• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.748-753
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• 2009

Large amounts of research results are being produced with the rapid growth of science and technology. The current method for constructing the database was way too time and cost consuming. In the currently upcoming technology and knowledge society, web service is required to provide the various professional service for national R&D reports. A process to manufacture E-Book for professional service is also required. This research shows the conversion models with efficient manufacturing process and the systems related to the development through defining the National R&D reports.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.74-84
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• 2015

The core activities of a bicycle manufacturer are design, engineering analysis, and manufacturing. Therefore, it is important to develop a configuration design system for bicycles in order to automate the design process and facilitate the use of design data in engineering analysis and manufacturing. In this paper, we present a method to develop a bicycle configuration design system based on the part-shape information model. The proposed method enables the construction of a CAD library using modeling functions with equations and parameters that are common to most 3D mechanical CAD systems. Furthermore, the part-shape information model ensures the independence between the configuration design system and the library, making it possible to extend the CAD library flexibly without changing the system architecture.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1681-1688
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• 2000

A dynamic model for the prediction of surface topography in high speed end milling process is developed. In this model the effect of tool runout, tool deflection and spindle vibration were taken in to account. An equivalent diameter of end mill is obtained by finite element method and tool deflection experiment. A modal parameter of machine tool is extracted by using frequency response function. The tool deflection, spindle vibration chip thickness and cutting force were calculated in dynamic cutting condition. The tooth pass is calculated at the current angular position for each point of contact between the tool and the workpiece. The new dynamic model for surface predition are compared with several investigated model. It is shown that new dynamic model is more effective to predict surface topography than other suggested models. In high speed end milling, the tool vibration has more effect on surface topography than the tool deflection.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2089-2104
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• 1995

A novel and efficient cutter path planning method for machining intricately shaped curved surfaces, called the steepest directed tree method, is presented. The curved surface is defined by triangular facets, the density and structure of which are determined by the intricacy and form accuracy of the surface. Geometrical form definition and recognition of the topological features are used to connect the nodes of the triangulated surface meshes for the successive and interconnected steepest pathways, which makes good use of end milling characteristics. The planetary cutter centers are determined to locate along smoothly changing paths and then the height values of the cutter are adjusted to avoid surface interference. Several machined examples of intersecting and intricate surfaces are presented to illustrate the benefits of the new approach. It is shown that due to more consistent geometry matching between cutter and surface(in comparison with the current CC Cartesian method) surface finish can be typically improved. Moreover, the material in concave fillets which is difficult to be removed by ball mills can be removed efficiently. The built-in positioning of cutter to avoid interference runs minutely in the sharp and discontinuous regions. The steepest upward movement of the cutter gives a stable dynamic cutting state and allows increase in the feedrate and spindle speed while remaining the stable cutting state.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1058-1059
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• 2015

최근 건축 구조물 설계에 있어서 외부 또는 내부로부터 발생될 수 있는 미지의 진동에 대하여 대책을 수립하여 구조물을 설계하고 있다. 뿐만 아니라 기타 제조업 분야에 있어서 정밀할 가공이 필요한 특수한 기계 가공기에 있어서 내부 또는 외부에서 발생될 수 있는 진동을 감안하여 시스템을 구성하고 있다. 이러한 구조물 및 기계시스템에 대하여 진동을 억제할 수 있는 진동 억제 알고리즘에 관해서는 많이 연구되고 있다. 본 논문에서는 구조물 및 기계시스템에서 발생될 수 있는 미지의 외란을 제거하기 위하여 내부모델제어(IMC)를 기반으로 수정된 적응 알고리즘을 매트랩 시뮬링크(matlab simulink)를 통하여 제어성능을 제시하고자 한다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.19-24
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• 2017

In this research, a practical stiffness calculation method is developed and applied for modifying the height of the headstock, turret, and tailstock of a CNC lathe to enlarge the turntable diameter. The casting structure is assumed to be a rigid body and the linear motion element to be an elastic spring to simplify the turret stiffness calculation model. The stiffness of the sliding guide and ball screw of the original lathe is measured with a push tester and LVDT sensor, and the turret stiffness of the modified lathe is predicted and compared with experimental results to verify the model. The measured stiffness of the original turret is $0.17kN/{\mu}m$ and that of the modified turret is $0.11kN/{\mu}m$, i.e., an 18% difference from the predicted result. The verified stiffness calculation model can be used to develop another modified lathe.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.59-65
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• 2019

