Daewon Lee

Proxy based seamless connection management method in mobile cloud computing

Nowadays, complex smartphone applications are developed that support gaming, navigation, video editing, augmented reality, and speech recognition which require considerable computational power and battery lifetime. The cloud computing provides a brand new opportunity for the development of mobile applications. Mobile Hosts (MHs) are provided with data storage and processing services on a cloud computing platform rather than on the MHs. To provide seamless connection and reliable cloud service, we are focused on communication. When the connection to cloud server is increased explosively, each MH connection quality has to be declined. It causes several problems: network delay, retransmission, and so on. In this paper, we propose proxy based architecture to improve link performance for each MH in mobile cloud computing. By proposed proxy, the MH need not keep connection of the cloud server because it just connected one of proxy in the same subnet. And we propose the optimal access network discovery algorithm to optimize bandwidth usage. When the MH changes its point of attachment, proposed discovery algorithm helps to connect the optimal access network for cloud service. By experiment result and analysis, the proposed connection management method has better performance than the 802.11 access method.

Efficient Resource Management and Task Migration in Mobile Grid Environments

Grid computing using wireless networks is receiving increasing attention and is expected to become a critical part of future grid computing. However, the inherent challenges of mobile environments such as mobility management, disconnected operation, device heterogeneity, service discovery, and resource sharing are significant issues in mobile grid computing. To achieve the best performance in a mobile grid computing environment, the mobile devices with the lowest probability of mobility should be selected for use first. We therefore focus on the idle state of mobile devices and use IP-paging scheme to identify the idle mobile devices. For this, we propose a user-defined checkpoint technique for task migration, which is based on the information of when a mobile device will leave the network or stop due to low battery. Our checkpoint technique performs checkpoints by two conditions: when a mobile device leaves its current cell and when it turns off due to low battery capacity.

An Estimation-Based Task Load Balancing Scheduling in Spot Clouds

Cloud computing is a computing paradigm in which users can rent computing resources from service providers according to their requirements. Cloud computing based on the spot market helps a user to obtain resources at a lower cost. However, these resources may be unreliable. In this paper, we propose an estimation-based distributed task workflow scheduling scheme that reduces the estimated generation compared to Genetic Algorithm (GA). Moreover, our scheme executes a user’s job within selected instances and stretches the user’s cost. The simulation results, based on a before-and-after estimation comparison, reveal that the task size is determined based on the performance of each instance and the task is distributed among the different instances. Therefore, our proposed estimation-based task load balancing scheduling technique achieves the task load balancing according to the performance of instances.

The Idle Mobile Resource Discovery and Management Scheme in Mobile Grid Computing Using IP-paging

In this paper, we tried to enable a mobile device as a resource to access to the grid network. By improved internet technique, the use of mobile devices is rapidly increased. And some researches in grid computing tried to combine grid computing with mobile devices. However, according to properties of mobile environments, mobile devices have many considerations, such as mobility management, disconnected operation, device heterogeneity, service discovery, resource sharing, security and so on. To conquest these problems, there are two trends for mobile grid computing: a proxy-based mobile grid architecture and an agent-based mobile grid architecture. We focused on a proxy-based mobile grid architecture with IP-paging, which easily manage idle mobile devices and grid resource status information. In result, to support mobile grid services, we propose the IP-paging scheme based on the mobile grid computing framework. Moreover, we have discussed some research issues: location tracking using IP-paging, limited power using grid paging cache, and service migration using reserved resource. And, we also propose a mobile proxy and paging agent prototype. Keywords-component; Mobile Grid Computing, IP-Paging, Active/Idle state, Power consumption

The resource running time manager for integrated environment

Latest scientific application and simulation are requiring powerful computing resources. To get the sufficient resources, more and more computer experts are constructing high-end supercomputer, cluster computing or cloud computing. Although most corporations are starting to use high performance computing by organizing cluster, they rarely add some extra resources dynamically when computing power is not sufficient. In addition, they are also expensive to use insufficient resources as cloud computing resources. To overcome resource limitations when using cloud computing to conduct large computations, we exploit underutilized personal desktops by organizing a heterogeneous cluster environment. An open-source based scheduler, Son of Grid Engine (SGE) is provided in the integrated environment to manage or control the extra computing resources. Two kinds of groups are classified according to the individuals degree of utilization: a full-time group that provides resources at any time, and a custom-time group that provides resources only at designated times. We developed a resource manager that can turn on/off and schedule the SGE execution daemon; this manager performs as the core engine. The resource running time manager efficiently allocates and controls the members of affiliated computing resources.

