bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of the Control Problems of Missiles and Manned Aircraft
Authors: Smith K. 
Published: July 2016

Summary
One of the main differences between manned aircraft and missiles is that in the former the “short period” dynamic characteristics should usually be at least moderately stable, while in the latter considerable instability can be tolerated.
However, this requires that the missile control system should have high gain “synthetic” feedback. Consequently, problems of stability associated with high gain are introduced, which do not occur with such severity in the manned aircraft. Typical missile stability problems of this kind, such as those arising from structural flexibility and propellant sloshing, are discussed.
Ballistic missiles, because they are required to operate in conditions where aerodynamic forces are sometimes negligible, need to utilise non-aerodynamic control forces. This introduces special problems, which have a parallel only in VTOL aircraft. The long duration attitude control of satellites in the presence of very small disturbances also presents a problem not encountered in the aircraft field.
The uncertainty of human pilot response is discussed in relation to the difficulties of adequate aircraft control system simulation. Some remarks are also made on the interaction between control about various axes. These interactions are often fundamentally different between aircraft and missiles.
The Helicopter Association of Great Britain
Authors: Richardson J. W. 
Published: July 2016

It is reasonable to date the prehistory of the Helicopter Association from the arrival in this country of Juan de la Cierva in 1925, at the invitation of lames Weir and his Associates.The helicopter idea had intrigued designers from the earliest days of aeronautical experiment but, so far, often to their detriment and the derision of their contemporaries. Cierva had been first in translating the theory of auto-rotation into practical terms and had proved that both stability and control in flight could be achieved regardless of forward air speed. The freely rotating rotor system of the Cierva Autogiro and other early gyroplanes, such as those of Kay and Hafner, provided the missing link which all had been seeking and from this point development proceeded by logical rapid sequence to the flight of the first potentially safe and controllable helicopter in Germany in 1937.
Four Combat Aircraft Concepts
Authors: Deplante H. 
Published: July 2016

The Twentieth Louis Blériot Memorial Lecture held jointly by the Society and the Association Française Ingenieurs et Techniciens de l’Aeronautique et de l’Espace (AFITAE) was given in London on 13th April by Monsieur Henri Deplante, Technical Director, Avions Marcel Dassault, on “Four Combat Aircraft Concepts”.The Chair was taken by Mr. A. D. Baxter, MEng, CEng, FRAeS, President of the Society. After welcoming French colleagues, especially Monsieur Jules Jarry, President d’Honneur of AFITAE, and several former Louis Blériot lecturers, Mr. Baxter said that Louis Btériot, one of France’s great aviation pioneers, had made the first practical link in aeronautics between their two countries; by the institution of this lecture they had initiated new technical links and provided inspiration on both sides of the Channel—he thought that inspiration had led to an industrial co-operation which they hoped would continue and extend to their mutual advantage.Introducing the lecturer, die President said that Monsieur Henri Deplante, who was now Technical Director of Avions Marcel Dassault, had been connected with aeronautical engineering since 1930 when he had joined the then Avions Marcel Bloch.Monsieur Deplante had served with the Free French Forces during the War; he was a member of the first Parachute Brigade in the Special Air Services and had been awarded the DSO. After the War he had helped to revive the French Aircraft Industry and the list of new aircraft which Dassault had designed in this post-war period was, he thought, evidence of his ability and success in that direction. Monsieur Deplante had lectured to four of the Society’s Branches since 1963 and they were delighted to have him as the 20th Louis Blériot Lecturer.
Admiralty Air Department 1915
Authors: Sutton Pipparo A. J. 
Published: July 2016

I have been asked to contribute some reminiscences of the first two years of the 1914–1918 War to this Centenary number. Selection has proved difficult: I did not keep a diary and so must rely on memory alone for what I write. This may result in errors of detail and for any such mistakes I apologise in advance.Early in February 1915 I received a telegram from the Admiralty as follows: “You have been appointed acting junior technical advisor to the Director of the Air Department and should present yourself for duty at the earliest possible moment”.
Materials in Aircraft Structures
Authors: Murphy A. J. 
Published: July 2016

A Definitive history of materials in aviation has not yet been written, and the present contribution makes no claim to fill the gap. It presents a mainly individual impression of significant stages in the development of the materials which have been used for the structures of aircraft from the beginning of practical aviation to the present time. The subject is limited to heavier-than-air machines.The basic requirement for the structural material of an aircraft is strength with lightness. A host of other properties is significant, and in some circumstances is of critical importance.
Hindsight is Always One Hundred Percent
Authors: Shenstone B. S. 
Published: July 2016

