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em Dalarna University College Electronic Archive


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Högskolan Dalarna har i samarbete med Naturbränsle i Mellansverige AB genomfört studier på ett nytt fordon för transport av skogsflis. Fordonet är försett med egen lastningsutrustning (kran och skopa), vilket innebär att flisskördaren kan tippa flisen direkt på marken eller på en i förväg utlagd duk (minskar risken för föroreningar i samband med lastning). Studier har också genomförts på transport av flis med lastväxlarfordon och container (traditionell metod) för att jämförelser skall kunna göras mellan de olika fordonstyperna. Studierna har finansie¬rats via anslag från Statens Energimyndighet och via ”naturabidrag” från deltagande företag.Studierna visar att det nya transportfordonet är ett bättre alternativ än de traditionella last¬växlarfordonen på större objekt med långa transportavstånd. Dessutom pekar studien på att det är sannolikt är bättre även på små objekt under förutsättning att flisningskostnaden kan hållas på en rimlig nivå. Studierna visar också att det bör finnas en viss utvecklingspotential på det nya fordonet (teknik- och metodutveckling), varför det bedöms kunna konkurrera med lastväxlarfordonen även på andra typer av objekt.Jämfört med de traditionella lastväxlarfordonen har det nya fordonet bl.a. följande fördelar:•Transportarbetet blir lättare att planera i och med att beroendeförhållandet mellan in¬blandade maskiner och fordon för flisproduktion och transport upphör.••Risken för störningar i transportflödet minskar.•Miljövinsterna blir större jämfört med lastväxlarfordon som måste ställa ut tomma con¬tainrar innan flisningen kan påbörjas.•Det finns inget behov av lastmaskiner på terminalerna.•Flis kan mellanlagras i skogen.Till nackdelarna med det nya fordonet hör bl.a. följande:•Framkomligheten är något sämre än för lastväxlarfordon på mycket smala och kurviga skogsbilvägar.•Det finns en viss risk för att föroreningar följer med vid lastning av fordonet. Studies were carried out on a new vehicle for transport of fuel chips from the forest. The vehicle was equipped with a crane and a bucket meaning that the chipper may tip the fuel chips right on the ground or on a mat (vira from wood processing industry) to prevent from dirt such as sand and stones when loading. Studies were also carried out on traditional main hauling with transport bins. Transport speed was the same for all vehicles except for the new self-loader on forest roads with lower quality.The studies show that the new system probably is a better alternative on large sites with long transport distances and on sites with only little parking place for transport bins. It is also likely that the new vehicle may be used on very small sites if they are close to each other and if moving cost for the chipper is low.The studies show that the new vehicle has the following advantages:•Transport and other work may be planned in a better way leading to that stress de¬creases.•Dependence between chipper operators and truck drivers decreases.•The risk for disturbances in transport flow decreases.•Environment benefits compared to traditional system with higher traffic intensity (less exhaust gases and lower stress on roads and bridges).•No need for loading machines on terminals.•Easier to store fuel chips on landing.

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Objective: To develop a method for objective quantification of PD motor symptoms related to Off episodes and peak dose dyskinesias, using spiral data gathered by using a touch screen telemetry device. The aim was to objectively characterize predominant motor phenotypes (bradykinesia and dyskinesia), to help in automating the process of visual interpretation of movement anomalies in spirals as rated by movement disorder specialists. Background: A retrospective analysis was conducted on recordings from 65 patients with advanced idiopathic PD from nine different clinics in Sweden, recruited from January 2006 until August 2010. In addition to the patient group, 10 healthy elderly subjects were recruited. Upper limb movement data were collected using a touch screen telemetry device from home environments of the subjects. Measurements with the device were performed four times per day during week-long test periods. On each test occasion, the subjects were asked to trace pre-drawn Archimedean spirals, using the dominant hand. The pre-drawn spiral was shown on the screen of the device. The spiral test was repeated three times per test occasion and they were instructed to complete it within 10 seconds. The device had a sampling rate of 10Hz and measured both position and time-stamps (in milliseconds) of the pen tip. Methods: Four independent raters (FB, DH, AJ and DN) used a web interface that animated the spiral drawings and allowed them to observe different kinematic features during the drawing process and to rate task performance. Initially, a number of kinematic features were assessed including ‘impairment’, ‘speed’, ‘irregularity’ and ‘hesitation’ followed by marking the predominant motor phenotype on a 3-category scale: tremor, bradykinesia and/or choreatic dyskinesia. There were only 2 test occasions for which all the four raters either classified them as tremor or could not identify the motor phenotype. Therefore, the two main motor phenotype categories were bradykinesia and dyskinesia. ‘Impairment’ was rated on a scale from 0 (no impairment) to 10 (extremely severe) whereas ‘speed’, ‘irregularity’ and ‘hesitation’ were rated on a scale from 0 (normal) to 4 (extremely severe). The proposed data-driven method consisted of the following steps. Initially, 28 spatiotemporal features were extracted from the time series signals before being presented to a Multilayer Perceptron (MLP) classifier. The features were based on different kinematic quantities of spirals including radius, angle, speed and velocity with the aim of measuring the severity of involuntary symptoms and discriminate between PD-specific (bradykinesia) and/or treatment-induced symptoms (dyskinesia). A Principal Component Analysis was applied on the features to reduce their dimensions where 4 relevant principal components (PCs) were retained and used as inputs to the MLP classifier. Finally, the MLP classifier mapped these components to the corresponding visually assessed motor phenotype scores for automating the process of scoring the bradykinesia and dyskinesia in PD patients whilst they draw spirals using the touch screen device. For motor phenotype (bradykinesia vs. dyskinesia) classification, the stratified 10-fold cross validation technique was employed. Results: There were good agreements between the four raters when rating the individual kinematic features with intra-class correlation coefficient (ICC) of 0.88 for ‘impairment’, 0.74 for ‘speed’, 0.70 for ‘irregularity’, and moderate agreements when rating ‘hesitation’ with an ICC of 0.49. When assessing the two main motor phenotype categories (bradykinesia or dyskinesia) in animated spirals the agreements between the four raters ranged from fair to moderate. There were good correlations between mean ratings of the four raters on individual kinematic features and computed scores. The MLP classifier classified the motor phenotype that is bradykinesia or dyskinesia with an accuracy of 85% in relation to visual classifications of the four movement disorder specialists. The test-retest reliability of the four PCs across the three spiral test trials was good with Cronbach’s Alpha coefficients of 0.80, 0.82, 0.54 and 0.49, respectively. These results indicate that the computed scores are stable and consistent over time. Significant differences were found between the two groups (patients and healthy elderly subjects) in all the PCs, except for the PC3. Conclusions: The proposed method automatically assessed the severity of unwanted symptoms and could reasonably well discriminate between PD-specific and/or treatment-induced motor symptoms, in relation to visual assessments of movement disorder specialists. The objective assessments could provide a time-effect summary score that could be useful for improving decision-making during symptom evaluation of individualized treatment when the goal is to maximize functional On time for patients while minimizing their Off episodes and troublesome dyskinesias.