Road construction is important to make transports safe and sustainable. To compact asphalt an amount of energy needs to be conducted into the material either by static pressure or dynamic vibrations. An asphalt-roller compact the material and increases its load-bearing capacity. An eccentric shaft that generates vibrations is attached inside the roller drums. The shaft has two modes, varying between high eccentricity with slower pulses and low eccentricity with faster pulses. The study has been performed with the purpose to decrease the mass moment of inertia by redesigning the present eccentric shaft and verifying the new concepts with linear and non-linear FEM simulations. The new models were to have the same functional properties as the present eccentric shaft.  The current cross-section of the shaft was changed to a cross-section of a circle in the periphery. This was done by adding all features in new geometry to a simple shaft base and creating an analysis chain. To create the new lengthwise design brainstorming was used to generate ideas. The ideas were then sorted by using a Pugh matrix. CAD was used to model the concepts with the desired eccentric properties. Simulation in FEM software was used to acquire information about the behaviors during operation. Academic validation and useful information have been gathered by doing a literature review.  Two resulting concepts with properties fulfilling the prevailing restrictions. The circular cross-section in the periphery was adapted and the eccentric properties were kept. The simulation results from FEM software ended satisfactorily within limits for both execution in steel and ductile iron. For both concepts the mass moment of inertia was minimized, with 40.5 % in steel and in ductile iron with 42.0 % and 42.6 %.  An analysis chain has been performed showing that a cross-section with a circular geometry is optimal when the intention is to minimize the mass moment of inertia. It is possible to minimize the mass moment of inertia without negatively affecting the eccentric properties. The lengthwise design of a shaft with eccentric properties has been studied and simulated. Two concepts with varied lengthwise designs have been created with conserved eccentric properties and significantly decreased mass moment of inertia. The concepts can compose a good basis to continue investigating the lengthwise design which hopefully ends in a manufacturable eccentric shaft that contributes to environmental asphalt construction with low energy usage. / Tillverkning av vägar är viktigt för att transporter ska kunna utföras på ett säkert och hållbart sätt. För att packa asfalt behövs en mängd energi överföras till materialet genom statiskt tryck eller dynamiska vibrationer. En asfaltsvält packar materialet och ökar dess belastningsförmåga. En excentrisk axel som genererar vibrationer sitter inuti trummorna på välten. Denna axel har två lägen som varierar mellan att ha hög excentricitet med lägre puls samt låg excentricitet med högre puls.  Studien har genomförts med syftet att minska den nuvarande excenteraxelns masströghetsmoment genom att designa om den samt verifiera nya koncept med linjära och icke-linjära FEM beräkningar. De nya modellerna skulle behålla samma funktionella egenskaper som den nuvarande excenteraxeln. Det nuvarande tvärsnittet i XY-planet ändrades till en cirkel i rotationsaxlens periferi, genom att lägga till alla funktioner med nya tvärsnitt på en enkel axelbas i en analyskedja. En ny design i längsled påbörjades med brainstorming för att generera nya idéer. Idéerna sorterades sedan med hjälp av en Pugh-matris. Koncepten modellerades sedan med önskade excentriska egenskaper i CAD. FEM-mjukvara användes för att simulera koncepten och samla information om beteenden under körning. Akademisk validering och användbar information samlades in i en litteraturstudie.  Arbetet resulterade i två koncept med egenskaper som uppfyllde rådande krav. Det cirkulära tvärsnittet i periferin behölls och likaså de excentriska egenskaperna. FEM resultaten visade sig hamna tillfredsställande under gränserna med materialen stål och segjärn. För båda koncepten minskade masströghetsmomentet varav 40.5 % i stål och 42.0 % respektive 42.6 % i segjärn.  En analyskedja har genomförts som visat att ett tvärsnitt av en cirkel i periferi är optimalt med intentionen att minska masströghetsmomentet. Det är möjligt att minska masströghetsmomentet utan att påverka de excentriska egenskaperna negativt. Designen längs med en axel med excentriska egenskaper har studerats och simulerat. Två koncept med varierad design har modellerats, koncepten har behållna excentriska egenskaper och betydligt minskat masströghetsmoment. Koncepten kan utgöra gott underlag för fortsatt undersökning av designen i längdled. Förhoppningsvis kan det i sin tur resultera i en tillverkningsbar excentrisk axel som bidrar till miljövänligare asfaltskonstruktion med låg energiåtgång.

When a structure undergoes seismic excitation, the intensities and spatial distributions of the reactive weights on the structure may not be the same as those assumed in original design. Such a difference is inevitable due to many facts with the random nature (e.g., redistribution of live load), resulting in accidental eccentricity and consequently torsional response in the system. The added torsion can cause excessive deformation and premature failure of the lateral force resisting system and its detrimental effect is typically accounted for in most building design codes with an arbitrarily specified accidental eccentricity value. While it tends to amplify drift response of buildings under earthquake excitations, it is unclear whether the code specified accidental eccentricity is quantitatively adequate or not in seismic fragility assessment of steel moment frames (including low-rise, mid-rise and high-rise frames) with random reactive weight distributions. This thesis applies surveyed dead and live load intensities and distributions to three representative steel moment resisting frame structures that have been widely investigated in a series of projects under the collaboration of the Structural Engineers Association of California (SEAOC), the Applied Technology Council (ATC), and Consortium of Universities for Research in Earthquake Engineering (CUREE), known as SAC. Based on an extensive parametric study and incremental nonlinear dynamic analyses, it is found that variable load intensity and eccentricity had negligible impacts on the inter-story drifts of the low- and high-rise steel moment frames. However, they affect to a higher degree the performance of the mid-rise steel moment frames. Moreover, it is found that under the maximum considered earthquake (MCE) event, the actual drifts in steel moment frames with random reactive weight distributions can be conservatively captured through consideration of the code specified accidental eccentricities.

