Theoretical Skeleton Research Articles

Experiment and restoring force model study of precast shear walls with new rabbet-unbonded horizontal connection

The 'rabbet-unbonded horizontal connection' (RUHC) is a new connection form of precast shear wall. This study conducted a low-cycle repeated loading test on three RUHC walls to investigate the hysteretic performance of the walls with the 'axial compression ratio' and 'unbonded level' as the main variables and the results showed that the above two parameters remarkably affected the seismic performance of RUHC walls. Based on the analysis of test skeleton and hysteresis curve characteristic, the influence of parameters such as axial compression ratio and unbonded level on the load and displacement during the loading process was analyzed. The theoretical values of yield, peak and limit points were calculated, and the skeleton curve model was proposed. Moreover, the unloading stiffness formula was proposed by the non-linear relation of dimensionless parameters and Matlab software fitting, and the hysteresis rule model was established. Finally, a three-fold-linear restoring force model of RUHC walls composed of the theoretical skeleton curve and hysteresis rule was established and verified. This model provides an effective prediction for the hysteresis characteristics and a theoretical basis for conducting elastic-plastic analysis of RUHC structures.

A restoring force model for a novel type of precast beam-to-column joints using mechanical connections

To investigate the restoring force model (RFM) for a novel type of precast beam-to-column joints using a mechanical connection (PBCJ-MCs), the low-cycle cyclic loading test of three PBCJ-MCs was first performed in this article. Subsequently, combined with the shape of the test hysteresis curves and skeleton curves, three key characteristic points of cracking point, yield point, peak point and a key parameter at the strength degradation stage, stiffness were defined in the theoretical skeleton model. Using the regression approach, a four-line skeleton curve model for PBCJ-MCs was fitted by the dimensionless test skeleton curve data. Then, a mathematical model for strength degradation of PBCJ-MCs at the same loading displacement was established based on the damage index. By the analysis of the hysteresis path, the hysteresis rules applicable to PBCJ-MCs were formulated. The RFM for PBCJ-MCs considering the slipping and pinching effect was determined by fitting and properly defining the inflection point, pinching point, unloading stiffness and reload stiffness of the hysteresis curve in the unloading-reloading path. Finally, the theoretical skeleton curves, hysteresis curves and energy dissipation capacity were compared with test results. The results illustrated that the proposed RFM for PBCJ-MCs can better consider the pinching effect of PBCJ-MCs. The theoretical hysteresis curves of the proposed RFM considering the damage effect were more consistent with the test hysteresis curves, which can be used for further theoretical analysis and engineering applications.

Seismic resilient rocking shear wall with dual self-centering energy dissipation system: Introduction and A preliminary study

In this paper, a new rocking shear wall with dual self-centering energy dissipation system is proposed for seismic resilient application. It mainly consists of pinned RC wall, pre-pressed disc spring friction damper (PDSFD) and pre-pressed disc spring brace with U-shaped steel damper (PDSBUSD), while the pinned wall with PDSFD located at the bottom (PDSFD-wall) and the PDSBUSD form the dual system to resist lateral load and dissipate energy. This study aims to introduce its details and preliminarily investigate the seismic performance. Firstly, mechanical models of PDSFD and PDSBUSD are revealed and reliable numerical models for them are built to analyze the hysteretic performance. Subsequently, theoretical skeleton model and design principle of PDSFD-wall component are derived, following which the cyclic behavior under different design parameters is numerically analyzed. Combined the above analyses, theoretical hysteresis model and design procedure of the presented rocking shear wall are given, and the influence of critical parameter on its cyclic behavior is discussed by performing numerical simulations. The results show that the theoretical hysteresis models are in accordance with the numerical results; by improving with PDSFD and PDSBUSD the bearing, energy dissipation and self-centering capacities are significantly enhanced, while the damage of RC wall is significantly reduced; the designed rocking shear walls exhibit desirable seismic resilience with about 80% of the energy dissipated by the replaceable friction and steel dampers, and the expected dual yielding energy dissipation mechanism is realized. During the design, it is suggested that the preload of PDSBUSD should be no less than the yielding strength of the steel damper; the ratio of preload to friction force for PDSFD adopts 1.5; the ratio of lateral resistance contribution of PDSBUSD to PDSFD-wall adopts 0.2–0.5.

