Bakgrund: Rullsulor används för att kompensera för ledstelhet, förbättra avveckling av steget, minska höga tryck plantart och minska böjningen vid tålederna.  Det finns dock få studier som undersöker om rullsulan verkligen minskar ledrörlighet i framfoten. Det saknas även information för betydelsen av rullsulans styvhet för böjmomentet av framfoten, vid avvecklingen av steget.   Metod: Fem friska kvinnor (n=5) gick med tre olika par skor, två par var modifierade med en likadan rullsula med olika styvheter och ett par utan rullsula. Fem upprepade mätningar för de tre olika skorna samlades in för alla deltagare. Det dorsala böjmomentet analyserades med sensorsulan (VebitoSCIENCE) som ersatte skons innersula.   Resultat: Det dorsala böjmomentet minskade för samtliga deltagare med en rullsula. Signifikant minskning av det dorsala böjmomentet vid MTP 1, för alla deltagare, när den styva rullsulan jämfördes med utan rullsula (94,4 – 20,1 Nmm) och mellan styv och flexibel rullsula för deltagare 1,2, 4 & 5 (68 – 22,2 Nmm).   Konklusion: Det dorsala böjmomentet minskade signifikant för MTP1 och MTP5 när en rullsula användes av friska kvinnor. Studien har också visat att en styv rullsula har en betydelse för att uppnå ett minskat dorsalt böjmoment vid MTP. / Background: Rocker soles are used to compensate for joint stiffness, reduce high plantar pressure and reduce the bending of the toe joints. Despite this, few studies have investigated if the rocker shoe really reduce the joint movement at the forefoot. There is also a lack of information regarding the importance of the rocker shoes stiffness for the bending moment of the forefoot, at the third rocker.   Method: Five healthy women (n=5) walked with three different pairs of shoes, two pairs were modified with the same rocker shape with different stiffness and one pair without a rocker. Five repeated measurements for the three different shoes were collected for all the participants. The dorsal bending moment was analyzed with a sensor sole (VebitoSCIENCE) that replaced the shoes insole.   Result: The dorsal bending moment was reduced for all participants with a rocker shoe. Significant reduction of the dorsal bending moment at MTP1, for all participants, when the stiff rocker was compared to the shoe without rocker (94,4 – 20,1 Nmm) and between the stiff and flexible rocker for participants 1,2,4 and 5 (68 -22,2 Nmm).   Conclusion: The dorsal bending moment was significantly reduced for MTP 1 and MTP 5 when a rocker shoe was used by healthy women, the study has also shown that the stiffness has an importance in order to achieve a reduction of the dorsal bending moment at MTP.

Numerical schemes for the partial differential equations used to characterize stiffly forced conservation laws are constructed and analyzed. Partial differential equations of this form are found in many physical applications including modeling gas dynamics, fluid flow, and combustion. Many difficulties arise when trying to approximate solutions to stiffly forced conservation laws numerically. Some of these numerical difficulties are investigated. A new class of numerical schemes is developed to overcome some of these problems. The numerical schemes are constructed using an infinite sequence of conservation laws. Restrictions are given on the schemes that guarantee they maintain a uniform bound and satisfy an entropy condition. For schemes meeting these criteria, a proof is given of convergence to the correct physical solution of the conservation law. Numerical examples are presented to illustrate the theoretical results.

在元代的時候，我們都知道，元朝是以蒙古人為中心，與其他民族聯合所建立的政權。由於帝國幅員廣闊、民族眾多，在政府各級機關中，均設有譯史、通事、怯里馬赤等翻譯人員，進行蒙漢或其他語言文字的翻譯工作。 　　然而，有些譯史在翻譯蒙文公牘時，因為過分地按照蒙古語的語法形式翻譯，使得譯成的漢文變得相當生硬，成為一種「蒙古式漢語」的公文，即具有蒙古語語法特徵的漢譯文，令人讀起來很不順暢，甚至詰屈聱牙，艱澀難懂。我們把這種譯文的文體就叫作「硬譯文體」；而因元代的官方文書中，出現許多像這樣的公文，所以就稱這類文獻的文體為「元代硬譯公牘文體」。 　　不過，有些學者認為，這就是所謂的元代漢語白話。雖然，我們不否認這些翻譯的公文，多是用元代漢語白話寫成的，但它那濃厚的蒙古語語法特徵，卻使它像「混合語」一樣，是漢語、蒙語之外的另一種新的「語言」，因此，是否還能稱它做「元代白話」或「元代漢語白話」，都是值得商榷的。 　　筆者針對元代硬譯公牘文體產生的背景、原因，及其語法特徵三方面進行討論，希望能夠釐清一些觀念，並瞭解其內容。

