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1.
As consumers are becoming increasingly selective of what they wear on their feet, manufacturers are experiencing problems developing and fitting the right footwear. Literature suggests that shoes with a shape similar to feet may be comfortable because they attempt to maintain the feet in a neutral posture. The objective of this paper is to develop a metric to quantify mismatches between feet and lasts and also to be able to generate the two-dimensional outline of the foot using the minimum number of landmarks. Fifty Hong Kong Chinese were participants in the experiment. In addition to subject weight, height, foot length and foot width, the left foot outlines were drawn and 18 landmarks were marked on each of the two-dimensional foot outlines. A step-wise procedure was used to reduce the chosen 18 landmarks to eight, such that the mean absolute negative error (an indicator of 'tightness') between the foot outline and the modelled curve was 1.3 mm. These eight landmarks seem to show an improvement over those proposed by other researchers, thus showing the importance of choosing the right landmarks for modelling the foot. The positive and negative absolute errors were on average 1.8 mm and 1.3 mm respectively. Moreover, the mean errors for the toe region and for the rest of the foot were 1.7 mm and 1.6 mm respectively. The results indicate that the foot outline, an important component for footwear functionality and fitting, may be modelled using eight critical landmarks.  相似文献   

2.
《Ergonomics》2012,55(4):364-383
As consumers are becoming increasingly selective of what they wear on their feet, manufacturers are experiencing problems developing and fitting the right footwear. Literature suggests that shoes with a shape similar to feet may be comfortable because they attempt to maintain the feet in a neutral posture. The objective of this paper is to develop a metric to quantify mismatches between feet and lasts and also to be able to generate the two-dimensional outline of the foot using the minimum number of landmarks. Fifty Hong Kong Chinese were participants in the experiment. In addition to subject weight, height, foot length and foot width, the left foot outlines were drawn and 18 landmarks were marked on each of the two-dimensional foot outlines. A step-wise procedure was used to reduce the chosen 18 landmarks to eight, such that the mean absolute negative error (an indicator of ‘tightness’) between the foot outline and the modelled curve was 1.3 mm. These eight landmarks seem to show an improvement over those proposed by other researchers, thus showing the importance of choosing the right landmarks for modelling the foot. The positive and negative absolute errors were on average 1.8 mm and 1.3 mm respectively. Moreover, the mean errors for the toe region and for the rest of the foot were 1.7 mm and 1.6 mm respectively. The results indicate that the foot outline, an important component for footwear functionality and fitting, may be modelled using eight critical landmarks.  相似文献   

3.
Epidemiological investigations indicate that nursing professionals experience a higher prevalence of musculoskeletal disorders (MSDs) than most other occupational groups. Most nursing activities require standing and walking for prolonged periods. Such job requirements may contribute to MSD problems in the lower extremities. Thus, wearing comfortable nursing shoes is essential to reduce the lower-extremity discomfort for clinical nurses. The objectives of this study are: (1) to evaluate three brands of commercially available nursing footwear and identify the important shoe features for adequate shoe support during nursing activities, and (2) to assess the effect of wearing compression hosiery by measuring the biomechanical, physiological, and psychophysical responses of test participants. The method of this study involved two phases. First, field observations were conducted to collect job demand data, including walking speed, and the ratios of walking, standing, and sitting. Second, an experiment was conducted to evaluate the functions of professional nursing footwear and examine the influence of compression hosiery on lower extremity discomfort relief. Measurements included electromyography (EMG) of the lower leg, joint range of motion (ROM) in the lower extremity, foot pressure, ground reaction force (GRF), and subjective discomfort ratings for the lower body and feet. Summarizing the findings of this study, comfortable footwear for nursing professionals should emphasize a footbed with arch support outside with 1.5 cm thickness of EVA materials in the metatarsal zone and heel height between 1.8 and 3.6 cm; this can minimize foot pressure distribution, impact force, and increase shin and ankle comfort. In addition, wearing compression hosiery is recommended to alleviate lower body and foot discomfort for clinical nurses.  相似文献   

