1,866 research outputs found
On Constructing the Analytical Solutions for Localizations in a Slender Cylinder Composed of an Incompressible Hyperelastic Material
In this paper, we study the localization phenomena in a slender cylinder
composed of an incompressible hyperelastic material subjected to axial tension.
We aim to construct the analytical solutions based on a three-dimensional
setting and use the analytical results to describe the key features observed in
the experiments by others. Using a novel approach of coupled series-asymptotic
expansions, we derive the normal form equation of the original governing
nonlinear partial differential equations. By writing the normal form equation
into a first-order dynamical system and with the help of the phase plane, we
manage to solve two boundary-value problems analytically. The explicit solution
expressions (in terms of integrals) are obtained. By analyzing the solutions,
we find that the width of the localization zone depends on the material
parameters but remains almost unchanged for the same material in the post-peak
region. Also, it is found that when the radius-length ratio is relatively small
there is a snap-back phenomenon. These results are well in agreement with the
experimental observations. Through an energy analysis, we also deduce the
preferred configuration and give a prediction when a snap-through can happen.
Finally, based on the maximum-energy-distortion theory, an analytical criterion
for the onset of material failure is provided.Comment: 27 pages 10 figure
Rationality of Euler-Chow series and finite generation of Cox rings
In this paper we work with a series whose coefficients are the Euler
characteristic of Chow varieties of a given projective variety. For varieties
where the Cox ring is defined, it is easy to see that in this case the ring
associated to the series is the Cox ring. If this ring is noetherian then the
series is rational. It is an open question whether the converse holds. In this
paper we give an example showing the converse fails. However we conjecture that
it holds when the variety is rationally connected. As an evidence of this
conjecture, It is proved that the series is not rational, and in a sense
defined, not algebraic, in the case of the blowup of the projective plane at
nine or more points in general position. Furthermore, we also treat some other
examples of varieties with infinitely generated Cox ring, studied by Mukai and
Hassett-Tschinkel. These are the first examples known where the series is not
rational. We also compute the series for Del Pezzo surfaces.Comment: 26 pages. In this last version we correct many typos and add a cite
of a work of Artebani and Laface in Theorem 1.6 which was brought to our
attention. More typo correction
Meshfree micromechanical modelling of the mechanical properties and responses of woven composites
Obtaining a clear understanding of the elastic properties and overall responses of woven composites is a significant prerequisite for cost-effective design of these materials. Such an understanding is often achieved via developing unit cell (UC) models using analytical or the FEM-based approaches, which leads to either the problem of a reduced accuracy, resulting from the analytical nature, or the concern of high complexity, associated with using elements. The aim of this work is to simultaneously address the above concerns by developing a meshfree-based UC modelling approach to predict the elastic properties and overall responses of woven composites. Specifically, high-fidelity UC models have been developed to describe the internal architecture of woven composites, which addresses the accuracy problem in analytical approaches. Also, meshfree methods have been employed to implicitly implement the UC models, eliminating the complexity problem in the FEM-based approaches. For predicting the overall responses, constitutive modelling has been performed for the constituents of woven composites, with a viscoplasticity-based model being selected to describe the nonlinear and rate-dependent behaviour of polymer matrix and a Weibull function based formulation being proposed to identify the damage of yarn material. Furthermore, in-house computer programs implementing the UC models, the constitutive models and the meshfree methods have been coded, and numerical examples have been conducted for predicting the elastic properties and overall responses of woven composites. It has demonstrated that the meshfree-based predictions agree well with the experimental results and the data in the literature, validating the proposed approach. The significance of this work is that it eliminates the problems in traditional approaches and meanwhile extends the capability of the UC modelling methodology from homogenising only the elastic properties in the normal directions to predicting the elastic properties and overall responses of woven composites in both the normal and off-axis directions.Open Acces
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Rejuvenation of a Once Beautiful Greenway: Beijing Tongzhou Grand Canal
Many years ago, the Beijing Tongzhou Grand Canal was the northern destination point of the journey along the Jing-Hang Grand Canal in China. It once operated as a shipping gateway through the country to Beijing y, and was a historicly significant greenway of China. Now, the Grand Canal is an important urban district for modern Beijing and requires greater attention to strategic planning. Our design team was hired by the municipal park department to produce a new master plan for a total area of 120 hectares along the waterway which had fallen into decay through the compounding consequences of a 2400 year history. The master plan provides guidelines for future development of this area. The scope of the project includes Phase I landscape design to improve a 80,000 square meter Tongzhou Grand Canal Cultural Plaza. The project landscape architects designed with an eye towards respecting and preserving the culture and environment by using local historic elements. They also applied sustainable development methods in their planning and design practice i.e. strict water management guidelines organized within the site serve to collect, store, and preserve rain water for plant materials. Retention ponds and dry wells were introduced to local landscape practice etc. Through a masterplanning process and phase I - Grand Canal Cultural Plaza site plan design, this portion of the historic canal has become a charming greenway corridor that the community is proud of and patrons are enthusiastic about
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A New Approach - Dealing With the Challenges of Rapid Urbanization in Hainan, China
During the rushed process to urbanize, land development practices can be harsh on local people as well as the natural and cultural character of the land. With strong governmental power in China, land acquisition by government and developers is usually much easier than in the US. Local residents may be relocated without asking for their input, making way for expensive housing and large hotels; the land they depended on to earn their living may be replaced by seemingly endless identical luxury vacation villas, shopping complexes, and theme parks. Residents face the threat of losing the traditional income source and, later, becoming a part of the social problems of the local society. In the conventional practice, the landscape architects’ role in urbanization development is limited in China. The government, the developer, and the local people all have their own different objectives. The team’s task becomes a key role in coordinating and guiding them, in creatively leading the development process
This presentation, using the Yanoda Ecotourism Zone Planning project of Hainan, China as an example, demonstrates the landscape architecture team’s successful attempt to work in a leading role and propose an Ecotourism and Sustainable Development method, a creative way to plan the land use that rejects the conventional model in favor of a progressive blend of ideas, directly involving and benefiting the local people in an ecologically and culturally sustainable way
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From a Concrete Bulkhead Riverbank to a Vibrant Shoreline Park--Suining South Riverfront Park
Living in a world beset by rising sea level, floods in urban and suburban areas, and air pollution, landscape architects face more challenges in landscape and greenway planning. The landscape architects should understand the responsibility to act in an impactful and enduring way for a more sustainable future. This paper takes the Suining South Riverfront Park Landscape Design Project as an example to analyze and present the impact of greenway as a park on riparian ecological systems, urban storm-water management, green infrastructure, public recreation, and environmental education.
