Horndeski Gravity and the Violation of Reverse Isoperimetric Inequality

We consider Einstein-Horndeski-Maxwell gravity, together with a cosmological constant and multiple Horndeski axions. We construct charged AdS planar black holes in general dimensions where the Horndeski anxions span over the planar directions. We analyse the thermodynamics and obtain the black hole volumes. We show that the reverse isoperimetric inequality can be violated, implying that these black holes can store information more efficiently than the Schwarzschild black hole.Comment: Latex, 25 pages, 1 figure, references adde

Collaborative Engine for Distributed Mechanical Design

Effective collaboration is essential for engineers at geographically dispersed locations to accomplish good design with less iteration. Over the last several years, more and more efforts have been put into such research as many industries have distributed their product development to locations with knowledge force. This paper presents a collaborative engine to facilitate collaborations among distributed mechanical designs. Using component-based software technology, collaboration functionality is developed into a set of groupware that makes the collaborative engine applicable to develop new collaborative applications or integrate legacy applications into collaborative environments. An XML-based information representation is developed to streamline the information transmission within the distributed environment. A case study is carried out to show how this engine facilitates designers to collaboratively create a 3D solid model of a same part in real time.Singapore-MIT Alliance (SMA

A Framework of Implementation of Collaborative Product Service in Virtual Enterprise

To satisfy new market requirements, manufacturing industry has shifted from mass production that takes advantage of the scale of production, to quality management that optimizes the internal enterprise functions, to e-manufacturing era that leverage intellectual capital via collaborative innovation. In the same time, the product itself is becoming the most important asset for sustainable business success. Consequently, the effectiveness, efficiency and innovation for the development of the product across the whole product lifecycle are becoming key business factors for manufacturing enterprise to obtain competitive advantages for survival. To tackle such challenges, a new business model called collaborative product services in virtual enterprise is proposed in this paper. The architecture of this new model is developed based on the framework and the application of web service and process management for collaboration product service in virtual enterprise. Indeed, it is hoped that this architecture will lay the foundation for further research and development of effective product lifecycle management in virtually collaborative enterprise environment.Singapore-MIT Alliance (SMA

Performance-Driven Microfabrication-Oriented Methodology for MEMS Conceptual Design with Application in Microfluidic Device Design

Performance and manufacturability are two important issues that must be taken into account during MEMS design. Existing MEMS design models or systems follow a process-driven design paradigm, that is, design starts from the specification of process sequence or the customization of foundry-ready process template. There has been essentially no methodology or model that supports generic, high-level design synthesis for MEMS conceptual design. As a result, there lacks a basis for specifying the initial process sequences. To address this problem, this paper proposes a performance-driven, microfabrication-oriented methodology for MEMS conceptual design. A unified behaviour representation method is proposed which incorporates information of both physical interactions and chemical/biological/other reactions. Based on this method, a behavioural process based design synthesis model is proposed, which exploits multidisciplinary phenomena for design solutions, including both the structural components and their configuration for the MEMS device, as well as the necessary substances for the chemical/biological/other reactions. The model supports both forward and backward synthetic search for suitable phenomena. To ensure manufacturability, a strategy of using microfabrication-oriented phenomena as design knowledge is proposed, where the phenomena are developed from existing MEMS devices that have associated MEMS-specific microfabrication processes or foundry-ready process templates. To test the applicability of the proposed methodology, the paper also studies microfluidic device design and uses a micro-pump design for the case study.Singapore-MIT Alliance (SMA