The pulse response of non-linear third order systems

The response of a third order non-linear system subjected to a pulse excitation is analysed. A transformation of the displacement variable is effected. The transformation function chosen is the solution of the linear problem subjected to the same pulse. With this transformation the equation of motion is brought into a form in which the method of variation of parameters is applicable for the solution of the problem. The method is applied to a single axis gyrostabilized platform subjected to an exponentially decaying pulse. The analytical results are compared with digital and analog computer solutions.

Third post-Newtonian angular momentum flux and the secular evolution of orbital elements for inspiralling compact binaries in quasi-elliptical orbits

The angular-momentum flux from an inspiralling binary system of compact objects moving in quasi-elliptical orbits is computed at the third post-Newtonian (3PN) order using the multipolar post-Minkowskian wave generation formalism. The 3PN angular-momentum flux involves the instantaneous, tail, and tail-of-tails contributions as for the 3PN energy flux, and in addition a contribution due to nonlinear memory. We average the angular-momentum flux over the binary's orbit using the 3PN quasi-Keplerian representation of elliptical orbits. The averaged angular-momentum flux provides the final input needed for gravitational-wave phasing of binaries moving in quasi-elliptical orbits. We obtain the evolution of orbital elements under 3PN gravitational radiation reaction in the quasi-elliptic case. For small eccentricities, we give simpler limiting expressions relevant for phasing up to order e(2). This work is important for the construction of templates for quasi-eccentric binaries, and for the comparison of post-Newtonian results with the numerical relativity simulations of the plunge and merger of eccentric binaries.

711 Third Avenue

[Book] The potential of electric light as a new building “material” was recognized in the 1920s and became a useful design tool by the mid-century. Skillful lighting allowed for theatricality, narrative, and a new emphasis on structure and space. The Structure of Light tells the story of the career of Richard Kelly, the field’s most influential figure. Six historians, architects, and practitioners explore Kelly’s unparalleled influence on modern architecture and his lighting designs for some of the 20th century’s most iconic buildings: Philip Johnson’s Glass House; Louis Kahn’s Kimbell Art Museum; Eero Saarinen’s GM Technical Center; and Mies van der Rohe’s Seagram Building, among many others. This beautifully illustrated history demonstrates the range of applications, building types, and artistic solutions he employed to achieve a “nocturnal modernity” that would render buildings evocatively different at night. The survival of Kelly’s rich correspondence and extensive diaries allows an in-depth look at the triumphs and uncertainties of a young profession in the making. The first book to focus on the contributions of a master in the field of architectural lighting, this fascinating volume celebrates the practice’s significance in modern design.

The third post-Newtonian gravitational wave polarizations and associated spherical harmonic modes for inspiralling compact binaries in quasi-circular orbits

The gravitational waveform (GWF) generated by inspiralling compact binaries moving in quasi-circular orbits is computed at the third post-Newtonian (3PN) approximation to general relativity. Our motivation is two-fold: (i) to provide accurate templates for the data analysis of gravitational wave inspiral signals in laser interferometric detectors; (ii) to provide the associated spin-weighted spherical harmonic decomposition to facilitate comparison and match of the high post-Newtonian prediction for the inspiral waveform to the numerically-generated waveforms for the merger and ringdown. This extension of the GWF by half a PN order (with respect to previous work at 2.5PN order) is based on the algorithm of the multipolar post-Minkowskian formalism, and mandates the computation of the relations between the radiative, canonical and source multipole moments for general sources at 3PN order. We also obtain the 3PN extension of the source multipole moments in the case of compact binaries, and compute the contributions of hereditary terms (tails, tails-of-tails and memory integrals) up to 3PN order. The end results are given for both the complete plus and cross polarizations and the separate spin-weighted spherical harmonic modes.