4.
《Ergonomics》2012,55(5):617-628
A shoe wearer's comfort is related to the shape of the footbed of a shoe. Even though the footbed shape is important in footwear design, there exists no methodology to evaluate the existing guidelines used in last making. Thirty-two females participated in an experiment where heel seat length, heel seat inclination and heel height were investigated using the profile assessment device. The dependent variables were plantar pressure and perceived feeling of each participant. The results show that perceived feel is best for wedge angles of 4° and 5° at a heel height of 25 mm, 10° and 11° at a heel height of 50 mm and 16° and 18° at a heel height of 75 mm. A regression model was derived and this explained approximately 80% of the variation of perceived feeling with the contact area, peak plantar pressure and percentage of force acting on the forefoot region. Both heel wedge angle and heel seat length play an important role in the perceived feel of high-heeled shoes. This study, in relation to the load-bearing heel part of a shoe, highlights the importance of good footbed design. The findings can be used to design footwear with enhanced comfort.  相似文献   

5.
6.
The use of 3D imaging techniques has been early adopted in the footwear industry. In particular, 3D imaging could be used to aid commerce and improve the quality and sales of shoes. Footwear customization is an added value aimed not only to improve product quality, but also consumer comfort. Moreover, customisation implies a new business model that avoids the competition of mass production coming from new manufacturers settled mainly in Asian countries.  相似文献   

7.
Neural Computing and Applications - The comfort in footwear is essential because the foot is one of the structures of the human body that supports more weight. Moreover, consumers are demanding...  相似文献   

8.
In this paper, we present a new methodology for custom VLSI layout which aims at a low turnaround time and a high quality of design. VLSI circuits are highly complex, and to speed up the design process we exploit the hierarchical structure of a design, splitting the problem domain into several levels. The process of layout at each level is divided into steps such as placement of rectangular blocks, determining block dimensions, determining interconnection paths, etc. In order to obtain high quailty, designs, we have systematically analyzed the relationship among the parameters being computed at various steps and have accordingly organized the flow of data and control through these steps. There are two novel features in our scheme. First, we do not follow the usual pure top-down or pure bottom-up approach, so as to take into account the influence of design decisions at the higher levels on design decisions made at the lower levels, as well as vice versa. For example, we determine the geometry, of a block taking into consideration the context in which it is placed, as well as the geometries of the lower level blocks it encloses. Second, we perform a look-ahead operation when the values of some parameters are needed before they are actually deterministically computable by the process. For example, at the time of placement, the area required for routing is estimated statistically (before doing the actual routing) so that a more routable placement can be obtained, thereby avoiding some unnecessary iterations.  相似文献   

9.
This paper presents a systematic framework for design customization of footwear for children and identifies three modules related to shoe styling: shoe surface, shoe bottom, and accessory. A new module, shoe cloth, is created to allow a quick change of shoe appearance. Consumers can specify various design attributes in each module, including color, texture, embroidery, and shape. A prototype design system is implemented using augmented reality and sensing technologies based on the framework. This system consists of novel functions that support customization, design evaluation, and pattern development. The user can virtually put a customized shoe model on his/her foot in a video stream. The proposed framework not only facilitates evaluating products that are highly interactive with users, but also helps engage them in the design process. This work realizes the concept of human-centric design for mass customization.  相似文献   

10.
Modeling wrinkles on smooth surfaces for footwear design   总被引:1,自引:0,他引:1  
We describe two new shape operators that superimpose wrinkles on top of a smooth NURBS surface. Previous research studying wrinkles focused mostly on cloth modeling or in animations, which are driven more by visual realism, but allow large elastic deformations. Our operators generate wrinkle-shaped deformations in a region of a smooth surface along a given boundary based on a few basic parametric inputs such as wrinkle magnitude and extent (these terms will be defined in the paper). The essential geometric transformation to map the smooth surface to a wrinkled one will be defined purely in terms of the geometry of the surface and the input parameters. Our model is based on two surface properties: geodesic offsets and surface energy. Practical implementation of the operators is discussed, and examples presented. Finally, the motivation for the operators will be given through their application in the computer-aided design and manufacture of footwear.  相似文献   

