The Stability of Aeroplanes

1914 ◽  
Vol 18 (70) ◽  
pp. 68-85
Author(s):  
Leonard Bairstow
Keyword(s):  
Solid Body ◽  
Vital Importance ◽  
The Subject ◽  
The Stability ◽  
Type Of Stability ◽  
Considerable Complexity ◽  
Naval Architect

The problems which arise in the course of a study of aeroplane stability are of considerable complexity as compared with those confronting engineers in other branches of locomotion. Ocean–going vessels provide another instance of the motion of a solid body in a fluid and their stability is clearly one of vital importance. Naval architects have consequently studied the subject and calculations are made for the stability of each new design of ship. The process is so well known and so well founded that it surprises no one that a newly launched vessel remains on an even keel. One instance, not connected with British shipbuilding, serves to remind designers of the serious consequences of faulty calculation. The disaster relates to a ship which was launched fully engined, etc., and which turned turtle and sank within a few minutes of launching. The type of stability which the naval architect needs to calculate most carefully is that which is concerned with the security of the ship when rolling.

Bankenwettbewerb und die Stabilität von Finanzsektoren

2021 ◽  
Vol 70 (1) ◽  
pp. 1-36
Author(s):  
Toni Richter
Keyword(s):  
Economic Policy ◽  
Precise Measurement ◽  
Policy Discourse ◽  
Competitive Effect ◽  
Too Big To Fail ◽  
Financial Systems ◽  
The Subject ◽  
State Of Research ◽  
The Stability ◽  
Elementary Basis

Abstract Since the financial crisis of 2008 and intensified during the corona crisis, the interdependence between the stability of the financial systems and the prevailing degree of competition (DC) has been the subject of scientific and economic policy discourse on fragmented markets and „too-big-to-fail“ banks. In theory and empiricism, two fundamentally contrary causal concepts are opposed, the elementary basis of which is the precise measurement of the DC: Competition-stability- versus Fragility-Hypothesis. Based on the recent state of research, it can be shown that alternative DC-Measurements consistently show significantly different competitive conditions and in consequence the evidence for or against a stability-enhancing competitive effect seems to be predetermined by the chosen DC-Measurement.

Adhesion of Fine Particles at Solid/Solution Interfaces

MRS Bulletin ◽  
1990 ◽  
Vol 15 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Nikola Kallay
Keyword(s):  
Fine Particles ◽  
Plane Surface ◽  
Solid Surfaces ◽  
Liquid Media ◽  
Latex Dispersions ◽  
Colloid Particles ◽  
The Subject ◽  
Kinetic Investigations ◽  
The Stability ◽  
Kinetics Of

The adhesion of particles at solid surfaces in liquid media has attracted the attention of scientists because of its various applications as well as the theoretical significance of the processes involved. Early studies were characterized either by poorly defined systems or limited by the properties of a few morphologically well-defined model colloids, such as latex dispersions. Consequently, results were either of semiquantitative nature or were related to some specific cases, which eluded general conclusions. New methods for preparing uniform particles of different compositions, shapes, and sizes make it possible to approach the problem in a more comprehensive manner. For example, to demonstrate difficulties caused by polydispersity, it is sufficient to mention that the electrostatic interaction energy between a plane surface and a particle is approximately proportional to the particle radius, yet the rate of deposition depends exponentially on the height of the energy barrier.In principle, static and dynamic approaches may be employed in the study of particle adhesion. The static method yields the force required to detach an adhered particle, while kinetic investigations of attachment and detachment give the rates of the respective processes. Both methods offer information on the stability of the system in terms of the bond strength of adhered solids. For small colloid particles, which are the subject of thermal random Brownian motion, the dynamic approach is more appropriate. This article emphasizes the kinetics of deposition and detachment of small colloid particles in liquid media.