The Suining South Riverfront Park Landscape Design Project is located in Suining City, Sichuan Province, China. The project site is a 4 kilometer stretch of riverside land adjacent to the city\u27s forthcoming urban growth district. Before the landscape architects were commissioned to design the 47.5 hectares park in mid-2017, the local government had been installing riverfront hydraulic engineering structures covering two-thirds of the length of the riverbank in an unappealing concrete bulkhead that was an eye-sore to the community. Being that the structure was required to remain in the park to prevent flooding, it was imperative for the design team to find creative solutions for dealing with this major obstacle between the city and the river. Repairing the ecological degradation to the river caused by the construction of the bulkhead was also paramount. This project transformed an ecologically and socially lifeless shoreline belt into a verdant and sustainable riverfront park by integrating ecological infrastructure, phytoremediation, urban-weaving and resilient strategies. The overall design is rooted in Suining City\u27s regional culture, which has a strong relationship with the legend of the Guanyin Buddha. A bold garden terrace pattern, derived from the auspicious cloud forms often associated with Guanyin Buddha. A much closer water-to-human relationship is introduced by concealing an existing bulkhead structure beneath stylized terraces of landscape inspired by regional culture, drawing city dwellers and urban visitors towards the forgotten natural beauty of the Fujiang River. The gray hydraulic dam in the outer edge of the city is transformed into a sought after, highly desirable riverfront destination. The re-establishment of native species within an intricate system of wetlands, ponds, islands and riparian habitats, in a previously barren terrain, contributed to an overall reacclimatizing of the riverfront that welcomes the return of native wildlife, cementing this project as a pilot for resilient green shores infrastructure initiatives(in other cities).
The result of the park has reformed the gray concrete embankment into a resilient, ecologically-sound riverfront with numerous riparian habitats, enhanced stormwater management and water cleansing system, recovered native habitats, and created a new cherished public space for gathering and multi-sensory enjoyment
On-device dialog management
This disclosure describes techniques for on-device dialog management that enable a voice-based multi-turn dialog without the need for network connectivity. Although the techniques support a fully hands-free mode, parts of the dialog can also be entered by the user using a touch or other interface
Assessing Customer-Based Brand Equity of E-Commerce Platform Based on Promotion Benefits
The prosperity of e-commerce in China leads to large amount of businesses venturing into this marketplace. Sales promotion has been widely used to improve their advantage, while platform-based sales promotion has been confirmed more successful. This research examines the impacts of the benefits of sales promotions based on electronic commerce platforms on customer-based brand equity (platform brand awareness and platform brand association) and how their relationships are moderated by the promotion type (pre- and post-purchase promotion). Based on the two functions of sales promotions (stimulation vs. maintaining), we propose a five-benefit framework including exploration, convenience, savings, social bonds and structural bonds. We suggested that both the two types of sales promotion could provide the five benefits of sales promotions and the positive effects of the benefits on consumer-based brand equity might be significant, while the differences between pre- and post-purchase sales promotions could be also significant
Behavior Coordination in E-commerce Supply Chains
This paper studies the behavior coordination of members in e-commerce supply chains with cooperative game theory. Under the environment of e-commerce, the retailers and the supplier can maximize their profits through the cooperation with the information provider. We study this cooperation by means of cooperative game theory and emphasize the importance of the information provider in the cooperation. We give a core allocation and a solution for these games
The Impacts of Environmental Cues and Browsing Experience on Impulse Buying on Social Shopping Website
Based on the stimulus-organism-response (S-O-R) paradigm, this study develops a model to theorize how environmental cues on social shopping website affect impulse buying behavior from the perspective of browsing experience. Social shopping websites bring a novel online browsing experience for customers. However, how browsing experience on this platform affect customers impulsively have received insufficient academic attention. The results reveal that the unique factors of social shopping website, namely the quality of user-generated content and social presence are critical for facilitating customers’ browsing experiences. The results also show that both utilitarian browsing and hedonic browsing experience have a positive impact on customers’ urge to buy impulsively. The theoretical and managerial implications are discussed
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