Design and numerical analysis of steel frame joints with replaceable buckling-restrained links

This paper proposes a steel frame joint with a replaceable buckling-restrained link to prevent the buckling of joint plates and enhance the seismic performance. The calculation formulas of the yield load and initial stiffness are derived to determine a theoretical skeleton curve. A design method for the joints is proposed to determine the design parameters of the core plate area and length, ear and end plate thicknesses, and restraining plate thicknesses, based on the design conditions of the designed joint yield load and core plate strain limited values, plate deformation limited values, and restraining ratios, respectively. The derived formulas and design method are verified by analyzing the results of a cyclic loading test and 37 parametric numerical models calibrated with the test results. The results show that the theoretical skeleton curve is in good agreement with the test and numerical results, and the performances of the joints designed using the proposed method are close to the design conditions, implying the satisfactory performance of the design theory. The influences of the design parameters on the joint are well reflected by the parametric analysis

Facing the Forecaster’s Dilemma: Reflexivity in Ocean System Forecasting

Unlike atmospheric weather forecasting, ocean forecasting is often reflexive; for many applications, the forecast and its dissemination can change the outcome, and is in this way, a part of the system. Reflexivity has implications for several ocean forecasting applications, such as fisheries management, endangered species management, toxic and invasive species management, and community science. The field of ocean system forecasting is experiencing rapid growth, and there is an opportunity to add the reflexivity dynamic to the conventional approach taken from weather forecasting. Social science has grappled with reflexivity for decades and can offer a valuable perspective. Ocean forecasting is often iterative, thus it can also offer opportunities to advance the general understanding of reflexive prediction. In this paper, we present a basic theoretical skeleton for considering iterative reflexivity in an ocean forecasting context. It is possible to explore the reflexive dynamics because the prediction is iterative. The central problem amounts to a tension between providing a reliably accurate forecast and affecting a desired outcome via the forecast. These two objectives are not always compatible. We map a review of the literature onto relevant ecological scales that contextualize the role of reflexivity across a range of applications, from biogeochemical (e.g., hypoxia and harmful algal blooms) to endangered species management. Formulating reflexivity mathematically provides one explicit mechanism for integrating natural and social sciences. In the context of the Anthropocene ocean, reflexivity helps us understand whether forecasts are meant to mitigate and control environmental changes, or to adapt and respond within a changing system. By thinking about reflexivity as part of the foundation of ocean system forecasting, we hope to avoid some of the unintended consequences that can derail forecasting programs.

Major phonemic problems of Bangladeshi learners of English: Reasons behind and solutions

The issue of Bangladeshi EFL learners’ phonemic challenges, though not very battered, has been addressed by some researchers at different times. Even after having a prolonged history of learning and teaching and some research in the field, awkward pronunciations and misunderstandings are still prevailing everywhere, from the primary level to tertiary level and beyond. This study is undertaken to heighten the importance of delving deeper into the root causes of phonemic difficulties of the learners and to pinpoint the major problems. To add flesh to the theoretical skeleton of the topic a group of university students was interviewed along with a questionnaire to check their understanding of English phonology along with some other basic questions related to pronunciation. It can firmly be stated that teaching/learning pronunciation and hence starting from the segmental level has never been followed. Like any other country where English is in the status of a second language or foreign language, it is very natural to face difficulties to master the intricate phonemic features of the target language for the learners. Supposedly, it mostly results from the lack of knowledge of phonology and phonetics of the target language and due to the phonemic differences between the first language and the target language. In this study, the focus is kept mainly on the salient phonemic challenges faced by Bangladeshi learners of English. Bringing in the basic ideas of consonant and vowel sounds, the sound production mechanism is shown, and then the differences between the vowels and consonants of two languages are held out. Tracing out the key difficulties, some suggestions are provided. This writing is expected to be of considerable and comprehensive help for the instructors as well as for the interested learners and crucial addition to the literature of the topic.

Differences in the Refusal Strategy of Shopping on Activities in English and Chinese: An OT Perspective

This research presents a general account of the theoretical skeleton of the Optimality Theory (OT) .On such basis, it attempts to provide an OT account of the difference of the refusal strategies of shopping on activities in Chinese to approach those in English by the contractive analysis of the research statistics.

Seismic performances of steel reinforced concrete bridge piers

The quasi static test of the steel reinforced concrete (SRC) bridge piers and rigid frame arch bridge structure with SRC piers was conducted in the laboratory, and the seismic performance of SRC piers was compared with that of reinforced concrete (RC) bridge piers. In the test, the failure process, the failure mechanism, hysteretic curves, skeleton curves, ductility coefficient, stiffness degradation curves and the energy dissipation curves were analyzed. According to the M-Φ relationship of fiber section, the three-wire type theoretical skeleton curve of the lateral force and the pier top displacement was proposed, and the theoretical skeleton curves are well consistent with the experimental curves. Based on the theoretical model, the effects of the concrete strength, axial compression ratio, slenderness ratio, reinforcement ratio, and the stiffness ratio of arch to pier on the skeleton curve were analyzed.

