bluuebunny/crossref_metadata_2025_split huggingface dataset:
The finite dam II
Authors: Roes P. B. M. 
Published: July 2016

Summary
A weir of capacity K is considered in which the water inflow is a process with stationary independent increments. Unless the weir is empty, there is a continuous release of water at unit rate; if K is finite the weir may become full in which case the excess water overflows instantaneously. A weir for which K is infinite will be referred to as infinite dam. For the latter the transient behaviour is well known if the input possesses a second moment (cf. e.g., Prabhu [7]) and serves as the starting point for the present paper. This result is first extended to yield the Laplace transform (L.T.) of the trivariate Laplace-Stieltjes transform (L.S.T.) of the content v(t) at time t, the input X(t) in (0, t) and the total time d(t) in the interval (0, t) during which the dam is dry. (Incidentally, the last two quantities, for relevant time intervals, will be carried throughout.) Then we use a relation between the latter and the L.S.T. of the expected number of downward level y crossings of the v(t) process established in Roes [9]. Since the dam processes considered are Markov processes, we have therewith the L.S.T. of the renewal function of the renewal process imbedded at level y. From this, one finds the L.S.T.'s of first entrance and taboo first entrance times (for their definition see introduction). Next we calculate the first skip times for the infinite dam from the first entrance times and the L.T. of the L.S.T. of v(t). It is then a routine matter to determine the taboo first skip times. From the (taboo) first entrance and skip times we derive the first entrance times for the finite dam, which in turn lead to the renewal functions of the renewal processes imbedded in the finite dam content process v*(t) and hence to the transient behaviour of the finite dam.
The advantage of the present approach over the one given in Roes [8] is that it is entirely probabilistic and avoids involved analytic arguments. As a result, the question of uniqueness of the solution does not arise, while more insight is obtained in the structure. The L.S.T. of several first entrance times and first skip times have been derived by Cohen [2] for compound Poisson input.
Recent results in information theory
Authors: Kotz Samuel 
Published: July 2016

Information theory, in the strict sense, is a rapidly developing branch of probability theory originating from a paper by Claude E. Shannon in theBell System Technical Journalin 1948,in which anew mathematical model ofcommunications systems was proposed and investigated.One of the central innovations of this model was in regarding the prime components of a communications system (the source of messages and the communication channel) as probabilistic entities. Shannon also proposed a quantitative measure of the amount of information based on his notion of entropy and proved the basic theorem of this theory concerning the possi bility of reliable transmission of information over a particular class of noisy channels.
Inequalities for branching processes
Authors: Heathcote C. R. , Seneta E. 
Published: July 2016

Summary
If F(s) is the probability generating function of a non-negative random variable, the nth functional iterate Fn
(s) = Fn–

1 (F(s)) generates the distribution of the size of the nth generation of a simple branching process. In general it is not possible to obtain explicit formulae for many quantities involving Fn
(s), and this paper considers certain bounds and approximations. Bounds are found for the Koenigs-type iterates lim
n→∞
m
−n
{1−Fn
(s)}, 0 ≦ s ≦ 1 where m = F′
(1) &lt; 1 and F′′
(1) &lt; ∞; for the expected time to extinction and for the limiting conditional-distribution generating function limn→∞{Fn
(s) − Fn
(0)} [1 – Fn
(0)]–1. Particular attention is paid to the case F(s) = exp {m(s − 1)}.
On infinite server queues with batch arrivals
Authors: Shanbhag D. N. 
Published: July 2016

The queueing system studied in this paper is the one in which

(i)
there are an infinite number of servers,

(ii)
initially (at t = 0) all the servers are idle,

(iii)
one server serves only one customer at a time and the service times are independent and identically distributed with distribution function B(t) (t &gt; 0) and mean β(&lt; ∞),

(iv)
the arrivals are in batches such that a batch arrives during (t, t + δt) with probability λ(t)δt + o(δt) (λ(t) &gt; 0) and no arrival takes place during (t, t + δt) with the probability 1 –λ(t)δt + o(δt),

