Stability and reliable operation under a spectrum of environmental conditions is still an open challenge for soft and continuum style manipulators. The inability to carry sufficient load and effectively reject external disturbances are two drawbacks which limit the scale of continuum designs, preventing widespread adoption of this technology. To tackle these problems, this work details the design and experimental testing of a modular, tendon driven bead-style continuum manipulator with tunable stiffness. By embedding the ability to independently control the stiffness of distinct sections of the structure, the manipulator can regulate it’s posture under greater loads of up to 1kg at the end-effector, with reference to the flexible state. Likewise, an internal routing scheme vastly improves the stability of the proximal segment when operating the distal segment, reducing deviations by at least 70.11%. Operation is validated when gravity is both tangential and perpendicular to the manipulator backbone, a feature uncommon in previous designs. The findings presented in this work are key to the development of larger scale continuum designs, demonstrating that flexibility and tip stability under loading can co-exist without compromise.

In this paper, we propose an energy and cost efficient WDM/OFDMA PON system architecture, referred to as NEWOPS. Based on a two-tiered semi-tree topology, NEWOPS allows a large number of ONUs to be connected to OLT using only a handful of colorless transceivers. NEWOPS' unique architecture not only facilitates high spectral efficiency and flexible sub-channel bandwidth allocation, but also enables the system to achieve high energy and cost efficiency. We conduct a theoretical study to identify and resolve a new data-rate performance issue due to the colorless and wavelength re-use design of the system. Experimental results show that when only 5-GHz bandwidth is allotted for each wavelength, NEWOPS successfully achieves symmetric 20-Gb/s downstream and upstream OFDM-16QAM transmissions via the same fiber trunk. As a demonstration of our system, we show how NEWOPS achieves energy efficiency that is two to twelve times higher than that of a typical tree-based WDM/OFDM PON when supporting 40 ONUs.

In this paper, we describe COCA -- Computation Offload to Clouds using AOP (aspect-oriented programming). COCA is a programming framework that allows smart phones application developers to offload part of the computation to servers in the cloud easily. COCA works at the source level. By harnessing the power of AOP, COCA inserts appropriate offloading code into the source code of the target application based on the result of static and dynamic profiling. As a proof of concept, we integrate COCA into the Android development environment and fully automate the new build process, making application programming and software maintenance easier. With COCA, mobile applications can now automatically offload part of the computation to the cloud, achieving better performance and longer battery life. Smart phones such as iPhone and Android phones can now easily leverage the immense computing power of the cloud to achieve tasks that were considered difficult before, such as having a more complicated artificial-intelligence engine.

OFDM PON has been considered to be one of the most prominent next-generation broadband wired access solutions. However, based on the current tree-architecture, existing OFDM PON systems face severe challenges when increasing the scalability and data-rate performance. In this paper, we propose a novel virtual-tree architecture of an OFDMA PON system (VTOPS). Coupled with the use of inexpensive direct modulation, VTOPS simultaneously achieves high reliability, scalability, and spectrum efficiency (i.e., high data rate) in a cost-effective manner. Theoretical and experimental results demonstrate that, by applying the pre-emphasis algorithm and subchannel adaptive modulation, VTOPS achieves 40-Gb/s downlink and uplink transmissions using low-cost 10-GHz directly modulated lasers.