Diverse bodies-space politics: Towards a critique of social (in)justice of built environment

Writing has long played an important role in the progression of architecture and the built environment. Histories of architecture are written, manifestoes that form the basis for a designer’s work are written and most importantly, the built environment advances itself through the act of critical writing. Not unlike the visual arts, literature and poetry, the tradition of written criticism has been crucial to the progression of architecture and its allied professions (Franz 2003). This article contributes to architecture and the built environment through the act of a written essay that critiques the problem of bodily diversity to architecture. In particular, the article explores the implications of body-space politics and abstracted body thinking on diverse bodies and their spatial justice. Using Soja’s Spatial Justice theory (2008), we seek to point out the underlying conceptions and power differentials assigned to different bodies spatially and how this leads to spatial injustices and contested spaces. The article also critically analyses the historical emergence of ‘the standardised body’ in architecture and its application in design theory and practice , and looks at how bodies often found on the outside of architecture highlight how such thinking creates in justices. Different theories are drawn on to help point to how design through the use of the upright, forward facing, male bod willingly and unwillingly denies access to resources and spatialities of everyday life. We also suggest ways to re-conceptualise the body in design practice and teaching.

Boundary value problems for third-order nonlinear ordinary differential equations

In this paper, we describe how to analyze boundary value problems for third-order nonlinear ordinary differential equations over an infinite interval. Several physical problems of interest are governed by such systems. The seminumerical schemes described here offer some advantages over solutions obtained by using traditional methods such as finite differences, shooting method, etc. These techniques also reveal the analytic structure of the solution function. For illustrative purposes, several physical problems, mainly drawn from fluid mechanics, are considered; they clearly demonstrate the efficiency of the techniques presented here.

Boundary value problems for third-order nonlinear ordinary differential equations

In this paper, we describe how to analyze boundary value problems for third-order nonlinear ordinary differential equations over an infinite interval. Several physical problems of interest are governed by such systems. The seminumerical schemes described here offer some advantages over solutions obtained by using traditional methods such as finite differences, shooting method, etc. These techniques also reveal the analytic structure of the solution function. For illustrative purposes, several physical problems, mainly drawn from fluid mechanics, are considered; they clearly demonstrate the efficiency of the techniques presented here.

On the study of a third-order mechanical oscillator

In this paper, the study of a third-order mechanical oscillator is presented by demonstrating its equivalence to the well-known R.C. multivibrator with two additional reactive elements. The conditions for the oscillator's possession of periodic solutions are presented. It is also shown that under certain conditions, the study of the given third-order autonomous system can be reduced to the study of an equivalent second-order, non-autonomous system.

Simultaneous heat and mass transfer in unsteady free convection from two-dimensional and axisymmetric bodies

The unsteady laminar free convection boundary layer flows around two-dimensional and axisymmetric bodies placed in an ambient fluid of infinite extent have been studied when the flow is driven by thermal buoyancy forces and buoyancy forces from species diffusion. The unsteadiness in the flow field is caused by both temperature and concentration at the wall which vary arbitrarily with time. The coupled nonlinear partial differential equations with three independent variables governing the flow have been solved numerically using an implicit finite-difference scheme in combination with the quasilinearization technique. Computations have been performed for a circular cylinder and a sphere. The skin friction, heat transfer and mass transfer are strongly dependent on the variation of the wall temperature and concentration with time. Also the skin friction and heat transfer increase or decrease as the buoyancy forces from species diffusion assist and oppose, respectively, the thermal buoyancy force, whereas the mass transfer rate is higher for small values of the ratio of the buoyancy parameters than for large values. The local heat and mass transfer rates are maximum at the stagnation point and they decrease progressively with increase of the angular position from the stagnation point.