(v)
the batch sizes are independent and identically distributed with mean α(&lt; ∞), and the probability that a batch size equals r is given by a
r(r ≧ 1),

(vi)
the batch sizes, the service times and the arrivals are independent.
On the conditional expected value of contributions from a renewal process
Authors: James M. F. 
Published: July 2016

The problem discussed in this paper arose from the study of the effects of unresolved resonances on neutron cross-sections, but it is considered here in more general terms.
Events in a modified renewal process occur at successive intervals x
1, x
2, …, and the ith event has associated with it a parameter Γ
i
. The random variables xi
and Γ
i
are all independent, and their probability distribution functions are known. Each event contributes to two quantities F(u) and G(v) measured at u and v respectively. The value of the total contribution of all events to G(v) is assumed to be known from observation: this paper gives formulae for the mean value of F(u) conditional on this known value of G(v).
Stationary joint distributions arising in the analysis of the M/G/1 queue by the method of the imbedded markov chain
Authors: Jenkins J. H. 
Published: July 2016

Summary
Probability generating functions are used to relate the joint distribution of the numbers of customers left behind by two successive departing customers to the marginal distribution of the number left behind by each departing customer. A probability generating function is then found for the joint distribution of the numbers of customers arriving in two successive departure intervals using the joint distribution of the numbers of customers left behind by three successive departing customers. The results could be obtained from general Markov chain theory but the method used in this paper is quicker.
Equilibrium distributions for an open migration process
Authors: Whittle P. 
Published: July 2016

Summary
We consider a system of colonies in which migration, immigration and emigration take place according to a fairly general rule. Necessary and sufficient conditions for equilibrium are given in the theorem of Section (3). The equilibrium distribution of colony numbers is determined by Equations (7) and (9); the colony sizes are thus statistically independent in equilibrium.
Attention is also paid to the case where one colony becomes a “bottleneck” to circulation, when equilibrium changes character
LOW PREVALENCE OF INTESTINAL SCHISTOSOMIASIS AMONG FISHERFOLK LIVING ALONG THE RIVER NILE IN NORTH-WESTERN UGANDA: A BIOSOCIAL INVESTIGATION
Authors: Pearson Georgina 
Published: July 2016

SummaryMass drug administration has been less successful as a technique for controlling intestinal schistosomiasis (S. mansoni) than anticipated. In Uganda, the mass distribution of praziquantel has been provided to populations at risk of infection since the early 2000s, but prevalence mostly remains high. This is the case, for example, at locations in north-western and south-eastern Uganda. However, there is a remarkable exception. Among Madi fishing populations and their immediate neighbours, living close to the border with South Sudan, the rate of infection has dropped dramatically. A parasitological survey carried out at twelve fishing sites in 2013 identified only three cases of S. mansoni among 383 adults tested. This article asks: why is the prevalence of S. mansoni so low among fisherfolk in northern Uganda? Taking a biosocial approach, it suggests that the mass distribution of drugs, free of charge, has had an impact. However, the low prevalence of infection cannot be attributed to this alone. Other important factors may also have contributed to the decline in infection. These include changing fishing livelihoods, local attitudes to public health interventions, access to water and sanitation facilities, hygiene practices and the use of anti-malarial treatments. Above all, the article highlights the importance of investigating both social and biological dimensions of infection simultaneously, and of recognizing the local complexities of sustainably treating this debilitating parasitic disease.
Extended applications of the endoscopic modified Lothrop procedure
Authors: Choudhury N , Hariri A , Saleh H 
Published: July 2016

