Earlier Theoretical Approaches Research Articles

Forum-Pre-Sabine room acoustic assumptions on reverberation and their influence on room acoustic design.

With his work on the Fogg Art Museum and Boston Symphony Hall between 1895 and 1900, Wallace C. Sabine laid a foundation for the field of architectural acoustics as a science. Prior to that, architects employed various quantifiable notions in acoustic design. Previous studies have reviewed metric guidelines based on the directivity of the human voice, which was utilized in at least 11 rooms in pre-Sabine times. Others studies have reviewed pre-Sabine design guidelines that were based on the quantification of the perception threshold between direct sound and first order reflections and which were followed in several rooms with acoustical performance needs. As the first studies concerned the direct sound and the second set concerned first order reflections, this study reviews opinions and knowledge regarding the later part of the acoustic response, also known as reverberation, during the 19th century. This effort brings to light a room acoustic design evolution showing why concert halls at the end of the 19th century mainly had surface finishes of wood and plaster as well as limited ceiling heights. While not equal to Sabine's thoroughness and completeness, numerous early experimental and theoretical reverberation approaches were found to hint at similar notions with both qualitative and quantitative efforts.

Regulation of Food Intake : A Complex Process

<p>Researchers have created a wealth of knowledge about the mechanisms that regulate food intake, appetite and therefore weight control. The control of appetite is a complex mechanism and involves the coordination of inputs from both physiological and environmental sources. Early theoretical approaches were based on the idea that the control mechanism was dedicated exclusively to signals from glucose metabolism, amino acids or proteins, or adipose tissue. However, a complex system of biologic and environmental factors regulates our appetite. The brain integrates chemical and nervous signals to control hunger and satiety. These controls include sensory and gastrointestinal signals, neurotransmitters and neuropeptides. This review paper summarizes the existing plethora of the highly convoluted process of appetite regulation and food intake.</p>

Direct link between boson-peak modes and dielectric α-relaxation in glasses.

We compute the dielectric response of glasses starting from a microscopic system-bath Hamiltonian of the Zwanzig-Caldeira-Leggett type and using an ansatz from kinetic theory for the memory function in the resulting generalized Langevin equation. The resulting framework requires the knowledge of the vibrational density of states (DOS) as input, which we take from numerical evaluation of a marginally stable harmonic disordered lattice, featuring a strong boson peak (excess of soft modes over Debye ∼ω_{p}^{2} law). The dielectric function calculated based on this ansatz is compared with experimental data for the paradigmatic case of glycerol at T≲T_{g}. Good agreement is found for both the reactive (real) part of the response and for the α-relaxation peak in the imaginary part, with a significant improvement over earlier theoretical approaches. On the low-frequency side of the α peak, the fitting supports the presence of ∼ω_{p}^{4} modes at vanishing eigenfrequency as recently shown [E. Lerner, G. During, and E. Bouchbinder, Phys. Rev. Lett. 117, 035501 (2016)PRLTAO0031-900710.1103/PhysRevLett.117.035501]. α-wing asymmetry and stretched-exponential behavior are recovered by our framework, which shows that these features are, to a large extent, caused by the soft boson-peak modes in the DOS.

Model-based learning: a synthesis of theory and research

This article provides a review of theoretical approaches to model-based learning and related research. In accordance with the definition of model-based learning as an acquisition and utilization of mental models by learners, the first section centers on mental model theory. In accordance with epistemology of modeling the issues of semantics, ontology, and learning with models as well as structural aspects and functions of mental models (such as simplification, idealization, analogy, simulation) will be discussed. Starting with early theoretical approaches in the realm of cognitive science, the emphasis will be on recent theoretical developments in the field of reinforcement learning that distinguish between model-based and model-free learning. These new theoretical approaches confirm, to a large extent, the early theories of mental models but they also contribute new insights in age-related aspects of model-based learning. The second main section of the article provides a review of basic and applied research on model-based learning. A short overview of basic research on mental models aims at sketching an “overall picture” followed by a more detailed description and discussion of findings in the field of instructional research, especially with regard to K-12 STEM education and the support of model-based learning through teaching and technology.

