• 제목/요약/키워드: Obstacles to change

검색결과 177건 처리시간 0.028초

인간 중심의 긴급 대응체계를 근거로 한 국제 방재 지원 - 이라크 보건의료방재지원 사례 중심 (International Disaster Assistance Based on Human Focused Emergency Response System : Example of Health Disaster Assistance to Iraq)

  • 왕순주
    • 한국재난정보학회 논문집
    • /
    • 제3권2호
    • /
    • pp.129-146
    • /
    • 2007
  • The disaster preparedness system in Korea has been developed in spite of many obstacles, but there are still many problems for response to various kinds of disasters in 21th century. Disaster response system in Korea was focused on policy, administration, hardwares in the past. But in the future it is necessary to change the system to adapt the global needs about the human based disaster response system and capacity to assist the international disaster by official assistance and research for that field. Because nearly all the disasters are associated with the safety, welfare, injury, disability and survival of human, health disaster preparedness and response system should be a important part in the whole disaster system considering the common value of human right to disaster preparedness for human.

  • PDF

전자계약의 효력에 관한 연구 (A Study on the Legal Effect of Electronic Contract)

  • 송계의
    • 통상정보연구
    • /
    • 제1권2호
    • /
    • pp.229-247
    • /
    • 1999
  • Where a paper document, a manual signature, or negotiability is required in statute, then solutions must be found through a change in the law. However, where the problem originates in commercial usage, then the solution can be easier, and speedy. Certainly, nearly all of the functions that paper document provides can be equally, or better, satisfied by electronic means. That is, Electronic Commerce(EC), which has been increasing rapidly and is a new type of transaction, may be hindered by legal obstacles to use of Electronic Message, or by uncertainty to its legal effect and validity. Therefore, it is important to sustain legal effect to Electronic Message for the prosperity of EC The one of solutions is to use reliable Electronic signature system by Certification Authority to verify the authenticity of Electronic Message.

  • PDF

장애물이 있는 환경하에서 여유자유도 로보트의 지능제어 방법 (Intelligent Control of Redundant Manipulator in an Environment with Obstacles)

  • 현웅근;서일홍
    • 대한전기학회논문지
    • /
    • 제41권5호
    • /
    • pp.551-561
    • /
    • 1992
  • A neural optimization network and fuzzy rules are proposed to control the redundant robot manipulators in an environment with obstacle. A neural optimization network is employed to solve the optimization problem for resolved motion control of redundant robot manipulators in an environment with obstacle. The fuzzy rules are proposed to determine the weights of neural optimization networks to avoid the collision between robot manipulators and obstacle. The inputs of fuzzy rules are the resultant distance and change of the distance and sum of the changes by differential motion of each joint. And the output of fuzzy rules is defined as the capability of collision avoidance of joint differential motion. The weightings of neural optimization networks are adjusted according to the capability of collision aboidance of each joint. To show the validities of the proposed method, computer simulation results are illustrated for the redundant robot of the planar type with three degrees of freedom.

Robust Multithreaded Object Tracker through Occlusions for Spatial Augmented Reality

  • Lee, Ahyun;Jang, Insung
    • ETRI Journal
    • /
    • 제40권2호
    • /
    • pp.246-256
    • /
    • 2018
  • A spatial augmented reality (SAR) system enables a virtual image to be projected onto the surface of a real-world object and the user to intuitively control the image using a tangible interface. However, occlusions frequently occur, such as a sudden change in the lighting environment or the generation of obstacles. We propose a robust object tracker based on a multithreaded system, which can track an object robustly through occlusions. Our multithreaded tracker is divided into two threads: the detection thread detects distinctive features in a frame-to-frame manner, and the tracking thread tracks features periodically using an optical-flow-based tracking method. Consequently, although the speed of the detection thread is considerably slow, we achieve real-time performance owing to the multithreaded configuration. Moreover, the proposed outlier filtering automatically updates a random sample consensus distance threshold for eliminating outliers according to environmental changes. Experimental results show that our approach tracks an object robustly in real-time in an SAR environment where there are frequent occlusions occurring from augmented projection images.

Optimal Path Planning Using Critical Points

  • Lee, Jin-Sun;Choi, Chang-Hyuk;Song, Jae-Bok;Chung, Woo-Jin;Kim, Mun-Sang
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2001년도 ICCAS
    • /
    • pp.131.4-131
    • /
    • 2001
  • A lot of path planning algorithms have been developed to find the collision-free path with minimum cost. But most of them require complicated computations. In this paper, a thinning method, which is one of the image processing schemes, was adopted to simplify the path planning procedure. In addition, critical points are used to find the shortest-distance path among all possible paths from the start to the goal point. Since the critical points contain the information on the neighboring paths, a new path can be quickly obtained on the map even when the start and goal points change. To investigate the validity of the proposed algorithm, various simulations have been performed for the environment where the obstacles with arbitrary shapes exist. It is shown that the optimal paths can be found with relative easiness.