In many industries, particle packing is adopted quite frequently. In the particle packing process, the Discrete Element Method (DEM) can analyze the multi-collision of particles efficiently. Two types of contact models are frequently used for the DEM. One is the linear spring model, which has the fastest calculation time, and the other is the Hertz-Mindlin model, which is the most frequently used contact model employing the DEM. Meanwhile, very tiny particles in the micrometer order are used in modern industries. In the micro length order, surface force is important to decreased particle size. To consider the effect of surface force in this study, we performed a simulation with the Hertz-Mindlin model and added the Johnson-Kendall-Roberts (JKR) theory depicting surface force with surface energy. In addition, three contact models were compared with several parameters. As a result, it was found that the JKR model has larger residual stress than the general contact models because of the pull-off force. We also validated that surface force can influence particle behavior if the particles are small.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.517-524
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• 2024

This study aims to train and implement a deep learning model for the fusion of website creation and artificial intelligence, in the era known as the AI revolution following the launch of the ChatGPT service. The deep learning model was trained using 3,000 collected web page images, processed based on a system of component and layout classification. This process was divided into three stages. First, prior research on AI models was reviewed to select the most appropriate algorithm for the model we intended to implement. Second, suitable web page and paragraph images were collected, categorized, and processed. Third, the deep learning model was trained, and a serving interface was integrated to verify the actual outcomes of the model. This implemented model will be used to detect multiple paragraphs on a web page, analyzing the number of lines, elements, and features in each paragraph, and deriving meaningful data based on the classification system. This process is expected to evolve, enabling more precise analysis of web pages. Furthermore, it is anticipated that the development of precise analysis techniques will lay the groundwork for research into AI's capability to automatically generate perfect web pages.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.85.1-85.1
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• 2013

GMT(Giant Magellan Telescope)는 25.4m의 주경과 3.2m의 부경으로 이루어진 거대망원경이다. 3.2m의 부경은 빠른 tip-tilt로 망원경을 제어하는 Fast Steering Mirror(FSM)와 적응광학계로 이루어진 Adaptive Secondary Mirror (ASM)로 구분된다. 한국천문연구원은 국내외 협력기관들과 함께 부경 FSM의 시험모델개발을 수행하고 있다. 부경은 1.06m의 반사경 일곱 개로 이루어져 있는데, 한 개의 광축 반사경 주위로 여섯개의 비축 반사경이 둘러싸여서 하나의 3.2m 반사경과 같은 기능을 하고 있다. 비축 비구면 반사경에 대한 시험모델의 반사면을 가공한 결과 표면가공 정밀도가 11.7nm rms의 정밀도를 갖는 반사경을 가공하였다(target : <20nm rms). 또한 test-bed를 제작하여 tip-tilt 정밀도를 제어한 결과 성능요구 조건 값인 0.03arcsec 제어에 성공하였고, 더 나아가 0.01arcsec의 tip-tilt 제어도 가능한 것으로 판단된다.

• Explosives and Blasting
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• v.36 no.3
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• pp.19-28
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• 2018

Locally damaged structures caused by earthquake or extraordinary external forces have been required to rapidly be dismantled because of its possibility of additional collapses. Particularly, steel frame structures were demolished by the shaped charge blasting method. Recently a research suggested a shape charge blasting technique which uses bent-shaped charge holder of copper plate and emulsion explosive charge to cut thick steel plates. This study simulated the cutting performance of the bent-shaped charge holder with considering types of explosives, thickness of copper liner and stand-off distances using LS-DYNA software. The shape charge blasting test of a 25mm thickness steel plate were used to calibrate the input parameters of the numerical models. The penetration depth and penetration width were analysed with different types of explosives, thickness of copper liner and stand-off distances.