Аналіз роботоздатності редуктора копачів коренезбиральної машини

Models and simulations are commonly used to study deep brain stimulation (DBS). Simulated stimulation fields are often defined and visualized by electric field isolevels or volumes of tissue activated (VTA). The aim of the present study was to evaluate the relationship between stimulation field strength as defined by the electric potential V, the electric field E, and the divergence of the electric field ∇(2) V, and neural activation. Axon cable models were developed and coupled to finite-element DBS models in three-dimensional (3-D). Field thresholds ( VT , ET, and ∇(2) VT ) were derived at the location of activation for various stimulation amplitudes (1 to 5 V), pulse widths (30 to 120 μs), and axon diameters (2.0 to 7.5 μm). Results showed that thresholds for VT and ∇(2) VT were highly dependent on the stimulation amplitude while ET were approximately independent of the amplitude for large axons. The activation field strength thresholds presented in this study may be used in future studies to approximate the VTA during model-based investigations of DBS without the need of computational axon models.This work was supported by the European Union's Seventh Framework Programme IMPACT (Grant 305814) and by the Swedish Research Council (Grant 621-2013-6078). Asterisk indicates corresponding author.</p

Faktorer som orsakar misslyckade data warehousingprojekt

Eftersom så många organisationer och företag använder sig av data warehouses idag kan inte innehavet av data warehouses räknas som ett strategiskt övertag, utan en strategisk nödvändighet för företagen eller organisationerna. Att införa ett data warehouse kräver dock stort engagemang från alla inblandade i projektet och ett misslyckande kostar företaget mycket resurser och kapital. Detta arbete undersöker vilka faktorer som främst bidrar till att ett data warehousingprojekt misslyckas. En litteraturstudie genomförs där misslyckade fall samt litteratur som beskriver författares generella uppfattningar angående faktorer med potentiell risk att orsaka ett misslyckat data warehousingprojekt undersöks. Undersökningen leder fram till en lista med faktorer som anses ha stor potential att orsaka ett misslyckande. Att identifera dessa faktorer bidrar till att organisationer och företag får möjligheten att i ett tidigt skede av projektet förhindra att dessa uppstår, vilket kan spara stora ekonomiska resurser

Jazz, recensioner och konstmusik : En analys av jazzmusikrecensioner och jazzmusikkultur

Abstract Mattias Åström: Jazz, recensioner och konstmusik. En analys av jazzmusikrecensioner och jazzmusikkultur. – Uppsala: Musikvetenskap 2001. 60 p. Syftet med uppsatsen är dels att undersöka hur jazzmusikkulturen idag speglas i recensionstexter i dagstidningarna Dagens Nyheter och Svenska Dagbladet och dels att undersöka om sättet att verbalisera jazzmusikrecensioner förändrats mot det konstmusikaliska i takt med att jazzen blivit allt mer accepterad som en form av konstmusik. Recensionerna som analyseras är 15 st. och publicerade 1998 och 1999 i Dagens Nyheter och Svenska Dagbladet. Den tidigare forskning på området som refereras är Sirpa Koiranens avhandling, Språk, musik och kultur, utgiven 1992. I uppsatsen används delar av Koiranens analysmetod – det som hon kallar för ramelement. De står för de allmänna förväntningarna som finns på en konsert och fungerar som ett slags minsta gemensamma nämnare för olika konsertsituationer och olika musikkulturer. Ramelementen är verktyg för att bena upp de olika recensionstexterna och kunna jämföra dem med varandra. I det första kapitlet förklaras sambanden mellan språk och kultur. I det andra redogörs för jazzmusikens förhållande till kulturen i stort och begrepp som diskuteras i samband med jazzmusikkulturen är sub- och motkulturbegreppen, status och konstmusik. I uppsatsen visas att de skillnader mellan de två musikkulturernas språkbruk som Koiranen kom fram till i sin undersökning i stort finns kvar. I uppsatsen visas dock att språket i jazzmusikrecensionerna på olika sätt har förändrats, bl.a. är språket neutralare. Dessa förändringar kan möjligen ha ett samband med jazzens ökade status och erkännande som en form av konstmusik. I uppsatsen diskuteras och ifrågasätts också om jazzrecensioner bär spår av motkultur i förhållande till konstmusikrecensioner, vilket Koiranen hävdade i sin avhandling

