The Designers Tasks

The described mold specifications clearly indicate the complexity of the designer s tasks. In his work, designers are assisted by numerous computerized aids. Computer-aided design has become fully established and widely accepted by now. This is not least due to the increased efficiency of affordable PCs and work stations. 

For the geometrical layout of a mold, CAD (Computer Aided Design) systems are available nowadays, with which an injection molding tool cannot only be described by two-dimensional drawings, but also shown as a complete 3-D model. The latter is of particular interest for the description of the often complex, shape-giving mold contours. The input for producing such a model 

The overall process of mold design is divided into three phases mold design 

Phase 2 Mold layout (rheological, thermal, mechanical) 

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In Chapters Three, Five, and Six, the MEN-synthesis techniques dealt with cases where the separation task was defined as part of the design task. Streams to be... 

Project reviews are not design reviews. Project reviews assess performance of the project and take into account timing, costs, organization, work assignments, subcontracts, etc. Design reviews look back at the technical aspects of design and look forward to the technical aspects of the design tasks ahead. 

Naturally, not all of these properties are improved at the same time nor is there usually any requirement to do so. In fact, some of the properties are in conflict with one another, e.g., thermal insulation versus thermal conductivity. The objective is merely to create a material that has only the characteristics needed to perform the design task. 

Mission statements and charters are often most useful when expressed in terms of job functions rather than of individuals, especially for long-term initiatives during which there may be turnover in the composition of the designated task team. 

Evaluation should be carried out on models that have previously been validated and tested, because the development of a new model suitable for the design task would be expensive and time consuming. This evaluation includes the following areas of concern for each model chosen14 ... 

Upconversion is included because it is a case, unlike aU the others presented, where the refractive index is not a concern in the design of the material. For upconversion, the important parameters for the designer include absorption bands and excited-state lifetimes. Einding the blank host to hold the emitters and keep them separated from each other is also part of the design task. In addition, this host often serves as the primary absorber of the tight to be upconverted. In the case of Er" ", the host contains Yb for this purpose. 

This contains all the design-task modeling elements of HDL, and has structured them, through message passing methods, in such a way that... 

A modeling language is needed to provide multi-faceted representation of the evolving design artifact, and represent the design tasks and their semantic relationships. 

All tasks whose types were already contained in the old definition can be migrated automatically to the new type version. In our example, this rule applies to the design task and the simulation tasks. In contrast, the estimation task s target type cannot be determined uniquely since it was introduced as an untyped task. After all objects have been migrated, the relationships can be migrated automatically. This is possible even for untyped relationships provided that there is only one matching relationship for each pair of object types. 

AHEAD also maintains a model of the overall design process with all design tasks and their interdependencies. Within the process model of AHEAD, the input and output documents of the design tasks are defined and related to product versions of the product model (indicated as links between product model elements and process model elements). 

The design task is to determine the amount of heat recovered from the heat sources of the process to the heat sinks, that is, to estimate the size of heat exchangers and the amount of external energy needed for heating or cooling of the effluent coming from the paper machine. Both summer and winter scenarios are included in the model by combining two parallel process models for summer and winter conditions that are solved simultaneously. Ambient air/water temperatures are 20/20 °C and -5/2 °C for summer and winter, respectively. 

In such subjective statements, detailed information was obtained about the nature of the design problems, the handling of tools (CAD, AI systems, conventional aids, etc.), and the environmental conditions (time pressure, disturbances, etc.). Beeause the design task was already finished, no time pressure exists to investigate all aspects of the stress situation. Because the situation was documented on video in different views (overall situation, CAD screen, desk views), the memory of the subject is maximally aided. 

Subjects were then confronted on videotape with these critical phases (strain-induced video-confixtntation as described earlier). They were asked to explain the causes for the strain they had experienced. The analysis of these interviews provides information to help improve the computer systems as well as describing how the design task is performed. For that purpose, every critical period was identified by at least one stress ctor according to what the engineers indicated as reasons for the strain. 

In contrast to a previous study (Springer et al., 1990), the mean levels of the strain measurements showed no significant difference between conventional and computer- aided work designers. A possible reason for this is the prevalence of the design task as the main stress factor, masking the differences that may exist between the two work modes. 

All of these problems normally occur in the concept phase because the embodiment phase eonsists mainly of drawing the seleeted variant. This also explains the higher amount of time spent in the concept phase as well as the higher strain on the designers who needed more time to finish the design task than the other designers (see Fig. 15.11). 

Many design methods have been proposed to synthesize RAAs. The majority of these methods (see chapter 1 for an overview) are based on an affine transformation (first described by Quinton [15] and Moldovan [12]) to map the index space of the application description to time and processor space. The use of such a transformation method simplifies the design task considerably and requires only a few parameters to characterize a design completely. Unfortunately, most of these methods start from a relatively low level specification, using sets of UREs (uniform recurrence equations) [3] or CUREs (conditional uniform recurrence equations) [17] to describe an application. Moreover, especially in the case of real-time signal processing applications, the resulting architecture is usually unnecessarily fast or too slow. 

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