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Birding, the active seeking out and identification of birds, is a wide‐spread and fast growing avocation on this continent, and indeed throughout the world. Jon Rickert's A Guide to North American Bird Clubs lists 17 national/continental organizations for both professional ornithologists and amateur birders and 844 state, provincial, and local associations. In addition, there are those legions of “unorganized” bird watchers and occasional, inquisitive discoverers of backyard birds. Members of this diverse congregation of birders have at least one thing in common — the need for a reliable identification tool enabling them to correctly label the just‐seen, unfamiliar bird. A field guide is just such a tool.

Increasing endurance was a very appropriate subject for the biomimetic approach. The study aims to design and manufacture a long-lasting mini unmanned aerial vehicle (UAV) using active gliding and soaring.

The endurance of mini UAVs is limited by battery or fuel capacity, and it is not always possible to increase these energy sources due to the fuselage size. Long endurance aircraft are required in various areas such as silent environment and traffic monitoring or search and rescue. Literature research on bird flight performance conducted to determine design parameters. These parameters are used in the theoretical design of the UAV for optimization. Computational fluid dynamics simulation and flight tests of the UAV performed to figure out the success of the design.

For a mini UAV to be produced in this class, it has been observed that it is more accurate to examine birds instead of gliders due to the size similarity. The UAV design reaches a 27.5 L/D (Glide ratio) ratio in the theoretical approach. However, flight results approved max L/D ratio is around 25 at the sea level. This flight performance is enough to outperform in glide ratio of Wandering albatrosses.

Sailplanes are known as sport aircraft. However, recent projects focus on glider designs due to fuel efficiency and silent tracking. Stemme S-14 that carries a high-resolution camera is one of the examples of these projects. The unmanned glider design can lead to these implications in the UAVs at least during the stand-by period in the air. Thanks to low weight, UAVs do not require strong thermals, which allows flying almost all over the world.

Researchers generally focus on increasing the battery capacity or the performance of the UAV. However, this study’s concentration is to increase the flight duration of the UAV by using geographical currents. For this purpose, taking advantage of bird morphology is quite a new topic. Also, glider type designs are rarely found in the field.

An algorithm is described for the incremental solution of elastic—plastic finite element analysis using a piecewise holonomic constitutive law based on a von Mises yield condition. The holonomic assumption effectively converts each incremental problem into a non‐linear elastic—plastic problem. The algorithm is iterative, substituting the non‐linear strain potential by a quadratic potential at each iteration, and convergence is proved. The algorithm has been implemented into a finite element program as a series of secant modulus approximations, and results for a variety of problems are given. The rate of convergence is fairly slow, but the algorithm can be very easily programmed as an extension of an elastic program, and may have value as an independent method of determining incremental elastic—plastic solutions.

This paper considers the classical problem of the deformation of an elastic‐plastic body subjected to a prescribed history of loading. Attention is focused on the basis for the time discretization of the problem for numerical solution. It is suggested that this discretization can be achieved consistently by conceiving of the problem as a sequence of holonomic, or non‐linear elastic, problems. Complementary work bounds can be given, in special circumstances, for increasing numbers of time steps. The holonomic problem for a single time step is a non‐linear mathematical programming problem: it is shown that the conventional Newton‐Raphson algorithm used in elastic‐plastic finite element analysis can be interpreted as an iterative procedure for finding the least value of the holonomic potential work functional.

The institution of food and cookery exhibitions and the dissemination of practical knowledge with respect to cookery by means of lectures and demonstrations are excellent things in their way. But while it is important that better and more scientific attention should be generally given to the preparation of food for the table, it must be admitted to be at least equally important to insure that the food before it comes into the hands of the expert cook shall be free from adulteration, and as far as possible from impurity,—that it should be, in fact, of the quality expected. Protection up to a certain point and in certain directions is afforded to the consumer by penal enactments, and hitherto the general public have been disposed to believe that those enactments are in their nature and in their application such as to guarantee a fairly general supply of articles of tolerable quality. The adulteration laws, however, while absolutely necessary for the purpose of holding many forms of fraud in check, and particularly for keeping them within certain bounds, cannot afford any guarantees of superior, or even of good, quality. Except in rare instances, even those who control the supply of articles of food to large public and private establishments fail to take steps to assure themselves that the nature and quality of the goods supplied to them are what they are represented to be. The sophisticator and adulterator are always with us. The temptations to undersell and to misrepresent seem to be so strong that firms and individuals from whom far better things might reasonably be expected fall away from the right path with deplorable facility, and seek to save themselves, should they by chance be brought to book, by forms of quibbling and wriggling which are in themselves sufficient to show the moral rottenness which can be brought about by an insatiable lust for gain. There is, unfortunately, cheating to be met with at every turn, and it behoves at least those who control the purchase and the cooking of food on the large scale to do what they can to insure the supply to them of articles which have not been tampered with, and which are in all respects of proper quality, both by insisting on being furnished with sufficiently authoritative guarantees by the vendors, and by themselves causing the application of reasonably frequent scientific checks upon the quality of the goods.