Theoretical accounts to practical models: Grounding phenomenon for abstract words in cognitive robots

This review concentrates on the issue of acquisition of abstract words in a cognitive robot with the grounding principle, from relevant theories to practical models of agents and robots. Most cognitive robotics models developed for grounding of language take inspiration from the findings of neuroscience and psychology to get the theoretical skeleton of these models. To better understand these modelling approaches, it is indispensable to work from the base (theoretical accounts) to the top (computational models). Therefore in this paper, succinct definition of abstract words is presented first, and then the symbol grounding issue and accounts of grounded cognition for abstract words are given. The next section discusses the computational modelling approaches for abstract words grounding phenomenon. Finally, important cognitive robotics models are reviewed. This paper also points out the strengths and weaknesses of relevant hypotheses and models for the representation of abstract words in the grounded cognition framework and helps the understanding of issues such as where and why modelling efforts stand to address this problem in comparison with theoretical findings.

Towards a Regime of Post-political Biopower? Dispatches from Greece, 2010–2012

This article makes the case that Greece has witnessed a transition from a ‘post-democratic’ condition in the ’90 s and the early 21st century to a regime of ‘post-political biopower’ in 2010–12 that can bid democracy farewell. To adequately theorize this modality of power in a way pertinent to contemporary Greece, the paper takes its bearings from Agamben’s take on biopower, the homo sacer and the endless state of exception. But the analysis fills in Agamben’s theoretical skeleton by drawing on Naomi Klein’s account of the ‘Shock Doctrine’, which captures a particular technique of biopower deployed by neoliberal hegemony, Deleuze’s insights about the ‘society of control’ and Lazzarato’s elaborations of these insights with reference to the ‘indebted man’, which can shed light on the political implications of the Greek debt crisis. Yet popular responses, initiatives and electoral politics, as well as the intricacies of dominant power relations, upset any monolithic and quasi-totalitarian account of sovereign rule, disclosing cracks, imbalances and dispersion in its edifice.

Ecological network planning – from paradigms to design and back: a cautionary note

Ecological network (EN) planning bases conservation actions on a strong theoretical skeleton offered by disciplines such as population and landscape ecology, insular biogeography, community ecology and population genetics. Nevertheless, a lack of precise definitions and of a body of practical information regarding implementation has hindered many EN projects whose effectiveness for species conservation appears to be dubious. For example, current policy responses to human-induced habitat fragmentation are often based on simplified spatial assumptions (‘putting a pattern on a map’) that lack a sound understanding of ecosystem functionality. In this opinion article, I would like to stimulate discussion on the problematic aspects of EN discipline. The ‘road map’ of this article includes a close examination of (1) the EN approach (site-based or target-oriented?); (2) the multidisciplinary debate; (3) how to select target species; (4) the ENs as networks of territorial objects (what about functional connectivity or structural contiguity?); (5) the role of Natura 2000 network; and (6) the weakness of the EN approach as a persuasive tool or an alibi.

Organizational improvisation: change or stability?

PurposeSome studies show that improvisation is a source of change, whereas others show that it is a source of stability. The purpose of this paper is to specify the factors which set the boundary between improvised change and improvised stability.Design/methodology/approachThe paper draws on two published studies and contrasts their findings to analyze the extent to which improvisation leads to organizational change or organizational stability.FindingsThe paper suggests that the most innovative instances of improvisation reproduce some features of everyday experience. The extent to which an improvisation is a source of stability or a source of change depends on the dynamics of variation, selection and retention therein.Research limitations/implicationsFuture research needs to add empirical flesh to this theoretical skeleton to push research on organizational improvisation beyond the study of its causes and into further research on its consequences.Originality/valueThe paper deals with the paradox of making sense about two apparently opposing streams of research on improvisation.

Reflexões sobre o terciário

O estudo sobre terciário requer um olhar multidisciplinar. Conferir ao terciário uma perspectiva multifacetada contribuirá para desvelarmos os caminhos de atividades que urgem por uma teorização. A complexidade do fenômeno requer uma releitura dos conceitos antigos e recentes para a construção de um arcabouço teórico próprio ao terciário, a fim de se compreender a realidade terciária como força vital do processo de produção atual e da reorganização dos territórios.
 
 Abstract 
 
 REFLECTIONS ON THE TERTIARY
 
 The study on tertiary demand a multidisciplinary look. To confer to the tertiary a multifaceted perspective will give us a contribuition to watch the ways of activities that urges for its own theory. The complexity of the phenomenon requests a new reading of the old and recent concepts for the construction of a particular theoretical skeleton to the tertiary to understand its reality as a vital force of the process of current production and reorganization of the territories.

