5,858 research outputs found
Predictive Non-equilibrium Social Science
Non-Equilibrium Social Science (NESS) emphasizes dynamical phenomena, for
instance the way political movements emerge or competing organizations
interact. This paper argues that predictive analysis is an essential element of
NESS, occupying a central role in its scientific inquiry and representing a key
activity of practitioners in domains such as economics, public policy, and
national security. We begin by clarifying the distinction between models which
are useful for prediction and the much more common explanatory models studied
in the social sciences. We then investigate a challenging real-world predictive
analysis case study, and find evidence that the poor performance of standard
prediction methods does not indicate an absence of human predictability but
instead reflects (1.) incorrect assumptions concerning the predictive utility
of explanatory models, (2.) misunderstanding regarding which features of social
dynamics actually possess predictive power, and (3.) practical difficulties
exploiting predictive representations.Comment: arXiv admin note: substantial text overlap with arXiv:1212.680
The Struggle for Leadership in the African American Church
This study focuses on looking at the struggles that African American leaders have within the church setting. It analyses the failings of the church in its mandate to offer spiritual and social nourishment to the black community. There have been concerns by clergy and the community at large that the reverent position that the church leader is no longer present. In its place, lies frustration and, in some cases, anger. The study will unravel the cause of the descent of the church. It examines a plethora of literature on the area, finding both supporting and opposing information. In the methodology, the study uses a mixed approach that incorporates the use of quantitative questionnaires in addition to intervention design. The results of this process indicate that the leaders are not aware of the issues facing their church. The dominance of power reduced inclination towards altruism and service leadership, diminished engagement with church congregants, poor planning for ministerial strategy, and lack of communication come of the leading problems in churches. The study thus recommends open dialogue on how to strengthen the church, especially within the younger generation, to encourage austerity of the black church. Further research can look at the shifting identity of black people and how it has affected the perceptions of the church
Studies Of The Cleavages And Stabilities Of Carbohydrate Epoxides And Epimines
A novel epoxide ring opening of benzyl 3,4-anhydro-2-benzylox-carbonylamido-2-deoxy-β-D-allopyranoside(I) was affected by phenylboronic anhydride in toluene. One of the products was demonstrated to be benzyl 2-benzyloxycarbonylamido-2-deoxy-4,6-0-phenylboronate-β-D-gulopyranoside. Another product isolated, while not identified, had the properties of an anhydro-sugar different from the starting compound(I). Benzyl 6-0-acetyl-2-benzyloxycarbonylamido-2-deoxy-β-D-allopyranoside(II) also underwent epoxide ring opening in a reaction with phenylboronic acid. An isolated product had the properties of a benzyl 2-benzyloxycarbonyiamido-2-deoxy-D-hexoside different from compounds isolate in the reaction of I with the phenyboronate. This indicated the necessity for an unsubstituted 6-OH group in order for the boron compound to be involved in the ring opening. Supporting this view is the lack of reaction between the blocked benzyl 2,3-anhydro-4,6-0-benzylidene-α-D-allopyranoside and phenylboronic anhydride.
The 2,3-epoxide ring of benzyl 2,3-anhydro-4,6-0-benzylidene-α-D-allopyranodie(III) was shown to be remarkably stable in a reaction with boron acetate in nitromethane. The product had retained the 2,3-epoxide ring under conditions that removed the benzylidene group.
Trimethylsilyl azide was prepared in good yield in a mild and direct method. The azide was then used to prepare a new, low-melting, compound by dilation of the 6-OH group of I. The epoxide ring remained stable under these conditions
The epimine ring of benyl 4,6-0-benzylidene-2,3-dideoxy-2,3-epimino-α-D-allopyranodie(IV) was found to be unreactive with phenylboronate. However IV was deaminated with HNO2 to give the 2,3-unsaturated to give benzyl 4,6-0-benzylidene-α-D-mannopyranoside. The purpose of this study was to test the reactivity of sugar epoxides toward novel, ring-opening reagents. The study is especially concerned with the opening of the epoxide ring of benzyl 3,4-anhydro-2-benzyloxycarbonylamido-2-deoxy-β-D-allopyranoside, which has been found to be quite stable.1 These reagents were also used in a comparative study of the reactivity of epimino rings of sugars. Epimino rings react in a manner analogous to eposice rings. They have also been found to be quite stable in sugars.2,1
The Master Experiment
A wideband low noise preamplifier system will be utilized for the A TS series of satellites at the Mojave Tracking Station. This particular preamplifier was developed by the Advanced Development Division of Goddard Space Flight Center, and involves a travelling wave maser and a closed cycle helium refrigerator. It operates over the 4.065- 4.195 gigahertz (Hz) band, with an effective noise temperature of less than 10°K, The functional maser system consists of the amplifier, a low noise header assembly, and a super conducting magnet. The antenna mounted support equipment includes the microwave pump, pump modulator, pump monitor, transfer switches , tunnel diode amplifier , and a noise source, as well as the closed cycle helium refrigerator . The major system components and their layout are shown in Figure 1.
