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Full-Text Articles in Engineering

Genetic Algorithms For Synthesis Design Of Metamaterials. (In Chinese), Chien Hsun Chen, P. Y. Chen Apr 2008

Genetic Algorithms For Synthesis Design Of Metamaterials. (In Chinese), Chien Hsun Chen, P. Y. Chen

Chien Hsun Chen

No abstract provided.


Tagtoo, Chien Hsun Chen Jan 2008

Tagtoo, Chien Hsun Chen

Chien Hsun Chen

Tagtoo is a web2.0 based image share and search framework. It is small now, but It would be the most important and famous work at all.


Synthesis Design Of Artificial Magnetic Metamaterials Using A Genetic Algorithm, Chien Hsun Chen, P. Y. Chen, H. Wang, J. H. Tsai, W. X. Ni Jan 2008

Synthesis Design Of Artificial Magnetic Metamaterials Using A Genetic Algorithm, Chien Hsun Chen, P. Y. Chen, H. Wang, J. H. Tsai, W. X. Ni

Chien Hsun Chen

In this article, we present a genetic algorithm (GA) as one branch of artificial intelligence (AI) for the optimization-design of the artificial magnetic metamaterial whose structure is automatically generated by computer through the filling element methodology. A representative design example, metamaterials with permeability of negative unity, is investigated and the optimized structures found by the GA are presented. It is also demonstrated that our approach is effective for the synthesis of functional magnetic and electric metamaterials with optimal structures. This GA-based optimization-design technique shows great versatility and applicability in the design of functional metamaterials.


Towards A Business Model For Cellular Network And Telecommunication Operators: A Theoretical Framework, Mutaz M. Al-Debei, Ramzi El-Haddadeh, David Avison Jan 2008

Towards A Business Model For Cellular Network And Telecommunication Operators: A Theoretical Framework, Mutaz M. Al-Debei, Ramzi El-Haddadeh, David Avison

Dr. Mutaz M. Al-Debei

Cellular networks and telecommunications bring major change to the way businesses are conducted. Mobility has become one of the main priorities for users and this has impacted on cellular networks and telecommunication operators (CNTOs). However, entrants into the cellular industry have been confounded primarily by inexistent or weak Business Models (BMs). Designing a BM for a CNTO is complex and requires multiple actors to balance different and often conflicting design requirements. Nevertheless, most research about CNTOs has been technically oriented and has mainly addressed the technological and engineering issues related to their infrastructure. Less attention has been given to the …


Defining The Business Model In The New World Of Digital Business, Mutaz M. Al-Debei, Ramzi El-Haddadeh, David Avison Jan 2008

Defining The Business Model In The New World Of Digital Business, Mutaz M. Al-Debei, Ramzi El-Haddadeh, David Avison

Dr. Mutaz M. Al-Debei

Recent rapid advances in ICTs, specifically in Internet and mobile technologies, have highlighted the rising importance of the Business Model (BM) in Information Systems (IS). Despite agreement on its importance to an organization’s success, the concept is still fuzzy and vague, and there is no consensus regarding its definition. Furthermore, understanding the BM domain by identifying its meaning, fundamental pillars, and its relevance to other business concepts is by no means complete. In this paper we aim to provide further clarification by first presenting a classification of definitions found in the IS literature; second, proposing guidelines on which to develop …


An Improved Robust Projection Identification Algorithm To Manned Maneuvering Units, Bin Xu Jan 2008

An Improved Robust Projection Identification Algorithm To Manned Maneuvering Units, Bin Xu

Bin Xu

空间载人机动装置(MMU )在进行救援过程中, 其动力学参数存在很大的不确定性。为解决这一辨识问题, 本文首先推导系统关于各动力学参数的线性化模型, 然后结合该线性模型的特点, 提出了一种用于估计动力学参数的改进鲁棒投影算法, 并在理论上分析了该算法的收敛性质, 数字仿真验证了方法的有效性。


A Framework For Evaluating Managerial Styles In Open Source Projects, Tony Wasserman, Eugenio Capra Dec 2007

A Framework For Evaluating Managerial Styles In Open Source Projects, Tony Wasserman, Eugenio Capra

Tony Wasserman

This paper presents the Software Project Governance Framework (SPGF) for characterizing management of software projects, based on mechanisms used for communication and collaboration, the organizational structure of projects, and testing and quality assurance procedures. The framework was developed and validated from interviews and surveys with leaders of more than 70 commercial and community based software projects, including both closed and open source projects.


