• Journal of information and communication convergence engineering
• /
• v.10 no.1
• /
• pp.61-65
• /
• 2012

Many public organizations have been adopting and operating various servers. These servers run on Windows, Unix, and Linux operating systems that generally use less than 10% of their capacity. For migrating a public organization to cloud computing, we must first virtualize the server environment. This article proposes a strategy for server virtualization that the National IT Industry Promotion Agency (NIPA) has done and describes the effects of a public organization migrating to cloud computing. The NIPA Computer Center planned an effective virtualization migration on various servers. This project of virtualization migration was conducted with the existing policy of separate x86 servers and Unix servers. There are three popular approaches to server virtualization: a virtual machine model, a paravirtual machine model, and virtualization at the operating system layer. We selected a VMware solution that uses the virtual machine model. We selected servers for virtualization in the following manner. Servers were chosen that had the highest rate of service usage and CPU usage and had been operating for five years or more. However, we excluded servers that require 80% or greater rates of CPU usage. After adopting the server virtualization technique, we consolidated 32 servers into 3 servers. Virtualization is a technology that can provide benefits in these areas: server consolidation and optimization, infrastructure cost reduction and improved operational flexibility, and implementation of a dual computing environment.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.2
• /
• pp.312-334
• /
• 2023

In large-scale computing, cloud computing plays an important role by sharing globally-distributed resources. The evolution of cloud has taken place in the development of data centers and numerous servers across the globe. But the cloud information centers incur huge operational costs, consume high electricity and emit tons of dioxides. It is possible for the cloud suppliers to leverage their resources and decrease the consumption of energy through various methods such as dynamic consolidation of Virtual Machines (VMs), by keeping idle nodes in sleep mode and mistreatment of live migration. But the performance may get affected in case of harsh consolidation of VMs. So, it is a desired trait to have associate degree energy-performance exchange without compromising the quality of service while at the same time reducing the power consumption. This research article details a number of novel algorithms that dynamically consolidate the VMs in cloud information centers. The primary objective of the study is to leverage the computing resources to its best and reduce the energy consumption way behind the Service Level Agreement (SLA)drawbacks relevant to CPU load, RAM capacity and information measure. The proposed VM consolidation Algorithm (PVMCA) is contained of four algorithms: over loaded host detection algorithm, VM selection algorithm, VM placement algorithm, and under loading host detection algorithm. PVMCA is dynamic because it uses dynamic thresholds instead of static thresholds values, which makes it suggestion for real, unpredictable workloads common in cloud data centers. Also, the Algorithms are adaptive because it inevitably adjusts its behavior based on the studies of historical data of host resource utilization for any application with diverse workload patterns. Finally, the proposed algorithm is online because the algorithms are achieved run time and make an action in response to each request. The proposed algorithms' efficiency was validated through different simulations of extensive nature. The output analysis depicts the projected algorithms scaled back the energy consumption up to some considerable level besides ensuring proper SLA. On the basis of the project algorithms, the energy consumption got reduced by 22% while there was an improvement observed in SLA up to 80% compared to other benchmark algorithms.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.26 no.1
• /
• pp.91-101
• /
• 2023

Modeling and Simulation(M&S) technology has been widely used to solve constraints such as time, space, safety, and cost when we implement the same development and test environments as real warfare environments to develop, test, and evaluate weapon systems for the last several decades. The integration and test environments employed for development and test & evaluation are required to provide Live Virtual Construction(LVC) simulation environments for carrying out requirement analysis, design, integration, test and verification. Additionally, they are needed to provide computing environments which are possible to reconfigure computing resources and software components easily according to test configuration changes, and to run legacy software components independently on specific hardware and software environments. In this paper, an Integration Test and Simulation for Engagement Control(ITSEC) bed using a bare-metal virtualization mechanism is proposed to meet the above test and simulation requirements, and it is applied and implemented for an air missile defense system. The engagement simulation experiment results conducted on air and missile defense environments demonstrate that the proposed bed is a sufficiently cost-effective and feasible solution to reconfigure and expand application software and computing resources in accordance with various integration and test environments.

• Journal of Korea Society of Industrial Information Systems
• /
• v.24 no.5
• /
• pp.129-137
• /
• 2019

Ubiquitous computing technology is emerging as information technology advances. In line with this, a number of studies are being carried out to increase device miniaturization and user convenience. Some of the proposed devices are user-friendly and uncomfortable with hand-held operation. To address these inconveniences, this paper proposed a virtual button that could be used in watching television. When watching a video on television, a camera is installed at the top of the TV, using the fact that the user watches the video from the front, so that the camera takes a picture of the top of the head. Extract the background and hand area separately from the filmed image, extract the outline to the extracted hand area, and detect the tip point of the finger. Detection of the end point of the finger produces a virtual button interface at the top of the image being filmed in front, and the button activates when the end point of the detected finger becomes a pointer and is located inside the button.

