scholarly journals On Kaufmann's theory of the impact of the pianoforte hammer

The theory of the vibrations of the pianoforte string put forward by Kaufmann in a well-known paper has figured prominently in recent discussions on the acoustics of this instrument. It proceeds on lines radically different from those adopted by Helmholtz in his classical treatment of the subject. While recognising that the elasticity of the pianoforte hammer is not a negligible factor, Kaufmann set out to simplify the mathematical analysis by ignoring its effect altogether, and treating the hammer as a particle possessing only inertia without spring. The motion of the string following the impact of the hammer is found from the initial conditions and from the functional solutions of the equation of wave-propagation on the string. On this basis he gave a rigorous treatment of two cases: (1) a particle impinging on a stretched string of infinite length, and (2) a particle impinging on the centre of a finite string, neither of which cases is of much interest from an acoustical point of view. The case of practical importance treated by him is that in which a particle impinges on the string near one end. For this case, he gave only an approximate theory from which the duration of contact, the motion of the point struck, and the form of the vibration-curves for various points of the string could be found. There can be no doubt of the importance of Kaufmann’s work, and it naturally becomes necessary to extend and revise his theory in various directions. In several respects, the theory awaits fuller development, especially as regards the harmonic analysis of the modes of vibration set up by impact, and the detailed discussion of the influence of the elasticity of the hammer and of varying velocities of impact. Apart from these points, the question arises whether the approximate method used by Kaufmann is sufficiently accurate for practical purposes, and whether it may be regarded as applicable when, as in the pianoforte, the point struck is distant one-eighth or one-ninth of the length of the string from one end. Kaufmann’s treatment is practically based on the assumption that the part of the string between the end and the point struck remains straight as long as the hammer and string remain in contact. Primâ facie , it is clear that this assumption would introduce error when the part of the string under reference is an appreciable fraction of the whole. For the effect of the impact would obviously be to excite the vibrations of this portion of the string, which continue so long as the hammer is in contact, and would also influence the mode of vibration of the string as a whole when the hammer loses contact. A mathematical theory which is not subject to this error, and which is applicable for any position of the striking point, thus seems called for.

2002 ◽  
Vol 12 (06) ◽  
pp. 1333-1356 ◽  
Author(s):  
YOSHISUKE UEDA ◽  
HIROYUKI AMANO ◽  
RALPH H. ABRAHAM ◽  
H. BRUCE STEWART

As part of an ongoing project on the stability of massively complex electrical power systems, we discuss the global geometric structure of contacts among the basins of attraction of a six-dimensional dynamical system. This system represents a simple model of an electrical power system involving three machines and an infinite bus. Apart from the possible occurrence of attractors representing pathological states, the contacts between the basins have a practical importance, from the point of view of the operation of a real electrical power system. With the aid of a global map of basins, one could hope to design an intervention strategy to boot the power system back into its normal state. Our method involves taking two-dimensional sections of the six-dimensional state space, and then determining the basins directly by numerical simulation from a dense grid of initial conditions. The relations among all the basins are given for a specific numerical example, that is, choosing particular values for the parameters in our model.


Author(s):  
Iuliia Rossius

The goal of this article consists in demonstration of the impact of research in the field of history and theory of law alongside the hermeneutics of Emilio Betti impacted the vector of this philosophical thought. The subject of this article is the lectures read by Emilio Betti (prolusioni) in 1927 and 1948, as well as his writings of 1949 and 1962. Analysis is conducted on the succession of Betti's ideas in these works, which is traced despite the discrepancy in their theme (legal and philosophical). The author indicates “legal” origin of the canons of Bettis’ hermeneutics, namely the canon of autonomy of the object. Emphasis is placed on the problem of objectivity in Betti's theory, as well as on dialectical tension between the historicity of the interpreted subject and strangeness of the object that accompanies legal, as well as any other type of interpretation. The article reveals the key moment of Betti's criticism of Hans-Georg Gadamer. Regarding the question of historicity of the subject of interpretation. The conclusion is made that the origin of the general theory of interpretation lies in the approaches and methods developed and implemented by Betti back in legal hermeneutics and in studying history of law.   Betti's philosophical theory was significantly affected by the idea on the role of modern legal dogma in interpretation of the history of law. Namely this idea that contains the principle of historicity of the subject of interpretation, which commenced  the general hermeneutical theory of Emilio Betti, was realized in canon of the relevance of understanding in the lecture in 1948, and later in the “general theory of interpretation”. The author also underlines that the question of objectivity of understanding, which has crucial practical importance in legal hermeneutics, was transmitted into the philosophical works of E. Betti, finding reflection in dialectic of the subject and object of interpretation.