IoT service classification and clustering for integration of IoT service platforms

With the rapid development of sensors, wireless communication, and cloud computing, information technology today focuses on service environments created by the Internet of Things (IoT). IoT technologies have become widely used in various contexts including smart homes, building management, surveillance services, and smart farms. Some IoT applications such as Siri are popular in everyday life. IoT requires communication and interaction between various devices and services. To solve the various complex problems associated with IoT services, earlier research focused on IoT service platforms such as gateways and mobile edge computing services. However, the similarities and reusabilities of IoT services have received little attention. In this paper, we develop an IoT service classification and clustering system. We classify the operation of an IoT service into four steps that differ in their characteristics. Based on this classification, we extend the classic EM (expectation–maximization) algorithm to cluster IoT services in terms of their similarities. To validate our proposed classification and clustering system, we divide over 100 commercial IoT services into five clusters, showing that such services are well clustered by similarity and purpose.

Efficient data synchronization method on integrated computing environment

To execute scientific applications and simulations of enormous scale, the computing paradigm is evolving into one of cluster computing and cloud computing that can exploit the large number of available computing resources. To maximize the utilization of them, company or research center needs a scheduler engine and its data space to construct a cluster computing environment. However, if certain data space is shared, problems related to the security of node, the network traffic imbalance between nodes, and the data protection could arise. To solve these issues, a manager synchronizing the shared data space for the nodes that constitute a cluster computing environment is designed. The synchronization manager shares data in two ways: First, under the cluster environment, the full synchronization group can mount a specific directory space of the master node via NFS. It is used for the data which can be globally referenced. Second, the partial synchronization group delivers data to assigned workers through rsync. It can be used to locally share data for the isolation. The partial synchronization group is superior to full synchronization group in security and efficiency because data are shared in separate manner. By applying adequate data-sharing method, the designed manager efficiently mediate sharing data as purposed.

Job submission and monitoring management in integrated computing environment for finite element analysis

Modeling and simulation (M&S) is a promising solution for manufacturers to verify and resolve errors in advance. Recently, M&S using high-performance computing has attracted attention as a technology trend for its efficiency in terms of the time and the cost. However, a huge amount of computing resources is still required to perform an M&S analysis workflow within a short time. For the resolution of this issue, we organize a heterogeneous cluster environment with individual nodes of the diverse performance and OS. An open source-based task scheduler named Son of Grid Engine is used for managing the heterogeneous resources for the experiment. To verify the efficiency and validity of the organization scheme, we have developed an environment for analyzing products and monitoring work through CalculiX, an open source-based finite element analysis solver.

Elaborate Synthetic Data Generation for Internet of Things Services at Smart Home Environment

The advent of IoT caused vigorous development of multiple services in diverse industry areas. Especially, smart home services have high accessibility than other services since they are based on everyday home appliances, so they gained special attention of application developers. Those services generate a large volume of data: it not only helps service providers to provide services more efficiently, but also helps them to guarantee Service Level Agreement (SLA) of those services. In this paper, we apply time dependency and usage continuity of daily appliances, and correlation between different services to model behavior patterns of service users and generate reliable synthetic data based on their real log data.

Proxy Based Seamless Connection Management Scheme for Smart Transportation Service

Abstract Nowadays, complex IoT devices are developed that support smart transportation service, medical alarm service, and smart surveillance camera which require communication to the computation server. Most of IoT devices communicate to their servers on fixed network through wireless channel. In this paper, we are focused on smart transportation service that is one of bus, train, airplane or ship that takes embedded IoT devices and passengers using IoT devices. Embedded IoT devices are communicated with embedded access router (AR) on transportation by Bluetooth/Z-wave/NFC, and passengers’ IoT devices are communicated with their own egg/AR on fixed network, or public AR on transportation. Transportation environment has a major problem that mobile node moves fast through multiple cells. Each IoT device in transportation keeps updating its current point of attachment to its home agent and corresponding node. To overcome this problem we consider feature of transportation. It has two major features. The one is mobile device has fast mobility by transportation. The other one is mobile device moves fixed route. It causes mobile device has intra mobility between several subnets of one agency when it moves into a subway or highway. Based on two features, we design proxy based architecture and extend router advertisement message to alert join in proxy domain. Then, we are classified the mobility into intra proxy mobility and global mobility. And we proposed proxy based mobility management scheme using prediction algorithm. By numerical analysis, we shows proposed scheme reduces signaling overheads and increase packet transfer rate than NEMO and proxy MIP.