• Journal of KIISE:Computer Systems and Theory
• /
• v.28 no.1_2
• /
• pp.80-89
• /
• 2001

The development in the mobile computing systems have arisen new and previously unforeseen problems, such as problems in information management of mobile host, disconnection of mobile host and low bandwidths of wireless communications. Especially, location information management strategy of mobile host results in an increased overhead in mobile computing systems. Due to the mobility of the mobiles host, the changes in the mobile host's address depends on the mobile host's location, and is maintained by mapping physical address on virtual address, Since previously suggested several strategies for mapping method between physical address and virtual address did not tackle the increase of mobile host and distribution of location information, it was not able to support the scalability in mobile computing systems. Thus, to distribute the location inrormation, we propose an advanced n-depth LiST (Location information Search Tree) and the parallel location search and update strategy based on the advanced n-depth LiST. The advanced n-depth LiST is logically a hierarchical structure that clusters the location information server by ring structure and reduces the location information search and update cost by parallel seatch and updated method. The experiment shows that even though the distance of two MHs that communicate with each other is large, due to the strnctural distribution of location information, advanced n-depth LiST results in good performance. Moreover, despite the reduction in the location information search cost, there was no increase in the location information update cost.

• KIISE Transactions on Computing Practices
• /
• v.23 no.4
• /
• pp.199-209
• /
• 2017

Recently, there has been growing interest in workload consolidation via virtualization for real-time systems. Meanwhile, due to virtualization, additional overhead from intervention of hypervisor increases the execution time of applications running on virtual machine. The increase in execution time decreases the performance of workloads on virtual machines, thus satisfying real-time requirements are not easy. To resolve the problem, we designed and implemented a hypervisor (the K-Hypervisor) that allows programs on virtual machines to access the physical resources, without intervention of the hypervisor. Experimental results show that programs running on K-Hypervisor increase their execution time by about 3% on an average, compared to the native environment. Moreover, it is suitable for real-time workload execution because of its uniform performance degradation, regardless of the resources accessed from tasks, and the frequency it is accessed.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.1
• /
• pp.66-71
• /
• 2006

Recently, there are lots of concerning on ubiquitous environment of robots and URC (Ubiquitous Robotic Companion). In this paper, a practical ubiquitous interface system far controlling mobile robots in indoor environments was proposed. The interface system was designed as a manager-agent model including a PC manager, a mobile manager, and robot agents for being able to be accessed by any network. In the system, the PC manager has a 3D virtual environment and shows real images for a human-friendly interface, and share the computation load of the robot such as path planning and managing geographical information. It also contains Hybrid Format Manager(HFM) working for transforming the image, position, and control data and interchanging them between the robots and the managers. Mobile manager working in the minimized computing condition of handsets has a mobile interface environment displaying the real images and the position of the robot and being able to control the robots by pressing keys. Experimental results showed the proposed system was able to control robots rising wired and wireless LAN and mobile Internet.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.6
• /
• pp.542-546
• /
• 2007

In the vision of ubiquitous computing environment, smart objects would communicate each other and provide many kinds of information about user and their surroundings in the home. This information enables smart objects to recognize context and to provide active and convenient services to the customers. However in most cases, context-aware services are available only with expert systems. In this paper, we present generalized activity recognition application in the smart home based on a naive Bayesian network(BN) and fuzzy clustering. We quantize continuous sensor data with fuzzy c-means clustering to simplify and reduce BN's conditional probability table size. And we apply mutual information to learn the BN structure efficiently. We show that this system can recognize user activities about 80% accuracy in the web based virtual smart home.

• 제어로봇시스템학회:학술대회논문집
• /
• 1999.10a
• /
• pp.177-180
• /
• 1999

Nowadays, one of the major technical issues in manufacturing is to create an environment to promote collaboration among diverse engineering activities. Collaborative engineering is an innovative approach integrating widely distributed engineering activities through promoting information sharing and actual collaboration. It requires close interactions among developers, suppliers and customers, and consideration of entire product life cycle from concept to disposal. A carefully-designed operating system is crucial for successful collaboration of many different activities in a Networked Virtual Manufacturing System(NVMS). High extensibility, flexibility and efficiency ale the key characteristics requested of an operating system to handle the complexity of the NVMSs. In this paper, we propose a model of the operating system for collaborative engineering using concurrent quasi-procedural method(QPM). QPM is a goal-driven data management technique for distributed and parallel computing environments. It is to be applied to the evaluation of activities to be executed, validities of input data, execution path of activities for a needed output, and expected to greatly improve the productivity of operations by preventing redundant evaluations. Collaboration among many different engineering activities in NVMSs is to be performed by the network of agents that encapsulate the capabilities of both users and their tools.

• Korean Journal of Computational Design and Engineering
• /
• v.19 no.3
• /
• pp.272-280
• /
• 2014

Most of the car navigation systems pzrovide 2D or 3D virtual map-based driving guidance. One of the important issues is how to reduce cognitive burden to the driver who should interpret the abstracted information to real world driving information. Recently, an augmented reality (AR)-based navigation is considered as a new way to reduce cognitive workload by superimposing guidance information into the real world scene captured by the camera. In particular, head-up display (HUD) is popular to implement AR navigation. However, HUD is too expensive to be set up in most cars so that the HUD-based AR navigation is currently unrealistic for navigational assistance. Meanwhile, smartphones with advanced computing capability and various sensors are popularized and also provide navigational assistance. This paper presents a research on cognitive effect and responsiveness of an AR navigation by a comparative study with a conventional virtual map-based navigation on the same smartphone. This paper experimented both quantitative and qualitative studies to compare cognitive workload and responsiveness, respectively. The number of eye gazing at the navigation system is used to measure the cognitive effect. In addition, questionnaires are used for qualitative analysis of the responsiveness.