11.
Dimensional differences for evaluating the quality of footwear fit   总被引:1,自引:0,他引:1  
Witana CP  Feng J  Goonetilleke RS 《Ergonomics》2004,47(12):1301-1317
Very few standards exist for fitting products to people. Footwear is a noteworthy example. This study is an attempt to evaluate the quality of footwear fit using two-dimensional foot outlines. Twenty Hong Kong Chinese students participated in an experiment that involved three pairs of dress shoes and one pair of athletic shoes. The participants' feet were scanned using a commercial laser scanner, and each participant wore and rated the fit of each region of each shoe. The shoe lasts were also scanned and were used to match the foot scans with the last scans. The ANOVA showed significant (p < 0.05) differences among the four pairs of shoes for the overall, fore-foot and rear-foot fit ratings. There were no significant differences among shoes for mid-foot fit rating. These perceived differences were further analysed after matching the 2D outlines of both last and feet. The point-wise dimensional difference between foot and shoe outlines were computed and analysed after normalizing with foot perimeter. The dimensional difference (DD) plots along the foot perimeter showed that fore-foot fit was strongly correlated (R(2) > 0.8) with two of the minimums in the DD-plot while mid-foot fit was strongly correlated (R(2) > 0.9) with the dimensional difference around the arch region and a point on the lateral side of the foot. The DD-plots allow the designer to determine the critical locations that may affect footwear fit in addition to quantifying the nature of misfit so that design changes to shape and material may be possible.  相似文献   

12.

Execution of multiple applications on Multi-Processor System-on-Chips (MPSoCs) significantly boosts performance and energy efficiency. Although various researchers have suggested Network-on-Chip (NoC) architectures for MPSoCs, the problem still needs more investigations for the case of multi-application MPSoCs. In this paper, we propose a fully automated synthesis flow in five steps for the design of custom NoC fabrics for multi-application MPSoCs. The steps include: preprocessing, core to router allocation, voltage island merging, floorplanning, and router to router connection. The proposed flow finds design solutions that satisfy the performance, bandwidth, and power constraints of all input applications. If the user decides, the proposed synthesis adds network-level reconfiguration to improve the efficiency of the obtained design solutions. With the reconfiguration option, the proposed flow comes up with adaptive NoC architectures that satisfy each application’s communication requirements while power-gate idle resources, e.g., router ports and links. If reconfiguration option is not set by the user, the proposed flow considers the top communication requirements among the applications in finding design solutions. We have used the proposed synthesis flow to design custom NoCs for several combined graphs of real-world applications and synthetic graphs. Results show that the reconfiguration option can save up to 98% in the energy-delay product (EDP) of the ultimate designs.

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13.
We address automated testing and interactive proving of properties involving complex data structures with constraints, like the ones studied in enumerative combinatorics, e.g., permutations and maps. In this paper we show testing techniques to check properties of custom data generators for these structures. We focus on random property-based testing and bounded exhaustive testing, to find counterexamples for false conjectures in the Coq proof assistant. For random testing we rely on the existing Coq plugin QuickChick and its toolbox to write random generators. For bounded exhaustive testing, we use logic programming to generate all the data up to a given size. We also propose an extension of QuickChick with bounded exhaustive testing based on generators developed inside Coq, but also on correct-by-construction generators developed with Why3. These tools are applied to an original Coq formalization of the combinatorial structures of permutations and rooted maps, together with some operations on them and properties about them. Recursive generators are defined for each combinatorial family. They are used for debugging properties which are finally proved in Coq. This large case study is also a contribution in enumerative combinatorics.  相似文献   

14.
With the ability of customization for an application domain, extensible processors have been used more and more in embedded systems in recent years. Extensible processors customize an application domain by executing parts of application code in hardware instead of software. Determining parts of application code as custom instruction generally requires subgraph enumeration and subgraph selection. Both subgraph enumeration problem and subgraph selection problem are computationally difficult problems. Most of previous works focus on sequential algorithms for these two problems. In this paper, we present a parallel implementation of a latest subgraph enumeration algorithm based on a computer cluster. A standard ant colony optimization algorithm (ACO), a modified version of ACO with local optimum search and a parallel ACO algorithm are also proposed to solve the subgraph selection problem in this work. Experimental results show that the parallel algorithms outperform the sequential algorithms in terms of runtime or (and) quality of results. In addition, we have formally proved the upper bound on the number of feasible solutions in subgraph selection problem with or without the overlapping constraint.  相似文献   

