• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 추계학술발표대회 개요집
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• pp.121-124
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• 2001

The main characteristic of the Electron Beam Welding technique is its high energy density which produces thin and deep welds with very little distortion. High accelerated electrons, focused in a beam of 0.5 ∼ 2mm diameter, produce narrow welds with deep penetration. The result is a small HAZ as well as a low and uniform distortion which is predictible within very narrow limits. But the small diameter of the EB increases the requirements for the equipment control system for centering the beam on the welding joint in order to avoid any lack of fusion. Therefore, in this paper, we introduce the system developed at our company and the quality of welding zone, the detail function of system.

• 한국산업융합학회 논문집
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• 제22권5호
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• pp.561-573
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• 2019

This study proposes a new approach to implement smart factory based on robot monitoring system for a small and medium sized enterprise. The simulator includes the forward kinematics and inverse kinematics analyzes of articulated robots. We also modeled the dynamics of the robot and made it possible to simulate it in the program. We studied the interface between the user and the monitoring programming system using the GUI environment of Windows OS, and it is configured to select the appropriate trajectory planning and control method. The reliability of simulator is illustrated by simulation test.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.667-670
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• 2009

교육용로봇시장의 발전과 함께 이용자들의 요구사항들이 증가하고 있다. 그러나 기존에는 이용자들이 원하는 제품이기 보다는 technical push 형태의 제품 개발이 진행되어 왔다. 이에 따라 본 연구에서는 교육용 로봇 이용자들의 특성과 Kano 모형을 활용하여 수요자들의 요구사항을 파악하여 교육용 로봇 기능을 도출함으로써 로봇시장을 창출하는데 기반이 되는 자료를 제시하고자 한다. 수요자들이 요구하는 기능으로는 학생 원격 통제 기능, 인터넷 검색 기능, 교육 콘텐츠 검색 기능, 학습 진도 관리 기능은 제공될 경우 호감이 상승하는 매력적 평가 속성으로 분류되었다.

• Journal of Hydrospace Technology
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• 제1권1호
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• pp.66-74
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• 1995

Unknown parameters can be determined by system identification techniques. Extended Kalman filter method was introduced as a real time estimator of hydrodynamic derivatives but it has the problem named the coefficient drift. In this study, 2nd order filter estimates hydrodynamic derivatives in Abkowitz model In order to reduce the coefficient drift, parallel processing is used. The measured state and ship trajectory are compared with the estimated values. Parallel processing of 2nd order filter gives very similar results to parallel processing of extended Kalman filter. Parallel processing cannot not remove the coefficient drift perfectly, but it reduces the estimation error.

• Acta Via Serica
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• 제5권2호
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• pp.91-110
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• 2020

This paper traces the trajectory of a variety of complicated economic and political developments between China and India - the world's most ancient civilizations connected by rich history. These recent developments, which are heavily acrimonious and include military clashes involving loss of lives, have greatly damaged bilateral relations. The paper examines the reasons behind the bilateral relations dipping to new lows. Aside from specific bilateral disputes like outstanding border problems, China-India relations have been affected by global and regional developments. The paper identifies rising tensions between the U.S. and China, the evolution of the Belt and Road Initiative, and the growth of the Indo-Pacific construct, as the reasons that have expanded distance and mistrust between the two countries. Both China and India are now part of country coalitions aiming to marginalize each other's strategic influences. The paper argues that such efforts by them are going to impact countries in their neighbourhood - such as in Central Asia - by forcing them to make complex choices in the areas of trade engagement and technological development.