The First time I ever saw an aeroplane was at the age of ten when the whole school was rushed out in the middle of class to see two small specks in the sky which I realised later were two Curtiss JN4 aircraft with OX5 engines, which were to be used for pilot training in Canada.My first real interest in aviation was inspired by a lecture by the late Wing Commander Stedman, RCAF. This led to my being a provisional pilot officer in the Royal Canadian Air Force taking flying training.
A Lifetime of Design
Authors: Camm Sydney 
Published: July 2016

Although it is only the future that matters, the Centenary of this Society justifies a glance at the past—but what is one to look at? So much has happened.There is one thing I must say at the outset—that I find it very difficult to believe that it has all happened. Cerainly what has been achieved could not possibly have been foreseen in 1914, and this leads me to something which I believe in very firmly indeed—that is, the futility of planning over a long period. Such planning must be on the most flexible basis possible.
The Engine Repair Shops Pont de L'Arche
Authors: Fell L. F. R. 
Published: July 2016

There can be little doubt that the rate of progress in the development of aviation which was achieved in the years between 1915 and 1918 has never been exceeded in any period since that time.The few “flying machines” with which the Royal Flying Corps went to war in 1914 were of many types, of primitive design and unreliable, having little relevance to war with the possible exception of reconnaissance duties. In 1914 there was no aircraft industry worthy of the name. The potential value of aircraft was only beginning to be fully realised by the middle of 1915.
Envoi
Authors: Masefield Peter G. 
Published: July 2016

One Century's end is but the beginning of the next. The completion of the First Hundred Years of the life of the Royal Aeronautical Society—“posterity's tributes to its favoured children of fame“—heralds the start of a Second Hundred Years the promise of which is no less glittering than the first.“Ring out the old, ring in the new“—our “cheerful yesterdays, our confident tomorrows”.
Sequential selection of an increasing subsequence from a sample of random size
Authors: Gnedin Alexander V. 
Published: July 2016

A random number of independent identically distributed random variables is inspected in strict succession. As a variable is inspected, it can either be selected or rejected and this decision becomes final at once. The selected sequence must increase. The problem is to maximize the expected length of the selected sequence.
We demonstrate decision policies which approach optimality when the number of observations becomes in a sense large and show that the maximum expected length is close to an easily computable value.
Multivariate Poisson flows on Markov step processes
Authors: Beutler Frederick J. , Melamed Benjamin 
Published: July 2016

A Markov step process Z equipped with a possibly non-denumerable state space X can model a variety of queueing, communication and computer networks. The analysis of such networks can be facilitated if certain traffic flows consist of mutually independent Poisson processes with respective deterministic intensities λ
i
(t). Accordingly, we define the multivariate counting process N = (N
1, N
2, · ·· N
c) induced by Z; a count in Ni
occurs whenever Z jumps from x (χ into a (possibly empty) target set . We study N through the infinitesimal operator Ã of the augmented Markov process W = (Z, N), and the integral relationship connecting Ã with the transition operator T

t
of W. It is then shown that Ni
depends on a non-negative function ri
defined on χ; ri
(x) may be interpreted as the expected rate of increase in Ni
, given that Z is in state x.

A multivariate N is Poisson (i.e., composed of mutually independent Poisson streams N

i
) if and only if simultaneous jumps are impossible in a certain sense, and if the conditional expectation E[r

i
(Z(t) | 𝒩

i
] = E[r

i
(Z(t))] for i = 1, 2, ···, c and each t ≧ 0, where 𝒩

i
is the σ-algebra σ{N(s), s ≦ t}. Necessary and sufficient conditions are also specified that, for each s ≦ t, the variates [N

i
(t)-N

i
(s)] are mutually independent Poisson distributed; this involves a weakened version of E[r

i
(Z(v)) | N(v) – N(u)] = E [r

i
(Z(v))] for i = 1, 2, ···, c and all 0 ≦ u ≦ v.
It is shown that the above criteria are automatically met by the more stringent classical requirement that N(t) and Z(t) be independent for each t ≧ 0.
The convexity of a general performance measure for multiserver queues
Authors: Harel Arie , Zipkin Paul 
Published: July 2016

This paper examines a general performance measure for queueing systems. This criterion reflects both the mean and the variance of sojourn times; the standard deviation is a special case. The measure plays a key role in certain production models, and it should be useful in a variety of other applications.
We focus here on convexity properties of an approximation of the measure for the M/G/c queue. For c ≧ 2 we show that this quantity is convex in the arrival rate. Assuming the service rate acts as a scale factor in the service-time distribution, the measure is convex in the service rate also.
A generalized bivariate exponential distribution
Authors: Marshall Albert W. , Olkin Ingram 
Published: July 2016