As veias abertas

It breaks of a context of the present time that concentrates all the productive strength and relations of production under the orbit of “globalization of the capital” (CHESNAIS, 1996) and, in the same way, a period in which the symbolic production is brought near, more and more, in the circles of production and reproduction of the commodity paying attention to definition of Fredric Jameson (2006) of “cultural logic” of the contemporary capitalism. In this context, the distinction of the book to change the world without taking the power of John Holloway has been occupying a privileged place, being debated by many thinkers, in the interior of the contemporary Marxism. Our hypothesis is what the exhibition of Holloway would be an example of an "eclectic" theory if it brought the imbalance together between text and context, therefore, that comes to impoverish the contexts of the theoretical discussions discussed by the same thing. to illustrate is longed and to confront some theoretical and practical insufficiencies of the author, demonstrated by the alignment of the arguments of Daniel Bensaïd and Michel Löwy, who comes, besides putting the relevance of a great deal of the subjects of Holloway (for example, the category of the fetishism), to demonstrate a fracture (principally in the political, historical and practical extent) between text and context through what it goes in the alluded work. One will try if - á it will attribute to the characteristics that structure the theoretical skeleton of Holloway and the possible interpretative differences for the optics of two marked authors.

Thermodynamic Behavior of Fluids Near the Critical Point

In this review we are concerned with the critical thermodynamic behavior of fluids, a field in which great activity and considerable progress has occurred in the past two decades. The field is considered mature, in the sense that the theoretical concepts have crystallized and that there appears to be consensus that theory and experiment are in agreement. Our purposes in this review are (a) to capture the present level of understanding and to pinpoint issues of substance that have not been resolved satisfactorily; (b) to sketch how much flesh has been put on the theoretical skeleton, that is, how far theory has led to practical formulations that can be used to describe real systems with accuracy and predictive power; and (c) to emphasize the most recent developments. Within the scope of a few dozen pages, it is impossible to be compre­ hensive. We have, on purpose, limited ourselves to ordinary critical points in gas-liquid systems. Both limitations are severe. Tricritical points have

Comment on N. K. Namboodiri’s “which couples at given parities expect to have additional births? an exercise in discriminant analysis”

N. K. Namboodiri deserves much credit for turning fertility analysis toward the study of the transition from one birth order to the next (Namboodiri, 1972). Economists are also modifying their approach to fertility in the same fashion (Heckman and Willis, n.d.; Michael and Willis, n.d.). In Namboodiri's recent attempt to put empirical flesh on his theoretical skeleton (Which Couples at Given Parities Expect to Have Additional Births? An Exercise in Discriminant Analysis, Demography, Vol. 11, February 1974, pp. 45-56), however, he arrives at conclusions which require further examination. Namboodiri's major finding, based on a discriminant analysis of the NFS data set, is that socioeconomic variables only discriminate among couples who have reached high parity levels with regard to birth expectations. We show, however, that this result is mainly the product of Namboodiri's experimental design and the misspecification of the discriminant functions with respect *to the socioeconomic variables. Based on a somewhat different analysis of the same data set, we obtain strong evidence that contradicts Namboodiri's conclusion that there exists a threshold below which economic and social characteristics have no bearing on birth decisions. The major reason for the low discriminatory power of the economic and sociological variables at low parities in Namboodiri's analysis appears to be the domination of the age variable at these levels. Since the relationship between age and birth expectations is not particularly informative-how much have we learned if we find that for women in parities 0, 1, and 2 a 43 year old is less likely to expect additional children than a 23 year old?-a better procedure to test the influence of the socioeconomic variables would have been to not stratify the sample by parity but to relate parity and age variables along with the social and economic proxies to birth expectations for the whole sample. This methodology would, in addition, have allowed a more precise testing with the use of interaction terms of the hypothesis that the sets of variables have different effects at each parity. Namboodiri's technique of comparing the R2's across parity levels (p. 51) is not informative in this regard because the variances in the independent variable (particularly age) differ by parity. Thus it is not unexpected that among higher-parity families, whose age variance is much less than that pertaining to low-parity families, Namboodiri finds that the predictive power of age is significantly lower. A more serious shortcoming in Namboodiri's analysis, which also would tend to reduce the significance of the set of socioeconomic variables, is his misspecification of these parameters. Since the deDendent variable is exDectational, it is

THE FUNDAMENTAL THESES OF NEURO‐ AND PSYCHOCYBERNETICS (NEUROCYBERNETICS)

Neurological sciences, cybernetics and general system theory achieved in the last decade enough progress to permit the establishment of a satisfactory theory of the functioning of the nervous system. We propose an axiomatic‐like theoretical skeleton for neurocybernetics and psychocybernetics in the form of eight theses. These theses can be considered as the essential aspects of the formal framework needed for the actual intepretation and the future development of our knowledge in the field of brain research.