• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.250-256
• /
• 2009

This paper presents a robotic tower-crane system using encoder and gyroscope sensors as path tracking devices. Tower crane work is often associated with falling accidents and industrial disasters. Such problems often incur a loss of time and money for the contractor. For this reason, many studies have been done on an automatic tower crane. As a part of 5-year 23-million-dollar research project in Korea, we are developing a robotic tower crane which aims to improve the safety level and productivity. We selected a luffing tower crane, which is commonly used in urban construction projects today, as a platform for the robotic tower crane system. This system comprises two modules: the automated path planning module and the path tracking module. The automated path planning system uses the 3D Cartesian coordinates. When the robotic tower crane lifts construction material, the algorithm creates a line, which represents a lifting path, in virtual space. This algorithm seeks and generates the best route to lift construction material while avoiding known obstacles from real construction site. The path tracking system detects the location of a lifted material in terms of the 3D coordinate values using various types of sensors including adopts encoder and gyroscope sensors. We are testing various sensors as a candidate for the path tracking device. This specific study focuses on how to employ encoder and gyroscope sensors in the robotic crane These sensors measure a movement and rotary motion of the robotic tower crane. Finally, the movement of the robotic tower crane is displayed in a virtual space that synthesizes the data from two modules: the automatically planned path and the tracked paths. We are currently field-testing the feasibility of the proposed system using an actual tower crane. In the next step, the robotic tower crane will be applied to actual construction sites with a following analysis of the crane's productivity in order to ascertain its economic efficiency.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2002년도 춘계학술대회 논문집
• /
• pp.184-189
• /
• 2002

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. Path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
• /
• pp.244-249
• /
• 2001

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. Path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
• /
• pp.113-118
• /
• 2000

Collision free task planning for dual-arm robot which perform many subtasks in a common work space can be achieved in two steps : path planning and trajectory planning. Path planning finds the order of tasks for each robot to minimize path lengths as well as to avoid collision with static obstacles. A trajectory planning strategy is to let each robot move along its path as fast as possible and delay one robot at its initial position or reduce speed at the middle of its path to avoid collision with the other robot.

• 대한교통학회지
• /
• 제22권6호
• /
• pp.121-131
• /
• 2004

다수경로 알고리즘은 비루프경로(Loopless Path: 또는 Simple Path)와 루프경로(Loop Path)를 탐색하는 방안으로 대별된다. 알고리즘의 난이도 측면에서 일반적으로 비루프경로를 탐색하는 방안이 루프경로를 탐색하는 방안보다 많은 노력이 소요된다. 바꾸어 말하면, 루프경로 탐색방안이 알고리즘의 이해 및 활용성 측면에서 용이하다는 장점이 존재한다. 루프경로탐색방안에서 경로삭제방식(Path Deletion Method)이 가장 효율적인 알고리즘으로 알려져 있다. 경로삭제방식은 K번째의 최적경로를 탐색하기 위하여 K-1번째의 경로의 탐색금지 상황설정이 필요하며, 이를 네트워크의 변형된 확장형태(Enlarged Transform)를 통하여 추구하는 방식이다. 그러나 이 알고리즘은 경로상에 노드 및 링크의 반복이 허용되는 루프를 생성시켜 교통망에 적용하기에는 한계가 존재하는 단점이 있다. 본 연구에서 링크표지를 활용하여 루프를 제거하는 방안을 개발한다. 이를 위해 K-1번째 확장네트워크에서 링크표지를 갱신하는 과정에서 대상링크와 전 링크의 부분경로와의 관계를 고려하여 루프가 생성되지 않도록 링크표지를 확정하여 원천적으로 루프의 생성을 방지한다. 본 연구에서 제안하는 비루프 알고리즘은 노드비루프와 링크비루프로 구분되며, 노드비루프는 경로 상에서 노드의 반복이 존재하지 않는 일반적인 단순경로(Simple Path)를 의미하며, 링크비루프는 경로 상에 링크의 반복이 존재하지 않는 경로를 의미한다. 특히 링크비루프는 도시 교차로에서 발생하는 U-턴, P-턴의 덩굴망 통행행태를 설명하기 위한 중요개념으로 확대 정의된다. 사례연구를 통하여 제안된 알고리즘의 활용성을 검증한다.

