• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 149
  • 72
  • 34
  • 19
  • 12
  • 11
  • 6
  • 6
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 383
  • 101
  • 43
  • 41
  • 36
  • 31
  • 24
  • 24
  • 23
  • 22
  • 22
  • 22
  • 21
  • 20
  • 20
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The reciprocal trade policy of the United States a study in trade philosophy,

Tasca, Henry J. January 1938 (has links)
Issued also as Thesis (Ph. D.)--University of Pennsylvania. / Bibliography: p. 337-366.
12

An Historical Critique of the Trade Agreements Program, 1932-1939, with Special Emphasis on the Latin American Phase

Jaynes, Robert O. January 1950 (has links)
No description available.
13

An Historical Critique of the Trade Agreements Program, 1932-1939, with Special Emphasis on the Latin American Phase

Jaynes, Robert O. January 1950 (has links)
No description available.
14

The Timing and Magnitude of Monetary Reward: Testing Hypotheses from Expectancy vs. Reciprocity Theory

Lehman, Philip Kent 18 November 2003 (has links)
Social psychologists have noted that compliance strategies based on the social norm of reciprocity can be an effective tool for changing behavior (e.g., Cialdini, 2001). In contrast to expectancy-based behavior-change strategies, which offer a reward after a behavior is completed (post-behavior reward); reciprocity-based strategies present the reward first in the form of a gift (pre-behavior reward). Although there are no explicit contingencies attached to the gift, a sense of obligation to reciprocate may be a powerful motivator to comply with the request. It was hypothesized that pre-behavior rewards would be more effective than post-behavior rewards at low magnitudes of reward, and that both strategies would be effective at higher levels. This study examined effects of the timing and magnitude ($1 vs. $10) of a cash reward on compliance with a request to use a specially designed thank-you card recognizing prosocial and proenvironmental behavior. The hypotheses were not supported. The highest rate of compliance occurred in the post-behavior $10 condition, where 35.5% of participants complied, followed by post-behavior $1 (18.8%), pre-behavior $1 (12.9%) and pre-behavior $10 (8.8%). Pairwise comparisons revealed compliance in the $10 post-behavior condition was significantly higher than the rate of compliance in the $1 and $10 pre-behavior conditions, Chi-Square (1, n = 62) = 4.31, p < .05 and Chi-Square (1, n = 65) = 6.82, p < .01 respectively. The lack of evidence for the effectiveness of pre-behavior reward strategy is discussed and contrasted with previous findings. / Master of Science
15

Interplay - An Architecture School for Duke University

Kranbuehl, Donald David 31 March 2000 (has links)
Architecture is explored as an interplay between nature and a composition of forms. This thesis involves a project, an architecture school for Duke University, and examines the idea of composition as a type of â structured play.â Structured play is used as a method to study reciprocal relationships in architecture. This exploration focuses on the relationship between inside and outside in order to create a place for education which unites nature with the man-made. / Master of Architecture
16

Utopia and Oblivion

Hack, Keith Martin 21 June 2021 (has links)
This project investigates the possibility of expropriating the industrial infrastructure of a now defunct oil refinery for the bioremediation of toxic soils, restoration of functional riparian ecologies, and reinhabitation of the site by human and non-human life. The context of the project is based on the assumption that such an undertaking is highly unlikely under the current economic and political paradigm. As such it is situated in the distant future, the result of prolonged liberatory struggles over many generations. / Master of Architecture / On the shores of the Schuylkill River in Philadelphia, the largest and longest operating oil refinery on the east coast has been recently closed following a massive explosion. The 1300+ acre facility is heavily polluted and contaminated with a multitude of toxic chemicals. This project proposes using the existing refinery infrastructure in conjunction with biological processes to clean the contaminated soil and make the site fit for all types of life again. Riparian ecosystems (those at the edges of waterways) are some of the most important to planetary healthy, and as such are an important area of focus in repairing the damage wrought by large-scale industrial and petrochemical processes. Because these processes of repair and reinhabitation require long periods of time, this project is imagined in a distant future.
17

Reciprocity in vector acoustics

Deal, Thomas J. 03 1900 (has links)
Approved for public release; distribution is unlimited / Reissued 30 May 2017 with Second Reader’s non-NPS affiliation added to title page. / The scalar reciprocity equation commonly stated in underwater acoustics relates pressure fields and monopole sources. It is often used to predict the pressure measured by a hydrophone for multiple source locations by placing a source at the hydrophone location and calculating the field everywhere for that source. That method, however, does not work when calculating the orthogonal components of the velocity field measured by a fixed receiver. This thesis derives a vector-scalar reciprocity equation that accounts for both monopole and dipole sources. This equation can be used to calculate individual components of the received vector field by altering the source type used in the propagation calculation. This enables a propagation model to calculate the received vector field components for an arbitrary number of source locations with a single model run for each received field component instead of requiring one model run for each source location. Application of the vector-scalar reciprocity principle is demonstrated with analytic solutions for a range-independent environment and with numerical solutions for a range-independent and a range-dependent environment using a parabolic equation model. / Electronics Engineer, Naval Undersea Warfare Center
18

Reciprocal Buying Practices of Selected Manufacturing Firms

Kissinger, Norris R. 08 1900 (has links)
The purpose of this study is to determine the manner in which a number of business concerns have dealt with the problem of reciprocity and how they are presently dealing with it.
19

Money, conflict and reciprocity in rural black families in South Africa.