Tiering Effects in Third-party Logistics: A First-tier Buyer Perspective

This doctoral dissertation takes a buy side perspective to third-party logistics (3PL) providers’ service tiering by applying a linear serial dyadic view to transactions. It takes its point of departure not only from the unalterable focus on the dyad levels as units of analysis and how to manage them, but also the characteristics both creating and determining purposeful conditions for a longer duration. A conceptual framework is proposed and evaluated on its ability to capture logistics service buyers’ perceptions of service tiering. The problem discussed is in the theoretical context of logistics and reflects value appropriation, power dependencies, visibility in linear serial dyads, a movement towards the more market governed modes of transactions (i.e. service tiering) and buyers’ risk perception of broader utilisation of the logistics services market. Service tiering, in a supply chain setting, with the lack of multilateral agreements between supply chain members, is new. The deductive research approach applied, in which theoretically based propositions are empirically tested with quantitative and qualitative data, provides new insight into (contractual) transactions in 3PL. The study findings imply that the understanding of power dependencies and supply chain dynamics in a 3PL context is still in its infancy. The issues found include separation of service responsibilities, supply chain visibility, price-making behaviour and supply chain strategies under changing circumstances or influence of non-immediate supply chain actors. Understanding (or failing to understand) these issues may mean remarkable implications for the industry. Thus, the contingencies may trigger more open-book policies, larger liability scope of 3PL service providers or insourcing of critical logistics activities from the first-tier buyer core business and customer service perspectives. In addition, a sufficient understanding of the issues surrounding service tiering enables proactive responses to devise appropriate supply chain strategies. The author concludes that qualitative research designs, facilitating data collection on multiple supply chain actors, may capture and increase understanding of the impact of broader supply chain strategies. This would enable pattern-matching through an examination of two or more sides of exchange transactions to measure relational symmetries across linear serial dyads. Indeed, the performance of the firm depends not only on how efficiently it cooperates with its partners, but also on how well exchange partners cooperate with an organisation’s own business.

Sensemaking in the Third Space - Essays on French-Finnish Bicultural Experiences in Organizations and Their Narratives (summary section only)

Research on cross-cultural and intercultural aspects in organizations has been traditionally conducted from an objectivist, functionalist perspective, with culture treated as an independent variable, and often the key explanatory factor. In order to do justice to the ontological relativity of the phenomena studied, more subjectivist research on intercultural interactions, and especially on their relationships with the dynamics of cultural identity construction, is needed. The present research seeks to address this gap by focusing on bicultural interactions in organizations, as they are experienced by the involved individuals. It is argued that such bicultural situations see the emergence of a space of hybridity, which is here called a ‘third space’, and which can be understood as providing ‘occasions for sensemaking’: it is this individual sensemaking that is of particular interest in the empirical narrative study. A first overall aim of the study is to reach an understanding of the dynamics of bicultural interactions in organizations; an understanding not only of the potential for learning and emancipatory sensemaking, but also of the possibility of conflict and alienatory ordering (this is mainly addressed in the theoretical essays 1 and 2). Further, a second overall aim of the study is to analyze the reflexive identity construction of four young French expatriates involved in such bicultural interactions in organizations in Finland, in order to examine the extent to which their expatriation experiences have allowed for an emancipatory opportunity in their cases (in essays 3 and 4). The primary theoretical contribution in this study lies in its new articulation of the dynamics of bicultural interactions in organizations. The ways in which the empirical material is analyzed bring about methodological contributions: since the expatriates’ accounts are bound to be some kind of construction, the analysis is made from angles that point to how the self-narratives construct reality. There are two such angles here: a ‘performative’ one and a ‘spatial’ one. The most important empirical contributions lie in the analysis of, on the one hand, the alternative uses that the young expatriates made of the notion of ‘national culture’ in their self-narratives, and, on the other hand, their ‘narrative practices of the third space’: their politics of escape or stabilization, their exploration of space or search for place, their emancipation from their origin or return to home as only horizon.

Double diffusive unsteady free convection on two-dimensional and axisymmetric bodies in a porous medium

The unsteady laminar free convection flow of an incompressible electrically conducting fluid over two-dimensional and axisymmetric bodies embedded in a highly porous medium with an applied magnetic field has been studied. The unsteadiness in the flow field is caused by the variation of the wall temperature and concentration with time. The coupled nonlinear partial differential equations with three independent variables have been solved numerically using an implicit finite-difference scheme in combination with the quasilinearization technique. It is observed that the skin friction, heat transfer and mass transfer increase with the permeability parameter but decrease with the magnetic parameter. The results are strongly dependent on the variation of wall temperature and concentration with time. The skin friction and heat transfer increase or decrease as the buoyancy forces from species diffusion assist or oppose the thermal buoyancy force. However, the mass transfer is found to be higher for small values of the ratio of the buoyancy parameters than for large values