This thesis involves the development and study of a finite element model of a hermetic, single-vane compressor and a single-phase alternating current induction motor assembled in a common housing. The manufacturer of this unit is experiencing a high scrap rate due to interference during operation between the stator and rotor of the motor. The rotor shaft of the motor is non-typical because of its cantilever design. The finite element model was first subjected to eigenvalue analysis. This revealed that the interference producing displacements were not the result of torque application to the rotor at a frequency close to an eigenvalue of the mechanical system. After a review of the literature and discussions with Electrical Engineering Department faculty possessing extensive motor experience, it was surmised that the physical phenomenon causing the rotor displacement was unbalanced magnetic pull. This phenomenon occurs in the air gap of rotating electric machines due to eccentricity in the air gap. The model was then subjected to simultaneous harmonic force inputs with magnitudes of unity on the rotor and stator surfaces to simulate the presence of unbalanced magnetic pull. It was found that the rotor shaft acts as a cantilever beam while the stator and housing are essentially rigid. The displacements due to these forces were examined and then scaled to develop the motor parameters necessary to produce the radial forces required for stator/rotor interference. Several recommendations were then made regarding possible solutions to the interference problem. / Master of Science

no / In normal vision, detecting a kink (a change in orientation) in a line is scale invariant: it depends solely on the length/width ratio of the line (D. Whitaker, D. M. Levi, & G. J. Kennedy, 2008). Here we measure detection of a change in the orientation of lines of different length and blur and show that strabismic amblyopia is qualitatively different from normal foveal vision, in that: 1) stimulus blur has little effect on performance in the amblyopic eye, and 2) integration of orientation information follows a different rule. In normal foveal vision, performance improves in proportion to the square root of the ratio of line length to blur (L: B). In strabismic amblyopia improvement is proportional to line length. Our results are consistent with a substantial degree of internal neural blur in first-order cortical filters. This internal blur results in a loss of scale invariance in the amblyopic visual system. Peripheral vision also shows much less effect of stimulus blur and a failure of scale invariance, similar to the central vision of strabismic amblyopes. Our results suggest that both peripheral vision and strabismic amblyopia share a common bottleneck in having a truncated range of spatial mechanisms-a range that becomes more restricted with increasing eccentricity and depth of amblyopia. / Leverhulme Trust, Wellcome Trust, NIH

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No / This essay explores some of the social, political, and cultural meanings of 'eccentricity' in nineteenth-century England. It does this through examining the treatment of 'local characters' extensively recorded in North-East histories, newspapers, and ballads, and depicted in visual material in the period c. 1800¿1901. The first part examines the typology emerging from these media; and demonstrates how mental and physical abnormality, transgression of social mores, and odd beliefs, were classed as 'eccentric'. A study of representations of eccentricity, many of which were commercially available, forms the second part, supported by illustrations relating to popular figures such as William Purvis, or Blind Willy, of Newcastle. Eccentricities were identified across the region, in rural areas as well as in the 'public spaces' of Durham, Sunderland, and Newcastle. The final part relates this chronicling of odd characters to Victorian culture; the region's social history; and local patriotism across the period, but especially the late Victorian period, when the popularity of local history ensured a prominent place for eccentrics as emblematic of the quaint past in the North-East (and, it is indicated, elsewhere). Finally, the uses of eccentric characters are briefly discussed more broadly in terms of moralism and stigmatism.

The field of computer vision offers tools that allow machines to derive meaningful infor-mation from video and images and consequently make decisions based on visual inputs. In the paper industry, implementation of machine vision (MV) can be used to automate and speed up processes that require visual inspection, particularly certain segments of quality control – one such application being detection and measurement of paper roll core eccentricity. Core eccentricity is a roll build error in which the roll core is offset from the geometric roll center, potentially causing runnability issues. This particular project aims to improve the detection of paper roll core eccentricity at the Mondi Dynäs integrated pulp and paper mill through creation, calibration and evaluation of a machine-vision-based tool for on-line core eccentricity measurement. The tool utilizes the Hough Transform (HT), since HT is a simple yet fast and robust algorithm when it comes to identification of basic shapes such as lines and circles. The proposed solution was evaluated in two ways; firstly by determining at what level of accuracy the measurements could be provided, accounting for how well the solution deals with correction of systematic error caused by environmental factors, and secondly by analyzing how well characteristic roll features could be accurately identified in large sets of data, necessary to consistently perform measurements. The evaluation of the proposed solution showed a 99.9% detection rate for characteristic paper roll features, and a 98.1% detection rate of laser lines used for correction of position and orientation induced error. Assessment of the measurement accuracy following successful detection was on par with the current optical measurement method, and the proposed solution was able to classify distinctive features with a 96.8% accuracy. Lastly, several improvement actions to address faulty detection were identified, and factors to be considered for future installment were highlighted.