• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.75-78
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• 2008

Tire molds are manufactured by aluminum casting, direct five-axis machining, and electric discharging machining. Master models made of chemical wood are necessary if aluminum casting is used. They are designed with a three-dimensional computer-aided design system and milled by a five-axis machine. In this paper, a method for generating and machining a tire surface model is proposed and demonstrated. The groove surfaces, which are the main feature of the tire model, are created using a parametric design concept. An automatically programmed tool-like descriptive language is presented to implement the parametric design. Various groove geometries can be created by changing variables. For convenience, groove surfaces and raw cutter location (CL) data are generated in two-dimensional drawing space. The CL data are mapped to the tread surface to obtain five-axis CL data to machine the master model. The proposed method was tested by actual milling using the five-axis control machine. The results demonstrate that the method is useful for manufacturing a tire mold.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.484-491
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• 2002

We developed a new type of human-sized BWR (biped walking robot) driven by a new actuator based on the ball screw which has high strength and high gear ratio. Each leg of the robot is composed of three pitch joints and one roll joint. In all, a 10 degree-of-freedom robot with two balancing joints was developed. A new type of actuator for the robot is proposed, which is composed of four bar link mechanism driven by the ball screw. The robot overcomes the limit of the driving torque of conventional BWRs. The BWR was designed to walk autonomously by adapting small DC motors for the robot actuators and has a space to board DC battery and controllers. In the performance test, the BWR performed sitting-up and down motion, and walking motion. Through the test, we found the possibility of a high performance biped-walking.

• Proceedings of the Optical Society of Korea Conference
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• 2009.10a
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• pp.331-332
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• 2009

We present an analysis on the quality factors of the Fourier hologram generated from multiple orthographic view images of three-dimensional object. In the analysis, we analyze both the maximum size of the reconstructed object and its spatial resolution. For the maximum size of the reconstruction, we found that the main factor is the orthographic projection angle interval. Too large projection angle interval causes overlapping in the reconstruction space domain. For the spatial resolution, there are three factors, i.e. the capturing lens array pitch which determines the spatial sampling rate of the original three-dimensional objects, the maximum orthographic projection angle, and the spatial frequency bandwidth of the object. The dominant factor is determined by the relationship between those three factors.

• Korean Institute of Interior Design Journal
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• no.41
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• pp.29-35
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• 2003

The purpose of this study is to analyze the architectural manifesto and design works characteristics of Walter Gropius. He was the director of Weimar Bauhaus that one of the advanced artificial movements in the early modern period. The almost of the early modern movements was related to the radical ideology and the manifesto. Especially Bauhaus originated from manifesto of artists teaching group with architect Walter Gropius. Therefore, the category of the study pitch upon Bauhaus architectural manifesto - Bauhaus Manifesto and Programme(1919) - and the representative works of Walter Gropius - Fagus Factory(1911-14), Dessau Bauhaus Building(1925-26), Siedlung Berlin-Siemensstadt(1929-30) and Harvard Graduate Center(1949). The conclusions of the study as per the above mentioned pill pose are the dynamic integration by non-symmetry in cubic form (formal characteristics) and organic continuity by reciprocality in transparent space (spatial characteristics).

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.811-816
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• 2008

Train dynamics affects significantly safe and efficient operation of a train, especially during traction or braking period. Train dynamics is intrinsically complex due to many DOF motions in a three-dimensional space, and its behavior during the braking stage is too complex to understand and design an effective braking logic of the train. In this paper, we present a two-dimensional model with three DOF motion in a longitudinal, vertical, and pitch direction for the Hanvit 200 tilting train, which is efficient to analyze a braking performance. Furthermore, we analyze the braking logic and simulate the braking process of the Hanvit 200 tilting train using Simulink.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.54-54
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• 2000