AbstractObjective:The endoscopic modified Lothrop procedure is mainly used for refractory frontal sinusitis. However, we have used it as an access procedure to facilitate treatment for an extended range of additional frontal sinus pathologies.Methods:A retrospective review of patients who underwent the endoscopic modified Lothrop procedure for ‘alternative’ frontal sinus pathologies was conducted. Patient data were reviewed. The main outcome parameter measured was signs of recurrence.Results:Twelve patients (6 males, 6 females) from a 7-year study period, with a mean age of 45.2 years (range, 16–78 years), were analysed. The surgical indications included frontoethmoidal mucoceles, cerebrospinal fluid leaks within the frontal sinus, cystic fibrosis, frontal sinus osteoma, frontal sinus ossifying fibroma and frontal silent sinus syndrome. The mean follow-up period was 33.3 months. There were no known recurrences.Conclusion:We have used the endoscopic modified Lothrop procedure for a range of frontal sinus pathologies, safely and effectively, with no peri-operative complications.
Old age expectations are related to how long people want to live
Authors: BOWEN CATHERINE E. , SKIRBEKK VEGARD 
Published: July 2016

ABSTRACTHow long do people want to live? Why do some people want to live a very long time, and others would rather die relatively young? In the current study we examine the extent to which the preference to die young (<80 years, less than average life expectancy) or to live somewhat longer or much longer than average life expectancy (90-99 years or 100+ years, respectively) is related to a person's positive and negative expectations of what their life will be like in old age. We use multinomial regression analysis based on survey data from a large sample of younger and middle-aged adults in the United States of America (USA) (N = 1,631, age 18-64 years). We statistically control for socio-demographic characteristics as well as self-reported happiness and health. We find that having fewer positive expectations for their own old age distinguishes people who prefer to die relatively young, while having fewer negative expectations distinguishes people who want to live beyond current levels of life expectancy. The results provide evidence that pessimistic expectations of life in old age can undermine the desire to live up to and beyond current average life expectancy. The study also provides descriptive data about how young and middle-aged adults in the USA anticipate their own ageing.
The Royal Aeronautical Society The First Fifty Years
Authors: Laurence Pritchard J. 
Published: July 2016

“There was a considerable attendance of members,” says the Sixth Annual Report of the Society of the meeting held on 17th July 1871, with James Glaisher in the Chair.The “considerable attendance” was not unexpected. The siege of Paris had drawn attention to the value of using the air for transport and mail in time of war. It was true that the besieged in Paris had to rely upon the way the wind blew and balloons, but enthusiasts of the Aeronautical Society were convinced that a heavier-than-air machine was not only possible, but would avoid all the drawbacks of the balloon being blown where the wind listeth. A large number of attempts had been made to make the balloon steerable, but with insignificant success.
Future Possibilities
Authors: Cornford E. C. 
Published: July 2016

MR. Hazell has outlined some of the future improvements both in performance and in experimental facilities—such as attitude measurement or control— which it is hoped to be able to offer for Upper Atmosphere Research in the sounding rocket Skylark. I propose to try to look further ahead and, in particular, into the future possibilities in the United Kingdom of upper atmosphere and space research in earth satellites.But before doing this I should like to rehearse briefly some of the arguments which suggest that sounding rockets and earth satellites will have a complementary part to play in upper atmosphere and space research in the future.
A Refined Estimate for the Damping Coefficient
Authors: Gladwell G. M. L. 
Published: July 2016

In the “Peak Amplitude” method of resonance testing the total amplitude of vibration is plotted against frequency or (frequency). The method is unreliable for systems which are heavily damped and for systems with close natural frequencies (for both of which a vector plot such as that suggested by Kennedy and Pancu should be used) but for many systems it provides a rough guide to the resonance properties. One of the principal difficulties attending the analysis of the amplitude plots is to find which part of a given peak is due to the resonant mode and which to the off-resonant vibration. In the note a method is described for analysing a peak assuming that:—
(i)only a single resonant mode is involved(ii)the contribution to the amplitude from the off-resonant vibration is constant in the neighbourhood of the peak.
NATO's Firstborn: The Atlantic
Authors: Bloch René 
Published: July 2016

