Automated generation of control skeletons for use in animation

Published online: 15 March 2002     

The average-case identifiability and controllability of large scale systems

Needs for increased product quality, reduced pollution, and reduced energy and material consumption are driving enhanced process integration. This increases the number of manipulated and measured variables required by the control system to achieve its objectives. This paper addresses the question of whether processes tend to become increasingly more difficult to identify and control as the process dimension increases. Tools and results of multivariable statistics are used to show that, under a variety of assumed distributions on the elements, square processes of higher dimension tend to be more difficult to identify and control, whereas the expected controllability and identifiability of nonsquare processes depends on the relative numbers of measured and manipulated variables. These results suggest that the procedure of simplifying the control problem so that only a square process is considered is a poor practice for large scale systems.     

Local haemodynamics of arterial bypass graft anastomoses

One of the main causes of failure of expanded polytetrafluoroethylene (PTFE) bypass grafts used in the lower limbs is the development of myointimal hyperplasia (MIH). Clinical studies show that higher patency rates can be obtained with the use of an autologous vein cuff (the Miller cuff) interposed between the graft and artery. The reasons for the improved performance are still unclear, but preliminary studies suggest that the change in local haemodynamics due to the cuff geometry may be the significant factor rather than the presence of autologous material. If this is the case, then PTFE grafts can be produced with an integral cuff, i.e. a precuffed graft, with similar haemodynamic patterns to that of the Miller cuff. In this paper, two different types of precuffed graft are presented and their flow patterns are compared with those recorded in the Miller cuff and the conventional end-to-side anastomosis. The haemodynamic studies were carried out using optically clear silicone rubber models under simulated in vivo pulsatile flow conditions. Flow structures similar to those observed in the Miller cuff were seen in the precuffed grafts.     

Why not Artificial Consciousness or Thought?

The purpose of this article is to show why consciousness and thought are not manifested in digital computers. Analyzing the rationale for claiming that the formal manipulation of physical symbols in Turing machines would emulate human thought, the article attempts to show why this proved false. This is because the reinterpretation of designation and meaning to accommodate physical symbol manipulation eliminated their crucial functions in human discourse. Words have denotations and intensional meanings because the brain transforms the physical stimuli received from the microworld into a qualitative, macroscopic representation for consciousness. Lacking this capacity as programmed machines, computers have no representations for their symbols to designate and mean. Unlike human beings in which consciousness and thought, with their inherent content, have emerged because of their organic natures, serial processing computers or parallel distributed processing systems, as programmed electrical machines, lack these causal capacities.     

Design and operation of a very large ring laser gyroscope

The design and initial operation of a vertical square He-Ne ring laser G0 with a perimeter of 14 m is discussed. This builds on earlier demonstrations of the feasibility of large ring lasers (perimeter approximately 4 m) for single-mode gyroscope operation and with lesser pulling than navigation gyroscopes. With servoing of the rf excitation to yield single-mode operation, G0 gave a quality factor 1 x 10(12) and a Sagnac line with a frequency of 287.8 +/- 1.0 Hz induced by Earth rotation Omega(E). This has confirmed some vital questions over the feasibility of very large gyroscopes for geodetic measurements at the level of 10(-9) Omega(E).     

中国现代城市住宅的历史和演变--《中国现代城市住宅》结语

自从1840年鸦片战争爆发以来,中国走向现代化的道路漫长而艰苦,充满了起伏动荡。当21世纪刚刚来临之时,中国发现自身正处于一个中等发达的水平,相对贫穷,承受着旧的经济和制度模式下的重负。中国经历了三个迥然不同的发展阶段。第一阶段,从1840年到1949年,其特征是尚未摆脱外来的影响和侵略,同时,一直占主导地位的封建社会的影响受到削弱。现代产业兴起,几个世纪以来的封建王朝的统治形式被打破,现代城市开始出现。中国所走过的正是与其他国家相比并不鲜见的轨迹,工业化导致都市化,现代房地产开始出现。住房从采用传统的居住样式并加以改良,…     

Warranty-based method for establishing reliability improvement targets

Modern day competition in manufacturing requires producers to rely heavily on continuous quality improvement methods to remain competitive. Reliability being a significant element of quality is the primary means for making design and process improvements. Current reliability allocation methods to establish improvement goals focus on cost reduction but do not necessarily give due consideration to the relative impact of component cost. A method is presented that uses warranty burden rates as a weighting factor to develop component improvement goals. A sample application is given to illustrate application of the method.     

高标准、低成本的设计实践

实施像这样的低成本预算并不是一件容易的事。另外一个复杂的因素是本地因工业的发展而被严重污染，并且在开发过程中,发现未爆炸的炮弹含有砷。此外,土地里含有大量泥煤而导致承重力较差。因此,建筑建在水泥柱和地梁上。一层楼板建在预制的混凝土块上。墙和地板是平行木框架结构，与楼梯、窗和门一样都是预制件。主要的技术问题来自南立面：大而重的玻璃如何与框架结构相协调。角窗和楼梯的开窗也存在同样的技术问题。