• KNOM Review
• /
• v.23 no.1
• /
• pp.51-62
• /
• 2020

Open IoT platform that shares communication infrastructure and provides cloud resources can flexibly reduce development period and cost of smart service. In this paper, as an open IoT platform, we propose a virtual IoT system based on edge computing that implements a virtual IoT device for a physical IoT device and allows service developers to interact with the virtual device. A management server in the edge cloud, near the IoT physical device, manages the creation, movement, and removal of virtual IoT devices corresponding to the physical IoT devices. This paper define the operations of the management server, the physical IoT device, and the virtual IoT device, which are major components of the virtual IoT system, and design the communication protocol required to perform the operations. Finally, through simulations, this paper evaluate the performance of the edge computing based virtual IoT system by confirming that each component performs the defined states and operations as designed.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.409-412
• /
• 2007

Demand for the technology for access to device control network in industry and for access to building automation system via internet is on the increase. In such technology integration of a device control network with a data network such as internet and organizing wide-ranging DCS(distributed control system) is needed, and it can be realized in the framework of VDN(virtual device network). Specifications for device control network and data network are quite different because of the differences in application. So a router that translates the communication protocol between device control network and data network, and efficiently transmits information to destination is needed for implementation of the VDN(virtual device network). This paper proposes the concept of NCS(networked control system) based on VDN(virtual device network) and suggests the routing algorithm that uses embedded system.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2009.01a
• /
• pp.834-837
• /
• 2009

Augmented Reality (AR) is a useful technology for various industrial systems. This paper suggests a new playground system which uses markerless AR technology. We developed a virtual playground system that can learn physics and kinematics from the physical play of people. The virtual playground is a space in which real scenes and CG are mixed. As for the CG objects, physics of the real world is used. This is realized by a physics engine. Therefore it is necessary to analyze information from cameras, so that CG reflects the real world. Various games options are possible using real world images and physics simulation in the virtual playground. We think that the system is effective for education. Because CG behaves according to physics simulation, users can learn physics and kinematics from the system. We think that the system can take its place in the field of education through entertainment.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.25-25
• /
• 2000

This paper presents a design method of sliding mode control (SMC) for single input linear systems with mismatched uncertainties. We define a virtual state based on the controllable canonical form of the nominal system. And we define a sliding surface for the augmented system with a virtual state. This sliding surface makes it possible to use SMC technique with various types of controllers. In this paper, we construct a controller that combines SMC with robust controller. We design a robust controller for the system with only mismatched uncertainties using a form of linear matrix inequality (LMI). We make a virtual state from this robust control input and the states of the nominal system. And we design a sliding mode controller that stabilizes the overall closed-loop system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.3
• /
• pp.193-197
• /
• 2001

This paper presents a design method of sliding model control (SMC) for single input linear systems with mismatched uncertainties. We define a virtual state based on the controllable canonical form of the nominal system. And we defined a sliding surface for the augmented system with a virtual state. This sliding surface makes it possible to use the SMC technique with various types of controllers. In this paper, we construct a controller that combines SMC with robust controller. We design a robust controller for the system with mismatched uncertainties using a form of linear matrix inequality(LMI). We make a virtual state from this robust control input and the states of the nominal system. And we design a sliding model controller that stabilizes the overall closed-loop system.

• IEIE Transactions on Smart Processing and Computing
• /
• v.3 no.2
• /
• pp.88-95
• /
• 2014

This paper proposes a novel desktop virtual reality system. Based on the position of the user's face, the proposed system selects the most appropriate image of an object from a set of photographs taken at various angles, and simply "pastes" it onto the display at the appropriate location and scale. Using this system, the users can intuitively feel the presence of the object.

• Journal of Intelligence and Information Systems
• /
• v.5 no.2
• /
• pp.121-132
• /
• 1999

최근 가상기업의 필요성이 증대하고 있다. 기업활동의 효율성을 높이고, 보다 고품질의 서비스를 고객에게 제공하기 위해서 많은 기업에서 도입을 추진하고 있다. 가상기업은 본래 취지를 효율적으로 달성하기 위하여 정보기술에 크게 의존하고 있다. 특히, 협업(Collaboration)과 지식관리(Knowledge Management)가 포함된 VESS(Virtual Enterprise Support System)가 본격적으로 논의되고 있고 유용한 정보의 공유, 가동, 재활용을 위하여 지식공학(Knowledge Engineering)의 효용성이 절실히 필요한 시점이다. 본 고는 이러한 배경에서 가상기업(Virtual Enterprise), 지식관리(Knowledge Management)의 상호 연계성과 시장 및 기술동향에 대해 기술하고 향후 과제를 도출한다.

• Journal of the Ergonomics Society of Korea
• /
• v.19 no.1
• /
• pp.63-76
• /
• 2000

In this study, the factors affecting reality aspect of virtual reality system were identified through Quality Function Deployment. The influence of some selected factors was evaluated in simulated performance test. It was shown that the factor of whether user can break through the objects in virtual space is the most sensitive to performance, followed by the factors of rotation angle and movement step. Also, the results implied that as more referents were provided to user, feeling of reality was enhanced.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2018.05a
• /
• pp.203-204
• /
• 2018

In recent years, interest in various virtual currencies has been increasing, starting with bit coin, and investment and trading of virtual currencies are being activated. However, since the price of virtual money is unstable and the rate of change of the price is very large, frequent confirmation of the amount of money is required, so that virtual money investors often have to check the virtual money market. Therefore, in this paper, we expect that it will reduce the wasted time on the exchange by using the price information guidance system that collects the virtual currency price information data and express it in RGB, and only the system user can understand the data expression and support the confidentiality.

• Journal of Korea Multimedia Society
• /
• v.9 no.9
• /
• pp.1247-1256
• /
• 2006

VM(Virtual Machine) can be considered as a software processor which interprets the abstract machine code. Also, it is considered as a conceptional computer that consists of logical system configuration. But, the execution speed of VM system is much slower than that of a real processor system. So, it is very important to optimize the code for virtual machine to enhance the execution time. In this paper, we designed and implemented the optimizer for the virtual(or abstract) machine code(VMC) which is actually SIL(Standard Intermediate Language) that is an intermediate code of EVM(Embedded Virtual Machine). The optimizer uses the pattern matching optimization techniques reflecting the characteristics of the VMC as well as adopting the existing optimization methodology. Also, we tried a benchmark test for the VMC optimizer and obtained reasonable results.