seven monosaturated FA (MUFAs) and ten polysaturated FA (PUFAs), were identified. The analysis of the concentration of metals and trace elements of the roach and white bream showed species-specific differences in their bioaccumulation. Four of all elements analyzed (As, Hg, Ni and Pb) correlated significantly with the changes in FA profiles in fish from both sampling sites, with the exception of Cu, which correlated with the FA profile at the site before, and Zn, whose concentration influenced the FA profile at the site after wastewater discharges. The lower PUFA content in the fish from a site under higher environment pressure could indicate that the fish are stressed. The results suggest that changes in lipid composition may be one of the protective mechanisms of cells to cope with anthropogenic stressors

KRSTARENJA PAN-EUROPSKIM KORIDOROM VII I NJIHOV EKONOMSKI ZNAČAJ NA RECEPTIVNE PROSTORE

This paper provides some tentative estimates of the economic impact of cruise tourism in receptive countries and regions along the Pan-European Corridor VII. Examples are provided to illustrate the potential benefit to Vojvodina Region (Case study). The results of the analysis have shown that the Corridor VII cruises have positive impact on Vojvodina Province, primarily the riparian area of the Danube (only Novi Sad - the “Port of Vojvodina for cruisers”). Although the benefits exclude accommodation and food expenditure, they are noticeable within the following segments: tourism promotion (broadening the scopes of Vojvodina Province as a receptive area for the foreign market through its cultural heritage and natural values); increase in foreign tourist turnover, visitor’s expenditures; new job opportunities (adequate infrastructure and superstructure – rendering services to ships, crew and passengers) – harbors, carriers, souvenir shops, etc. / new products, business net, exchange money, invisible export, etc. The results of the research may initiate further studies on the cause and effect connections between this type of travelling and resources of receptive countries, upon which the travels are based, both aiming at adequate design and launching of the tourist offer, i.e. the optimal development of receptive countries through sustainable tourism. Also, the discussion provides potentially useful information to the different stakeholders in the evolving cruise tourism industry, particularly regarding expected (private or social) returns on investment.Ovim radom su analizirana međunarodna turistička krstarenja Pan-europskim Koridorom VII, odnosno njihov utjecaj (potencijalne dobrobiti) na ekonomiju receptivnih prostora. Studijom slučaja (Vojvodina) dati su primjeri koji to ilustriraju. Rezultati analize pokazuju da kruzevi Koridorom VII utječu pozitivno na Vojvodinu, prvenstveno na priobalnu, podunavsku regiju i to u Novom Sadu (gdje brodovi pristaju). Iako se beneficije ne odnose na korištenje usluga smještaja i hrane na kopnu, dobrobit se ogleda u sljedećim segmentima: turistička promocija (širenje pozitivnog plasmana Vojvodine kao receptivnog prostora na inozemnom tržištu – predstavljanje kulturne baštine i prirodnih vrijednosti); porast inozemnog turističkog prometa, a samim tim i potrošnje posjetilaca; otvaranje novih radnih mjesta (adekvatna infrastruktura i suprastruktura – serviseri različitih usluga brodovima, posadi i putnicima) – pristaništa, špediteri, suvenir tržnice i dr. / novi proizvodi, širenje poslovne mreže, promjena valute, nevidljivi izvoz itd. Rezultati istraživanja mogu pomoći daljim proučavanjima uzročno-posljedičnih veza između ovakvog vida putovanja i resursa receptivnih zemalja na kojima se ova putovanja događaju, a sve u cilju adekvatnog osmišljavanja i plasmana turističke ponude, odnosno optimalnog razvoja receptivnih zemalja kroz održivi turizam. Rad pruža i informacije različitim partnerima („stakeholders“) uključenim u turističko privređivanje kruzeva, koji očekuju privatnu i društvenu dobit od svojih ulaganja