Mitigation Of Control Channel Jamming Under Node Capture Attacks, Patrick Tague, Mingya Li, Radha Poovendran Dec 2007

Mitigation Of Control Channel Jamming Under Node Capture Attacks, Patrick Tague, Mingya Li, Radha Poovendran

Patrick Tague

Availability of service in many wireless networks depends on the ability for network users to establish and maintain communication channels using control messages from base stations and other users. An adversary with knowledge of the underlying communication protocol can mount an efficient denial of service attack by jamming the communication channels used to exchange control messages. The use of spread spectrum techniques can deter an external adversary from such control channel jamming attacks. However, malicious colluding insiders or an adversary who captures or compromises system users are not deterred by spread spectrum, as they know the required spreading sequences. For …


Byzantium Beneath The Black Sea, Bridget Buxton, Robert Ballard, Michael Brennan, Dwight Coleman, Katy Croff, Christopher Roman, Dan Davis, Dennis Piechota, Sergiy Voronov Dec 2007

Byzantium Beneath The Black Sea, Bridget Buxton, Robert Ballard, Michael Brennan, Dwight Coleman, Katy Croff, Christopher Roman, Dan Davis, Dennis Piechota, Sergiy Voronov

Christopher N. Roman

This poster reports on the August 2007 Black Sea Expedition of the Institute for Archaeological Oceanography at the University of Rhode Island (IAO) and the Institute for Exploration (IFE), in collaboration with the Department of the Underwater Heritage of Ukraine. This year’s work marks a new phase in a multi-year (2000–2012) archaeological and oceanographic survey of the Black Sea. 2007 fieldwork focuses on two Byzantine shipwrecks. The 10th century C.E. shipwreck Chersonesos A (discovered in 2006) lies at 140 m depth in the suboxic zone off the Crimean peninsula. The ship carried a cargo of one-handled jars of a widely …


Ontologies And Shape Grammars: Communication Between Knowledge-Based And Generative Systems, Francois Grobler, Ajla Aksamija, Hyunjoo Kim, Ramesh Krishnmurti, Kui Yue, Casey Hickerson Dec 2007

Ontologies And Shape Grammars: Communication Between Knowledge-Based And Generative Systems, Francois Grobler, Ajla Aksamija, Hyunjoo Kim, Ramesh Krishnmurti, Kui Yue, Casey Hickerson

Ajla Aksamija

This paper discusses information flow between knowledge-based models and shape grammars for generation of building designs, explaining the interaction, system and implementation. The benefit for using the interactive system is that the complementary properties of the two schemes are used to strengthen the overall process. Shape grammar contains rules about the geometric organization, while knowledge-based model supports the contextual information.


On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu Dec 2007

On Collision-Tolerant Transmission With Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Min-You Wu

Hong-Ning Dai

The application of directional antennas in wireless networks brings numerous benefits, such as increased spatial reuse and mitigated interferences. Most MAC protocols with directional antennas are based on the RTS/CTS mechanism which works well in wireless networks using omni-directional antennas. However, RTS/CTS frames cannot mitigate the interfering nodes completely. Besides, they also contribute a lot to the performance overhead. This paper studies the problem from a new perspective. We analyze the transmission success probability under directional transmission and directional reception when the antenna beamwidth is quite narrow. Motivated by the analytical results, we design a lightweight MAC protocol without RTS/CTS …


On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu Dec 2007

On The Capacity Of Multi-Channel Wireless Networks Using Directional Antennas, Hong-Ning Dai, Kam-Wing Ng, Raymond Chi-Wing Wong, Min-You Wu

Hong-Ning Dai

The capacity of wireless ad hoc networks is affected by two key factors: the interference among concurrent transmissions and the number of simultaneous transmissions on a single interface. Recent studies found that using multiple channels can separate concurrent transmissions and greatly improve network throughput. However, those studies only consider that wireless nodes are equipped with only omnidirectional antennas, which cause high collisions. On the other hand, some researchers found that directional antennas bring more benefits such as reduced interference and increased spatial reuse compared with omnidirectional antennas. But, they only focused on a single-channel network which only allows finite concurrent …


Diagnosing Faults In Electrical Power Systems Of Spacecraft And Aircraft, Ole J. Mengshoel, Adnan Darwichse, Keith Cascio, Mark Chavira, Scott Poll, Serdar Uckun Dec 2007

Diagnosing Faults In Electrical Power Systems Of Spacecraft And Aircraft, Ole J. Mengshoel, Adnan Darwichse, Keith Cascio, Mark Chavira, Scott Poll, Serdar Uckun

Ole J Mengshoel

Electrical power systems play a critical role in spacecraft and aircraft. This paper discusses our development of a diagnostic capability for an electrical power system testbed, ADAPT, using probalistic techniques. In the context of ADAPT, we present two challenges, regarding modelling and real-time performance, often encountered in real-world diagnostic applications. To meet the modelling challenge, we discuss our novel high-level specification language which supports auto-generation of Bayesian networks. To meet the real-time challenge, we compile Bayesian networks intro arithmetic circuits. Arithmetic circuits typically have small footprints and are optimized for the real-time avionics systems found in spacecraft and aircraft. Using …