1,037 research outputs found

    A survey to evaluate how non designers perceive aesthetic properties of styling features

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    World-wide market competition and the need to create products that better satisfy the market expectations require a more comprehensive involvement of the customer in the product definition loop. Therefore, it is crucial to provide customers with very easy-to-use shape definition and modification tools, allowing them to verify and evaluate possible shape alternatives without requiring specific knowledge on geometric modeling. A set of aesthetic properties guiding the shape characterization and appraisal have been identified together with measures for their evaluation and shape modeling methods for their direct modification. Since these properties have been indicated by stylists, no guarantee exists that they are usable in a context directly involving customers in the product definition loop. To verify the extent to which the terms indicating the properties, their meaning and their measures are significant and understandable by non-expert designer people we carried out a survey. This paper describes the methodology adopted and the outcomes of this survey

    Automatic Extraction of Assembly Component Relationships for Assembly Model Retrieval

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    AbstractEven if during the Product Design Process, assembly models are described in terms of their constitutive components and associated relationships, only the position of each component is often stored within the Digital Mock-Up. Thus, the mating information are lost. However, these relationships are crucial for many applications, such as retrieval, assembly planning and finite element simulations. In this paper, we propose a method for the detection and use of the mating relationships for assembly model retrieval. The proposed approach detects and analyses the interferences between parts to compute their degree of freedom and kinematic pairs. To support the retrieval of assembly models, the extracted information are formalized and capitalized in a newly proposed hierarchical assembly model descriptor. Results of the application of the method are also provided to show the system capabilities. Moreover, considering that a same joint can be defined in multiple ways, this work provides also a method for retrieving assemblies in a dataset according to the part relationships and their class of equivalence

    Microzooplankton composition in the winter sea ice of the Weddell Sea

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    Sympagic microzooplankton were studied during late winter in the northern Weddell Sea for diversity, abundance and carbon biomass. Ice cores were collected on an ice floe along three dive transects and seawater was taken from under the ice through the central dive hole from which all transects were connected. The areal and vertical microzooplankton distributions in the ice and water were compared. Abundance (max. 1300 ind. l-1) and biomass (max. 28.2 μg C l-1) were high in the ice cores and low in the water below the sea ice (max. 19 ind. l-1, 0.15 μg C l-1, respectively). The highest abundances were observed in the bottom 10 cm of the ice cores. The microzooplankton community within the sea ice comprised mainly aloricate ciliates, foraminifers and micrometazoans. In winter, microzooplankton represent an important fraction of the sympagic community in the Antarctic sea ice. They can potentially control microalgal production and contribute to particulate organic carbon concentrations when released into the water column during the ice melt in spring. Continued reduction of the sea ice may undermine the roles of microzooplankton, leading to a reduction or complete loss of diversity, abundance and biomass of these sympagic protists

    Towards an automatic semantic annotation of car aesthetics

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    The design of a new car is guided by a set of directives indicating the target market and specific engineering and aesthetic constraints, which may include also the preservation of the company brand identity or the restyling of products already on the market. When creating a new product designers are used to evaluating other existing products to take inspiration or to possibly reuse successful solutions. In the perspective of an optimised styling workflow a great benefit could come from the opportunity of easily retrieving the related documentation and existing digital models both from internal and external repositories. In fact, the rapid growth of the web contents and the widely spread adoption of computerassisted design tools have made a huge amount of digital data available, whose exploitation could be improved by more selective retrieval methods. In particular, the retrieval of aesthetic elements may help designers to more efficiently create digital models conforming to specific styling properties. The aim of the research described in this document is the definition of a framework able to support a (semi-) automatic extraction of semantic data from 3D models and other multimedia data to allow car designers to reuse knowledge and design solutions within the styling department. The first objective is then capturing and structuring both the explicit and implicit elements that contribute to the car aesthetics and can be realistically tackled through computational models and methods. The second step is the definition of a system architecture able to transfer such semantics through an automatic annotation of car models

    Coexistence Mechanism for Colocated HDR/LDR WPANs Air Interfaces

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    This paper addresses the issues of interference management among Low Data Rate (LDR) and High Data Rate (HDR) WPAN air interfaces that are located in close-proximity (up to 10 cm) and eventually on the same multimode device. After showing the noticeable performance degradation in terms of Bit Error Rate (BER) and goodput due to the out-of-band interference of an HDR air interface over an LDR air interface, the paper presents a novel coexistence mechanism, named Alternating Wireless Activity (AWA), which is shown to greatly improve the performance in terms of goodput of the most interference vulnerable air interface (i.e., the LDR air interface). The main difference of the proposed mechanism with respect to other collaborative mechanisms based on time-scheduling is that it synchronizes the transmission of the LDR and HDR WPANs at the superframe level instead of packet level. Advantages and limitations of this choice are presented in the paper. Furthermore the functionalities of the AWA mechanism are positioned in a common protocol layer over the Medium Access Control (MAC) sublayers of the HDR and LDR devices and it can be used with any standard whose MAC is based on a superframe structure

    Zero-point fixture systems as a reconfiguration enabler in flexible manufacturing systems

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    ABSTRACT: Today's manufacturing systems need to be able to quickly adapt to customer demands, ranging from high volumes of mass production to high volumes of mass customization. Flexible Manufacturing Systems provide a high degree of flexibility to cope with these challenges. They consist of machine tools capable of executing a wide range of machining operations while the use of pallets to reference and block the parts allows the decoupling of the setup operations from the machining centers activity. This paper presents an ontology-based framework to support the design and management of flexible manufacturing systems, aimed at integrating the various involved activities including the pallet configuration and process planning, the management policies for short-term production planning and the pallet checking to verify the correct configuration of the physical pallet
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