• Title/Summary/Keyword: Obstacle problems

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A Study on the Problem of Terminology in Calculus (미분법 단원에서 용어의 문제)

  • 한대희
    • Journal of Educational Research in Mathematics
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    • v.8 no.2
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    • pp.495-507
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    • 1998
  • This article intends to review what problems the terms in calculus have and how those problems are caused. For this purpose We make examinations on the considerations in the analysis of mathematical terminology, which includes the problems of general and technical terms, the meaning and the boundary of words, their consistency, the name and meaning, concept and their concept images, translations and qwerty effects. And in chapter 3, We analyse the textbook which are currently used, through which I was able to find out that the terms in calculus have some problems, In other words, the key terms such as "differentiable", "differential coefficient", "differential" have their roots in the term "differential" but the term "derived function" is very distinct from other terms and thus obstructs the consistency of terms. And the central term "differential" is being used without clear definition. In particular, the fact that "differential", when used in its arbitrary definition, has the image of "splitting minutely" can be an obstacle to understanding the exact concepts of calculus. In chapter 4, We make a review on the history of calculus and the term "differential" currently used in modern mathematics so that I can identify the origin of the problem connected with the usage of the term "differential". We should recognize the specified problems and its causes and keep their instructional implications in mind. Furthermore, following researches and discussions should be made on whether the terminology system of calculus should be reestablished and how the reestablishment should be made.e terminology system of calculus should be reestablished and how the reestablishment should be made.

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A Study on Legal and Regulatory Improvement Direction of Aeronautical Obstacle Management System for Aviation Safety (항공안전을 위한 장애물 제한표면 관리시스템의 법·제도적 개선방향에 관한 소고)

  • Park, Dam-Yong
    • The Korean Journal of Air & Space Law and Policy
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    • v.31 no.2
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    • pp.145-176
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    • 2016
  • Aviation safety can be secured through regulations and policies of various areas and thorough execution of them on the field. Recently, for aviation safety management Korea is making efforts to prevent aviation accidents by taking various measures: such as selecting and promoting major strategic goals for each sector; establishing National Aviation Safety Program, including the Second Basic Plan for Aviation Policy; and improving aviation related legislations. Obstacle limitation surface is to be established and publicly notified to ensure safe take-off and landing as well as aviation safety during the circling of aircraft around airports. This study intends to review current aviation obstacle management system which was designed to make sure that buildings and structures do not exceed the height of obstacle limitation surface and identify its operating problems based on my field experience. Also, in this study, I would like to propose ways to improve the system in legal and regulatory aspects. Nowadays, due to the request of residents in the vicinity of airports, discussions and studies on aviational review are being actively carried out. Also, related ordinance and specific procedures will be established soon. However, in addition to this, I would like to propose the ways to improve shortcomings of current system caused by the lack of regulations and legislations for obstacle management. In order to execute obstacle limitation surface regulation, there has to be limits on constructing new buildings, causing real restriction for the residents living in the vicinity of airports on exercising their property rights. In this sense, it is regarded as a sensitive issue since a number of related civil complaints are filed and swift but accurate decision making is required. According to Aviation Act, currently airport operators are handling this task under the cooperation with local governments. Thus, administrative activities of local governments that have the authority to give permits for installation of buildings and structures are critically important. The law requires to carry out precise surveying of vast area and to report the outcome to the government every five years. However, there can be many problems, such as changes in the number of obstacles due to the error in the survey, or failure to apply for consultation with local governments on the exercise of construction permission. However, there is neither standards for allowable errors, preventive measures, nor penalty for the violation of appropriate procedures. As such, only follow-up measures can be taken. Nevertheless, once construction of a building is completed violating the obstacle limitation surface, practically it is difficult to take any measures, including the elimination of the building, because the owner of the building would have been following legal process for the construction by getting permit from the government. In order to address this problem, I believe penalty provision for the violation of Aviation Act needs to be added. Also, it is required to apply the same standards of allowable error stipulated in Building Act to precise surveying in the aviation field. Hence, I would like to propose the ways to improve current system in an effective manner.

