• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.462-467
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• 2005

This paper presents virtual machining system in order to realize turning process in virtual space. A reliable virtual turning process simulation was developed based on the surface shaping system which is capable of considering geometric model, thermal error model, and vibration model. Accuracy of surface shape resulting from proposed machining simulator was verified experimentally. This paper also developed the watchdog agent that continuously assessed, diagnosed, and predicted performance of products and machines in machining. The Watchdog agent extracted feature signal using time-frequency analysis among various signals from multi-sensor and evaluated machining condition using performance confidence value.

• 한국공작기계학회논문집
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• 제12권3호
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• pp.31-37
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• 2003

With the paradigm shifting from the principal of manufacturing efficiency to business globalism and rapid adaptation to its environments, more and more enterprises are being virtually organized as manufacturing network of different units in web. The formation of these enterprise called as Virtual Enterprise(VE) is becoming a growing trend as enterprises concentrating on core competence and economic benefit. 13us paper proposes multi-agent based task assignment system for VE, which attempts to address the selection of individually managed partners and the task assignment to them A case example is presented to illustrate how the proposed system can assign the task to partners.

• 한국공작기계학회논문집
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• 제13권3호
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• pp.91-97
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• 2004

The door closer is a typical system which consists of spring and damper. The door closer is a device to close the door more slowly. The virtual prototypes of cylinder-type door closer are developed. The simulations of virtual prototype are performed to obtain the load history of the guide pin. The structural strength assessment of the guide pin is performed to verify a design safety. The fatigue life and damage of the guide pin are predicted using a FEMFAT 4.3h based on the finite element analysis.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.304-309
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• 2004

As it is difficult to construct a micro-fluidic system composed of micro-mixers, micro-channels and/or micro-chambers in a single process, an assembly process is typically used. The assembling and bonding of micro-parts, however, introduces other problems. In this work, a virtual assembly process was developed that can be used to design various micro-fluidic systems before actual fabrication commences. In the process, the information required for the micro-stereolithography process is generated automatically. Consequently, complex micro-fluidic systems can be fabricated in a single process, thereby avoiding the need for additional assembly or bonding processes. Using the developed process, several examples were fabricated.

• International Journal of Contents
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• 제12권3호
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• pp.29-33
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• 2016

Cloud computing makes extensive use of virtual machines that permit for workloads, as well as resource usage, to be isolated from one another, and a hypervisor can be used by a virtual machine to construct cloud computing infrastructure. However, the hypervisor has high resource usage when constructing virtual machines, which results in a waste of allocated resources when not activated. Docker provides a more light-weight method to obtain agile computing resources based on a container technique that handles this problem. In this study, we have chosen this specific tool due to the increasing popularity of MapReduce and cloud container technologies such as Docker. This study aims to automatically configure Twister workloads for container-driven clouds. Basically, this is the first attempt towards automatic configuration of Twister jobs on a container-based cloud platform VM for many workloads.

• 컴퓨터교육학회논문지
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• 제7권3호
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• pp.45-56
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• 2004

웹 환경과의 연동, 병렬 프로그래밍, 객체지향 프로그래밍, 안전성(컴파일 시간 에러 검출, 예외 처리 기법)과 이식성, GUI 등을 지원함으로써, 프로그래밍 언어 자바(Java)의 활용도가 점점 증가하고 있다. 객체지향 프로그래밍 언어로서 자바는 클래스, 인스턴스, 정보은닉, 상속, 다형성 등 객체지향 개념들에 기반하고 있다. 그러나 자바 프로그램 수행시 이들과 관련된 제반 현상이 자바가상기계(Java Virtual Machine) 내부에 감추어지기 때문에, 자바 언어를 배우거나 활용하는 대부분의 사용자들이 큰 어려움을 겪는다. 이 문제에 대한 효과적 해결책으로서, 본 연구에서는 자바가상기계 내부의 현상을 객체지향 개념과 연계시켜 시각화해 주는 도구 Alpha를 개발하였고, 본 논문은 그 설계와 특징들을 기술하고 있다. Alpha는 실용성과 확장성을 높이기 위해 MVC(Model-View-Controller) 구조로 설계되었고, 이를 통해 자바가 상기계 내부의 현상(인스턴스 생성 및 소멸, 메쏘드 호출 및 복귀, 필드 접근, 인스턴스 간의 상호 참조관계 변화, 쓰레드의 수행 흐름 등)을 사용자의 수준이나 활용 목적에 맞게 다양한 방식으로 시각화시켜 준다.

