Interactive design of 3D models with geometric constraints

In this paper, an interactive graphical approach for the design of parameterized part-hierarchies is presented. Primitive solids can be grouped into compound objects, and multiple instances of a compound object can be used in further designs. Geometric relations between primitives and instances are specified by geometric constraints between their local coordinate systems. The user can specify and edit a model by direct manipulation on a perspective or parallel projection with a mouse, whereas a procedural model representations is automatically generated via visual programming. The obtained twoview approach offers two concurrent interface styles to the end-user and enables the combination of an intuitive direct manipulation interface with the expressiveness of a procedural modeling language.     

The need for a DML: Why a library interface isn''t enough

‘Associative Access’ will contribute significant benefits to object-oriented data base management systems and is best obtained through embedded Data Manipulation Languages. This conclusion stresses the need for a standard DML.     

灵巧手运动学分析

本文研究了灵巧手操作物体的运动学问题,在分析手指与物体接触条件的基础上,建立了手指与物体之间单点接触作纯滚动和作可控制滑动的运动学方程,给出了3R,4R 和5R 手指的运动约束条件,并对5-4-5型灵巧手进行了速度仿真和图形仿真.     

EXTRACELLULAR PROTEASE ACTIVITY IN A STRAIN OF SACCHAROMYCES CEREVISIAE

The isolation and analysis of a strain of laboratory yeast with extracellular protease activity is described. The proteolytic activity found in culture supernatants exceeded the parental strain by at least an order of magnitude and apparently was due neither to cell lysis nor to increased cell wall permeability. The extracellular proteases were heterogeneous in composition, consisting of possibly 3 aberrantly secreted intracellular proteinases. This extracellular protease activity was conferred by a single recessive mutation (epr1.1) in a gene displaying classical Mendelian inheritance. EPR1 was tentatively assigned to chromosome XV with loose linkage to the HIS3 gene. Strains carrying the mutant epr1.1) allele also possessed increased levels of secreted invertase activity and it is proposed that EPR1 is closely involved in the intracellular protein translocation pathway of yeast.     

Programmable applications for the arts: computational tools for hand, eye and mind

Commercial applications for the arts tend to enforce a division between the use of learnable direct manipulation interfaces and the use of powerful, well supported programming environments. In contrast, programmable applications integrate these two software-design paradigms (i.e. direct manipulation and programming languages) and thereby attempt to exploit the strengths of both. A sample graphics application, SchemePaint, is outlined, and some of the issues related to the creation of programmable applications for the arts are discussed.     

一种支持复杂语义实现的直接操纵界面模型

具有高度真实感和“人性化“用户界面的软件系统便于学习和使用，直接操纵技术向这方面前进了一步。然后目前尚不能采用纯粹的直接操纵技术，主要困难在于界面对象的表现语义和操纵语义的高度复杂性。     

Data schemata based on directed graphs

Rooted, labeled, directed graphs (RLDs) are taken as the basis for describing data structures. A constructive formalism is set up to describe RLDs, generate them by means of grammars, and carry out operations such as accessing nodes, inserting and deleting data items, and recognizing graph patterns. It is shown how the formalism can be translated into languages for data definition and data manipulation, of the type associated with data-base systems. The availability of the formalism allows a systematic development of such languages, and provides a method of incorporating consistency preconditions to structural operations and proving the correctness of the data structures that arise in using such languages.     

Robots in Space: U.S. Missions and Technology Requirements into the Next Century

The Telerobotics Program of the National Aeronautics and Space Administration (NASA) Office of Space Science is developing innovative telerobotics technologies to enable or support a wide range of space missions over the next decade and beyond. These technologies fall into four core application areas: landers, surface vehicles (rovers), and aerovehicles for solar system exploration and science; rovers for commercially supported lunar activities; free-flying and platform-attached robots for in-orbit servicing and assembly; and robots supporting in-orbit biotechnology and microgravity experiments. Such advanced robots will enable missions to explore Mars, Venus, and Saturn's moon Titan, as well as probes to sample comets and asteroids. They may also play an important role in commercially funded exploration of large regions on Earth's Moon, as well as the eventual development of a human-supporting Lunar Outpost. In addition, in-orbit servicing of satellites and maintenance of large platforms like the International Space Station will require extensive robotics capabilities.     

Integrating specification of human-computer interface with Jackson system development

Procedures for integrating task analysis and design of the human-computer interface (HCl) with a structured system development method, Jackson system development (JSD), are described. Process structure diagrams (PSDs), the major modelling notation of JSD, described tasks, and task specifications were evaluated for cognitive complexity. Task complexity analysis helped allocation and design of human tasks and to produce computer task support specifications. The cognitive dimension of task analysis highlighted the need for task support actions, especially information display support for working memory. Dialogue specification for a direct manipulation interface design was based on the JSD entity/event model from which the interaction metaphor, screen design, and permissible manipulations were derived. Further PSDs were constructed to specify interface object management processes. Preliminary evaluation of the method was carried out using JSD analysts. Results showed the method proved easy to learn even for non-HCl specialists.     

Suboptimal synthesis of a robust decentralized control for large-scale mechanical systems

For a large-scale nonlinear mechanical system, a set of nominal trajectories is prescribed together with a region of allowable parameter values. The system is viewed as a set of decoupled linear time-invariant subsystems and a local controller is synthesized for each subsystem neglecting, in the first step, nonlinear coupling among subsystems. An iterative procedure is established to choose unique linear local controllers which can accommodate all nominal trajectories and withstand parameter variation. If such controllers cannot be found a force feedback is implemented as a global control in order to compensate for the influence of nonlinear and variable coupling. An example of a six-degree-of-freedom industrial manipulator is presented.