For its synergistic relationship, an integrated SDINS/GPS system has been adopted in many navigation areas. As an application of SDINS/GPS integration, the in-flight alignment process of a SDINS utilizing GPS carrier phase measurements is introduced and analyzed via an observability analysis using nul1 space method. A measurement model of double-differenced GPS carrier phase measurements is newly derived in order to be used with a SDINS error model. Also, conditions for determining the complete observability of a SDINS/GPS system are suggested and proved. Consequently, it is shown that the system is not completely observable in case of one basel me. With one baseline aligned with y-axis of body frame, pitch error and x-axis accelerometer bias are unobservable states. Also shown is that al1 states are completely observable when sequential maneuver is performed. Above results are confirmed by a covariance analysis.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.158-158
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• 2015

전해동박(Electrodeposited Copper Foil)은 전기도금 공정으로 제조되는 얇은 구리 포일로서, 주로 TV, PC, 스마트폰 등 전자제품의 인쇄회로기판에서 전기신호를 전달하는 회로소재로 사용이 되며, 최근에는 모바일 IT, 전기자동차, 지능형 로봇, 그린 에너지 산업 등에서 필수적으로 적용되는 소재로 이용이 급증하고 있는 핵심소재이다. 모바일, Network 고속 통신 기술의 발전에 따라 Data 사용량의 폭증으로 고속/고주파 신호전송이 필요성이 증대되고 있으며 무선 충전 기술의 도입 및 웨어러블 기기의 보급으로 점차 FCCL도 3layer에서 2layer로 점차 그 수요가 바뀌어 가고 있다. 이에 따라 전해동박도 고속/고주파 신호 전송 및 고밀도 특성에 맞추어 저조도, 고밀착력 특성을 요구되는 방향으로 개발 되고 있으며 Line Space 가 기존 $25{\mu}m/25{\mu}m$ 패턴에서 $20{\mu}m/20{\mu}m$ 패턴으로 Fine pitch를 요구함에 따라 전해동박의 박막화, 저조도 고 밀착력 특성이 더 요구되고 있다.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.2
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• pp.194-201
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• 2005

For engineers in the industry, this study considers a reliable and practical finite element modeling technique to estimate the behavior of closed thin-walled members with spot weldings. Dynamic and static experiments confirm that the technique - modeling the spot weldings with solid elements which have the adjusted rotational freedoms and fill the welding space - Yields satisfactory results. Numerical studies on the double hat-shaped members. adopting this modeling technique. show the effect of the spot welding Pitch and the spot welding location in the flange on the stiffness of the members Using the principal stiffness and newly proposed GSPI(global stiffness performance index), we also carefully examine how the spot welding curvature, and sectional shape, etc.. synthetically influence the stiffness of a real excavator pillar in the field.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.48.3-48
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• 2001

A gain-scheduled autopilot design for a bank-to-turn (BTT) missile is developed by using the Linear Matrix Inequality (LMI) optimization technique and a state-space lineal interpolation method. The missile dynamics are brought to a quasilinear parameter varying (quasi-LPV) form. Robust linear control design method is used to obtain state feedback controllers for the LPV systems with exogenous disturbances at the frozen values of the scheduling parameters. Two gam-scheduled controllers for the pitch axis and the yaw/roll axis are constructed by linearly interpolating the robust state-feedback gains. The designed controller is applied to a nonlinear six-degree-of-freedom (6-DOF) simulations.

• Progress in Superconductivity and Cryogenics
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• v.25 no.4
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• pp.32-39
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• 2023

One of the main problems faced in developing India's first HTS power cable was that of shrinkage in length of the double-walled vacuum-insulated cryostat. The shrinkage was due to the evacuation of the annular vacuum space which results in a shorter working cable length. This work reports experimentally observed contraction during evacuation and analyses corrugated pipes/bellows which house the cable core of HTS cables. The effect of corrugation geometry including length, corrugation pitch and depth, diameters of corrugated pipes and thicknesses of pipes is studied numerically to realize the degree of shrinkage due to vacuum as well as chill down. Finally, necessary length compensation and associated cost is determined to tackle the shrinkage issue.