• Journal of Platform Technology
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• 제11권3호
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• pp.32-44
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• 2023

블록체인 브릿지(이하 '브릿지'이라 한다.)는 블록체인간 자산 이동을 가능하게 해주는 서비스를 말한다. 브릿지는 사용자에게 가상 자산을 입금 받고 다른 블록체인의 사용자에게 동일한 가상 자산을 전달하는 역할을 한다. 블록체인 환경은 각각 독립적이기 때문에 일반적인 방식으로 다른 블록체인으로 자산을 옮길 수 없기 때문에 사용자는 브릿지를 이용한다. 따라서 브릿지를 이용한 자산 이동은 일반적인 방식으로 추적할 수 없다. 만약 악성 행위자가 브릿지를 통해 자금 이동을 하였다면 기존의 자산 추적 도구로는 추적에 한계가 있다. 따라서 본 논문에서는 브릿지의 구조를 파악하고 브릿지 요청에 대한 이벤트 로그를 분석하여 브릿지 이용 정보를 획득하는 방법에 대하여 제안한다. 우선 브릿지의 구조를 파악하기 위해 Ethereum Virtual Machine(EVM) 기반 블록체인에서 작동하는 브릿지를 대상으로 분석을 진행하였다. 분석한 내용을 바탕으로 임의의 브릿지 이벤트에 대하여 적용해보았다. 나아가 실제 추적에 사용될 수 있도록 브릿지 이용정보를 지속적으로 수집하여 저장하는 자동화 도구를 제작하였다. 실제 브릿지 이용 후 도구를 통해 이용 정보를 추출하여 송신 블록체인, 수신 블록체인, 전달받는 지갑 주소, 전송한 토큰의 종류, 수량과 같은 추적에 중요한 정보들을 확인할 수 있었다. 이를 통해 블록체인 브릿지를 이용한 자산 이동 추적의 한계를 극복할 수 있음을 보여주었다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 추계학술대회 논문집
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• pp.60-63
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• 1995

The behavior of the work materials in the chip-tool interface in extremely high strain rates and temperatures is more that of viscous liquids than that of normal solid metals. In these circumstances the principles of fluid mechanics can be invoked to describe the metal flow in the neighborhood of the cutting edge. In the present paper an Eulerian finite element model is presented that simulates metal flow in the vicinity of the cutting edge when machining a low carbon steel with carbide cutting tool. The work material is assumed to obey visco-plastic (Bingham solid) constitutive law and Von Mises criterion. Heat generation is included in the model, assuming adiabatic conditions within each element. the mechanical and thermal properties of the work material are accepted to vary with the temperature. The model is based on the virtual work-stream function formulation, emphasis is given on analyzing the formation of the stagnant metal zone ahead of the cutting edge. The model predicts flow field characteristics such as material velocity effective stress and strain-rate distributions as well as built-up layer configuration

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.765-767
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• 2001

Linear pulse Motors(LPM) are widely used in fields where smooth linear motion is required, and their position accuracy is higher than other motors. Hybrid linear pulse motors(HLPM) are regarded as an excellent solution to positioning problems that require high accuracy, rapid acceleration and high-speed. The LPM has low mechanical complexity, high reliability, precise open-loop operation and low inertia etc. in many application areas such as factory automation speed positioning, computer peripherals and numerically controlled machine tools. This motor drive system is especially suitable for machine tools the high position accuracy and repeatability. This paper describes about that need of the embroider machine, we want to design position-scanning device for the embroidery machine. At first, to be analysed characteristics of the machine and next designed the LPM. we used the field analysis program, The finite element method(FEM) program tool is employed for calculation the force. The reluctance models will be used the magnetic permeance of air gap by static- conditions. The forces between forcer and platen have been calculated using the virtual work method.

• 한국공작기계학회논문집
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• 제16권5호
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• pp.211-217
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• 2007

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body kinematics and dynamics has been presented. We have developed a virtual imprinting machine to evaluate the prototype design in the early design stage. The simulation using CAE for the imprinting machine is not only to analyze static and dynamic characteristics of the machine but also to determine design parameters of the components for the imprinting machine, such as dimensions and specifications of actuators and sensors. Structural components as the upper plate, the rotator, the shaft and the translator have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism. In addition, we made the 4-axis stage model to compare the dynamic behavior with that of 3-axis stage model.