The paper considers a plane joint or interface element suitable for implementation into a standard non‐linear finite element code. Sliding of the joint is assumed to be governed by Coulomb friction, with a non‐associated flow rule and no cohesion. The constitutive equations are formulated in a manner appropriate for a backward difference discretization in time along the path of loading. It is shown that the backward difference assumption can lead to an explicit formulation in which no essential distinction need be drawn between opening and closing of the joint and sliding when the joint is closed. However, an inherent limitation of the dilatant Coulomb model becomes evident; the final formulation is internally consistent but does not describe reversed shear displacement in a physically reasonable way. Explicit equations for the consistent tangent stiffness and for the corrector step (or return algorithm) of the standard Newton—Raphson iterative algorithm are given. The equations have been implemented as a user element in the finite element code ABAQUS, and illustrative examples are given.

Since the appearance of Simon Rottenberg's seminal paper on the baseball players' labour market in the Journal of Political Economy (1956), the literature on the economics of professional team sports has increased rapidly, fuelled by major changes in the restrictive rules which had pervaded these sports, themselves a consequence of battles in the courts and the collective bargaining arena. These changes have not been limited to North America, to which most of the literature relates, but also apply to Western Europe and Australia in particular. This monograph surveys this literature covering those various parts of the world in order to draw out both theoretical and empirical aspects. However, to argue that the existence of what is now an extensive literature “justifies” such a survey on professional team sports clearly begs a number of questions. Justification can be found in at least two major aspects.

At a recent inquest upon the body of a woman who was alleged to have died as the result of taking certain drugs for an improper purpose, one of the witnesses described himself as “an analyst and manufacturing chemist,” but when asked by the coroner what qualifications he had, he replied : “I have no qualifications whatever. What I know I learned from my father, who was a well‐known ‘F.C.S.’” Comment on the “F.C.S.” is needless.

Bird strike risk (BSR) evaluation is a significant part of the avian radar system worldwide installed and operated at airports. The paper aims to discuss these issues.

This paper proposed a method using the real-time avian radar data to evaluate BSR with the estimations of bird strike probability and severity. The probability estimation model considered the attributes of the relative positions of the flock and the runway, the altitude of the flock and the aircraft, the flight path of the aircraft, and the ability of the bird species to avoid collision. The severity was estimated by the combination of the Delphi method and the analytic hierarchy process (AHP), called DAHP, which took full advantage of the expert knowledge and quantitative calculation.

The model was tested successfully on the simulated data at Beijing Capital International Airport (BCIA) with three runways and real data at Beihai Fucheng Airport (BFA) with one runway.

The BSR evaluation model was specifically designed for the airports with avian radars. It enabled the airport managers to objectively evaluate the risk in real time and to take effective measures.

The proposed BSR evaluation model was constructed with the real-time features of birds and aircraft based on the DAHP framework, providing scientific guidance for aviation safety and environmental management at the airport.

The purpose of this paper is to determine the stochastic net present value (NPV) of a model smallholder poultry operation in Rwanda under production and market uncertainty.

A discounted cash flow calculator was used to determine the NPV of operator investments and operating cash flows, including time, materials and capital. Broiler production data, market prices and variable input costs were collected from 125 smallholder operations in the Musanze District, Rwanda. These data were combined with a historical price index tracking the inflation rate of Rwanda’s currency. Policies including overstocking, technical support repayment scheduling, selling broilers at a spot market price, using marketing contracts and selling poultry manure were compared using non-parametric paired comparisons and stochastic dominance.

Risk-neutral and risk-averse producers would prefer overstocking, delaying repayment of technical support services and selling manure to status quo operational policy. No differences were observed between the option to sell birds at spot market prices or through contracts.

This analysis demonstrates how individual managerial or an intervention in smallholder broiler production affects financial performance.

To mitigate risk associated with this novel enterprise, producers should consider overstocking birds. If local markets for manure were developed, the risks faced by new or beginning poultry operators could be mitigated.

A stochastic, discounted cash flow model calculator was used to determine the NPV and discounted payback period of operator investments and operating cash flows, including time, materials and capital.