Simplified Cooperative Collision Avoidance Method Considering the Desired Direction as the Operation Objective of Each Mobile Robot

  • Yasuaki, Abe;Yoshiki, Matsuo
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1927-1932
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    • 2003
  • In a previous study, the authors have proposed the Cooperative Collision Avoidance (CCA) method which enables mobile robots to cooperatively avoid collisions, by extending the concept of the Velocity Obstacle to multiple robot systems. The method introduced an evaluation function considering an operation objective so that each robot can choose the velocity which optimizes the function. As the evaluation function could be of an arbitrary type, this method is applicable to a wide variety of tasks. However, it complicates the optimization of the function especially in real-time. In addition, construction of the evaluation function requires an operation objective of the other robot which is very hard to obtain without communication. In this paper, the CCA method is improved considering such problems for implementation. To decrease computational costs, the previous method is simplified by introducing two essential assumptions. Then, by treating the desired direction of locomotion for each robot as the operation objective, an operation objective estimator which estimates the desired direction of the other robot is introduced. The only measurement required is the other robot's relative position, since the other information can be obtained through the estimation. Hence, communicational devices that are necessary for most other cooperative methods are not required. Moreover, mobile robots employing the method can avoid collisions with uncooperative robots or moving obstacles as well as with cooperative robots. Consequently, this improved method can be applied to general dynamic environments consisting of various mobile robots.

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A Basic Study on Development of Web-based Visual Perception Test Program Prototype (웹 기반 시 지각 진단 프로그램의 모형 개발을 위한 기초연구)

  • Ahn, Seong-Hye
    • Archives of design research
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    • v.19 no.2 s.64
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    • pp.5-14
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    • 2006
  • Visual perception is ability that analyze visual information about things accepting through eyes in central nervous system. That is, it is ability that recognize and discriminates a visual stimulus, and analyzes by combining such stimulus with previous experience. At today, work which clears visual perception obstacle's cause through visual perception test and grasps all special quality of visual perception obstacle's is used method of treating that improve visual perception obstacle by visual perception training program. Present, visual perception test tools using the paper and pens are used mainly on psychological consultation of welfare facilities and education for the handicapped or occupational therapy, but a lot of problems are discovered in it. Therefore, purpose of this paper is to develop prototype of web-based visual perception test program that can construct to database to solve existing problem, and to design graphic item. As a result, classified measurement pattern that can diagnose visual perception by three, and illustrated development direction of graphic item for examination with this. Also, extracted check list item that should consider for design and construction of visual perception test program and the variable for feasibility study of believability, and presented process for prototype development.

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Prehospital care and improvement of 119 emergency medical technician for the insect bite patients (119 구급대원의 곤충교상환자에 대한 응급처치 현황 및 개선방안)

  • Kim, Ji-Hye;Lee, Kyoung-Youl
    • The Korean Journal of Emergency Medical Services
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    • v.17 no.1
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    • pp.63-78
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    • 2013
  • Purpose : This study aimed to improve quality of prehospital emergency care for the insect bite patients by figuring out its current situations and problems. Methods : This study was conducted to 219 insect bite patients who were transferred to the hospital by 119 ambulance in D-City from July 1, 2009 to June 30, 2011. This study was a descriptive study by 119 run sheets. A total of 171 emergency medical technicians(EMTs) working in D-city and C-province completed the questionnaire. All of data were analyzed by SPSS 18.0. Results : Among the 219 patients, bee sting accounted for 62.6% and wasp sting accounted for 20.1%. Some patients complained of dizziness, headache, dyspnea, and disturbance of consciousness. The 119 EMTs initially treated the patients with oxygen supply to 57 patients (31.1%). Knowledge toward insect bite was statistically significant (p=.000) between advanced EMTs and basic EMTs. The obstacle to the prehospital care, many EMTs answered that the obstacle was due to the lack of 119 EMTs. Conclusion : It is necessary to differentiate the patients' symptoms and provide the better prehospital emergency care to verify the exact symptoms and signs.

Superpixel-based Vehicle Detection using Plane Normal Vector in Dispar ity Space

  • Seo, Jeonghyun;Sohn, Kwanghoon
    • Journal of Korea Multimedia Society
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    • v.19 no.6
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    • pp.1003-1013
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    • 2016
  • This paper proposes a framework of superpixel-based vehicle detection method using plane normal vector in disparity space. We utilize two common factors for detecting vehicles: Hypothesis Generation (HG) and Hypothesis Verification (HV). At the stage of HG, we set the regions of interest (ROI) by estimating the lane, and track them to reduce computational cost of the overall processes. The image is then divided into compact superpixels, each of which is viewed as a plane composed of the normal vector in disparity space. After that, the representative normal vector is computed at a superpixel-level, which alleviates the well-known problems of conventional color-based and depth-based approaches. Based on the assumption that the central-bottom of the input image is always on the navigable region, the road and obstacle candidates are simultaneously extracted by the plane normal vectors obtained from K-means algorithm. At the stage of HV, the separated obstacle candidates are verified by employing HOG and SVM as for a feature and classifying function, respectively. To achieve this, we trained SVM classifier by HOG features of KITTI training dataset. The experimental results demonstrate that the proposed vehicle detection system outperforms the conventional HOG-based methods qualitatively and quantitatively.

