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Browsing by Author "Wang, Yi"

Now showing 1 - 3 of 3
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    Design and Evaluation of Contextualized Video Interfaces
    Wang, Yi (Virginia Tech, 2010-08-05)
    If “a picture is worth a thousand words,” then a video may be worth a thousand pictures. Videos have been increasingly used in multiple applications, including surveillance, teleconferencing, learning and experience sharing. Since a video captures a scene from a particular viewpoint, it can often be understood better if presented within a larger spatial context. We call such interactive visualizations that combine videos with their spatial context "Contextualized Videos". Over recent years, multiple innovative Contextualized Video interfaces have been proposed to taking advantage of the latest computer graphics and video processing technologies. These interfaces opened a huge design space with numerous design possibilities, each with its own benefits and limitations. To avoid piecemeal understanding of the design space, this dissertation systematically designs and evaluates Contextualized Video interfaces based on a taxonomy of tasks that can potentially benefit from Contextualized Videos. This dissertation first formalizes a design space. New designs are created incrementally along the four major dimensions of the design space. These designs are then empirically compared through a series of controlled experiments using multiple tasks. The tasks are carefully selected from a task taxonomy, which helps to avoid piecemeal understanding of the effect of the designs. Our design practices and empirical evaluations result in a set of design guidelines on how to choose proper designs according to the characteristics of the tasks and the users. Finally, we demonstrate how to apply the design guidelines to prototype a complex interface for a specific video surveillance application.
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    Do enterprise systems necessarily lead to innovation? Identifying the missing links with a moderated mediation model
    Cui, Xiling Celine; Zhou, Qiang; Lowry, Paul Benjamin; Wang, Yi (AIS, 2022-01-31)
    Background: Despite widely implemented, enterprise systems remain an unsettled role in organizational innovation. This study purposes to address the effects of enterprise systems (ES) on firm innovation by adopting resource-based theory and capability building theory to focus on ES-enabled competence, rather than ES investment or implementation. ES-enabled competence is proposed to mediate the effect of ES integration on innovation performance. We further propose that continuous improvement moderates (1) the relationship between ES integration and ES-enabled competence, and (2) the relationship between ES-enabled competence and innovation performance. By examining these effects, we aim to discover how ES enables innovation at operational and strategic levels separately. Method: A survey method is conducted to explore the relationship between enterprise systems (ES) and innovation. Data are collected from manufacturing companies in 10 countries of three regions, i.e., Europe, Asia-Pacific, and the USA, and analyzed by using structural equation modeling technique. Results: We confirm the roles of enterprise systems as a resource and a capability and the effects of these roles on innovation—including the operational outcome, new product development performance, and the strategic one, innovation uniqueness. We demonstrate that continuous improvement moderates the mediation paths, namely “ES integration – ES-enabled competence – innovation performance”. The moderated mediation effect exists among continuous improvement, ES integration, ES-enabled competence, and innovation uniqueness. Conclusion: This study contributes to the ES and innovation research by uncovering the micro-foundation underlying ES-enabled innovation from a capability-based framework and elaborating the moderating role of continuous improvement in enhancing innovation.
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    Renewable fatty acid ester production in Clostridium
    Feng, Jun; Zhang, Jie; Ma, Yuechao; Feng, Yiming; Wang, Shangjun; Guo, Na; Wang, Haijiao; Wang, Pixiang; Jimenez-Bonilla, Pablo; Gu, Yanyan; Zhou, Junping; Zhang, Zhong-Tian; Cao, Mingfeng; Jiang, Di; Wang, Shuning; Liu, Xian-Wei; Shao, Zengyi; Borovok, Ilya; Huang, Haibo; Wang, Yi (2021-07-16)
    Bioproduction of renewable chemicals is considered as an urgent solution for fossil energy crisis. However, despite tremendous efforts, it is still challenging to generate microbial strains that can produce target biochemical to high levels. Here, we report an example of biosynthesis of high-value and easy-recoverable derivatives built upon natural microbial pathways, leading to improvement in bioproduction efficiency. By leveraging pathways in solventogenic clostridia for co-producing acyl-CoAs, acids and alcohols as precursors, through rational screening for host strains and enzymes, systematic metabolic engineering-including elimination of putative prophages, we develop strains that can produce 20.3g/L butyl acetate and 1.6g/L butyl butyrate. Techno-economic analysis results suggest the economic competitiveness of our developed bioprocess. Our principles of selecting the most appropriate host for specific bioproduction and engineering microbial chassis to produce high-value and easy-separable end products may be applicable to other bioprocesses. Esters can be used as fuels and specialty chemicals for food flavoring, cosmetic and pharmaceutical industries. Here, the authors systematically engineer clostridia, including discovery and deletion of prophages to increase strain stability, for the production of butyl acetate and butyl butyrate from corn stover at low cost.