15.
Custom-instruction selection is an essential phase in instruction set extension for reconfigurable processors. It determines the most profitable custom-instruction candidates for implementing in the reconfigurable fabric of a reconfigurable processor. In this paper, a practical computing model is proposed for the custom-instruction selection problem that takes into account the area constraint of the reconfigurable fabric. Based on the new computing model, two heuristic algorithms and an exact algorithm are proposed. The first heuristic algorithm, denoted as HEA, dynamically assigns priorities to the custom instruction candidates and incorporates efficient strategies to select custom instructions with the highest priority. The second heuristic algorithm, denoted as TSA, employs an efficient tabu search algorithm to refine the results of HEA to near-optimal ones. Also, a branch-and-bound algorithm (BnB) is proposed to produce exact solutions for relatively small-sized problems or problems with stringent area-constraints. Experimental results show that HEA can produce more specific approximate solutions with a difference of only about 3% when compared to the optimal solutions produced by BnB. This difference is further reduced to about 0.6% by TSA. In addition, for large-sized problems where the exact algorithm becomes prohibitive, HEA and TSA can still produce solutions within reasonable time.  相似文献   

16.
《Ergonomics》2012,55(12):1301-1317
Very few standards exist for fitting products to people. Footwear is a noteworthy example. This study is an attempt to evaluate the quality of footwear fit using two-dimensional foot outlines. Twenty Hong Kong Chinese students participated in an experiment that involved three pairs of dress shoes and one pair of athletic shoes. The participants' feet were scanned using a commercial laser scanner, and each participant wore and rated the fit of each region of each shoe. The shoe lasts were also scanned and were used to match the foot scans with the last scans. The ANOVA showed significant (p?<?0.05) differences among the four pairs of shoes for the overall, fore-foot and rear-foot fit ratings. There were no significant differences among shoes for mid-foot fit rating. These perceived differences were further analysed after matching the 2D outlines of both last and feet. The point-wise dimensional difference between foot and shoe outlines were computed and analysed after normalizing with foot perimeter. The dimensional difference (DD) plots along the foot perimeter showed that fore-foot fit was strongly correlated (R 2?>?0.8) with two of the minimums in the DD-plot while mid-foot fit was strongly correlated (R 2?>?0.9) with the dimensional difference around the arch region and a point on the lateral side of the foot. The DD-plots allow the designer to determine the critical locations that may affect footwear fit in addition to quantifying the nature of misfit so that design changes to shape and material may be possible.  相似文献   

17.
Object-oriented design for manufacture   总被引:4,自引:0,他引:4  
Economically effective and timely product manufacture requires that appropriate decisions are taken during the design of the product. Recent years have seen very considerable growth in the study and communication of knowledge in the area of design for manufacture (DFM). At the same time there have appeared many additional pressures on the design process: rapid changes in market requirements, evolution and revolution in product and process technologies, legislated strictures and liabilities, and quality and cost issues which must increasingly be addressed earlier in the course of product design. As a consequence there is a strongly perceived need to enhance design methods in order to address the many disparate aspects of design in an efficient manner. In this paper the DFM problem is addressed within this larger context. The approach described in the paper begins with the hypothesis that the concept of manufacturability can be established as one of a number of required attributes of a part which is to be designed and manufactured. An information model is then proposed which provides the potential to allow determination of manufactur-ability to be made in an ongoing fashion in parallel with other design activities. The nature of the information model is shown to be in harmony with object-oriented programming environments. Finally, the information model is used to illustrate the potential to embody the large body of DFM knowledge which is already in existence but which has yet to be systematically encoded.  相似文献   

18.
Computing the weighted girth,which is the sum of weights of edges in the minimum weight cycle,is an important problem in network analysis.The problem for distri...  相似文献   

19.
本文将 APPLE-Ⅱ计算机与电化学系统联机,研制了微机控制的微电极伏安仪。该仪器除能做稳态实验外,还可以进行结果计算和处理。其电势扫描速度达到几十伏/秒,能用于较快速电势扫描的研究。自动化程度大大提高。  相似文献   

20.
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