THE ROLE OF ACCOUNTING AND CONTROL IN THE MANAGEMENT OF ECONOMIC SECURITY OF AN ORGANIZATION

2021 ◽  
Vol 7 (2) ◽  
pp. 165-178
Author(s):  
Nicolay T. Labyntsev ◽  
Lyubov F. SHILOVA ◽  
Ocsana V. Chukhrova
Keyword(s):  
Economic Security ◽  
Accounting Profession ◽  
Economic Management ◽  
Economic Interests ◽  
Doing Business ◽  
The Subject ◽  
The Stability ◽  
High Level ◽  
And Control

This article revises the mission and the name of the accounting profession in the context of strengthening the economic security of enterprises under the conditions of digitalization of the economy. The authors note that in the contemporary conditions of economic management, enterprises should form and ensure the functioning of the economic security of the enterprise at the proper level. The necessity of in-depth research of economic security at microlevel was considered, the factors influencing the stability of the enterprise were highlighted. High level of economic security of the subject of management consists in guaranteeing him maximum effective and stable functioning now and in future. Subjects of economic security were individual enterprises, and objects — their economic interests. The main goals of ensuring economic security of the enterprise in the part of accounting were singled out, the tasks of accounting policy, aimed at ensuring economic security, were determined. The prospects of the accounting profession in the process of ensuring economic security and reliable safe presentation of the results of doing business in reporting are substantiated. The study contains proposals on the revision of requirements for the qualifications of accountants in order to emphasize their activities aimed at strengthening the economic security of the enterprise.

Probability—the difficulties of definition.

1951 ◽  
Vol 10 (03) ◽  
pp. 204-212
Author(s):  
S. R. Searle
Keyword(s):  
Nineteenth Century ◽  
Sixteenth Century ◽  
Marine Insurance ◽  
Good System ◽  
Vital Importance ◽  
Fields Of Study ◽  
The Subject

Although the subject of probability is of such vital importance to insurance, no great detailed study was given to it until the sixteenth century. This was nearly two thousand years after the world's first insurance venture, that of Antimenes on behalf of Greek slave-owners against loss of their slaves (the early Greeks had also a good system of marine insurance). As in many fields of study, the early students of probability met with a great deal of opposition, which must have extended well into the nineteenth century, judging from the evidence of de Morgan's book of 1838.

Strategic Miscalculation

2016 ◽  
Author(s):  
Andrew Stewart
Keyword(s):  
East Africa ◽  
Raw Materials ◽  
Good Deal ◽  
Suez Canal ◽  
Military Officers ◽  
Vital Importance ◽  
Compelling Argument ◽  
The Subject ◽  
Potential Challenge ◽  
And Training

This chapter discusses how there was a good deal of confusion about what strategy to follow in defending East Africa. The thinking of the few politicians interested in the subject, and within the regional governments, was flawed, with the dangers misunderstood or overlooked. Successive British governments showed no real sense of recognizing that this could be an important wartime hub for raw materials and training. These significant failings were compounded by the failure of senior military officers to make a compelling argument about Italian intentions and the potential challenge these presented. While the Chiefs of Staff in London were right to assume that Mussolini would focus on Egypt, due to the vital importance attached to controlling the Suez Canal, they were wrong to conclude that he would enter the war at the first opportunity.

1. On Cases of Instability in Open Structures

1888 ◽  
Vol 14 ◽  
pp. 106-106
Author(s):  
E. Sang
Keyword(s):  
Linear Structures ◽  
Symmetric Structure ◽  
Linear Resistance ◽  
Open Structures ◽  
Extensive Class ◽  
The Subject ◽  
The Stability ◽  
Special Case

AbstractIn the course of some remarks on the design proposed for the Forth Bridge, the author of this paper had enunciated the remarkable theorem, that any symmetric structure built on a rectangular base, and depending on linear resistance alone, is necessarily unstable. The proof of it, given in the eleventh volume of the Transactions of the Royal Scottish Society of Arts, is derived from considerations affecting the special case; but this theorem is only one of an extensive class, and therefore the subject of instability among linear structures in general is here taken up.In the case of regular or semi-regular arrangements, having the corners of an upper supported from the corners of an under polygon, it is shown that when the figures are of odd numbers the structures are stable, while those with even numbers are unstable ; unless indeed the polygons be placed conformably, in which case the stability extends to both classes.

scholarly journals Skriftsprogskompetence og skriftsprogsvalg hos to kommandanter på Kronborg i 2. halvdel af 1600-tallet

2016 ◽  
Vol 52 ◽  
Author(s):  
Birgit Christensen
Keyword(s):  
Empirical Study ◽  
Language Skills ◽  
Written Language ◽  
German Language ◽  
Construction Work ◽  
Command Language ◽  
Vital Importance ◽  
The Subject ◽  
Professional Writers ◽  
Selection Of

