• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1935-1944
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• 1994

FMS is a distributed system composed of various programmable manufacturing hardware such as robots and NC machines. For the autonomous operation of such a system, an integrated software layer for the control and monitoring in needed on top of the manufacturing hardware. However, constructing and maintaining such a software layer is difficult due to the complexity of a underlying FMS and its frequently changing nature. To cope with this problem, this paper proposes an object-oriented FMS integration model, in which objects acting as virtual manufacturing cells are instantiated for each physical cell in the underlying object-oriented database. Various other entities involved in manufacturing processes and their relationship to the cell objects are also captured in the database. This paper describes the structure of this object-oriented FMS database on our prototype implementation called FREE.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.131-133
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• 2012

본 연구에서는 컴퓨터의 개념을 학부 신입생 교육과정에서 쉽게 이해할 수 있도록 ARM 명령어 집합의 부분 집합을 정의하고, 어셈블리 언어 코드를 입력받아 실행하는 가상 머신을 설계하고 구현하였다. 기존 교육 과정의 컴퓨터 구조 과목에서 다루는 어셈블리 언어는 실제의 머신을 기반으로 하기 때문에 개념을 학습하는데 있어서 불필요하게 복잡하다는 단점이 있다. 하지만 본 연구에서는 교육에 필요한 내용만을 포함한 가상 머신을 새롭게 정의함으로써 좀 더 우아한 방법으로 컴퓨터의 개념을 이해할 수 있도록 하였다. 특히 어셈블리 언어 학습을 통해서 컴퓨터 구조와 고급 언어 간의 상호작용을 이해하는데 도움이 될 수 있다. 제안한 가상 머신은 자바로 구현하였으며, 스캐너 및 파서를 구현하기 위해서 오픈소스 컴파일러-컴파일러 시스템을 사용하였다. 해당 가상 머신은 공과대학 학부 신입생을 위한 실습 프로그램으로 사용되었으며 컴퓨터 개념의 이해를 돕는데 유의미한 기여를 하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.1
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• pp.59-66
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• 2017

Hackers have obfuscated their malware to avoid being analyzed. Recently, obfuscation tools translate original codes into bytecodes to use virtualized-obfuscation, so that bytecodes are executed by virtual machines. In such cases, malware analysts fail to know about the malware before execution of the codes. We found that program slicing is one of promising program analysis techniques to solve this problem. The main concepts of program slice include slicing criteria given by analysts and sliced statements according to the slicing criteria. This paper proposes a deobfuscation method based on program slicing technique.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.1103-1104
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• 2017

본 연구는 가상현실 기술을 사이클링 머신에 접목시키는 운동기구 개발에 관한 것이다. 우리 제품은 기존 사이클링 머신과 비교하여 두 가지 개선점이 있다. 첫 번째로 실내 사이클링 머신은 장소의 변화가 없기 때문에 사용자가 포기하기 쉽다. 본 연구는 Unity를 활용해 다양한 맵을 생성했다. 이를 통해 사용자가 운동을 하는 동안 역동성을 느낄 수 있으며 공간 제약 없이 지속 가능한 운동 체계를 만들 수 있도록 도와준다. 두 번째로 운동 주기, 운동량 변화, 본인 최단 기록 등을 사용자에게 제공하여 체계적인 운동을 유도할 수 있다. 사용자들은 다른 사용자와 비교를 통해 운동량을 조절할 수 있다. 이는 운동을 장기적으로 할 수 있도록 도움을 준다. 본 연구에서는 제안하는 가상현실 기반 사이클링 머신을 직접 구현하였고 기능을 검증하였다.

• Fashion & Textile Research Journal
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• v.13 no.6
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• pp.866-876
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• 2011

We find ourselves living in a post-human era when technology and images coexist with humans. A cyborg, a combination of an organic body and a machine could be called a human fused with a machine. It could be understood as a new species where humans and machines have combined rather than simple protoplasm or an organic body. The purpose of this study is to demonstrate that a concept of a body in post humanism era is finding expression in fashion illustration through cyborg images. The concepts of post humanism and cyborg are analysed by means of research into literature and characteristics in which cyborg images as post humans are expressed through art, and images of a cyborg body in fashion illustration and their meanings are explored with the foregoing as a framework of reference. Cyborg image reflects new images and concept of a human in post humanism. The cyborg body images in fashion illustration are expressed through the addition of mechanical images, digital virtual body, monster image by means of hybrid combination, distorted physical transformation and fragmented body and body absence. And cyborg image in fashion illustration shows the extension of body concepts through the technology and uncertain and ambiguous identity.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1634-1641
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• 2006

High-precision centerless grinding machines are emerging as a means of finishing the outer diameter grinding process required for ferrules, which are widely used as fiber optic connectors. In this study, a sensitivity analysis for structural and thermal characteristics was carried out using a virtual prototype of a centerless grinding machine to realize systematic design technology and performance improvements required to manufacture ferrules. The prototype consisted of a concrete-filled bed, hydrostatic grinding wheel (GW) and regulating wheel (RW) spindle systems, a hydrostatic RW table feed mechanism, a RW swivel mechanism, and on-machine GW and RW dressers. The results of the structural sensitivity analysis illustrated that the vertical stiffness of hydrostatic guideway for the RW table feed system greatly influenced the horizontal loop stiffness, and the results of the thermal sensitivity analysis illustrated that the heat generation rates at hydrostatic bearings and belt pulley greatly influenced the temperature rise of hydrostatic bearings and the deviation of thermal displacement between GW and RW.

