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An alliance portfolio can help latecomer firms to acquire the necessary knowledge and resources to catch up with market leaders. However, how latecomer firms construct an alliance portfolio in terms of the nature of windows of opportunity has not been fully analyzed. This paper aims to explore how latecomer firms can build appropriate coalitions according to the nature of the window of opportunity to achieve technological catch-up in different catch-up phases.

Based on a longitudinal case study from 1984 to 2018 of Sunny Group, now a leading manufacturer of integrated optical components and products, this paper explores the process of technological catch-up of latecomer firms building different types of alliance portfolio in different windows of opportunity.

This paper finds that there is a sequence when latecomers build an alliance portfolio in the process of catch-up. When the uncertainty of opportunity increases, the governance mechanism of the alliance portfolio will change from contractual to equity-based. Also, latecomer firms build market-dominated and technology-dominated alliance portfolios to overcome their market and technology disadvantages, respectively.

These conclusions not only enrich the theory of latecomer catch-up from the perspective of windows of opportunity but also expand research on alliance portfolio processes from a temporal perspective.

The Brunet les Mureaux Reconnaissance Monoplane THE Ateliers des Mureaux, who are now using the old Kene Tarnpier works at Boulogne‐sur‐Seine, on the outskirts of Paris, have recently completed a scries of test flights at the Villacoublay Field with their newest monoplane designed for reconnaissance work. This machine, known as the 130 A‐2, is a two‐seater, high‐performance monoplane powered with a 500‐h.p. Hispano‐Suiza engine, and was designed by Brunet, one of the younger French aeronautical engineers. The parasol wing is of metal construction throughout, and, owing to its rigid structure and the absence of wires and smaller bracing members, can be dismantled in a very short time.

WORDS, the currency of human thought, are easily debased. Frequent repetition can empty them of serious meaning. Rightly used they can, with the brevity and directness of a road sign, provide the pith of a subject. Only when they are widely adopted and used as a label to stick on every package do they lose significance.

This paper aims to propose a new method for robust simulations of passive heat transfer in two-fluid flows with high volumetric heat capacity contrasts.

This paper implements a prediction–correction scheme to evolve the volumetric heat capacity. In the prediction substep, the volumetric heat capacity is evolved together with the temperature. The bounded downwind version of compressive interface capturing scheme for arbitrary meshes and central difference scheme are used for the spatial discretization of the advection and diffusion terms of the heat transfer equation, respectively. In the correction substep, the volumetric heat capacity is updated in accordance with the interface captured by using a coupled level-set and volume-of-fluid method to capture the interface dynamics precisely.

The proposed method is verified by simulating the advection of a hot droplet with high volumetric heat capacity, a stationary air–water tank with temperature variation between top and bottom walls and heat transfer during wave plunging at Re=108. The test results show that the proposed method is practical and accurate for simulating two-fluid heat transfer problems, especially for those feature high volumetric heat capacity contrasts.

To ensure the numerical stability, this paper solves an additional conservative form of volumetric heat capacity equation along with the conservative form of temperature equation by using consistent spatial-discretization and temporal-integration schemes.

IT is roughly twenty‐eight years since Taylor and White first startled the engineering world by the introduction of what are known everywhere now as high‐speed steels. The modern world has, however, recently suffered a revolution in machine‐shop conditions comparable to that which was introduced by the tungsten high‐speed steels. It is important that the aircraft engineer should familiarise himself with the latest developments in line tool steels, because the lowering of production costs by the quickening up of cutting speeds and the raising of cutting power is of ever‐increasing value. Not only can materials be cut more quickly now than ever before, and larger cuts be taken, but also metals which have never previously been capable of being machined commercially can now be turned in the lathe, planed, or drilled without difficulty.

This paper aims to provide a posture generation method of robot deposition paths based on intersection topology, which is helpful to contribute to improving the flexibility and deposition capability of the deposition system.

Via the geometry information and normal vector information of the stereolithography (STL) model, the intersecting edge information is generated and the topological relationship of the model is established. Through the removal of redundant points for the STL model and the sort of robot path points, the position information of robot path points is obtained. According to the geometric relationship between the normal vector information of the STL model and the robot deposition path points, combining with the robot posture representation method of roll-pitch-yaw angles, the posture information of path points is achieved. Then, the generation from CAD model of parts to robot paths for laser melting is realized, and the experimental verification is carried out.

For simple parts, the laser melting process can be completed without the posture information of deposition paths. However, in the melting process of a turbine blade, there are some accumulated burls on the sidewall. The posture generation method of robot deposition paths based on the intersection topology can solve this problem. The light spot of deposition points irradiates on the surface of the forming part, and the forming process can proceed smoothly.

As a motion platform in laser melting deposition (LMD), the application of the multi-joint robot can improve the flexibility and deposition capability of the deposition system, as well as promote the LMD application for individuation manufacturing, parts repair and green remanufacturing.

The posture is essential for robot deposition paths. This paper first proposes a posture generation method of deposition paths for LMD to improve the flexibility and deposition capability of LMD systems.

AT the suggestion of Herbert Charles Sadler, now Dean of the Engineering College of the University of Michigan, Professor Felix W. Pawlowski was invited in 1913 to join the faculty of the University and offered the opportunity of developing courses in aeronautics. The result has been the establishment of one of the first, and now one of the best, departments of aeronautical engineering in the United States.

WHILE the general principles of gas‐fuel propulsion for airships have been enunciated in a former article, there remain to be considered both the gases available and the means whereby they can be procured.

IN order to study the relationship of load factors to the stresses which arise in the normal manoeuvring of aircraft, it is customary to employ recording accelerometers. These instruments have been found quite satisfactory for this purpose, and almost as many models have been devised as the countries that use them. The instruments built in this country have been the very best of the type: the record is usually, though not invariably, made on a moving photographic film. For certain purposes, however, a simpler form suffices; one in which an easily‐visible pointer moving in front of an easily‐visible scale gives the maximum acceleration during any sustained manoeuvre, such as turning, rolling, looping, pulling out of a steep dive, etc. The inertia of the mechanical parts, though, of course, exceeding that of the mirror and spring of the usual recording type, can be made low enough to keep pace with the ordinary motions of an ordinary aircraft. Such a device needs to be light in weight, slight in bulk, and simple to use and maintain.

A PROBLEM which has attracted some attention since the advent of the tricycle undercarriage is that of the tendency to oscillate or “shimmy ” sometimes shown by the nose‐wheel, which is normally free to rotate about the vertical or castoring axis, subject to the restraint imposed by frictional or hydraulic dampers. Various attempts have been made to predict the amount of damping required to prevent the building‐up of a dangerous wobble; in the simplified investigation which follows it is believed that all the essential variables have been retained, and the basic character of the motion correctly reproduced.