In a previous paper (Marshall and Olkin (1966)) the authors have derived a multivariate exponential distribution from points of view designed to indicate the applicability of the distribution. Two of these derivations are based on “shock models” and one is based on the requirement that residual life is independent of age.
The practical importance of the univariate exponential distribution is partially due to the fact that it governs waiting times in a Poisson process. In this paper, the distribution of joint waiting times in a bivariate Poisson process is investigated. There are several ways to define “joint waiting time”. Some of these lead to the bivariate exponential distribution previously obtained by the authors, but others lead to a generalization of it. This generalized bivariate exponential distribution is also derived from shock models. The moment generating function and other properties of the distribution are investigated.
The lengths of fragments covering a fixed marker in randomly cut linear or circular DNA
Authors: Litwin Samuel 
Published: July 2016

A linear DNA molecule may be labelled at a fixed locus by a minute complementary radioactive molecule. A collection of identical molecules is to be so labelled and each one independently cut at a random number, N, of random places, X (N Poisson, X uniform). Fragments containing the label are to be collected and assayed by length. It is shown that the recovery pattern (fragment length distribution) contains a jump discontinuity at the fixed locus and may be used to determine the distance between the attachment site and the nearest end of the molecule.
The recovery pattern under the hypothesis that the collection of molecules are circularly permuted, i.e. the labelled locus is uniformly distributed over the length of the molecule, does not contain such discontinuities. The case where the labelling molecule has a non-negligible extent is also treated.
On the Weak form of Zipf's law
Authors: Chen Wen-Chen 
Published: July 2016

Zipf's laws are probability distributions on the positive integers which decay algebraically. Such laws have been shown empirically to describe a large class of phenomena, including frequency of words usage, populations of cities, distributions of personal incomes, and distributions of biological genera and species, to mention only a few. In this paper we present a Dirichlet–multinomial urn model for describing the above phenomena from a stochastic point of view.
We derive the Zipf's law under certain regularity conditions; some limit theorems are also obtained for the urn model under consideration.
Two classification theorems of states of Markov chains
Authors: Kim C. W. 
Published: July 2016

Summary
Two theorems on Markov chains, both of which already appear in the literature: the classification of the states into the set of all non-recurrent (transient) states and recurrent classes, and the corresponding classification for idempotent Markov chains due to Doob, are proved from the viewpoint of ergodic theory.
On the work load process in a general preemptive resume priority queue
Authors: Schassberger R. 
Published: July 2016

Consider the following queuing system: A sequence of customers arrive at a service unit in a recurrent stream. A customer is of priority k with probability πk
, k = 1, …, n. A class i customer preempts service of class k, k &gt; i. Interrupted service is resumed without loss or gain in service time. Service is FIFO within classes. Service times for class k are drawn from a general distribution function Bk
(t).
Using the method of phases and a resolution technique from the theory of Markov processes we obtain Laplace transforms of various distributions.
An optimal sequential policy for controlling a Markov renewal process
Authors: McNamara J. M. 
Published: July 2016

This paper discusses a renewal process whose time development between renewals is described by a Markov process. The process may be controlled by choosing the times at which renewal occurs, the objective of the control being to maximise the long-term average rate of reward. Let γ ∗ denote the maximum achievable rate. We consider a specific policy in which a sequence of estimates of γ ∗ is made. This sequence is defined inductively as follows. Initially an (a priori)estimate γo is chosen. On making the nth renewal one estimates γ ∗ in terms of γ
o, the total rewards obtained in the first n renewal cycles and the total length of these cycles. γ n
then determines the length of the (n + 1)th cycle. It is shown that γ n
tends to γ ∗ as n tends to∞, and that this policy is optimal.
The time at which the (n + 1)th renewal is made is determined by solving a stopping problem for the Markov process with continuation cost γ n
per unit time and stopping reward equal to the renewal reward. Thus, in general, implementation of this policy requires a knowledge of the transition probabilities of the Markov process. An example is presented in which one needs to know essentially nothing about the details of this process or the fine details of the reward structure in order to implement the policy. The example is based on a problem in biology.
Characterizations of the normal distribution by suitable transformations
Authors: Beer S. , Lukacs E. 
Published: July 2016

Yu. V. Linnik showed that certain transformations, given by Formulae (1.1), (1.6) and (1.7) transform a normal sample into itself. The transformations (1.1) and (1.7) apply to samples of size 2 while (1.6) admits an arbitrary sample size. It is also assumed that the population mean is zero.
In the present paper the converse theorems are proven so that characterizations of the normal distribution are obtained. The problem leads to the functional equations (2.3) and (2.13) whose solution yields the desired results.
On possible rates of growth of age-dependent branching processes with immigration
Authors: Grey D. R. 
Published: July 2016