Bewitched and Bedeviled: A Cognitive Approach to Embodiment in Early English Possession by Kirsten C. Uszkalo

Reviewed by: Bewitched and Bedeviled: A Cognitive Approach to Embodiment in Early English Possession by Kirsten C. Uszkalo Patrick J. Murray KEYWORDS Patrick J. Murray, K. Uszkalo, possession, embodied religion, English Christianity, Early Modern Christianity, demonic possession, demonology, demons, witchcraft, English witchcraft, Early Modern witchcraft, demonology kirsten c. uszkalo. Bewitched and Bedeviled: A Cognitive Approach to Embodiment in Early English Possession. Basingstoke and New York: Palgrave Macmillan, 2015. Pp. 264. The study of bedeviling and its attendant literature offers a unique insight into the world of possession in early modern culture. As Kirsten C. Uszkalo [End Page 268] writes in the opening chapter to this new book Bewitched and Bedeviled: A Cognitive Approach to Embodiment in Early English Possession, "As we read our own literature, fiction and nonfiction, as reflecting something of the human condition, in describing the demoniac's language, gestures, and torments, possession literatures provide insight into 'real' experiences that underpin early modern possessions" (1). Consequently, by interrogating what possession meant for Renaissance thinkers and writers, we gain insight into not only those deemed "bedeviled," but also, more profoundly, an understanding of their ostensibly clearheaded contemporaries. The performance and recording of possessions, and the subsequent dissemination of "possession literature" was a minor, but nonetheless substantial field of early modern literary production. According to Uszkalo there were approximately 133 people recorded as being possessed between 1564 and 1699, out of a total of 621 "victims of witchcraft in early modern English texts counted so far" (3). Within this, the corpus varied dramatically in genre—some were ephemeral accounts, others depositions, while many of the most well known (such as that of Charity Philipot in 1681) were extended narratives, containing details such as current medical case histories. Uszkalo guides us through this body of work, attempting to synthesize recent findings in neuroscience with theoretical paradigms of sociocultural discourse and practice to help elucidate our understanding of what possession meant for the tumultuous age of sixteenth- and seventeenth-century England. "This project," the author writes, "couples close reading with the use of concepts from cognitive science and discoveries from neuroscience as interpretive tools useful to interrogate various stages of possession" (3). Always, however, Uszkalo is mindful of the very real human experience at the heart of the literature—"[t]he experience [of possession]," she correctly notes, "is embodied, not transcendent; it is a situated event" (7). Direct consideration of both theoretical and actual environments are at the forefront of the book. Analyzing the experiential accounts of figures such as the aforementioned Philipot, Mary Hall, and Joyce Dovey, Uszkalo attempts to interpret the discourses at play within the social dynamic between the possessed and the recorder. Beginning appropriately with how possession was first diagnosed in a patient, Bewitched and Bedeviled shows how symptoms were deemed psychological as well as physiological—convulsions and glossolalia, rage, and ulcers were deemed as signifying preternatural influence. In addition to this broad scope of manifestation, causes were similarly multiple. While physiological theory made its interventions, the dominant debate of the period—which centered on these symptoms' religious meaning—held sway. "Reformation [End Page 269] ideas of election and reprobation meant that no 'good works' one did on earth would change the state of one's soul in the afterlife," Uszkalo informs us, and thus, "damnation was a thread that tied the bewitched and bedeviled together" (7). Fear of inescapable hell understandably drove some—such as Joan Drake (who swallowed pins) and Hannah Allen (who entombed herself beneath the floorboards of her attic)—to seemingly possessed behaviors. If Chapter 1 provides a survey of the types of possession recorded, Chapter 2 sketches out how they were interpreted and understood in their own time. Here Uszkalo touches upon the seminal ideas of early modern theoretical approaches developed by the likes of Helkiah Crooke, Thomas Adams, and John Downame. Furthermore, in keeping with her attempt to comprehend and diagnose the underlying causes of possessive behaviors, Uszkalo pays particular attention not only to contemporaneous medicinal textbooks such as Crooke's Microcosmographia (1616), but also late-twentieth- and early-twentyfirst-century approaches to possession literature. Citing the important work of Diane Purkiss and Nathan Johnstone, Uszkalo shows how historians of medicine, sociology...