INTERACTION OF THE DRY MATTER ON CONTENTS OF BIOGAS PRODUCED FROM PIG MANURE

Korištenje svinjske gnojovke kao biomase za proizvodnju bioplina jedan je od načina za učinkovitu uporabu otpada uz minimalan utjecaj na okoliš. Prednost bioplina i biomase u odnosu na fosilna goriva je neusporedivo manje emisije štetnih plinova i otpadnih tvari. Opterećenje atmosfere ugljik dioksidom (CO2) pri korištenju biomase je zanemarivo, jer je količina emitiranog CO2 prilikom izgaranja jednaka količini apsorbiranog CO2 tijekom rasta biljaka. Materijal istraživanja je svinjska gnojovka sa farme u okolici Osijeka gdje su svinje držane na rešetkastom podu a u istraživanju koristila se standardna metoda i kvantitativni postupak. Na uzorku se ispitivao postotak suhe tvari (ST) i njegova ovisnost o količini nastalog bioplina različitog sastava. Količina (ST) je niska i teoretski se kreće se od 0,5 do 10 %. Ona je varijabilna i ovisi o pasmini, hranidbi, uvjetima držanja, tehnologiji, izgnojavanju itd. Uzorak sa niskom količinom (ST) sadržavao je veliku količinu pepela te je njegov postotak iznosio više od 50 %. Većina uzoraka s najvećim postotkom suhe tvari imala je visoki postotak (iznad 70 %) hlapljive organanske tvari (OT). Udio dušika (N) i CO2 viši je u bioplinu proizvedenom iz svinjske gnojovke s većim udjelom ST. Količina N obrnuto je proporcionalna količini metana (CH4) /r=-0,948; p<0,001/. Dokazana je visoko pozitivna korelacija između koncentracije ST i količine bioplina (r = 0,947, p<0,001). Količina bioplina ovisi o sadržaju ST s posebnim naglaskom na visoki postotak OT. Koncentracija CH4 najveća je kod skupine s najnižom proizvodnjom bioplina. Što je veći sadržaj suhe OT i udio masti u supstratu, veći je i postotak CH4.Taking advantage of pig manure as biomass for production of biogas, is one of the ways of efficient use of waste with minimum interaction with the environment. Biogas and biomass oposite on fossil fuels has less emission of harmfull gasses and wastage rate. Emissions of carbon dioxide (CO2) in biomass, as a fuels, become from burning out is almost equal with amoung of apsorpted CO2 during growth of plants. Material from investigation was pig manure from a farm near Osijek, where all the pigs were kept on latticed floor. Methods of investigation were quantitative procedure with standard methods. On pig manure was investigated percent of dry matter (DM) and her correlation on amount of biogas with different composition. Amount of (DM) is low and teoreticaly between 0,5- 10 %. Results are variable and depends on rase, nutrition, handeling conditions, technology... The sample with low (DM) had high amount of ash > 50 % mineral part and high amount of (DM) had > 70 % dry organic matter (DOM). Higher amount of (DM) represents nutritive base for microorganisms with growing faster and produce more methane (CH4). High amount of (DM) gave high percentage of nitrogen N and CO2. Amount of N was in inverse proportion to the amount of CH4 (r=-0,948; p<0,001). Highly positive correlation was determined between (DM) on special accent on (DOM) and biogas amount (r = 0,947, p<0,001). Methane concentration was the highest in the group with the lowest biogas production. Higher content the (DOM) and the share of has positive correlation with fat in pig manure and gave high percentage of CH4

Spectral parameters for finger tapping quantification

A miniature inertial sensor placed on fingertip of index finger while performing finger tapping test can be used for an objective quantification of finger tapping motion. Temporal and spatial parameters such as cadence, tapping duration, and tapping angle can be extracted for detailed analysis. However, the mentioned parameters, although intuitive and simple to interpret, do not always provide all the necessary information regarding the subject's motor performance. Analysis of frequency content of the finger tapping movement can provide crucial information about the patient's condition. In this paper, we present parameters extracted from spectral analysis that we found to be significant for finger tapping assessment. With these parameters, tapping's intra-variability, movement smoothness and anomalies that may occur within the tapping performance can be detected and described, providing significant information for further diagnostics and monitoring progress of the disease or response to therapy