• Journal of Korea Society of Industrial Information Systems
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• v.26 no.4
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• pp.11-18
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• 2021

We propose a method that combines learning in a virtual environment and a real environment for indoor autonomous driving through reinforcement learning. In case of learning only in the real environment, it takes about 80 hours, but in case of learning in both the real and virtual environments, it takes 40 hours. There is an advantage in that it is possible to obtain optimized parameters through various experiments through fast learning while learning in a virtual environment and a real environment in parallel. After configuring a virtual environment using indoor hallway images, prior learning was carried out on the desktop, and learning in the real environment was conducted by connecting various sensors based on Jetson Xavier. In addition, in order to solve the accuracy problem according to the repeated texture of the indoor corridor environment, it was possible to determine the corridor wall object and increase the accuracy by learning the feature point detection that emphasizes the lower line of the corridor wall. As the learning progresses, the experimental vehicle drives based on the center of the corridor in an indoor corridor environment and moves through an average of 70 steering commands.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5642-5670
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• 2017

Antivirus is an important issue to the security of virtual machine (VM). According to where the antivirus system resides, the existing approaches can be categorized into three classes: internal approach, external approach and hybrid approach. However, for the internal approach, it is susceptible to attacks and may cause antivirus storm and rollback vulnerability problems. On the other hand, for the external approach, the antivirus systems built upon virtual machine introspection (VMI) technology cannot find and prohibit viruses promptly. Although the hybrid approach performs virus scanning out of the virtual machine, it is still vulnerable to attacks since it completely depends on the agent and hooks to deliver events in the guest operating system. To solve the aforementioned problems, based on in-memory signature scanning, we propose an agentless runtime antivirus system VirtAV, which scans each piece of binary codes to execute in guest VMs on the VMM side to detect and prevent viruses. As an external approach, VirtAV does not rely on any hooks or agents in the guest OS, and exposes no attack surface to the outside world, so it guarantees the security of itself to the greatest extent. In addition, it solves the antivirus storm problem and the rollback vulnerability problem in virtualization environment. We implemented a prototype based on Qemu/KVM hypervisor and ClamAV antivirus engine. Experimental results demonstrate that VirtAV is able to detect both user-level and kernel-level virus programs inside Windows and Linux guest, no matter whether they are packed or not. From the performance aspect, the overhead of VirtAV on guest performance is acceptable. Especially, VirtAV has little impact on the performance of common desktop applications, such as video playing, web browsing and Microsoft Office series.

• Journal of Drive and Control
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• v.18 no.4
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• pp.77-83
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• 2021

With the progress in virtual reality technology, various virtual objects can be displayed using head-mounted displays (HMD). However, force feedback sensations such as pushing against a virtual object are not possible with an HMD only. Focusing on force feedback, desktop-type devices are generally used, but the user cannot move in a virtual space because such devices are fixed on a desk. With a wearable force feedback device, users can move around while experiencing force feedback. Therefore, the authors have developed a wearable force feedback device using a magnetorheological fluid clutch and pneumatic rubber artificial muscle, aiming at presenting the elasticity, friction, and viscosity of an object. To date, we have developed a wearable four-degree-of-freedom (4-DOF) force feedback device and have quantitatively evaluated that it can present commanded elastic, frictional, and viscous forces to the end effector. However, sensory evaluation with a human has not been performed. In this paper, therefore, we conduct a sensory evaluation of the proposed method. In the experiment, frictional and viscous forces are rendered in a virtual space using a 4-DOF force feedback device. Subjects are asked to answer questions on a 1- to 7-point scale, from 1 (not at all) to 4 (neither) to 7 (strongly). The Wilcoxon signed rank test was used for all data, and answer 4 (neither) was used as compared standard data. The experimental results confirmed that the user could feel the presence or absence of viscous and frictional forces. However, the magnitude of those forces was not sensed correctly.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.118-128
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• 2015

Recently BIM technology has been expanded for using in construction project. Due to the high-cost of BIM infrastructure development, lack of regulations, lack of process and so forth, usage of BIM has been delayed than initial expectations. In design phase, especially, collaboration based on BIM system has been a key factor for successful next generation building project. Through the analysis of current research trends about IT technologies, virtualization and BIM service, data exchange such as drawings, 3D model, object data, properties using cloud computing and virtual server system is defined as a most successful solution. The purpose of this study is to enable the cloud computing BIM server to provide several main functions such as editing models, 3D model viewing and checking, mark-up and snapshot in high-performance quality by proper design of VDI system. Concurrent client connection performance is a main technical index of VDI. Through testing of test-bed server client, developed VDI system's multi-connect control is evaluated. Performance-test result of BIM server VDI effect to development direction of cloud computing BIM service for commercialization.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.3
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• pp.139-150
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• 2015