In this thesis, the problem of controlling a surgical masterand slave system with force reflection is studied. The problemof stiff contacts between the slave and the environment isgiven specific attention. The work has been carried out at KTHbased on an initial cooperation with Karolinska Sjukhuset. Theaim of the over all project is to study the possibilities forintroduction of a force reflective teleoperator in neurologicalskullbase operations for the particular task of bone millingand thereby, hopefully, increase patient safety, decreasesurgeon workload and cost forthe society. The main contributions of this thesis are: Derivation of a dynamical model of the master andoperator’s finger system and, experimental identificationof ranges on model parameter values. Based on this model, theinteraction channel controllers optimized for transparency arederived and modified to avoid the influence of the uncertainmodel parameters. This results in a three channel structure. Todecrease the influence of the uncertain parameters locally atthe master, a control loop is designed such that the frequencyresponse of the reflected force is relatively unaffected by theuncertainties, a result also confirmed in a transparencyanalysis based on the H-matrix. The developed teleoperatorcontrol structure is tested in experiments where the operatorcould alter the contact force without facing any problems aslong as the slave is in contact with the environment. As a result of the severe difficulties for the teleoperatorto move from free space motion to in-contact manipulationwithout oscillative behaviour, a new detection algorithm basedon passivity theory is developed. The algorithm is able todetect the non-passive behaviour of the actual teleoperatorinduced by the discrete change in system dynamics occurring atthe contact instant. A stabilization controller to be activatedby the detection algorithm is designed and implemented on themaster side of the teleoperator. The detection algorithm andthe stabilization controller are shown highly effective in realexperiments. All major research results presented in the thesis have beenverified experimentally. KeywordsTeleoperator, Force Feedback, Passivity, StiffContacts, Control, Robustness, Transparency, Bone Milling,Uncertainty

<p>In this thesis, the problem of controlling a surgical masterand slave system with force reflection is studied. The problemof stiff contacts between the slave and the environment isgiven specific attention. The work has been carried out at KTHbased on an initial cooperation with Karolinska Sjukhuset. Theaim of the over all project is to study the possibilities forintroduction of a force reflective teleoperator in neurologicalskullbase operations for the particular task of bone millingand thereby, hopefully, increase patient safety, decreasesurgeon workload and cost forthe society.</p><p>The main contributions of this thesis are:</p><p>Derivation of a dynamical model of the master andoperator’s finger system and, experimental identificationof ranges on model parameter values. Based on this model, theinteraction channel controllers optimized for transparency arederived and modified to avoid the influence of the uncertainmodel parameters. This results in a three channel structure. Todecrease the influence of the uncertain parameters locally atthe master, a control loop is designed such that the frequencyresponse of the reflected force is relatively unaffected by theuncertainties, a result also confirmed in a transparencyanalysis based on the H-matrix. The developed teleoperatorcontrol structure is tested in experiments where the operatorcould alter the contact force without facing any problems aslong as the slave is in contact with the environment.</p><p>As a result of the severe difficulties for the teleoperatorto move from free space motion to in-contact manipulationwithout oscillative behaviour, a new detection algorithm basedon passivity theory is developed. The algorithm is able todetect the non-passive behaviour of the actual teleoperatorinduced by the discrete change in system dynamics occurring atthe contact instant. A stabilization controller to be activatedby the detection algorithm is designed and implemented on themaster side of the teleoperator. The detection algorithm andthe stabilization controller are shown highly effective in realexperiments.</p><p>All major research results presented in the thesis have beenverified experimentally.</p><p><b>Keywords</b>Teleoperator, Force Feedback, Passivity, StiffContacts, Control, Robustness, Transparency, Bone Milling,Uncertainty</p>

Fibrin is a biopolymer that assembles into a network during blood coagulation to become the structural scaffold of a blood clot. The precise mechanics of this network are crucial for a blood clot to properly stem the flow of blood at the site of vascular injury while still remaining pliable enough to avoid dislocation. A hallmark of fibrin's mechanical response is strain-stiffening: at small strains, its response is low and linear; while at high strains, its stiffness increases non-linearly with increasing strain. The physical origins of strain-stiffening have been studied for other biopolymer systems but have remained elusive for biopolymer networks composed of stiff filaments, such as fibrin. To understand the origins of this intriguing behavior, we directly observe and quantify the motion of all of the fibers in the fibrin networks as they undergo shear in 3D using confocal microscopy. We show that the strain-stiffening response of a clot is a result of the full network deformation rather than an intrinsic strain-stiffening response of the individual fibers. We observe a distinct transition from a linear, low-strain regime, where all fibers avoid any internal stretching, to a non-linear, high-strain regime, where an increasing number of fibers become stretched. This transition is characterized by a high degree of non-affine motion. Moreover, we are able to precisely calculate the non-linear stress-strain response of the network by using the strains on each fiber measured directly with confocal microscopy and by assuming the fibers behave like linearly elastic beams. This result confirms that it is the network deformation that causes the strain-stiffening behavior of fibrin clots. These data are consistent with predictions for low-connectivity networks with soft, bending, or floppy modes. Moreover, we show that the addition of small contractile cells, platelets, increases the low-strain stiffness of the network while the high-strain stiffness is independent of the presence of the platelets; this is also consistent with expectations for small contractile elements in a network with low connectivity. Our results elucidate the origins of strain-stiffening in fibrin networks as well as the mechanism underlying platelet-induced clot stiffening. / Physics

In this work, we present an amplitude-shape method for solving evolution problems described by partial differential equations. The method is capable of recognizing the special structure of many evolution problems. In particular, the stiff system of ordinary differential equations resulting from the semi-discretization of partial differential equations is considered. The method involves transforming the system so that only a few equations are stiff and the majority of the equations remain non-stiff. The system is treated with a mixed explicit-implicit scheme with a built-in error control mechanism. This approach proved to be very effective for the solution of stiff systems of equations describing spatially dependent chemical kinetics. / Thesis (Ph.D.)-University of Natal, 1997.