It is a rule of thumb that the army’s command language was German until 1773 andafter that Danish. But along with the language of the army, the army’s administrationalso had a written language, and that is the subject of this brief empirical study. Thestudy will discuss the written language skills and the choice of written language by twocommandants of the same age at Kronborg, who were otherwise very different people,each holding the position of commandant at the fortress for a number of years in thesecond half of 17th century, in a selection of letters from them to the king and thecentral administration. The letters are often about the construction work, which tookplace at Kronborg at the time. The following questions are asked: Which language wasused when writing to whom? And what language did they allow to be written to whom,when they used professional writers? In what situations did they use professional writers?Was the choice of language determined by the recipient? The first is the Danishnobleman Eiller Holck (1627–1696). The letters examined are from 1660–1664. EillerHolck, who was quite well-educated, was skilled at writing in both Danish and German,but mostly used a writer, and when writing himself, he seldomly wrote more than ashort text near his signature. When he himself wrote to the king, he wrote Danish,but when writing to the king using a writer, the writer used German. This was also thecase when writing to the Danish/Norwegian nobleman Jørgen Bielke. This is perhapslinked with the language skills of the writer that was available. Holck took into accountthe fact that his superior, Danish Field Marshall Hans Schack, preferred German. BothHans Schack and Eiller Holck used translations in communications with their troops.The second is Jacob Geueke, son of a commoner from Burg on the German island ofFemern (1617–1699). The letters examined are from 1688–1692. He used German language writers, only wrote amendments on the letters himself and only in Germanand was not satisfied with his own standard of writing. Perhaps he understood Danish.It is of vital importance that many of the recipients of the letters in the central administrationwere from Holsten. Perhaps the delivered correspondence would have beenin Danish to a greater extent had Jørgen Bielke been more involved in the administration?

scholarly journals New DTC strategy of multi-machines single-inverter systems for electric vehicle traction applications

2020 ◽  
Vol 11 (2) ◽  
pp. 641
Author(s):  
Taibi Ahmed ◽  
Hartani Kada ◽  
Allali Ahmed
Keyword(s):  
Electric Vehicle ◽  
Control Strategy ◽  
Control Structure ◽  
Synchronous Machines ◽  
Permanent Magnet Synchronous Machines ◽  
Structure Control ◽  
The Subject ◽  
Simulation Results ◽  
The Stability ◽  
Traction System

In high power traction system applications two or more machines are fed by one converter. This topology results in a light, more compact and less costly system. These systems are called multi-machines single-converter systems. The problems posed by different electrical and mechanical couplings in these systems (MMS) affect various stages of the systems and require control strategy to reduce adverse effects. Control of multi-machines single-converter systems is the subject of this paper. The studied MMS is an electric vehicle with four in-wheel PMS motors. A three-leg inverter supplies two permanent magnet synchronous machines which are connected to the front right and rear right wheels, and another inverter supplies the left side. Several methods have been proposed for the control of multi-machines single-inverter systems, the master-slave control structure seems best adapted for our traction system. In this paper, a new control structure based on DTC method is used for the control of bi-machine traction system of an EV. This new control has been implanted in simulation to analyze its robustness in the presence of the various load cases involved in our electric vehicle traction chain. Simulation results indicated that this structure control allowed the stability of the traction system.

scholarly journals Det första nationella provet i samhällskunskap - en studie i bedömarsamstämmighet

2018 ◽  
Vol 12 (4) ◽  
pp. 13
Author(s):  
Arne Löfstedt
Keyword(s):  
Interrater Reliability ◽  
Intraclass Correlation ◽  
Ninth Graders ◽  
National Agency ◽  
Final Grade ◽  
The Subject ◽  
And Mathematics ◽  
The Stability ◽  
National Tests ◽  
National Test

