A City Metaphor to Support Navigation in Complex Information Spaces

A major problem in modern information systems is to locate information and to re-find information one has seen before. Systems like the World Wide Web are heavily interlinked, but do not show structures that help users to navigate the information it contains. The use of appropriate navigation metaphors can help to make the structure of modern information systems easier to understand and therefore easier to use.We propose a conceptual user interface metaphor based on the structure of a city. Cities are very complex spatial environments and people know how to get information, how to reach certain locations in a city, and how to make use of the available infrastructure, etc. Cities provide a rich set of navigational infrastructure that lends itself to creating sub-metaphors for navigational tools. A city metaphor makes this existing knowledge about a structured environment available to the user of a computerized information system.We first focus on several properties necessary for future user interfaces (or user interface metaphors) that will distinguish them from current systems, like the richness of information or the use of visualizations to show the structure of information spaces. We also describe the strengths and problems of spatial user-interface metaphors. Then we present the structure of the information city metaphor, its structuring and navigation metaphors and what we see as its main advantages and problems. We further outline a few scenarios of how an Information City might work. Finally, we compare implementing this metaphor using either a textual or a graphical virtual environment or a combination.     

Optimal treatment of cancer diseases

A new optimal control model of chemotherapeutic cancer treatment is presented including both the number of cancer cells and the level of toxicity as state variables. It is shown that under certain conditions, periodic drug administration is optimal. Although the model is highly stylized and too simple to describe realistic chemotherapeutic treatment patterns, it may be seen as a first step to prove that periodic treatment strategies are superior to therapies with monotonic decreasing or increasing dosage rates.     

DANUBIA: AN INTEGRATIVE SIMULATION SYSTEM FOR GLOBAL CHANGE RESEARCH IN THE UPPER DANUBE BASIN

We describe the concepts and design principles of the integrative simulation system DANUBIA, which supports the analysis of water-related global change scenarios in the Upper Danube Basin. DANUBIA provides an Internet-based platform integrating the distributed simulation models of all socioecological and natural science disciplines taking part in the GLOWA-Danube project, which is part of the German Programme on Global Change in the Hydrological Cycle. As a result of coupled simulations, transdisciplinary effects of mutually dependent processes can be analyzed and evaluated. Actually 13 simulation models of meteorology, land surface, water research, and social sciences are integrated in the DANUBIA system.

The development of DANUBIA is based on object-oriented software engineering and Web engineering methods and on the Unified Modeling Language (UML), which is used by all partners as a common graphical notation for modeling the integrative aspects of the system.

We describe how the mutually exchanged information between components is modeled and documented by interfaces, we discuss spatial aspects and show how simulation areas are represented, and we consider temporal aspects and describe the coordination of local models by a global time controller which constitutes the heart of any integrative DANUBIA simulation. Finally, we provide an overview of the architecture of the DANUBIA implementation that has been realized in Java. The implementation integrates a wrapper framework that hides the technical details of network communications.     

Absorbing Technological Spillovers: Simulations in an Evolutionary Framework

This paper offers a simulation analysis of firm strategies whichdiffer by the degree of absorbing technical know-how generatedelsewhere. It investigates the success of those firm strategiesin a hetergeneous oligopoly setting in which firms compete byintroducing new products and processes. Simulation results showthat building up absorptive capacities tends to be a superiorstrategy in technologically heterogeneous environments. Reducingspillover effects leads to a slowdown of technological progressbecause cross-fertilization effects are of minor relevance.Where market competition is reduced the absorptive strategytends to be only technologically superior.     

A COMPARATIVE ASSESSMENT OF R/C STRUCTURES DESIGNED TO THE 1995 EUROCODE 8 AND THE 1985 CEB SEISMIC CODE

Two regular R/C ten-storey buildings, a frame and a dual (frame + wall) structure are designed and detailed to the 1985 CEB Seismic Code and to the 1995 Eurocode 8, for a design acceleration of 0·25g and the medium ductility level. The two designs are first compared in terms of cost of materials; then their inelastic response to a number of accelerograms normalized to various earthquake intensities, corresponding to different limit states, is analysed. The resulting demands on each building for each earthquake intensity are checked against the corresponding capacities both at the member and at the storey level, thus allowing an assessment of their seismic performance to be made. A superior performance is found in the Eurocode designed structures, especially the frame structure, which is characterized by adequate drift control even under the maximum credible (‘survival’) earthquake; however, a significant difference in the seismic reliability of column critical regions and the remaining parts of the stuctures has to be pointed out. © 1997 John Wiley & Sons, Ltd.     

