6,220 research outputs found
Middleware platform for distributed applications incorporating robots, sensors and the cloud
Cyber-physical systems in the factory of the future
will consist of cloud-hosted software governing an agile
production process executed by autonomous mobile robots
and controlled by analyzing the data from a vast number of
sensors. CPSs thus operate on a distributed production floor
infrastructure and the set-up continuously changes with each
new manufacturing task. In this paper, we present our OSGibased
middleware that abstracts the deployment of servicebased
CPS software components on the underlying distributed
platform comprising robots, actuators, sensors and the cloud.
Moreover, our middleware provides specific support to develop
components based on artificial neural networks, a technique that
recently became very popular for sensor data analytics and robot
actuation. We demonstrate a system where a robot takes actions
based on the input from sensors in its vicinity
Extending Eventually Consistent Cloud Databases for Enforcing Numeric Invariants
Geo-replicated databases often operate under the principle of eventual
consistency to offer high-availability with low latency on a simple key/value
store abstraction. Recently, some have adopted commutative data types to
provide seamless reconciliation for special purpose data types, such as
counters. Despite this, the inability to enforce numeric invariants across all
replicas still remains a key shortcoming of relying on the limited guarantees
of eventual consistency storage. We present a new replicated data type, called
bounded counter, which adds support for numeric invariants to eventually
consistent geo-replicated databases. We describe how this can be implemented on
top of existing cloud stores without modifying them, using Riak as an example.
Our approach adapts ideas from escrow transactions to devise a solution that is
decentralized, fault-tolerant and fast. Our evaluation shows much lower latency
and better scalability than the traditional approach of using strong
consistency to enforce numeric invariants, thus alleviating the tension between
consistency and availability
Building Regular Registers with Rational Malicious Servers and Anonymous Clients
The paper addresses the problem of emulating a regular register in a synchronous distributed system where clients invoking and operations are anonymous while server processes maintaining the state of the register may be compromised by rational adversaries (i.e., a server might behave as rational malicious Byzantine process). We first model our problem as a Bayesian game between a client and a rational malicious server where the equilibrium depends on the decisions of the malicious server (behave correctly and not be detected by clients vs returning a wrong register value to clients with the risk of being detected and then excluded by the computation). We prove such equilibrium exists and finally we design a protocol implementing the regular register that forces the rational malicious server to behave correctly
File Tracking For Mobile Devices
Since 2010, the smart device has become an integral part of people’s daily lives. The popularity of smart devices has increased dramatically. However, as the number of devices owned by an individual user increases, so does the risk of data leakage and loss. This problem has started to draw attention because the data contained on smart devices tends to be personal or sensitive in nature. Many people have so much data on their devices that they have no idea as to what they are missing when a device is lost. Although there are already some solutions for data recovery, a data backup system on a remote server, these solutions are not accessible in the non-Internet environment. Development of a data recovery system that is accessible in the non-Internet environment is essential because of the constraints of mobile devices, such as unreliable network. This research proposes an architecture that allows the data recovery in both Internet (cloud) and Non-Internet (local) network by using different connection technologies. A data tracking mechanism has also been designed to monitor data flow among multiple devices, such as the cloud server, mobile devices, and tablets. Additionally, a synchronization system has been developed to ensure the consistency of tracking information. By designing and implementing this architecture, the two problems regarding to the data: "what is where" and "who has what" are resolved
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