Skolämnet samhällskunskap som eget ämne existerar i princip enbart i de nordiska länderna. I många andra länder delar flera skolämnen på ämnesinnehållet, till exempel geografi och civics. Ämnesinnehållet är stort och genomgår ständig förändring. År 2013 genomfördes de första nationella proven i samhällskunskap i Sverige för årskurs 9. Med tanke på ämnets karaktär kan det vara speciellt viktigt att undersöka om dessa prov är ”rättvisa.” Avsikten med denna studie är att undersöka en aspekt av denna ”rättvisa”, nämligen interbedömarstabilitet, dvs om samma elevsvar ger upphov till samma bedömning oavsett bedömare. Skolverket i Sverige genomförde 2009 en större studie av de ämnen som då genomförde nationella prov och föreliggande studie försöker dels efterlikna och dels bygga ut upplägget från Skolverket. Studien genomfördes på de första nationella proven i samhällskunskap 2013. Genom att pröva olika reliabilitetsmått inom kategorierna ”consensus estimates”, och ”consistency estimates” analyseras resultaten, bland annat diskuteras måttet intraclass correlation. Syftet är också, då detta var de första proven, att skapa en ram för återkommande studier av Interbedömarreliabilitet. Upplägget med en större mängd lärare som genomför totalt tre bedömningar av de utvalda hela proven försöker också efterlikna bedömningssituationen ute på skolorna såtillvida att det var relativt många lärare med i studien, och de kom från olika skolor spridda över Sverige. Genom detta testas också bedömningsanvisningarnas stabilitet. Själva genomförandet var omfattande och tog två hela dagar. Resultaten pekar på en god överensstämmelse för provbetyget, det sammanfattande omdöme eleverna får. Studien avses att återupprepas under kommande år.Nyckelord: Samhällskunskap, nationella prov, interbedömarreliabilitet, intraclass correlationThe first national test in samhällskunskap – a study of interrater reliabilityAbstractThe Swedish school subject Samhällskunskap (Societal knowledge) exists basically only in the Nordic countries. In other countries a number of different subjects, such as geography and civics, share the content. The content of the subject is constantly changing, depending on how society is changing. The first national tests in Samhällskunskap for all Swedish ninth graders took place in 2013. A large part of the test contains constructed responses.  Given the characteristics of the subject we consider it especially important to investigate whether these tests are “fair” or not. The intent of this study is to investigate one aspect of “fairness”, interrater reliability, meaning the degree to which the same student responses are scored equally by different raters.  In 2009, the National Agency of Education in Sweden conducted a large study of the subjects Swedish, English and Mathematics. Our study aims to mimic and further develop the design of the study from 2009. Our study was carried out on the first national tests in 2013. The results were analyzed by exploring different reliability measures within the categories consensus estimates, and consistency estimates. As the 2013 tests were the first tests of its kind in Sweden the purpose was also to create a framework for regular studies of interrater reliability. The rater design with a relatively large number of teachers from all over the country, each assessing a total of three complete student test responses aimed at mimicking the way the tests are assessed in schools. This also allowed us to study the stability of our assessment rubrics. The study itself was extensive and took two days to perform. The results indicate a large compliance when it comes to the final grade of the test. The study is meant to be repeated in the coming years.Keywords: Social science, civics, national testing, interrater reliability, intraclass correlation

MIGRATION AND DEMOGRAPHIC PROCESSES IN MONGOLIA IN THE COVID-19 PANDEMIC

2021 ◽  
pp. 46-60
Author(s):  
Irina V. Imideeva ◽  
◽  
Nandinceza Boldbaatar ◽  
Nikita S. Ryazantsev ◽  
◽  
...  
Keyword(s):  
National Security ◽  
The State ◽  
Demographic Development ◽  
National Interests ◽  
Territorial Integrity ◽  
External Threats ◽  
Demographic Processes ◽  
The Subject ◽  
The Stability ◽  
Demographic Policy

The aim of the study is to analyze the factors of Mongolia's national security in the context of the country's security and approaches to the implementation of demographic policy. The object of the study is the demographic processes in Mongolia during the COVID-19 pandemic in the context of ensuring the country's national security. The subject of the study is the measures taken by the state authorities of Mongolia during the COVID-19 pandemic to protect national interests from internal and external threats, the patterns and principles of implementing and ensuring the national security of the state in the context of solving the country's demographic problems. The most important element of the stability of the national security of the state is demographic security, as it is responsible for the process of reproduction of the country's population, in quantitative and qualitative terms. The approach of the Mongolian state in the context of a pandemic is aimed at protecting every citizen, society and country as a whole from internal and external threats, which allows maintaining the sovereignty, sustainable socio-economic and demographic development, territorial integrity of Mongolia. The study analyzed demographic processes during the COVID-19 pandemic, including fertility, mortality, migration, nuptiality and divorce. The features of migration processes during the COVID-19 pandemic are considered, including the return of Mongolian citizens to their homeland through channels organized by the state — export flights. The links between the socio-economic situation and changes in the demographic sphere in the country are revealed. The key risks in the development of demographic processes in Mongolia during the COVID-19 pandemic, affecting the sustainability of national security, have been identified. Based on the results obtained, measures are proposed to strengthen the demographic policy in Mongolia.

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