• 전자통신동향분석
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• 제39권3호
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• pp.36-47
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• 2024

Low Earth Orbit (LEO) satellite communications has become a crucial technology for next-generation communication networks owing to its hyperconnectivity capabilities. We examine the progress and application areas of LEO satellite communication services. The LEO satellite communication industry has transitioned from being predominantly driven by governments and institutions to being led by the private sector, following the trajectory of the NewSpace movement. Leading corporations such as SpaceX Starlink and Eutelsat OneWeb are deploying LEO satellite networks to offer internet services, while Telesat is preparing to establish its satellite communication network. LEO satellite communications is expected to have a major impact on various sectors of society, particularly for upcoming sixth-generation services. Therefore, the South Korean government must promptly formulate policy support strategies aimed at invigorating the LEO satellite communication industry. This can be achieved through initiatives such as bolstering research and development and extending corporate assistance.

• Journal of Biosystems Engineering
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• 제33권2호
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• pp.94-100
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• 2008

Present chemical application method using a power sprayer has been labor intensive, costly and ineffective. Therefore, a small agricultural unmanned helicopter was suggested to replace the conventional spray system. In this study, conceptual design for developing the helicopter and a consequential prototype were reported. The overall conceptual design was initiated by deciding the type of agricultural helicopter, as the single rotor helicopter with a tail system. As the first step of the designing, an air-cooled, 2-stroke engine was selected and a prototype transmission was designed by determining the rotating speed of main rotor shaft. A 'pusher' type tail rotor system was adapted to balance the reaction torque and reduce the power use. The tail boom length was designed to avoid the rotating trajectory of the main rotor. The RF console consisted of the engine control, attitude control, and emergency control modules. Assembling the prototype concluded the mechanical development of the agricultural helicopter.

• Spatial Information Research
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• 제13권3호
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• pp.211-220
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• 2005

건설교통부에서는 기존의 도로현황을 더욱 빠르고 정확하게 파악하기 위해 도로관리통합시스템에서 전국의 일반국도에 대해 위치정보를 가진 디지털 영상을 제공하는 방안을 추진 중에 있다. 이를 위해 한국건설기술연구원에서는 도로를 주행하면서 일정거리간격으로 2매의 고해상도의 칼라 CCD영상을 취득할 수 있는 도로영상취득차량을 개발하였다. 본 논문에서는 특히 영상취득 S/W와 동기화장치 개발에 대해 기술하였으며 실험을 통해 차량의 궤적 정확도, 영상취득 S/W, 동기화 장치의 성능을 검토한 결과 도로관리통합시스템에서 필요한 도로영상을 취득하는데 적합한 것으로 판단된다.

• 한국군사과학기술학회지
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• 제18권3호
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• pp.234-243
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• 2015

It is required to have the capability to predict the impact point of the ballistic target in order to assign the firing unit with high engagement possibility for the interception in the ballistic target defense systems. In this paper, a novel method is proposed to predict the impact point of the ballistic target using a flight phase discrimination algorithm given the insufficient measurements on the partial trajectory. The flight of a ballistic target is composed of a boost phase and a ballistic phase with different dynamics. The flight phase is discriminated by using the normalized innovation distance between measurements and a priori estimated measurements. The threshold and tolerance in the flight phase discrimination are determined from the probabilistic characteristics of the estimation error. Monte Carlo simulations are performed to verify the proposed method.

• 한국항공우주학회지
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• 제32권10호
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• pp.127-133
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• 2004

본 논문은 무인항공기의 자동비행을 위한 이동형 지상제어 시스템 개발에 관한 연구이다. 본 연구에서는 휴대와 이동을 수월하게 하기 위한 이동형 지상제어시스템 (PGCS)을 개발하였다. 일반적으로 지상제어시스템은 항공기가 수행해야할 임무정보를 전송하고, 원활한 조종을 위하여 항공기 위치, 자세, 상태, 항법 정보를 항공기로부터 실시간 수신할 수 있어야 한다. 이동형 지상제어시스템 구성은 노트북 컴퓨터, 지상제어시스템과 항공기간의 통신을 위한 모뎀, 입/출력 보드, 무선조종 수신기 그리고 여러 개의 스위치와 LED 램프로 구성된다. 소형 무인항공기를 이용한 비행시험으로서 본 연구에서 개발한 이동형 지상제어시스템 성능 검증을 수행하였다.