The Seventh Sir Henry Royce Memorial Lecture of the Derby Branch of the Society —"NATO's Firstborn: The Atlantic" by Captain R. Bloch, F.N., F.R.Ae.S., A.F.A.I.A.A., given on 5th November 1962—was also the 53rd Main Lecture of the Society to be given at a Branch Centre. Mr. A. A. Rubbra, F.R.Ae.S., Chairman of the Derby Branch opened the proceedings by welcoming the members of Council who were present, the visitors from other Branches and, especially, their distinguished visitors from Belgium, France and Germany. He expressed the regrets of the Branch that the President was unable to be present because of his absence overseas, but welcomed the President-elect, Professor A. R. Collar, M.A., D.Sc, F.R.Ae.S., F.A.I.A.A., F.C.A.S.I., Professor of Aeronautical Engineering at Bristol University, who would preside for the rest of the evening.Professor Collar said how delighted he was to be at Derby again on such an occasion; it was also the first time he had presided at a Main Lecture of the Society. Introducing Captain Bloch, Professor Collar said that although he was not yet 40 years of age he had had a distinguished career. He had achieved distinction at the Ecole Polytechnique, and at the Licencié es-Sciences and was also an M.A. of Harvard University. Captain Bloch was an Ingénieur du Génie Maritime and Ingénieur de l'Aéronautique and held the Diploma du Centre de Perfectionnement dans l'Administration des Affairs. He was a Chevalier de la Legion d'Honneur and a Combatant Volontaire de la Resistance and held the Médaille de la France Libre and the Médaille de l'Aéronautique. From 1952 to 1961 Captain Bloch had been head of Research and Development for French Naval Aviation and since 1961 had been Assistant Director of Aeronautics for International Affairs in the French Defence Ministry. He was also the French Representative of the NATO Maritime Patrol Aircraft Steering Committee and Permanent Chairman of the Technical SubCommittee; since 1957 he had been French Co-Chairman of the Anglo-French Naval Aviation Committee. He was an Associate Fellow of the American Institute of Aeronautics and Astronautics, a member of the American Institute of Radio Engineers, a member of AFITAE and a Fellow of the Society.
Estimation of Maximum Lift of Swept Wings at Low Mach Number.
Authors: Bore C. L. , Boyd A. T. 
Published: July 2016

Summary:A semi-empirical method is given, together with systematic data sufficient for estimating the maximum lift characteristics of wings at Mach numbers below 0·6. The method gives the effect of sweep, aspect ratio, taper ratio, camber, leading-edge radius, maximum-thickness position and Reynolds number. The accuracy is good for most wings at full-scale Reynolds numbers, but deteriorates for wings with trailing-edge angles greater than about 12° (which for conventional sections correspond with thickness/chord ratios about 0·140), and for heavily cambered sections.
Flight Requirements for the Operation of Rotorcraft.
Authors: Scanlon John 
Published: July 2016

Throughout the years that rotorcraft have been on the British Register of Civil Aircraft, the single reciprocating engined, single main rotor helicopter has been the predominant representative of this particular family of aircraft. These helicopters were certificated to the British Civil Airworthiness Requirements (BCAR), Section G, “Rotorcraft,” issued in January 1954, which was written in terms of such helicopters.During the past few years there have been significant changes in rotorcraft design—the turbine engine has been introduced and the multi-engined type has become a reality.Basic changes in the design trends of any type of aircraft must inevitably involve a re-appraisal of the appropriate requirements by the responsible airworthiness authority. The BCAR are subjected to a constant process of refinement and revision and, as a result of the development of new types, the Air Registration Board has been considering the airworthiness implications and preparing amendments to most parts of Section G, but I wish to discuss only Flight Requirements which are in the main contained in one Sub-Section of Section G—Sub-Section G2. From the recent revisions I have extracted only the significant changes, although there are still problem areas I would like to put on record.
Education of the Airline Engineer
Authors: Wilkinson K. G. 
Published: July 2016

I have approached this topic from the point of view of an airline, but the conclusions may be of value over a number of industries. In order to make the approach clear, it is worth defining some terms and also giving a simplified map of the subject.I have referred in a number of places to “operational” engineering as opposed to “design and manufacture”; the term operational used in this sense should be understood to cover any activity based primarily on the use of machines to produce a service or material of some kind, rather than the design and creation of machines themselves. For example, transport as a whole would come in this category, as would the distribution of goods, the distribution of power in the form of electricity, and possibly mining operations and the production and distribution of crude petroleum.
A Method of Measuring Helicopter Landing Loads
Authors: Harding M. J. H. 
Published: July 2016