Gouveia, Joanne Ailsa 03 March 2009 (has links)
There is a rich body of literature examining multiple aspects of money in the social sciences yet the role of money in organising and shaping family interactions in the South African context appears limited. The aims of this research were to explore money and its link to conflict in the family and develop an understanding of how money is organised in and influenced by culture and gender in rural Black families in South Africa. Ten women undergraduate students were selected, using nonprobability snowball sampling, to participate in individual semi-structured interviews. Detailed biographical information was collected alongside responses to ten open ended money related questions. Interviews were transcribed and thematic content analysis was used to identify and analyse themes in the data both within and across the ten interviews. The research was dominated by five key findings the most significant being a relative lack of conflict between the interviewees’ family members in general and specifically with regard to money. This was influenced by the shared hierarchy of priorities within the family that informs and directs the allocation of resources. The authority of parents related to a particular set of social and cultural norms determined familial interaction influencing the limited expression of conflict. The presence and significance of reciprocity in the interviewees’ families was widely accepted within an extended family structure and exhibited no striking generational differences in adherence to the generalised norm of reciprocity. The interviewees’ families also displayed a marked lack of gendered difference in the allocation of resources among family members. The study while achieving its goal of providing some understanding of how money works in a particular group of rural Black families highlights the need for further exploration of money and conflict in the family in the South African context.
20

Reciprocity-based imaging using multiply scattered waves

Ravasi, Matteo January 2015 (has links)
In exploration seismology, seismic waves are emitted into the structurally complex Earth. Its response, consisting of a mixture of arrivals including primary reflections, conversions, multiples, and transmissions, is used to infer the internal structure and properties. Waves that interact multiple times with the inhomogeneities in the medium probe areas of the subsurface that are sometimes inaccessible to singly scattered waves. However, these contributions are notoriously difficult to use for imaging because multiple scattering turns out to be a highly nonlinear process. Conventionally, imaging algorithms assume singly scattered energy dominates data. Hence these require that energy that scatters more than once is attenuated. The principal focus of this thesis is to incorporate the effect of complex nonlinear scattering in the construction of subsurface elastic images. Reciprocity theory is used to establish an exact relation between the full recorded data and the local (zero-offset, zero-time) scattering response in the subsurface which constitutes our image. Fully nonlinear, elastic imaging conditions are shown to lead to better illumination, higher resolution and improved amplitudes in pure-mode imaging. Strikingly it is also observed that when multiple scattering is correctly handled, no converted-wave energy is mapped to any image point. I explain this result by noting that conversions require finite time and space to manifest. The construction of wavefield propagators (Green’s functions) that are used to extrapolate recorded data from the surface to points in the Earth’s interior is a crucial component of any imaging technique. Classical approaches are based on strong assumptions about the propagation direction of recorded data, and their polarization; preliminary steps of wavefield decomposition (directional and modal) are required to extract upward propagating waves at the recording surface and separate different wave modes. These algorithms also generally fail to explain the trajectories of multiply scattered and converted waves, representing a major problem when constructing nonlinear images as we do not know where such energy interacted with the scatterers to be imaged. A secondary aim of this thesis is to improve on the practice of wavefield extrapolation or redatuming by taking advantage of the different nature of multi-component data compared with single-mode acoustic data. Two-way representation theorems are used to define novel formulations in elastic media which allow both up- and downward propagating fields to be back-propagated correctly without ambiguity in the direction, and such that no cross-talk between wave modes is generated. As an application of directional extrapolation, the acoustic counterpart of the new approach is tested on an ocean-bottom cable field dataset acquired over the Volve field, North Sea. Interestingly, the process of redatuming sources to locations beneath a complex overburden by means of multi-dimensional deconvolution also requires preliminary wavefield separation to be successful: I propose to use the two-way convolution-type representation as a way to combine full pressure and particle velocity recordings. Accurate redatumed wavefields can then be obtained directly from multi-component data without separation. Another major challenge in seismic imaging is to construct detailed velocity models through which recorded data will be extrapolated. Nowadays the information contained in the extension of subsurface images along either the time or space axis is commonly exploited by velocity model building techniques acting in the image domain. Recent research has shown that when both extensions are taken into account, it is possible to estimate the data that would have been recorded if a small, local seismic survey was conducted around any image point in the subsurface. I elaborate on the use of nonlinear elastic imaging conditions to construct such so-called extended image gathers: missing events, incorrect amplitudes, and spurious energy generated from the use of only primary arrivals are shown to be mitigated when multiple scattering is included in the migration process. Finally, having access to virtual recordings in the subsurface is also very useful for target-oriented imaging applications. In the context of one-way representation, I apply the novel methodology of Marchenko redatuming to the Volve field dataset as a way to unravel propagation effects in the overburden structure. Constructed wavefields are then used to synthesize local, subsurface reflection responses that are only sensitive to local heterogeneities, and detailed images of target areas of the subsurface are ultimately produced. Overall the findings of this thesis demonstrate that, while incorporating multiply scattered waves as well as multi-component data in imaging may be not a trivial task, such information is vital for achieving high-resolution and true-amplitude seismic imaging.

Page generated in 0.0242 seconds