• 한국컴퓨터정보학회논문지
• /
• 제19권9호
• /
• pp.197-204
• /
• 2014

AS(Autonomous System) 안에서 라우터들끼리 라우팅 정보를 주고 받기 위한 내부용 라우팅 프로토콜(IGP : Interior Gateway Protocol)인 RIP, EIGRP, OSPF에 대하여 metric을 이용한 경로선택 방법들이 연구되고 있으나, 학습자들이 이론으로 이해한 내용을 실습을 통해 검증하는 구현 사례는 많지 않았다. 각 라우팅 프로토콜별로 해당 토폴로지에 기반 한 Cost value를 이론적으로 계산하여 Best Path를 결정한 후, 시뮬레이터 상에서 가상망을 구현하여 각 Routing Protocol 별로 경로선택을 검증한 결과와 서로 일치함을 확인하였다. 본 논문에서 제안한 학습방안을 활용하면 라우팅 프로토콜의 경로선택 과정을 체계적으로 이해할 수 있어 우수한 학습 결과를 성취할 수 있을 것으로 기대된다.

• Journal of Computational Design and Engineering
• /
• 제3권2호
• /
• pp.132-139
• /
• 2016

In this paper, a minimum time path planning strategy is proposed for multi points manufacturing problems in drilling/spot welding tasks. By optimizing the travelling schedule of the set points and the detailed transfer path between points, the minimum time manufacturing task is realized under fully utilizing the dynamic performance of robotic manipulator. According to the start-stop movement in drilling/spot welding task, the path planning problem can be converted into a traveling salesman problem (TSP) and a series of point to point minimum time transfer path planning problems. Cubic Hermite interpolation polynomial is used to parameterize the transfer path and then the path parameters are optimized to obtain minimum point to point transfer time. A new TSP with minimum time index is constructed by using point-point transfer time as the TSP parameter. The classical genetic algorithm (GA) is applied to obtain the optimal travelling schedule. Several minimum time drilling tasks of a 3-DOF robotic manipulator are used as examples to demonstrate the effectiveness of the proposed approach.

• 한국IT서비스학회지
• /
• 제20권1호
• /
• pp.93-115
• /
• 2021

Various policy declarations and institutional experiments involving artificial intelligence are being made in most countries. Depending on how the artificial intelligence policy changes, the role of the government, the scope of the policy, and the policy means used may vary, which can lead to the success or failure of the policy. This study proposed a perspective on AI(Artificial Intelligence) in policy research, investigated the theory of path change, and derived the characteristics of path change in AI policy. Since AI policy is related to a wide range of policy areas and the policy making is at the start points, this study is based on the neo-institutional path theory about the types of institutional changes. As a result of this study, AI policy showed the characteristics of path creation, and in detail presented the conflict relationship between institutional design elements, the scalability of policy areas, policy stratification and policy mix, the top policy characteristics transcending the law, and the experiment for regulatory innovation. Since AI can also be used as a key tool for policy innovation in the future, research on the path and characteristics of AI policy will provide a new direction and approach to government policy or institutional innovation seeking digital transformation.

• 산업공학
• /
• 제12권4호
• /
• pp.506-513
• /
• 1999

We use a path analysis to identify influential latent variables on employees' anticipated commitment to a merged bank. Survey samples are taken from Hanvit bank which is a merged form of Hanil and Sangup. Latent variables used in the path analysis are perceptions of organizational support, contact conditions, organizational unity, employee threat and organizational commitment. We find an interesting pre-merger group membership effect as well as merger pattern perceived by employees on the path for the anticipated commitment to the merged bank.

• Journal of applied mathematics & informatics
• /
• 제7권1호
• /
• pp.279-287
• /
• 2000

A simple estimate of Feynman path-integration with general potential via its new definition is given and found to be very useful. This new method will help find the value of some Feynman path-integrals as precise as one wants.