Obstacle Avoidance Algorithm of a Mobile Robot using Image Information (화상 정보를 이용한 이동 로봇의 장애물 회피 알고리즘)

  • Kwon, O-Sang;Lee, Eung-Hyuk;Han, Yong-Hwan;Hong, Seung-Hong
    • Journal of IKEEE
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    • v.2 no.1 s.2
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    • pp.139-149
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    • 1998
  • There are some problems in robot navigations with a single kind of sensor. We propose a system that takes advantages of both CCD camera and ultrasonic sensors for the concerning matter. A coordinate extraction algorithm to avoid obstacles during the navigation is also proposed. We implemented a CCD based vision system at the front part of the vehicle and did experiments to verify the suggested algorithm's availability. From experimental results, the error rate was reduced when a CCD camera was used rather than when only ultrasonic sensors were used. Also we can generate path to avoid those obstacles using the measured values.

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Path Planning and Tracking for Mobile Robots Using An Improved Distance Transform Algorithm (개선된 거리변환 알고리즘을 이용한 이동 로봇의 경로 계획 및 추적)

  • Park Jin-Hyun;Park Gi-Hyung;Choi Young-Kiu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.4
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    • pp.782-791
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    • 2005
  • In this paper, path planning and tracking problems are mentioned to guarantee efficient and safe navigation of autonomous mobile robots. We focus on the path planning and also deal with the path tracking and obstacle avoidance. We improved the conventional distance transform (DT) algorithm for the path planning. Using the improved DT algorithm, we obtain paths with shorter distances compared to the conventional DT algorithm. In the stage of the Path tracking, we employ the fuzzy logic controller to conduct the path tracking behavior and obstacle avoidance behavior. Through computer simulation studies, we show the effectiveness of the Nosed navigational algorithm for autonomous mobile robots.

Mutual Interference on Mobile Pulsed Scanning LIDAR

  • Kim, Gunzung;Eom, Jeongsook;Choi, Jeonghee;Park, Yongwan
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.1
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    • pp.43-62
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    • 2017
  • Mobile pulse scanning Light Detection And Ranging (LIDAR) are essential components of intelligent vehicles capable of autonomous travel. Obstacle detection functions of autonomous vehicles require very low failure rates. With the increasing number of autonomous vehicles equipped with scanning LIDARs to detect and avoid obstacles and navigate safely through the environment, the probability of mutual interference becomes an important issue. The reception of foreign laser pulses can lead to problems such as ghost targets or a reduced signal-to-noise ratio. This paper will show the probability that any two scanning LIDARs will interfere mutually by considering spatial and temporal overlaps. We have conducted four experiments to investigate the occurrence of the mutual interference between scanning LIDARs. These four experimental results introduced the effects of mutual interference and indicated that the interference has spatial and temporal locality. It is hard to ignore consecutive mutual interference on the same line or the same angle because it is possible the real object not noise or error. It may make serious faults because the obstacle detection functions of autonomous vehicle rely on heavily the scanning LIDAR.

Path Planning and Tracking for Mobile Robots Using An Improved Distance Transform Algorithm (개선된 거리변환 알고리즘을 이용한 이동 로봇의 경로 계획 및 추적)

  • Park, Jin-Hyun;Park, Gi-Hyung;Choi, Young-Kiu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.295-299
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    • 2005
  • In this paper, path planning and tracking problems are mentioned to guarantee efficient and safe navigation of autonomous mobile robots. We focus on the path planning and also deal with the path tracking and obstacle avoidance. We improved the conventional distance transform (DT) algorithm for the path planning. Using the improved DT algorithm, we obtain paths with shorter distances compared to the conventional DT algorithm. In the stage of the path tracking, we employ the fuzzy logic controller to conduct the path tracking behavior and obstacle avoidance behavior. Through computer simulation studies, we show the effectiveness of the proposed navigational algorithm for autonomous mobile robots.

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