Woodin proved the theorem in perhaps 1986 or 1987, using stationary tower forcing and (through the work of Martin and the author) iteration trees. The proof we give here uses only iteration trees. Stationary tower forcing is replaced by “genericity iterations”, as it can be in certain related contexts as well. We believe that the unity of method in the resulting proof gives it some interest. Th...

As an important quality index of high voltage electricity transmission tower, zinc coating thickness detection and quality control is more and more attention in recent years. The coating thickness and uniformity of tower materials provided by the suppliers are tested through the traditional method by the power department, the detection precision of this method is low efficiency and analysis res...

In this paper, the two-dimensional vibration controls of a power transmission tower with a pounding tuned mass damper (PTMD) under multi-component seismic excitations are analyzed. A three-dimensional finite element model of a practical power transmission tower is established in ABAQUS (Dassasult Simulia Company, Providence, RI, USA). The TMD (tuned mass damper) and PTMD are simulated by the fi...

A tower crane can be reduced the sway oscillation easily by controlling the rotation acceleration. With the proposed open-loop fast control method which is operated by controlling acceleration, the sway angle of suspended load can be maintained during the movement as well as reduced oscillation during and at the end of movement. In this paper, we design and produce a scaled tower crane with a s...

In a molten-salt solar power tower, liquid salt at 290oC (554oF) is pumped from a ‘cold’ storage tank through the receiver where it is heated to 565oC (1,049oF) and then on to a ‘hot’ tank for storage. When power is needed from the plant, hot salt is pumped to a steam generating system that produces superheated steam for a conventional Rankinecycle turbine/generator system. From the steam gener...

We study two aspects of a generalization of the Tower of Hanoi puzzle. In 1981, D. Wood suggested its variant, where a bigger disk may be placed higher than a smaller one if their size difference is less than k. In 1992, D. Poole suggested a natural disk-moving strategy for this problem, but only in 2005, the authors proved it be optimal in the general case. We describe the family of all optima...

The Burj Dubai Project will be the tallest structure ever built by man; when completed the tower will be more than 700 meters tall and more than 160 floors. The early integration of aerodynamic shaping and wind engineering considerations played a major role in the architectural massing and design of this residential tower, where mitigating and taming the dynamic wind effects was one of the most...

The present study proposes a novel tower-control technique that couples linear control feedback theory with an online time-frequency analysis of the tower vibrations, with the aim to widen the research area of situational control of wind turbines. Numerical simulations were conducted for two 5MW-class offshore wind turbines, and the performance of the proposed control method has been tested in ...

conclusions the results of this study led to the identification of many of the errors and conditions that affect the performance of controllers, providing the ability to define safety and ergonomic interventions to reduce the risk of human error. therefore, the results of this study can be a basis for planning atm to prioritize prevention programs and safety enhancement results the analysis of ...