The scheme of operation is as follows: the signal from the antenna is passed through the header assembly to and from the maser by C- band waveguides , and to the post- amplifier by coaxial cable. In the maser, 27 db of amplification is achieved, and an additional 10 db is provided by the post amplifier.
The equipment for controlling and monitoring the system is located in the Operations Building. Here are located the power supplies for all the components , with the exception of the closed cycle refrigerator, which is supplied with its own 440 v, 3-phase 10 kva supply di rectly at the antenna. The maser system performance characteristics are listed in Table I
a Learned And Honorable Body : The Professionalization Of The Ontario Bar, 1867-1929
This dissertation analyses the development of the Ontario bar during the late nineteenth century and early twentieth centuries. Ontario lawyers, like many other groups in post-Confederation Canada, were faced with a rapidly changing world. The bar was no longer a small cohort of gentlemen whose relationships with each other and the rest of society could be comfortably governed by informal custom. Major structural changes, such as industrialization and urbanization, produced a new and different society and an environment of uncertainty for lawyers.;The bar responded to these changes by attempting to professionalize. Professionalization is defined here as a striving for occupational autonomy. This study argues that during the late nineteenth and early twentieth centuries, lawyers in Ontario tried to establish, formalize, and justify the bar\u27s occupational autonomy. The analysis focusses on four specific ways in which Ontario lawyers sought to establish and entrench the bar\u27s indigenous control over the practice of law.;Firstly, the bar attempted to secure a monopoly over the supply of legal services in two ways. Its governing body, The Law Society of Upper Canada, tried to establish itself as the sole agency of admission by preventing the legislature from issuing private statutory licenses to practise law. It also sponsored legislation to prohibit non-lawyers from offering advice concerning conveyancing.;Secondly, in 1889, the Law Society established a mandatory law school at Osgoode Hall in Toronto. It did so in order to justify its claims to professional status but, unlike its American counterparts, it refused to delegate any of its authority in the field to the universities. In this way, the legal profession maintained a higher degree of autonomy.;Similarly, between 1876 and 1923 the Ontario bar achieved the ability to maintain autonomous self-discipline by transferring this authority from the courts, an agency of the state, to the Law Society, an agency of the bar itself.;Finally, between 1879 and 1914, lawyers in Ontario established a network of bar associations at the county, provincial, and national levels to, among other things, provide vehicles and forums to justify its autonomy
Model Reference Predictive Adaptive Control for Large Scale Soft Robots
Past work has shown Model Predictive Control (MPC) to be an effective strategy for controlling continuum joint soft robots using rudimentary models, however the in-accuracies of these models often mean that an integration scheme must be combined with MPC. Presented in this work is a novel dynamic model formulation for continuum joint soft robots which is more accurate than the authors’ previous models yet remains fast enough for MPC. This model is based on the Piecewise Constant Curvature (PCC) assumption and a relatively new configuration representation and allows for computationally efficient simulation. Due to the difficulty in determining model parameters (damping and spring effects) as well as effects common in continuum joint soft robots (hysteresis, complex pressure dynamics, etc.), we submit that most model-based controllers of continuum joint soft robots would benefit from some form of model adaptation. In this work a novel form of adaptive MPC is presented based on Model Reference Adaptive Control (MRAC). We call our novel adaptive MPC approach MRPAC. We show that like MRAC, MRPAC is able to compensate for ”known unknowns” such as unknown inertias and spring and damper coefficients. Our experiments also show that like MPC, MRPAC is also robust to ”unknown unknowns” such as unmodeled external forces and any forces not represented in the form of the adaptive model. Experiments in simulation and hardware show that MRPAC outperforms MPC and MRAC in every case except for that in which MPC uses a perfect model in simulation
Image remapping strategies applied as protheses for the visually impaired
Maculopathy and retinitis pigmentosa (rp) are two vision defects which render the afflicted person with impaired ability to read and recognize visual patterns. For some time there has been interest and work on the use of image remapping techniques to provide a visual aid for individuals with these impairments. The basic concept is to remap an image according to some mathematical transformation such that the image is warped around a maculopathic defect (scotoma) or within the rp foveal region of retinal sensitivity. NASA/JSC has been pursuing this research using angle invariant transformations with testing of the resulting remapping using subjects and facilities of the University of Houston, College of Optometry. Testing is facilitated by use of a hardware device, the Programmable Remapper, to provide the remapping of video images. This report presents the results of studies of alternative remapping transformations with the objective of improving subject reading rates and pattern recognition. In particular a form of conformal transformation was developed which provides for a smooth warping of an image around a scotoma. In such a case it is shown that distortion of characters and lines of characters is minimized which should lead to enhanced character recognition. In addition studies were made of alternative transformations which, although not conformal, provide for similar low character distortion remapping. A second, non-conformal transformation was studied for remapping of images to aid rp impairments. In this case a transformation was investigated which allows remapping of a vision field into a circular area representing the foveal retina region. The size and spatial representation of the image are selectable. It is shown that parametric adjustments allow for a wide variation of how a visual field is presented to the sensitive retina. This study also presents some preliminary considerations of how a prosthetic device could be implemented in a practical sense, vis-a-vis, size, weight and portability
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