  • PDF

Neural optimization networks with fuzzy weighting for collision free motions of redundant robot manipulators

  • Hyun, Woong-Keun;Suh, Il-Hong;Kim, Kyong-Gi
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
    • /
    • pp.564-568
    • /
    • 1992
  • A neural optimization network is designed to solve the collsion-free inverse kinematics problem for redundant robot manipulators under the constraints of joint limits, maximum velocities and maximum accelerations. And the fuzzy rules are proposed to determine the weightings of neural optimization networks to avoid the collision between robot manipulator and obstacles. The inputs of fuzzy rules are the resultant distance, change of the distance and sum of the changes. And the output of fuzzy rules is defined as the capability of collision avoidance of joint differential motion. The weightings of neural optimization networks are adjusted according to the capability of collision avoidance of each joint. To show the validities of the proposed method computer simulation results are illustrated for the redundant robot with three degrees of freedom,

  • PDF

장애물 높이에 따른 성인과 노인의 족저압 분포 비교 (The Comparison of Plantar Foot Pressure Distribution in Adult and Elderly according Obstacle Heights)

  • 장종성;이명희
    • The Journal of Korean Physical Therapy
    • /
    • 제26권4호
    • /
    • pp.257-261
    • /
    • 2014
  • Purpose: The purpose of this study was to compare plantar foot pressure distribution in adults and elderly according to obstacle height. Methods: Nine healthy adults and nine older adults were recruited and the subjects provided written informed consent consent prior to participation. Both groups walked and crossed obstacles with heights of 0%, 10%, 20%, and 30% of their height. Foot pressure was measured by peak pressure using the Pedar System (Novel Gmbh, Germany) during obstacle walking with barefeet in shoes. Three trails were calculated on eight areas and then averaged for data analysis. Results: A significant difference in great toe, little toes, and lateral metatarsal area was observed between adults and elderly groups, but other areas did not show significant differences. Foot pressure was increased in groups according to obstacle height. Conclusion: These findings showed that change in foot pressure distribution is more lateral in elderly in order to maintain postural control during obstacle crossing.

TIMSS 2011 결과에 나타난 초등학교 4학년 학생들의 수학에 대한 정의적 태도와 교사 변인과의 관계 분석 (An analysis of teacher effects on fourth-grade students' attitudes toward mathematics based on TIMSS 2011 results)

  • 김성희
    • 한국수학교육학회지시리즈A:수학교육
    • /
    • 제54권2호
    • /
    • pp.195-206
    • /
    • 2015
  • The purpose of this study is to examine the effects of teacher on fourth-grade students' attitudes toward mathematics using data from TIMSS 2011. Students' attitudes toward mathematics included interest in learning mathematics, interest in mathematics lessons, and confidence in their mathematics ability. Teacher factors included mathematics professional development, confidence in teaching mathematics, teacher-centered mathematics instruction, and enhancing student mathematical thinking. The two level Hierarchical Linear Model was employed to analyze the relationship between teacher factors and student attitudes. Results showed that teacher-centered mathematics instruction significantly and positively predicted students' confidence about their mathematics ability. The findings suggest that school systems and mathematics educators need to provide teachers with the curriculum, assessment, and research-based practices and knowledge to overcome the obstacles to change their mathematics classroom.

스마트폰 제어기반의 반자율 네비게이션을 갖춘 개인용 이동 시스템 구현 (Development of a Smartphone Controlled Personal Mobility System (PMS) with Semi-autonomous Navigation)

  • 김연균;김동헌
    • 제어로봇시스템학회논문지
    • /
    • 제22권2호
    • /
    • pp.97-103
    • /
    • 2016
  • In this paper, a smartphone-controlled personal mobility system (PMS) with semi-autonomous navigation is developed. The proposed PMS moves to waypoints and then reaches the destination where the waypoints and destination are selected by the user using Google maps in a smartphone. The hardware environment consists of a GPS (Global Positioning System) in the smartphone and a compass sensor. In addtion, while it is moving in autonomous mode, the user can intervene and change the direction and speed of the PMS in order to avoid obstacles that may be encountered accidentally in a dynamic environment. That is why it is called "semi-autonomous navigation". Experimental results showed that the proposed PMS is effectively able to migrate to the waypoints and destination in both autonomous and manual modes.

Real time trajectory control for two wheeled mobile robot under dynamic environments

  • Lee, Jin-Woo
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 2001년도 ICCAS
    • /
    • pp.120.4-120
    • /
    • 2001
  • In this paper, a method of generating trajectories in real time for a mobile robot in a dynamic environment is proposed. Specifically, this method is focused on soccer-playing robots that need to calculate trajectories in real time, which are constantly subject to rapidly change as targets and obstacles move. The robots also should move at the fastest available speed, while tracking the generated trajectories. The method proposed in this paper solves the geometric problem of finding a smooth curve that joins two endpoints. To have this solved, we assign five constraints to each endpoint, which are the usual x, y, theta, and curvature as well as the influence of the initial robot velocity on the path. With these five constraints, the path generated can always be physically followed by robot. Through this method, the travel time of the robot over the entire path can b optimized. Therefore it can ...

  • PDF