The major components of IoT(Internet of Things) environment are IoT devices rather than the conventional desktop computers. One of the intrinsic characteristics of IoT devices is diversity in view of data type and data access method. In addition, IoT devices usually deal with real-time data. In order to use such IoT data for internal business or cloud services, an IoT platform capable of easy domain management and consistent data access interface is required. This paper proposes a Linux FUSE-based virtual file system connecting IoT devices on POSIX file system view. It is possible to manage IoT domain with the native Linux utilities such as mkdir, mknod, ls and find in the file system. Also, the file system makes it possible to access or control IoT devices through POSIX interface such as open(), read(), write() or close() without any separate APIs or utilities. A test result shows that the management performance of the file system is lower than that of linux file system negligibly.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1057-1068
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• 2022

This paper compares the combination performance of feature point-based matching algorithms as a study to confirm the matching possibility between image taken by a user and a virtual texture image with the goal of developing mobile-based real-time image positioning technology. The feature based matching algorithm includes process of extracting features, calculating descriptors, matching features from both images, and finally eliminating mismatched features. At this time, for matching algorithm combination, we combined the process of extracting features and the process of calculating descriptors in the same or different matching algorithm respectively. V-World 3D desktop was used for the virtual indoor texture image. Currently, V-World 3D desktop is reinforced with details such as vertical and horizontal protrusions and dents. In addition, levels with real image textures. Using this, we constructed dataset with virtual indoor texture data as a reference image, and real image shooting at the same location as a target image. After constructing dataset, matching success rate and matching processing time were measured, and based on this, matching algorithm combination was determined for matching real image with virtual image. In this study, based on the characteristics of each matching technique, the matching algorithm was combined and applied to the constructed dataset to confirm the applicability, and performance comparison was also performed when the rotation was additionally considered. As a result of study, it was confirmed that the combination of Scale Invariant Feature Transform (SIFT)'s feature and descriptor detection had the highest matching success rate, but matching processing time was longest. And in the case of Features from Accelerated Segment Test (FAST)'s feature detector and Oriented FAST and Rotated BRIEF (ORB)'s descriptor calculation, the matching success rate was similar to that of SIFT-SIFT combination, while matching processing time was short. Furthermore, in case of FAST-ORB, it was confirmed that the matching performance was superior even when 10° rotation was applied to the dataset. Therefore, it was confirmed that the matching algorithm of FAST-ORB combination could be suitable for matching between virtual texture image and real image.

• IE interfaces
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• v.17 no.2
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• pp.158-168
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• 2004

A technology roadmap was developed for haptic interface technologies to be applied to games. Haptic interface technologies are expected to play an important role in games to provide gamers with interaction and immersive perception in near future, even though haptic interface technologies have been less studied than other perception-related technologies with respect to games. Information on two types of haptic interfaces - portable and desktop - and their evolution processes were analyzed in terms of technological demands. Haptic feedback technologies to realize these demands were inspected with the time frame and haptic feedback technologies were derived using a technology tree. The technology roadmap of haptic interfaces in game was finally constructed by mapping the technological demands in time with game technology trends. The technology roadmap of haptic interfaces will have implications on developing haptic interfaces to be applied to many applications including virtual realities and games.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.18-21
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• 2016

VDI 기반 가상 세스크탑 사용자에게 높은 만족도를 제공하기 위해서는 높은 CPU 속도 및 충분한 메모리와 저장공간, 네트워크 대역폭 등의 고성는 디바이스를 제공할 필요가 있다. 하지만 VDI 구축은 많은 비용이 소모되므로 서비스 사용자 수를 고려하여 해당 인프라 규모를 신중하게 결정할 필요가 있다. 특히 클라우드 기반 VDI 서비스에서는 각 서버에서 구동하는 가상 데스크탑의 수가 증가함에 따라 하이퍼바이저의 관리에 대한 연산이 증가하여 서버의 가용성이 감소된다. 본 논문에서는 한국전자통신연구원에서 개발한 클라우드 DaaS 시스템을 기반으로 VDI 산업 표준 성능 테스트 도구인 LoginVSI를 사용하여, 서비스 규모별 최적의 VDI 솔루션을 찾아내고 구축하기 위한 성능 측청 방법을 제시하고 결과를 분석 한다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.20-23
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• 2011

하나의 물리 머신만으로 복수개의 가상 머신을 지원할 수 있는 가상화 기술[5,6]이 발달함에 따라, 기업에서는 비용 절감을 위해 가상 데스크탑 기술 도입이 많이 이루어지고 있다. 또한, 일반 사용자들을 위한 가상 데스크탑 기반의 클라우드 서비스 역시 많이 소개되고 있는데, 이러한 가상 데스크탑의 효과적인 사용을 위해서는 원격 접속 기술이 필수적이지만, 이는 키보드, 마우스 및 디스플레이가 감추어져 있는 PC와 같은 정형적인 컴퓨터 환경에서만 접속이 가능하다[3,4]. 본 논문에서는 스마트폰을 이용하여, 사용자 주변에서 원격 컴퓨팅 장치로 사용할 수 있는 LCD TV, 키보드 등의 레거시 디바이스를 검색하고 해당 디바이스를 원격지에 있는 가상 데스크탑과 연계시켜[1,2] 사용자 주변의 디바이스를 통해 원격 가상 데스크탑 제어를 연계 할 수 있는 중계 소프트웨어에 대한 설계 및 구현 내용을 기술하고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.65-68
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• 2014