超低碳钢连铸过程中Ti和P对水口结瘤的影响

浇注含Ti超低碳钢时,浸入式水口内产生结瘤,严重影响生产效率,同时对产品质量造成危害。根据企业生产的经验,随着超低碳钢中Ti和P含量的增加,水口结瘤的问题越来越严重。通过深入分析实际生产过程的试样和实验室研究,阐明浇注超低碳钢时Ti和P对水口结瘤的影响。分析了含Ti含P的超低碳钢水口结瘤物的成分,结果表明结瘤物的主要成分是氧化铝(>90%),Ti含量较少(0.58%～3.58%)。采用脉冲分布解析原子发射光谱法(OES-PDA)测得氧化夹杂物的大小随Ti含量的增加而变小。采用液滴法测定了溶质Ti和P对钢液/Al2O3体系的润湿性影响,结果表明Ti和P使体系接触角和钢液表面张力降低,其中Ti能够降低体系的接触角只是在其具有反应湿润性的情况下。研究表明Ti和P对产生结瘤的作用有显著区别:只要形成的表层界面具有润湿性,Ti就可以降低Al2O3夹杂物的大小,而氧化铝夹杂物颗粒越小,越容易结瘤。为了不产生结瘤就必须控制好Al脱氧的时间和Ti的加入时间。P可以增加Fe-Ti-P三元体系的润湿性是因为P可以增加Ti的活度,降低钢液的粘度。与Ti相比,P对产生结瘤的影响较小。     

PARTICLE-SIZE DISTRIBUTION INFLUENCE IN HIGH-SPEED EROSION OF ALUMINIUM

ABSTRACT

The paper discusses the influence of the abrasive particle-size distribution on typical high speed abrasive-waterjet erosion parameters. The size distributions of the used abrasive particles are modelled by a Rosin-Rammler-Sperling (RRSB) grain-size distribution containing the distribution parameters D and n. Both parameters are independently varied to characterise different particle-size distributions. Aluminium specimens are eroded by abrasive-waterjets at velocities of 320 m/s, and the erosion depth, depth distribution, and the surface roughness are measured. The depth distribution and the surface roughness are very sensitive to the particle-size distribution parameters, whereas the average erosion depth is not influenced significantly. These results offer the possibility to select an “optimum” grain-size distribution for maximum surface quality at fixed kinematics conditions.     

Development of an Apparatus to Investigate Friction Characteristics of Constant-Velocity Joints

Constant-velocity (CV) joints have become standard design and an integral part of modern vehicles, primarily due to their superiority in terms of CV torque transfer. Despite widespread usage of constant velocity joints there are certain aspects of their friction, wear, and contact characteristics that are not well understood. In this article, the need to directly measure CV joint internal contact and friction forces is addressed by designing and constructing an instrumented advanced CV joint friction apparatus using actual tripod-type joint assemblies. The apparatus is capable of measuring key performance parameters such as friction and wear under different realistic operating conditions of oscillatory speeds and CV joint articulation angles. The apparatus incorporates a custom-installed triaxial force sensor inside of the CV joint to measure in situ internal CV joint forces (including friction). The CV joint apparatus is under full computer control and is communicating with all measurement components via a master Labview control program. Experiments under different articulation angles and lubrication conditions were performed and the measurements were correlated with published data.     

Four years of ocean colour remote sensing with MOS-IRS

The imaging spectrometer MOS on IRS-P3 was launched in March 1996 as the first example of a new generation of ocean colour sensors. It consists of three different spectrometers in the visible/near-infrared spectral region with 18 channels. The IRS-P3 mission is focused on the remote sensing of case 2 water, particularly the derivation of different water constituents in coastal waters. Due to the more complex spectral behaviour of case 2 water, a new methodological approach was developed which works directly with satellite measured top-of-atmosphere radiance and accounts for the correlation of the different water constituents as well as for the spectral shape.

This paper gives an overview of the mission, the scientific goals and the development and improvement of the retrieval algorithms. The potential of the algorithm is demonstrated and examples of selected European coasts are shown. Derived maps of water constituents are presented.