Modelling, Simulaltion, and Visualization of Deep Brain Stimulation

Deep brain stimulation (DBS) is an effective surgical treatment for neurological diseases such as essential tremor, Parkinsonʹs disease (PD) and dystonia. DBS has so far been used in more than 70 000 patients with movement disorders, and is currently in trial for intractable Gilles de la Tourette’s syndrome, obsessive compulsive disorders, depression, and epilepsy. DBS electrodes are implanted with stereotactic neurosurgical techniques in the deep regions of the brain. Chronic electrical stimulation is delivered to the electrodes from battery-operated pulse generators that are implanted below the clavicle. The clinical benefit of DBS is largely dependent on the spatial distribution of the electric field in relation to brain anatomy. To maximize therapeutic benefits while avoiding unwanted side-effects, knowledge of the distribution of the electric field in relation anatomy is essential. Due to difficulties in measuring electric fields in vivo, computerized analysis with finite element models have emerged as an alternative. The aim of the thesis was to investigate technical and clinical aspects of DBS by means of finite element models, simulations, and visualizations of the electric field and tissue anatomy. More specifically the effects of dilated perivascular spaces filled with cerebrospinal fluid on the electrical field generated by DBS was evaluated. A method for patient-specific finite element modelling and simulation of DBS was developed and used to investigate the anatomical distribution of the electric field in relation to clinical effects and side effects. Patient-specific models were later used to investigate the electric field in relation to effects on speech and movement during DBS in patients with PD (n=10). Patient-specific models and simulations were also used to evaluate the influence of heterogeneous isotropic and heterogeneous anisotropic tissue on the electric field during DBS. In addition, methods were developed for visualization of atlas-based and patient-specific anatomy in 3D for interpretation of anatomy, visualization of neural activation with the activating function, and visualization of tissue micro structure. 3D visualization of anatomy was used to assess electrode contact locations in relation to stimulation-induced side-effects (n=331) during DBS for patients with essential tremor (n=28). The modelling, simulation, and visualization of DBS provided detailed information about the distribution of the electric field and its connection to clinical effects and side-effects of stimulation. In conclusion, the results of this thesis provided insights that may help to improve DBS as a treatment for movement disorders as well as for other neurological diseases in the future

Modelling, Simulaltion, and Visualization of Deep Brain Stimulation

Deep brain stimulation (DBS) is an effective surgical treatment for neurological diseases such as essential tremor, Parkinsonʹs disease (PD) and dystonia. DBS has so far been used in more than 70 000 patients with movement disorders, and is currently in trial for intractable Gilles de la Tourette’s syndrome, obsessive compulsive disorders, depression, and epilepsy. DBS electrodes are implanted with stereotactic neurosurgical techniques in the deep regions of the brain. Chronic electrical stimulation is delivered to the electrodes from battery-operated pulse generators that are implanted below the clavicle. The clinical benefit of DBS is largely dependent on the spatial distribution of the electric field in relation to brain anatomy. To maximize therapeutic benefits while avoiding unwanted side-effects, knowledge of the distribution of the electric field in relation anatomy is essential. Due to difficulties in measuring electric fields in vivo, computerized analysis with finite element models have emerged as an alternative. The aim of the thesis was to investigate technical and clinical aspects of DBS by means of finite element models, simulations, and visualizations of the electric field and tissue anatomy. More specifically the effects of dilated perivascular spaces filled with cerebrospinal fluid on the electrical field generated by DBS was evaluated. A method for patient-specific finite element modelling and simulation of DBS was developed and used to investigate the anatomical distribution of the electric field in relation to clinical effects and side effects. Patient-specific models were later used to investigate the electric field in relation to effects on speech and movement during DBS in patients with PD (n=10). Patient-specific models and simulations were also used to evaluate the influence of heterogeneous isotropic and heterogeneous anisotropic tissue on the electric field during DBS. In addition, methods were developed for visualization of atlas-based and patient-specific anatomy in 3D for interpretation of anatomy, visualization of neural activation with the activating function, and visualization of tissue micro structure. 3D visualization of anatomy was used to assess electrode contact locations in relation to stimulation-induced side-effects (n=331) during DBS for patients with essential tremor (n=28). The modelling, simulation, and visualization of DBS provided detailed information about the distribution of the electric field and its connection to clinical effects and side-effects of stimulation. In conclusion, the results of this thesis provided insights that may help to improve DBS as a treatment for movement disorders as well as for other neurological diseases in the future

