Boon Yaik Ooi

Dynamic service placement and redundancy to ensure service availability during resource failures

Service placement algorithms have been introduced to automatically manage services in distributed environments. However, most of these algorithms aim to improve service performance or to reduce operation cost and do not consider the reliability and availability of their resources. Most of them do not consider events when machines in their resource pool malfunction. These malfunctioned machines could cause services to halt or, worse, to produce transient and intermittent errors. Presently, most of the solutions proposed to improve service availability are based on having redundancy units that do not consider the amount of work and resources needed to create replicas, which greatly increases the complexity of the management of a distributed system. In this paper, we survey state-of-the-art techniques that could improve service availability in distributed environments and propose an autonomie algorithm based on team building concept that dynamically performs service placement to improve service availability even in the event of resource failures.

Resource selection using fuzzy logic for Dynamic Service Placement and Replication

One of the core components of the DSPR framework is the resource evaluation function. The Dynamic Service Placement and Replication (DSPR) framework is designed to manage services on distributed environment by repetitively searching for the best combination of distributed machines from a resource pool until the best working group is attained to satisfy the requirements of the service. In this research, a fuzzy logic based resource evaluation technique is proposed for the DSPR framework. The proposed technique is then compared with existing resource evaluation methods such as rule-based, utility-based and constraint-based. Besides that, the ability of DSPR to increase service availability in the event of multiple continuous failures is measured. The performance difference between using DSPR and conventional system with failover capability in the event of disaster was carried out. These experiments justify the suitability of using the proposed resource evaluation techniques compare to the existing work.

A Store-and-Delivery Based MAC Protocol for Air-Ground Collaborative Wireless Networks for Precision Agriculture

Due to rapid population growth, the demand for food is also elevating, which inspires farmers to embrace precision agriculture to increase production by exploiting predictive analytics on relevant real-time data. The exactitude of a prediction is vital to decide the next course of actions to be taken to compensate current demands, which again relies on a competent data acquisition technique. The Media Access Control (MAC) protocols have significant contribution in designing data acquisition technique. In this paper, we propose a new Store-and-Delivery base MAC (SD-MAC) protocol for Air-Ground Collaborative Wireless Networks (AGCWNs) to acquire data efficiently from the sensing devices which are deployed in the agricultural field. Our proposed protocol takes into consideration of the factors of network architecture and transforms them into advantages to attain higher throughput. The performance of the proposed protocol is evaluated using simulations and involving another such protocol, where the proposed protocol outperforms the other protocol.

Scalability of Database Bulk Insertion with Multi-threading

The advancement of multicore processors and database technologies have enable database insertion to be implemented concurrently via multithreading programming. In this work, we evaluate the performance of using multithreading technique to perform database insertion of large data set with known size. The performance evaluation includes techniques such as using single database connection, multithreads the insertion process with respective database connections, single threaded bulk insertion and multithreaded bulk insertion. MySQL 5.2 and SQL Server 2008 were used and the experimental results show that larger datasets bulk insertion of both databases can drastically be improved with multithreading.

An IPS Evaluation Framework for Measuring the Effectiveness and Efficiency of Indoor Positioning Solutions

The indoor positioning system (IPS) has been attracting great attention from researchers, thanks to the rapid adoption of smartphone technologies. Although there are many IPS proposed in the past decade that claimed to have good performance, all of them use their own method to evaluate and compare the accuracy of the proposed solution. During the evaluation phase, the method of gathering ground truth data (original position) is often not well described. As such, it is very difficult for other researchers to reproduce the work and improve on the existing methods. In this paper, we proposed a simple to implement framework to facilitate the process of evaluating IPS accuracy. Under this framework, the IPS position coordinates and ground truth are sent to the server using REST protocol when the phone reads an event triggered from tags scan placed on a fix position. We evaluated an existing well-known IPS technique, the Pedestrian Dead Reckoning (PDR) technique using our IPS evaluation framework. From our experiments, we showed that in addition to measuring the accuracy of IPS, the proposed solution can also measure the IPS accuracy deviation over time. Instead of relying on precision and recall, the framework also includes visualization tool for researchers to observe the overall accuracy of an IPS.

Towards Natural Gestures for Presentation Control Using Microsoft Kinect

Microsoft Kinect was initially developed for gaming and has since been used in a variety of applications. The work here addressed some of the challenges for it to be used as a gesture driven presentation application. The proposed use of Hidden Markov Model to provide a smoother, and hence a step towards a more natural movement, is demonstrated.