2018 ◽  
Vol 10 (4) ◽  
pp. 412-420 ◽  
Author(s):  
Aleksandr Gudkov ◽  
Elena Dedkova ◽  
Kristina Dudina

PurposeThis paper aims to discuss recent developments in the Russian tourism industry and the main reasons for new initiatives in local destination development.Design/methodology/approachThe study is based on qualitative research methodology. A summary of key literature is presented alongside the analysis of the survey results.FindingsThis paper sheds light on the challenges and changes that took place in the Russian tourism business between 2014 and 2017. The subject is poorly covered in academic literature. The basic data for analysis presented in official statistics are scarce. Therefore a more effective way of obtaining relevant information was to conduct a survey using a semi-structured questionnaire, with tourism business actors as respondents.Research limitations/implicationsThis paper provides mostly conceptual analysis based on limited empirical data; directions for further empirical research are proposed in the conclusion.Originality/valueThe paper reveals something of the impact of economic and geopolitical factors, both negative and positive ones, on the restructuring of the Russian tourism market and the emergence of promising opportunities for the development of new domestic destinations. As a result, tourism market actors are able to become more diverse.


2021 ◽  
Author(s):  
Patrick Kuntze ◽  
Annette Miltenberger ◽  
Corinna Hoose ◽  
Michael Kunz

<p>Forecasting high impact weather events is a major challenge for numerical weather prediction. Initial condition uncertainty plays a major role but so potentially do uncertainties arising from the representation of physical processes, e.g. cloud microphysics. In this project, we investigate the impact of these uncertainties for the forecast of cloud properties, precipitation and hail of a selected severe convective storm over South-Eastern Germany.<br>To investigate the joint impact of initial condition and parametric uncertainty a large ensemble including perturbed initial conditions and systematic variations in several cloud microphysical parameters is conducted with the ICON model (at 1 km grid-spacing). The comparison of the baseline, unperturbed simulation to satellite, radiosonde, and radar data shows that the model reproduces the key features of the storm and its evolution. In particular also substantial hail precipitation at the surface is predicted. Here, we will present first results including the simulation set-up, the evaluation of the baseline simulation, and the variability of hail forecasts from the ensemble simulation.<br>In a later stage of the project we aim to assess the relative contribution of the introduced model variations to changes in the microphysical evolution of the storm and to the fore- cast uncertainty in larger-scale meteorological conditions.</p>


1966 ◽  
Vol 1 (4) ◽  
pp. 593-615
Author(s):  
J. J. Lador-Lederer

The problem of personality in international law is destined, apparently, to remain an obstacle to development, control and responsibility-norms binding on international non-State and non-IGO entities. In short, is this international social phenomenon still subject to the dogma of “States only” in international law? Or, conversely, is international law still the law for inter-State relations only? This writer's views are on record with an analysis of the NGO-phenomenon; he would like to add a few observations on the subject of International Corporations (IC), and on the impact they might possibly have on the general problem of personality of the non-State international entity.When, thirty-six years ago, the structure and organization of the Bank for International Settlements (BIS), Basle, had been settled by a team of noted draftsmen, Sir John Fischer Williams noted in a paper on this subject: “We theorists have to take heed to build our doctrines on tendencies rather than on ‘facts’; otherwise, when we have finished constructing our systems, it may happen that the facts are no longer what they were when we started building, and the system is out of date before it is established.” In the meantime, several other corporations of a similar nature have been set up but in spite of a number of valuable papers on this subject, we are still without a systematic integration of what has gone on around us—although it is now clear that the traditional pedagogic categories have become unsatisfactory.


2019 ◽  
Vol 6 (2) ◽  
pp. 309
Author(s):  
I Made Dipadewanda ◽  
I Gusti Agung Oka Mahagangga

The research is conducted in Banjar Berawa/Desa Adat Berawa, nort Kuta district, Badung Regency. The study purposes to know the impact of tourism growth to the society consumptive pattern in Berawa. The technique of the data collection use direct observation technique to the location, interviewing for informan, I.E.Bendesa Adat Berawa, Klian Desa Berawa, Klian Dinas Berawa, Klian Subak Tibubeneng Village, Local society, and documentation by taking photos. The data are analysed by using qualitative data analysis technique which are working based on data, searching and finding pattern, getting interesting data and deciding the data that will be ssuced. The technique of informants assigmnen is purposive sampling which is assigning the sample by using particular consideration so, deserves to be a sample. The data analysis includes with collection data, reduction data, displaying data, conclusion and  verivication. The result of the study shows the society point of view to the aconomy establishmemt of educational aspec of the society which is getting increase, society in Banjar Berawa are also starting to enterpreneurship by set up abussiness such as homestay and laundy. The point of view of society to the customary order is the society seens strong with the wealth that they have. The society fulfill their family neededs by taking many kends of occupation.  Keywords :Impact, tourism, consumptionpattern, society


Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 917
Author(s):  
Jean-Christophe CREBIER ◽  
Theo LAMORELLE ◽  
Silvain MARACHE ◽  
Thanh Hai PHUNG ◽  
Van-Sang NGUYEN ◽  
...  