Bibliography: leaves 184-192. / xii, 198 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis reports on problems associated with design and structural modification of vibratory systems. Several common problems encountered in practical engineering applications are described and novel strategies for solving this problems are proposed. Mathematical formulations of these problems are generated, and solution methods are developed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1997

Made available in DSpace on 2014-06-11T19:27:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-15Bitstream added on 2014-06-13T20:35:13Z : No. of bitstreams: 1 costa_cg_me_prud.pdf: 10846333 bytes, checksum: edd825f26c64cc382ef405066dbf048d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As equações diferenciais parciais hiperbólicas tem recebido uma atenção especial nos últimos anos devido sua grande aplicabilidade em diversas áreas da ciência e pelas dificuldades numéricas que elas impõem. O presente projeto leva em conta a importância do termo fonte e as implicações que isto representa na solução numérica das equações hiperbólicas, em especial nas leis de conservação. Todo o trabalho é focado no caso bidimensional das leis de conservação hiperbólicas, considerando termos fonte stiff. Este tipo de termo fonte impõe diferença de escala de propagação das ondas e das escalas advindas do próprio termo fonte. A equação hiperbólica com termo fonte deve ser tratada de forma especial. Utilizando os métodos mais recomendados na prática, resolvemos tal equação separando-a em duas ou mais partes, e depois acoplamos as partes na solução final. Os métodos utilizados em cada parte separada tem grande influência na solução... / The hyperbolic partial differential equations has had special attention in recent years due to their wide application in various areas of science and the numerical difficulties they impose. This project takes into account the importance of the font term and the implications this represents in the numerical solution of hyperbolic equations, especially in conservation laws. All work is focused on the case of two-dimensional hyperbolic conservation laws, considering the font terms stiff. This type of font term imposes difference in scale propagation of waves and those scales that comes from the font term. The hyperbolic equation with font term should be treated in a special way. Using the methods recommended in practice, we solve this equation by separating it into two or more parts, and then put the parties together in the final solution. The methods used... (Complete abstract click electronic access below)

In many applications, ordinary differential equations can be additively partitioned \[y'=f(y)=\sum_{m=1}^{N}\f{}{m}(y).] It can be advantageous to discriminate between the different parts of the right-hand side according to stiffness, nonlinearity, evaluation cost, etc. In 2015, Sandu and G\"{u}nther \cite{sandu2015gark} introduced Generalized Additive Runge-Kutta (GARK) methods which are given by \begin{eqnarray*} Y_{i}^{\{q\}} & = & y_{n}+h\sum_{m=1}^{N}\sum_{j=1}^{s^{\{m\}}}a_{i,j}^{\{q,m\}}f^{\{m\}}\left(Y_{j}^{\{m\}}\right)\\ & & \text{for } i=1,\dots,s^{\{q\}},\,q=1,\dots,N\\ y_{n+1} & = & y_{n}+h\sum_{m=1}^{N}\sum_{j=1}^{s^{\{m\}}}b_{j}^{\{m\}}f^{\{m\}}\left(Y_{j}^{\{m\}}\right)\end{eqnarray*} with the corresponding generalized Butcher tableau \[\begin{array}{c|ccc} \c{}{1} & \A{1,1} & \cdots & \A{1,N}\\\vdots & \vdots & \ddots & \vdots\\ \c{}{N} & \A{N,1} & \cdots & \A{N,N}\\\hline & \b{}{1} & \cdots & \b{}{N}\end{array}\] The diagonal blocks $\left(\A{q,q},\b{}{q},\c{}{q}\right)$ can be chosen for example from standard Runge-Kutta methods, and the off-diagonal blocks $\A{q,m},\:q\neq m,$ act as coupling coefficients between the underlying methods. The case when $N=2$ and both diagonal blocks are implicit methods (IMIM) is examined. This thesis presents order conditions and simplifying assumptions that can be used to choose the off-diagonal coupling blocks for IMIM methods. Error analysis is performed for stiff problems of the form \begin{eqnarray*}\dot{y} & = & f(y,z)\\ \epsilon\dot{z} & = & g(y,z)\end{eqnarray*} with small stiffness parameter $\epsilon.$ As $\epsilon\to 0,$ the problem reduces to an index 1 differential algebraic equation provided $g_{z}(y,z)$ is invertible in a neighborhood of the solution. A tree theory is developed for IMIM methods applied to the reduced problem. Numerical results will be presented for several IMIM methods applied to the Van der Pol equation.