Suppression technique for discrete polarisation‐dependent loss in a polarisation modulated link

A link employing a polarisation modulator aligned for intensity modulation applications is presented in which a discrete source of polarisation-dependent loss (PDL) is mitigated by intentionally altering the bias phase point of the link. The experimental data is verified by an earlier theoretical approach which describes a discrete PDL impairment in an otherwise ideal RF photonic link. The cancellation technique provided as much as 20 dB suppression of second-order distortion in the link.

Was kann und soll Rationale Rekonstruktion hermeneutischer Interpretationsansätze (nicht) leisten?

AbstractIn the field of empirical analytic sciences, the approach of ›Rational Reconstruction‹ offers a way to use older theories that are fruitful in the Humanities even today, rather than merely explicate their historical value. It denotes a procedure that attempts to adapt a historically earlier theoretical approach, in its precision and consistency, to current meta-theoretical standards, yet without altering the underlying concept of this approach in the process. According to this conception, the goal is to represent what it is that a theory could accomplish were it expanded and supplemented by new levels of knowledge. In contrast to classical hermeneutics, Rational Reconstruction is thus geared toward an approach that is not purely descriptive but also prescriptive, insofar as the criteria of precision and logical consistency are combined with the criterion of similarity (resemblance to the starting theory). In addition to a historical, diachronic consideration of theories, Rational Reconstruction displays its particular appeal in precisely the possibility of also explicating theoretical approaches in a systematic, synchronic manner, that is, in compliance with current standards of the theory of science as well as the content of theoretical findings. In addition to providing information about a historical theory, the result of such a reconstruction is in particular the elaboration of historical theories in regard to their content and (methodological) structure through a contemporary updating.To this end, we have to maintain a balance between a descriptive and a prescriptive method: The Rational Reconstruction must neither overrun the descriptive function, by attempting to justify any given theoretical approach, nor shall its prescriptive function lead through the backdoor, as it were, to the stipulation of new theoretical approaches. Nevertheless, there remains a wide range of possibilities within which Rational Reconstruction can become a fruitful procedure. Precisely because it is not only concerned with showing what a theory wished to state at the time of its formation, there arises both the extreme that theories cannot be rationally reconstructed and the extreme that in the end the scientific criteria have to be expanded in order to do justice to an existing theoretical approach.Seeking to elaborate this scope of Rational Reconstruction with reference to hermeneutic interpretive approaches, this essay differentiates and discusses by way of example four paradigmatic cases, namely:1. Rational Reconstruction as a means to – further – explicate existing theories (2. Rational Reconstruction applied to theories which by all means lay the same claim to rationality yet, due to earlier states of knowledge, cannot as optimally implement them as is possible with the content and meta-theoretical knowledge of today. Here, Rational Reconstruction can help to expand and clarify (even more) such theoretical approaches (3. Rational Reconstruction as evidence of the non-rational: It holds for some theories that structurally they do not fulfill basic meta-theoretical requirements, and not in the least because they themselves programmatically reject these requirements. Rational Reconstruction here serves as a means for exemplifying this refusal (4. Rational Reconstruction as a touchstone for scientific criteria: In the case of a theory containing variations of precision and consistency, which in this form have previously not been contained in the meta-theoretical canon of scientific criteria, the procedure of Rational Reconstruction can contribute to the expansion or adaptation of these criteria. We would like to show that there are areas in which, for good reasons, previous models of rationality should be expanded and supplemented (The examples used in this essay provide a look at the possible application of Rational Reconstruction. The essay thereby shows how an utterly heterogeneous set of theoretical approaches can be constructively and fruitfully elaborated in an improved (more precise) variant and hence, if need be, revived. Likewise, it can be shown that the procedure of Rational Reconstruction is able to demonstrate the limits of rationality of certain theories and, as a result, to obtain the added value of rational precision and constructiveness for the entire discipline.