It is shown that if ϕ is a given function out of a large class satisfying a certain regularity condition, then a supercritical age-dependent branching process {Z(t)} exists with deterministic immigration and given life-length and family-size distributions such that Z(t)/(eat ϕ(t)) converges in probability to a non-zero constant, a being the appropriate Malthusian parameter.
As an easy corollary one discovers the asymptotic behaviour of some processes with random immigration.
Stochastic asymptotic exponential stability of stochastic integral equations
Authors: Tsokos Chris P. , Hamdan M. A. 
Published: July 2016

The object of this paper is to study the stochastic asymptotic exponential stability of a stochastic integral equation of the form

A random solution of the stochastic integral equation is considered to be a second order stochastic process satisfying the equation almost surely. The random solution, y(t, ω) is said to be. stochastically asymptotically exponentially stable if there exist some β &gt; 0 and a γ &gt; 0 such that for t∈ R
+.
The results of the paper extend the results of Tsokos' generalization of the classical stability theorem of Poincaré-Lyapunov.
A bounded growth population subjected to emigrations due to population pressure
Authors: Trajstman A. C. 
Published: July 2016

A model is presented for a bounded growth population subjected to random-sized emigrations that occur due to population pressure.
The deterministic growth component examined in detail is defined by a Prendiville process. Results are obtained for the times between emigration events and for the population increase between emigrations. Some information is obtained about the mean time to extinction and also for the mean population level when the emigration-size distribution is negative exponential.
Some limit theorems for the general semi-Markov storage model
Authors: Balagopal K. 
Published: July 2016

In this paper we treat the general version of the semi-Markov storage model, introduced first by Senturia and Puri: transitions in the state of the system occur at a discrete sequence of time points, described by a two-state semi-Markov process. An input occurs at an instant of transition to state 1 and a demand for release occurs at an instant of transition to state 2.
Assuming general distributions for all the variables involved, we show that the dam contents just after the nth input converges properly in distribution as n →∞ under conditions of stability; likewise that after the nth demand. We also show that the demand lost due to shortage of stock, accumulated over instants of demand as well as over time, obeys a strong law and a central limit theorem.
Optimal insurance premium rates when the distribution of claims is unknown
Authors: Venezia Itzhak 
Published: July 2016

We analyze here the optimal premium rates for an insurance company for the case where the claims process is a stochastic process with unknown parameters. The beliefs of the insurance company about these parameters are represented by some prior distribution function, and the premium rates are determined on the basis of this distribution. The insurer learns about the unknown parameters from the past behavior of the claims process, and revises the prior distribution whenever new information is obtained (i.e., a claims stream is observed).
The learning process introduces multi-period dynamic considerations to the problem of the rate determination, since the rates determined at any period affect the claims process, and thus the information available for future decisions. We show how the optimal rates can be obtained by using some dynamic programming techniques. We also prove that the optimal rates obtained in our case are lower than those determined by an insurance company that does not revise its distribution.
A note on the probability of extinction in a class of population-size-dependent Galton-Watson processes
Authors: Höpfner R. 
Published: July 2016

In a class of population-size-dependent Galton-Watson processes where extinction does not occur with probability 1 we describe the rate of decay of qi (the probability that the process starting from i ancestors will become extinct) as the number i of ancestors increases.
The results are related to the asymptotic behavior of the Green's function of the critical Galton-Watson process with immigration.
The construction of limiting distributions of response probabilities
Authors: Marliss G. S. , McGregor J. R. 
Published: July 2016

As stated elsewhere [9], the two experimenter-controlled events learning model of Bush and Mosteller [1] may be described by a Markov process X
0,X
1, ···satisfying the following conditions.

(i)
Xo has an arbitrary distribution on (0, 1).

(ii)
If Xn is given, then with probability π1 and with probability π2

(ii)
Stochastic comparisons of random processes, with applications in reliability
Authors: Pledger Gordon , Proschan Frank 
Published: July 2016

The usual definition of stochastic comparison of random vectors is extended to stochastic comparison of random processes. Conditions are stated under which {X (t), t ≧ 0} stochastically larger than {Y (t), t ≧ 0} implies that for increasing functionals f.
Applications are made to reliability problems, yielding stochastic comparisons for systems of independently operating machines assuming exponential failure and exponential repair. From these stochastic comparisons we may then deduce similar stochastic comparisons for functionals of practical importance in reliability applications, such as the total machine up-time, the first time that the number of functioning machines drops below a specified number, the total time during which at least a specified number of machines are functioning, etc.