在這一篇論文中我們討論的是下列這個非線性初值問題： u''(t)=u'(t)^q(c_1+c_2u(t)^p) u(0) = u_0; u'(0) = u_1: 我們關注於上述問題正解的一些性質。我們發現了一些爆破(Blow-up)現象，並獲得一些結果，有關爆破率(Blow-up rate)、爆破常數(Blow-up constant)以及爆破時間(Blow-up time)。 / In this paper we study the following initial value problem for the nonlinear equation, u''(t)=u'(t)^q(c_1+c_2u(t)^p) u(0) = u_0; u'(0) = u_1: We are interested in properties of positive solutions of the above problem.We have found blow-up phenomena and obtained some results on blowup rates, blow-up constants and life-spans.

It is the purpose of this thesis to examine the effect of Doriden on problem solving. Specifically, the present study was designed as an exploratory investigation of the effects of Doriden on the maze learning ability of mice.

ABSTRACT Two different implant impression materials viz. a polyether (Impregum ®) and a plaster (Plastogum ®) impression material were used and compared with respect to the accuracy with which abutment positions were reproduced from a stainless steel master model containing five implant analogues. Ten polyether impressions and ten plaster impressions were taken and cast in stone. The positions of the precision impression copings on the twenty impressions were measured using a Reflex Microscope. The positions of the implant analogues on the twenty casts were also measured and compared to the positions on the stainless steel master model. Statistical analysis indicated significant differences between the polyether impression and the plaster impression for full arch implant supported prostheses. The use of plaster resulted in smaller interabutment error but with less predictable variance in dimensions.

Pipelines from offshore petroleum fields must frequently pass overareas with uneven seafloor.  In such cases the pipeline may havefree spans when crossing depressions. Hence, if dynamic loads canoccur, the free span may oscillate and time varying stresses maygive unacceptable fatigue damage. A major source for dynamicstresses in free span pipelines is vortex induced vibrations (VIV)caused by steady current. This effect is in fact dominating ondeep water pipelines since wave induced velocities andaccelerations will decay with increasing water depth. Thechallenge for the industry is then to verify that such spans cansustain the influence from the environment throughout the lifetimeof the pipeline.\\\\The aim of the present project is to improve the understanding ofvortex induced vibrations (VIV) of free span pipelines, andthereby improve methods, existing computer programs and guidelinesneeded for design verification.  This will result in more costeffective and reliable offshore pipelines when laid on a veryrugged seafloor.\\\\VIV for multiple span pipeline is investigated and the dynamicalinteraction between adjacent spans has been shown. The interactionmay lead to increased or decreased response of each spansdepending on the current speed and the properties for the twospans. The extension of the contact zone between the spans andseafloor parameters will of course also be important for theinteraction effect.\\\\The influence from temperature variation on vortex inducedvibrations has been demonstrated. The response frequency isinfluenced through changes in pipe tension and sag. Both increaseand decrease of the response frequency may be experienced.Moreover, it is shown that the influence from snaking of the pipeon the temperature effect is small, at least for large diameterpipes.\\\\A free span pipeline will necessarily oscillate close to the seabed.The presence of the seabed will therefore have some influences onthe ambient flow profile and also on the flow pattern around thecylinder during oscillation. Hydrodynamic parameters may thereforevary when the pipe is close to the seabed. In the present work, theinfluence from spatial varying current profiles is investigated forboth single and multiple span pipeline. It is shown that thedifference between using uniform and spatial varying currentprofiles is significant for some current speeds. It is also shownthat use of spatial varying current profiles can be even moreimportant for multiple span pipeline.\\\\The comparison of VIVANA analysis results with MARINTEK testresults has been given. It shows VIVANA predicts the cross-flow responsegenerally much higher than the test measurements, especially for thehigher mode responses. To improve understanding of this phenomena, the VIVANA model was tuned tothe test model and results are compared in different cases. Attempts were made to obtain a better agreement by adjusting some of the input parameters to VIAVANA. The reference point is tuned by changing various hydrodynamic properties, i.e. $C_{L}$, $St$ and added mass. The response frequenciesare also tuned in order to have a better agreement on the results. It is been concluded that the method used here by VIVANA is not able to describe VIV for free spanning pipelines adequately. It is not possible to find a set of parameter in a rational way that will give reasonably correct results. The discrepancy between the analysis and test results are highlighted which confirms the interaction between the in-line and cross-flow vibrations.Discussions are given and addressed on different reasons which may cause this phenomena.\\\\An improved strategy for non-linear analysis of free span pipelineis outlined. Time domain analysis for free span pipeline hasbeen performed. The difference between time and frequency domainanalysis has also been investigated by varying boundary conditions,pipe properties and axial tension. A significant difference is shownbetween results from time and frequency domain analysis at each endof the span where the pipe is started to interact with the seafloor.Due to high fatigue at this point, the importance of usingnon-linear time domain analysis is therefor obvious and highlyrecommended.

The set of compact connected metric spaces (continua) can be divided into classes according to the complexity of their descriptions as inverse limits of polyhedra. The simplest such class is the collection of chainable continua, i.e. those which are inverse limits of arcs. In 1964, A. Lelek introduced a notion which is related to chainability, called span zero. A continuum X has span zero if any two continuous maps from any other continuum to X with identical ranges have a coincidence point. Lelek observed that every chainable continuum has span zero; he later asked whether span zero is in fact a characterization of chainability. In this thesis, we construct a non-chainable continuum in the plane which has span zero, thus providing a counterexample for what is now known as Lelek's Problem in continuum theory. Moreover, we show that the plane contains an uncountable family of pairwise disjoint copies of this continuum. We discuss connections with the classical problem of determining up to homeomorphism all the homogeneous continua in the plane.

The set of compact connected metric spaces (continua) can be divided into classes according to the complexity of their descriptions as inverse limits of polyhedra. The simplest such class is the collection of chainable continua, i.e. those which are inverse limits of arcs. In 1964, A. Lelek introduced a notion which is related to chainability, called span zero. A continuum X has span zero if any two continuous maps from any other continuum to X with identical ranges have a coincidence point. Lelek observed that every chainable continuum has span zero; he later asked whether span zero is in fact a characterization of chainability. In this thesis, we construct a non-chainable continuum in the plane which has span zero, thus providing a counterexample for what is now known as Lelek's Problem in continuum theory. Moreover, we show that the plane contains an uncountable family of pairwise disjoint copies of this continuum. We discuss connections with the classical problem of determining up to homeomorphism all the homogeneous continua in the plane.

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Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed March 2, 2010). PDF text: 1 v. (ca. 170 p.) : ill. ; 184 K. UMI publication number: AAT 3386553. Includes bibliographical references. Also available in microfilm and microfiche formats.

Universiẗat, Diss., 2006--Stuttgart.

Thesis (M.A. in Security Studies (Homeland Security and Defense))--Naval Postgraduate School, December 2008. / Thesis Advisor(s): Bergin, Richard. "December 2008." Description based on title screen as viewed on February 2, 2009. Includes bibliographical references (p. 117-131). Also available in print.