Abstract LB-97: Optimizing SELEX with high-throughput sequencing

Abstract SELEX (systematic evolution of ligands by exponential enrichment) identifies oligonucleotide “aptamers” that bind their protein targets with high affinity and specificity. Beyond inhibiting all protein function, aptamers can target specific functional regions (e.g., phosphorylation sites and catalytic domains) leaving other function intact. This selective inhibition is a valuable tool for dissection of signal transduction pathways, such as the growing list implicated in cancer by sequencing efforts interrogating tumor genomes. New technological innovations in aptamer discovery aim to keep pace with this need by improving the efficiency of the traditional SELEX enrichment process wherein oligonucleotides are iteratively bound to target, eluted, and amplified to purify an initial random library to a few high-affinity aptamers. Principal among these advances is the adoption of high-throughput sequencing (HTS-SELEX) to detect enrichment of candidate aptamers within the evolving pool. The improved sensitivity of high-throughput sequencing over the traditional use of cloning and sequencing reduces the number of rounds required to reach detectable enrichment. As with traditional SELEX, enrichment and hence number of rounds and overall efficiency are dependent on the free target and oligonucleotide pool concentrations. Though early theoretical approaches have addressed these issues for traditional SELEX, realizing the potential efficiency gains of the new HTS-SELEX approach requires an analysis and resulting protocol tailored to it specifically. Here we provide such an analysis and also re-examine earlier theoretical approaches to traditional SELEX. We show that HTS-SELEX motivates an optimization condition different from that of traditional SELEX and consider the role of stochastic fluctuations in the relatively low multiplicities of the enriched species resulting from the earlier enrichment detection of HTS-SELEX. Unlike previous approaches seeking to maximize some measure of per-round enrichment, this analysis is a global optimization of the entire SELEX process. It results in a specific recommendation for free target concentration, constant across rounds and simply related to the desired affinity, and for corresponding total ligand concentration. Applying the global analysis to an optimization condition appropriate for traditional SELEX again yields recommendations that are provably optimal and that differ from those previously published. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-97. doi:1538-7445.AM2012-LB-97

Upstream ions converting into downstream pick-up ions: the effect of shock-decelerated frozen-in fields

Context. Observations by Voyager-2 at the crossing of the solar wind termination shock have led to unexpected discoveries, such as the downstream solar wind protons still having Mach numbers higher than 1 and temperatures, though increased by a factor of about 30, nevertheless being much lower than those expected from classical MHD shock theory. Though our earlier semi-kinetic theories of the ion passage over the termination shock, in which the conservation of the magnetic ion moment was required, provided interesting insights into the detailed microphysics occurring at the shock, our predictions for the downstream ion pressure and temperature in view of observations were both too low. Aims. Here we improve on our earlier theoretical approach by introducing a so-called “effective magnetic moment” by which we not only take into account the increase in the magnetic field magnitude over the shock, but we also respect that the ions comoving with the bulk of the plasma flow gyrate around a decelerated frozen-in field. Methods. We derive ad ifferential equation for the behaviour of the perpendicular pressure across the shock, which accounts for the conservation of the newly derived effective magnetic moment, and generalises the results of earlier studies. The resulting differential equation is then solved analytically. Results. With this new concept of conservation of the newly introduced “effective magnetic moment” we arrive at interesting new relations between upstream and downstream ion pressures and temperatures which now nicely represent the recent Voyager-2 results.

Modelling bedload yield in braided gravel bed rivers

This paper outlines an approach for estimating the annual bedload yield of a braided channel. This procedure is based on the extension of theory of flow and sediment transport in braided rivers recently presented by Paola (1996). The revised approach accounts explicitly for the relationship between increasing discharge and varying channel hydraulics, and is suitable for use in obtaining bedload transport rate estimates over a range of discharges. Integration of such estimates using flow-duration data allows annual bedload yield to be determined. Model parameterisation is achieved using topographic survey data for the Waimakariri River, New Zealand. Comparison of modelled bedload yield with values estimated from repeated topographic surveys indicates that the model is able to accurately predict both the medium-term (c. 30 years) mean annual bedload yield of the Waimakariri at Crossbank (the section 17.8 km upstream of the river mouth), and also short-term fluctuations in bedload yield associated with varying annual flow statistics. Streamwise patterns of volumetric erosion and deposition determined for a 45-km length of the Waimakariri using the model are also in broad agreement with trends identified in topographic survey data for the period 1961–1997. However, significant deviations between modelled and surveyed volumes of cut and fill are evident at some locations. Comparison of model performance with conventional applications of bedload transport equations, which tend to underestimate transport rates for braided channels, suggests that the approach presented here may represent a significant improvement. This is the case because the model quantifies the relationship between braid intensity and spatial variability in flow hydraulics at a cross-section. Output from the model suggests that braided rivers may transport a significant proportion of their annual bedload at lower discharges than those indicated by earlier theoretical approaches. Results also provide quantitative support for the argument that increased intensity of braiding may promote higher rates of bedload transport in gravel bed rivers.

