Chien-Liang Fok

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Wireless sensor networks (WSNs) are difficult to program and usually run statically-installed software limiting its flexibility. To address this, we developed Agilla, a new middleware that increases network flexibility while simplifying application development. An Agilla network is deployed with no pre-installed application. Instead, users inject mobile(More)
Agilla is a mobile agent middleware that facilitates the rapid deployment of adaptive applications in wireless sensor networks (WSNs). Agilla allows users to create and inject special programs called mobile agents that coordinate through local tuple spaces, and migrate across the WSN performing application-specific tasks. This fluidity of code and state has(More)
This article presents Agilla, a mobile agent middleware designed to support self-adaptive applications in wireless sensor networks. Agilla provides a programming model in which applications consist of evolving communities of agents that share a wireless sensor network. Coordination among the agents and access to physical resources are supported by a tuple(More)
This paper presents Limone, a new coordination model that facilitates rapid application development over ad hoc networks consisting of logically mobile agents and physically mobile hosts. Limone assumes an agent-centric perspective on coordination by allowing each agent to define its own acquaintance policy and by limiting all agent-initiated interactions(More)
This paper presents MobiQuery, a spatiotemporal query service that allows mobile users to periodically gather information from their surrounding areas through a wireless sensor network. A key advantage of MobiQuery lies in its capability to meet stringent spatiotemporal performance constraints crucial to many applications. These constraints include query(More)
Many applications operate in heterogeneous wireless sensor networks, which represent a challenging programming environment due to the wide range of device capabilities. Servilla addresses this difficulty in developing applications by offering a new middleware framework based on service provisioning. Using Servilla, developers can construct(More)
This paper discusses the actuator-level control of Valkyrie, a new humanoid robot designed by NASA’s Johnson Space Center in collaboration with several external partners. We focus on several topics pertaining to Valkyrie’s series elastic actuators including control architecture, controller design, and implementation in hardware. A decentralized approach is(More)
In December 2013, sixteen teams from around the world gathered at Homestead Speedway near Miami, FL to participate in the DARPA Robotics Challenge (DRC) Trials, an aggressive robotics competition, partly inspired by the aftermath of the Fukushima Daiichi reactor incident. While the focus of the DRC Trials is to advance robotics for use in austere and(More)
As mobile cyber-physical systems (MCPS) begin to pervade our everyday environments, tools and techniques for robustly and reliably evaluating system solutions are an essential but as yet missing component for the development process. Our current methods and tools for validation and evaluation allow examination of components of the overall system in(More)
As wireless sensor networks become increasingly integrated with the Internet, the Internet of Things (IOT) is beginning to emerge. The IOT is a massive cyber-physical system that presents many software engineering challenges. One fundamental challenge is the need for multi-dimensional QoS that can satisfy the individual constraints of the many participants(More)