Modelling, Simulaltion, and Visualization of Deep Brain Stimulation

Deep brain stimulation (DBS) is an effective surgical treatment for neurological diseases such as essential tremor, Parkinsonʹs disease (PD) and dystonia. DBS has so far been used in more than 70 000 patients with movement disorders, and is currently in trial for intractable Gilles de la Tourette’s syndrome, obsessive compulsive disorders, depression, and epilepsy. DBS electrodes are implanted with stereotactic neurosurgical techniques in the deep regions of the brain. Chronic electrical stimulation is delivered to the electrodes from battery-operated pulse generators that are implanted below the clavicle. The clinical benefit of DBS is largely dependent on the spatial distribution of the electric field in relation to brain anatomy. To maximize therapeutic benefits while avoiding unwanted side-effects, knowledge of the distribution of the electric field in relation anatomy is essential. Due to difficulties in measuring electric fields in vivo, computerized analysis with finite element models have emerged as an alternative. The aim of the thesis was to investigate technical and clinical aspects of DBS by means of finite element models, simulations, and visualizations of the electric field and tissue anatomy. More specifically the effects of dilated perivascular spaces filled with cerebrospinal fluid on the electrical field generated by DBS was evaluated. A method for patient-specific finite element modelling and simulation of DBS was developed and used to investigate the anatomical distribution of the electric field in relation to clinical effects and side effects. Patient-specific models were later used to investigate the electric field in relation to effects on speech and movement during DBS in patients with PD (n=10). Patient-specific models and simulations were also used to evaluate the influence of heterogeneous isotropic and heterogeneous anisotropic tissue on the electric field during DBS. In addition, methods were developed for visualization of atlas-based and patient-specific anatomy in 3D for interpretation of anatomy, visualization of neural activation with the activating function, and visualization of tissue micro structure. 3D visualization of anatomy was used to assess electrode contact locations in relation to stimulation-induced side-effects (n=331) during DBS for patients with essential tremor (n=28). The modelling, simulation, and visualization of DBS provided detailed information about the distribution of the electric field and its connection to clinical effects and side-effects of stimulation. In conclusion, the results of this thesis provided insights that may help to improve DBS as a treatment for movement disorders as well as for other neurological diseases in the future

Automatic text summarization : an experimental study

The principal aim of this thesis is to test if extracts, produced by the automatic summarizer &quot;Copernic Summarizer&quot;, are possible to use as abstracts. The aim is also to give a picture of what automatic summarization is and why it is motivated. Three questions are asked: What is automatic summarization and what can it be used for? Is it possible to replace the author-written abstracts with extracts from &quot;Copernic Summarizer&quot;? Is automatic summarization motivated for the different areas of use that are identified in the first question? An automatic summarizer is a program that is intended to summarize text automatically and it can be used for different purposes, for example for summarizing WebPages or scientific articles. To answer the second question an experiment is carried out. Five empirical articles are summarized with &quot;Copernic Summarizer&quot; and a qualitative method is used which is intended to evaluate the content and readability of the extracts. The content of the extracts is compared against the author-written abstracts. The results show that two of five extracts could replace the abstracts, though one of the acceptable extracts was a borderline case. The conclusion is that in most of the cases you can not replace abstracts with extracts from &quot;Copernic Summarizer&quot;, even though the result sometimes is acceptable. The last question is discussed and the author suggests that automatic summarization might be more useful on the Internet than for producing abstracts from scientific articles.Uppsatsnivå:

Designförslag till nästa generation effektpedaler

Validerat; 20101217 (root