The paper deals with arrays of numerous power conversion cells, associated in series and/or in parallel to build larger step up or step down direct current (DC)/DC isolated converters. The work focuses on the impact of the spread and distribution of the conversion cell characteristics on the characteristics and performance of the power converter array (PCA). Based on a characterization protocol, about 130 conversion standard cells (CSC) are characterized and classified from a statistical point of view. Three families are defined and representatives are chosen and implemented in various configurations, in open and closed loop control, to analyze the impact of their spread characteristic over the global converter, the PCA. The paper is based on an extended practical set up and protocols, all described in details. Guidelines on CSCs implementation with respect to their dispersion are provided at the end on the paper.


The authors have recently made a series of observations on some cases of inter-crystalline fracture in various metals, occurring as the result of the prolonged application of stress. In explanation of these phenomena they have formulated an hypothesis which appears to afford a satisfactory account of the present observations and to correlate them with other well-known phenomena whose exact nature has, however, hitherto remained obscure. In putting their observations and hypothesis on record at the present stage, the authors are well aware that much fuller experimental investigation of the whole subject is required, and they hope to carry this forward. The evidence now available, however, appears to them to justify preliminary publication, especially in view of the fundamental interest and great practical importance of the subject. The present paper relates to a group of phenomena some of which have long been known, in the case of brass, as “season cracking.” Brass articles which have been manufactured by a process of alternate cold-working and annealing—such, for instance, as cartridge-cases and other articles made by operations of cupping and drawing—sometimes exhibit a tendency, after a period which may vary from a few hours to several years, to undergo spontaneous cracking. The occurrence of this type of failure of brass has been a serious manufacturing difficulty and much study has been given to the subject; as a result, modifications of both the annealing and the drawing processes have been made, which, to a considerable extent, eliminate the trouble. A satisfactory explanation of “season cracking” has not, however, been put forward so far as the authors are aware. From the present point of view, perhaps the most interesting fact which has been observed about "season cracking” in brass is that the fracture—in those cases where its path can be traced clearly among the micro-constituents of the metal—markedly follows the inter-crystalline boundaries. An example of such a crack is illustrated, under a magnification of 100 diameters, in fig. 1, where the inter-crystalline character of the fracture can be clearly traced (Plate 1).


Author(s):  
Татьяна Черкашина ◽  
Tatiana Cherkashina ◽  
Н. Новикова ◽  
N. Novikova ◽  
О. Трубина ◽  
...  

The article considers the conceptualization of the world from the point of view of its methodological paradigm assessment in the context of the globalizing world. A retrospective analysis of the relationship between language and human speech activity is given. The authors explain the role of language as a socio-cultural phenomenon in the formation of worldview systems that develop in the consciousness with the help of minimal units of human experience in their ideal meaningful representation in special concepts, which allows the individual to think within the boundaries of a certain linguistic picture of the world. Analyzes the problems of the functioning of communicative norms with regard to the hierarchy of the spiritual representations of the world. The article attempts to consider the impact of the “blurring” of the information boundaries of the globalizing world on the cognitive abilities of the individual in the nomination, qualification of the subject, phenomenon, process.


The ease with which explosives detonate on receiving a sharp blow or shock is of practical importance in determining manufacturing precautions and safety in handling, and also in deciding what initiators can be used. Physical tests on sensitiveness have hitherto imitated either manufacturing or service conditions as closely as possible. With any one physical test, such as that of the impact machine (cf. part III (1)), it is possible to arrange explosives in a scale of sensitiveness. The order of sensitiveness in a scale determined in any one way may be quite different from the order determined in other ways, but owing to the empirical nature of the tests it is often difficult to explain why anomalies occur. Results in accordance with each other are, however, obtained in many cases. Progress in synthetic organic chemistry has increased the range of possible explosives to such an extent that some more scientific information on sensitiveness would be most useful in orienting future developments. Various developments in the experimental knowledge on the subject are discussed in the following sections.


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