Anomalous phase separation dynamics in the presence of surfactants.

We study the phase separation of water and oil in a water-oil-surfactant microemulsion, from a totally disordered phase in both two and three dimensions using extensive Monte Carlo simulations of a spin model of microemulsions. The evolution of the characteristic length scale and the structure factor are measured and compared with recent experiments and theoretical work. At relatively high surfactant concentrations and off-critical quenches, we obtain results in agreement with earlier theoretical approaches. For critical quenches at very low surfactant concentrations, we observe the surprising result that it is easier to get to the scaling regime than in the pure binary case. @S1063-651X~96!50809-3# PACS number~s!: 82.70.Kj , 64.75.1g , 64.60.Ht The kinetics of phase separation of two immiscible phases, such as a binary mixture of water and oil, from a totally disordered initial state has been the subject of considerable study in recent years @1,2#. The essential behavior of such systems is the separation, immediately after the quench, of the two phases into small domains that grow in time. The morphology of these domains may be an interconnected structure or isolated clusters, depending on the relative fractions of the two phases and on whether or not the order parameter f(r), a measure of the local relative fractions of the phases, is conserved. While there is as yet no full scaling theory describing the evolution of the domains, a good number of experimental results may be understood within the framework of the ‘‘dynamic scaling hypothesis’’ @3#. This proposes that at late times, there is one characteristic length scale of the system, L, which grows as a function of time according to the asymptotic power law, L~ t!;t 1/z ,

Theory of energy loss in scanning transmission electron microscopy of supported small particles.

A general expression for the energy loss probability in scanning transmission electron microscopy (STEM) is derived. The method uses a Green's function for the incident and scattered electrons and then folds the specimen into a local response function. Our expression is appropriate to any target geometry and dielectric response. As an application, the energy loss spectrum of a STEM electron moving close to an Al sphere half-embedded in an Al planar surface is calculated. The coupling between different l modes, neglected in earlier theoretical approaches, is taken into account.

Intermolecular translational-rotational contribution to nuclear-spin relaxation in liquids.

The intermolecular contribution to spin relaxation by translational-rotational diffusion dynamics in molecular liquids is calculated for arbitrary relative time scales of the two stochastic processes. The resulting relaxation times are functions of variables that are proportional to ratios between rotational and translational diffusion constants, in substantial generalization of earlier theoretical approaches. In the first part the general treatment for symmetric-top molecules is given with a reduction to quadratures and a simpler version for the spherical case

A theory of desorption and surface processes: I. General formulation

A method is presented for the calculation of rate constants for surface processes such as desorption and hopping. Contact is made with the mechanics of dynamical processes at surfaces and with earlier theoretical approaches such as the work of Kramers. The theory is presented for classical atomic interactions but can be readily generalised.

Government Policies and Secular Inflation under Flexible Exchange Rates

The early theoretical approaches to the problem of internal and external balance in small open economies, for example those of Swan [33], Salter [28], and Corden [5], require substantial modification in the light of recent experience. For global inflation has persisted for nearly a decade now; the world's capital markets have become increasingly integrated; and industrial countries have increasingly adopted flexible exchange rates, thereby attempting to secure (among other objectives) a measure of insulation from foreign disturbances. Broadly speaking, the theoretical literature which builds on the early contributions, yet is able to encompass these recent developments, has adopted one of two approaches. First, there is the traditional Keynesian or what might now be more appropriately referred to as the KeynesPhillips approach; as shown by Takayama [35], Helliwell [16], and more recently, Turnovsky and Kaspura [42]. These models tend to be shortrun (or at least one-period) and to focus usually on the price level rather than the inflation rate, insofar as they seek to examine the question of insulation from foreign disturbances such as global price instability. On the other hand, there is the recent approach. Contributions within this framework which deal with the case of flexible exchange rates include Johnson [17], Kouri [19], and Dornbusch [7; 8]. It differs from the Keynesian approach in two essential respects. First, central to it is the notion that the exchange rate, being a relative price of monies, is basically a monetary phenomenon. Secondly, it tends to focus much more on stock rather than flow equilibrium relationships, and on the accumulation of assets, part of which takes place through the current account of the balance of payments. Most of the existing literature deals with a non-inflationary world in the sense that the