Device scaling engineering is facing major challenges in producing reliable transistors for future electronic technologies. With shrinking device sizes, the total circuit sensitivity to both permanent and transient faults has increased significantly. Research for fault tolerant processors has primarily focused on the conventional processor architectures. Neural network computing has been employed to solve a wide range of problems. This paper presents a design and implementation of a physical neural network that is resilient to permanent hardware faults. To achieve scalability, it uses tiled neuron clusters where neuron outputs are efficiently forwarded to the target neurons using source based spanning tree routing. To achieve fault resilience in the face of increasing number of permanent hardware failures, the design pro-actively preserves neural network computing performance by selectively replicating performance critical neurons. Furthermore, the paper presents a spanning tree recovery solution that mitigates disruption to distribution of neuron outputs caused by failed neuron clusters. The proposed neuron cluster design is implemented in Verilog. We studied the fault resilience performance of the described design using a RBM neural network trained for classifying handwritten digit images. Results demonstrate that our approach can achieve improved fault resilience performance by replicating only 5% most important neurons.

Magnetic tapes have been a primary medium of backup storage for a long time in many organizations. In this paper, the possibility of establishing an inter-network accessible, centralized, tape based data backup facility is evaluated. Our motive is to develop a cloud storage service that organizations can use for long term storage of big data which is typically Write-Once-Read-Many. This Infrastructure-as-a-Service (IaaS) cloud can provide the much needed cost effectiveness in storing huge amounts of data exempting client organizations from high infrastructure investments. We make an attempt to understand some of the limitations induced by the usage of tapes by studying the latency of tape libraries in scenarios most likely faced in the backing up process in comparison to its hard disk counterpart. The result of this study is an outline of methods to overcome these limitations by adopting novel tape storage architectures, filesystem, schedulers to manage data transaction requests from various clients and develop faster ways to retrieve requested data to extend the applications beyond backup. We use commercially available tapes and a tape library to perform latency tests and understand the basic operations of tape. With the optimistic backing of statistics that suggests the extensive usage of tapes to this day and in future, we propose an architecture to provide data backup to a large and diverse client base.

Increasingly, cyber attacks (e.g., kernel rootkits) target the inner rings of a computer system, and they have seriously undermined the integrity of the entire computer systems. To eliminate these threats, it is imperative to develop innovative solutions running below the attack surface. This paper presents MGuard, a new most inner ring solution for inspecting the system integrity that is directly integrated with the DRAM DIMM devices. More specifically, we design a programmable guard that is integrated with the advanced memory buffer of FB-DIMM to continuously monitor all the memory traffic and detect the system integrity violations. Unlike the existing approaches that are either snapshot-based or lack compatibility and flexibility, MGuard continuously monitors the integrity of all the outer rings including both OS kernel and hypervisor of interest, with a greater extendibility enabled by a programmable interface. It offers a hardware drop-in solution transparent to the host CPU and memory controller. Moreover, MGuard is isolated from the host software and hardware, leading to strong security for remote attackers. Our simulation-based experimental results show that MGuard introduces no speed overhead, and is able to detect nearly all the OS-kernel and hypervisor control data related rootkits we tested.

Electrophoretic displays (EPDs) and organic light emitting diode (OLEDs) are two key technologies used in mobile de-vices. In this paper, we propose the design of an integrated hybrid display combining a transparent OLED (TOLED) and a low power EPD, which is adaptive to show contents of a frame partially on either the TOLED or the EPD. A windows-based predictive model and a calibration algorithm on TOLED are introduced to decide how frame contents can be split between the two displays for achieving the best tradeoff between power reduction and user experiences. A simulation environment that can estimate both the energy consumption and optical properties of the proposed hybrid display is set up based on actual physical measurements. Simulation results show that the predictive model can make right decisions on choosing proper displays in over 90% of the test cases, and this new display design can save over 70% power under many mobile application contexts and still sup-port contents that require fast update rates.

Service discovery systems over MANETs are demanded to find available services at an appropriate cost, even if nodes in MANETs frequently move, randomly join or leave, and services may be revoked by their owners. SCN4M-DL is an adaptive directory-less service discovery system for MANETs, and it meets the above challenges by deeply coupling with underlying geographic routing algorithm and setting configurable service renewal. The storage consumption and network traffic are under control due to the adopted ring-based service register and discovery mechanism. Extensive experiments are also conducted. The result data, i.e. the discovery request's success rates and the corresponding costs, show that SCN4M-DL can adapt well to MANET's characteristics and the changes of service states.

Efficiently discovering services in terms of diversified service constraints in a dense MANET is a challenging issue. This paper proposes to build a distributed suffix tree on backbone nodes as XML-based services¿ index to provide a concise profile for service descriptions. Moreover, a content-addressable P2P overlay and corresponding fault-tolerance mechanisms are introduced to support the distributed suffix tree and deal with the changes in network topology. In such a way, the precision and recall for service discovery are guaranteed and can also be degraded gracefully in the face of node failures. Experimental results show that our approach can increase at least 30% precision in comparison with existing distributed index solutions, and our newly-added messages for every 100 queries are only 22% as many as the ones of the compared solutions.