• Tribology and Lubricants
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• v.30 no.2
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• pp.116-123
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• 2014

The objective of this study is to model and simulate the nonlinear lubrication performance of the sliding part between the piston and cylinder wall in a hydrostatic swash-plate-type axial piston pump. A numerical algorithm is developed that facilitates simultaneous calculation of the rotating body motion and fluid film pressure to observe the fluid film geometry and power loss. It is assumed that solid asperity contact, so-called mixed lubrication in this study, invariably occurs in the swash-plate-type axial piston pump, which produces a higher lateral moment on the pistons than other types of hydrostatic machines. Two comparative mixed lubrication models, rigid and elastic, are used to determine the reaction force and sliding friction. The rigid model does not allow any elastic deformation in the partial lubrication area. The patch shapes, reactive forces, and virtual local elastic deformation in the partial lubrication area are obtained in the elastic contact model using a simple Hertz contact theory. The calculation results show that a higher reaction force and friction loss are obtained in the rigid model, indicating that solid deformation is a significant factor on the lubrication characteristics of the reciprocating piston part.

• Journal of Information Technology Services
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• v.18 no.4
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• pp.97-113
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• 2019

With the development of sensor, communication and intelligent software technology, expectation of IoT-based service which can receive desired service automatically and anytime, anywhere is getting higher. In addition, IoT-based services have begun to anticipate the development of a hyper-connected society. Despite these expectations and anticipations, few studies have empirically identified ways to improve the intentions of prospective customers to use IoT-based services. Therefore, the purpose of this paper is to propose a theoretical model that can explain the factors that determine the intention of using IoT-based services. In addition, this study investigates what factors affect the intention to use IoT-based services focusing on the connectedness. Especially, perceived connectivity with the (virtual) community, unlike the connectivity with the machines, is newly proposed, to understand the IoT technology adoption behavior. The empirical results suggest that social relationship is one of the critical factors to affect the use of services running on interconnected technology such as IoT. When IoT-based service is recognized as a link to other communities, it has been found to have a positive effect on intention to use via perceived belongingness.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.333-338
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• 2007

시스템 가상머신 환경은 높은 하드웨어 효율성과 높은 보안을 요구하는 시스템에서 그 사용이 점차 늘어나고 있다. 최근 많이 알려진 하이퍼바이저 가상머신 시스템은 높은 아이솔레이션과 보안성을 보장하나 각 게스트 운영체제 별로 운영체제 이미지를 가지기 때문에 하드웨어 효율성이 떨어지는 반면, 컨테이너 기반 가상머신 시스템은 운영체제 이미지의 공유로 인하여 높은 자원 효율성과 확장성을 가진다. 그러나 메모리 자원의 아이솔레이션에 대하여 취약점을 갖는 문제점을 안고 있다. 본 논문에서는 컨테이너 기반 가상머신 시스템에서 동적으로 각 가상머신별로 메모리 사용량 증가에 따른 페이지 히트율-곡선(Hit-Ratio-Curve)을 측정하였다. 이 곡선을 관찰해 보면 각 가상머신의 메모리 필요량을 알 수 있으며 이를 기반으로 메모리 자원을 할당하게 될 경우 효과적으로 메모리 자원의 아이솔레이션을 제공할 수 있게 된다. 본 논문에서는 대표적인 컨테이너 기반 가상머신인 리눅스 VServer가 적용되어 있는 리눅스 2.6.17 커널에 직접 구현하였으며, Lmbench 및 리눅스 커널 컴파일 등을 통하여 오버헤드를 측정하였고 $1.6{\sim}7.2%$의 적은 오버헤드로 이를 측정할 수 있음을 확인하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.851-856
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• 2005

The precision fabrication of aspherical lenses is increasingly required for the latest applications of compact and high resolution video-recording or camera systems. Micro-optical components, including micro-spherical or aspherical lenses and reflecting mirrors, are generally required to be manufactured with high shape accuracy, extremely low surface roughness and no surface damage. To meet the needs of the precision fabrication system, a bed which supports the micro aspherical lens fabrication machines stably and safely is required. In this study, the thickness of the ribs of the bed is optimized using the CAD integrated optimal design system, a virtual DS program.