SummaryTests have been made to examine the dynamic response of representative heliport structures to helicopter landing loads. The loads applied by an S.5S helicopter were measured by British European Airways and the corresponding strains, reactions and deflections occurring in the instrumented test platform were recorded by the Building Research Station.This paper describes the specially designed recording equipment fitted to the helicopter and discusses the data obtained from over 400 heavy landings. It is concluded that:—(a)The tyre deflection method used to measure applied load was better than the others considered.(b) Overall accuracy achieved was in the order of ± 10 to 15 percent.(c) Accuracy could have been improved if more time had been available to eliminate the effects of follower bounce and to establish the exact degree of sideloading present on the mainwheels.(d) There was inconsistency in oleo performance which had a marked effect on the time-history of load application.(e) The time-history of load application also depended on whether or not the rotor was running and providing lift.(f) In very few of the landings from a low hover and in none of the 30 or so run-on landings did all four wheels touch together; this is the most critical loading of the structure.(g) Despite the large number of heavy landings earlier in the trial the undercarriage finally failed at 19 fps which was considerably in excess of its design velocity.
The Effect of Base Bleed on a Periodic Wake
Authors: Wood C. J. 
Published: July 2016

Summary:—Measurements of profile drag, base pressure, wake turbulence and vortex shedding frequency have been made on a 9 per cent thick aerofoil in the presence of a secondary air flow, ejected from the blunt trailing edge. It is shown that the decrease in profile drag caused by the base bleed is associated with a decrease in the strength of the vortex street. The initial formation of the vortices occurs further downstream as the bleed quantity is increased. As a result, a greater proportion of the shed vorticity is diffused before the street is formed.
The Speed of Sound and Mach Number Effects
Authors: Watson W. G. 
Published: July 2016

Since I have not been concerned with matters thermo-dynamic for some years, I have hesitated to enter the lists on the recent discussions on “The Speed of Sound and Mach Number Effects,” but I cannot let the comments of Mr. Naylor (Journal, January 1964, p. 63) and the reply by Messrs. Bragg and Smith stand without further comment.I am in agreement with Mr. Naylor in the specific circumstances with which he deals, but I believe his concentration upon the polytropic efficiency obscures the more fundamental approach.
The Damped Vibration Absorber as a Problem in Closed Loop Control
Authors: James J. I. 
Published: July 2016

It is of interest to investigate the design of a damped vibration absorber as a problem in feedback control. The method can then be compared with the vector solution presented in reference 2.The auxiliary system M2, K2, c is regarded as a feedback element modifying the response of the main system. The method leads to the use of approximations to construct the response curve and for optimising the design of the damper.
Theoretical and Experimental Investigation of Indoor Flying Models
Authors: Hacklinger Max 
Published: July 2016

SummaryThe development of a special model aeroplane technique is reviewed which renders possible easy and illustrative experimenting In the Reynolds number regime from 1 to 5000. The models are built in extremely light-weight construction; with wing span from 0·1 to 1 metre and all-up weights from 0·01 to 2 grammes, flight velocities between 0·1 and 1 m/ sec are reached. The requirement of extremely low wing loading, together with the special air flow characteristics in this region, leads to rather unconventional construction principles with the materials balsa wood, nichrome wire and cellulose film. These principles are reviewed briefly. The problem of optimum propulsion for such model aeroplanes is treated analytically. Some results are given for flight performance optimisation. By combining theory and experiment there has been evolved, e.g. the Schwebeleistungs method (power required for horizontal flight) for optimising the duration of indoor model aeroplanes without exact knowledge of their aerodynamic characteristics. Flight characteristics with some elasticity of the structure present formidable problems and are reviewed in some examples. Finally, some problems of hangar meteorology are mentioned.