• Title/Summary/Keyword: Track following

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Position Control of Mobile Robot for Human-Following in Intelligent Space with Distributed Sensors

  • Jin Tae-Seok;Lee Jang-Myung;Hashimoto Hideki
    • International Journal of Control, Automation, and Systems
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    • v.4 no.2
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    • pp.204-216
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    • 2006
  • Latest advances in hardware technology and state of the art of mobile robot and artificial intelligence research can be employed to develop autonomous and distributed monitoring systems. And mobile service robot requires the perception of its present position to coexist with humans and support humans effectively in populated environments. To realize these abilities, robot needs to keep track of relevant changes in the environment. This paper proposes a localization of mobile robot using the images by distributed intelligent networked devices (DINDs) in intelligent space (ISpace) is used in order to achieve these goals. This scheme combines data from the observed position using dead-reckoning sensors and the estimated position using images of moving object, such as those of a walking human, used to determine the moving location of a mobile robot. The moving object is assumed to be a point-object and projected onto an image plane to form a geometrical constraint equation that provides position data of the object based on the kinematics of the intelligent space. Using the a priori known path of a moving object and a perspective camera model, the geometric constraint equations that represent the relation between image frame coordinates of a moving object and the estimated position of the robot are derived. The proposed method utilizes the error between the observed and estimated image coordinates to localize the mobile robot, and the Kalman filtering scheme is used to estimate the location of moving robot. The proposed approach is applied for a mobile robot in ISpace to show the reduction of uncertainty in the determining of the location of the mobile robot. Its performance is verified by computer simulation and experiment.

A Study on the $20^{th}$-century Korean Art History: Focusing on the 1960s-70s Art (20세기 한국미술사 연구를 위한 소고: 1960-70년대 미술을 중심으로)

  • Park, Choon Ho
    • The Journal of Art Theory & Practice
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    • no.16
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    • pp.7-40
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    • 2013
  • Historian Eric J. Hobsbawm once said "the task that historians have is to analyze the meanings of the past within the context of society and to track the changes and implementation." It would not be too far of a stretch to apply Hobsbawm's quote to art historian since art history, although quite specific, is still history. In addition, Hobsbaum also asserted that, "a mold called the past continuously forms the present or at least thought to be." It is my recognition that the major westernization of the last century took place under the Japanese colonization which served as the channel to usher in western art; however, the current 20thcentury Korean art history fails to recognize that the mold of the past, namely western art in this case, has formed the modern art of the present. Based on this recognition, attention was given to what lacked in the analysis of the current 20th-century Korean art history in terms of "Informel" which was identified as the turning point towards "modern art" in the Korean art history as well as the following "experimental art." My belief is that the art history of Korea has to be reassessed from, a socio-cultural perspective as well as adopting multi-level and diachronic understanding. However, the existing Korean art, especially the one between the end of 1950s to the 1970s was based on the perspective of "severance"; thus, raising the needs for the starting point of a new perspective. It is my conviction that meta perspective on writing is most essential in order to lay a solid basis for the Korean art scene to have a productive discussion. I feel the utmost necessity to reinterpret the typified history analysis and criticism which stemmed from the trauma under the Japanese colonization. The most urgent task is to avoid academic closeness and to share the research. Painting is an individual expression of the artist, but the act of expression is not free from the cultural and societal influence to which the artist belongs.

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Brief review of the field test and application of a superconducting fault current limiter

  • Hyun, Ok-Bae
    • Progress in Superconductivity and Cryogenics
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    • v.19 no.4
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    • pp.1-11
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    • 2017
  • This article reviews the recent activities of field testing and application of superconducting fault current limiters (SFCL) based on high-temperature superconductors (HTS). The review particularly focuses on the trends in the field tests in terms of the technical aspects and commercial activities of the SFCLs. Stimulated by the discovery of HTS, numerous research and development activities have been conducted worldwide for SFCLs operating from distribution voltages to transmission voltages. Different types of SFCLs have been developed and field-tested. Consequently, more than 20 field tests and applications have been performed on real grids worldwide while supplying electric power to the customers. These field tests have not only provided the track records of the operation experiences including the problems and maintenance during operation, but also proved their current limiting capabilities against real faults, rendering this new technology highly viable. Through these activities, the following trends in the status of field testing and application are observed. Resistive-type SFCLs with HTS-coated conductors were dominantly used in the most recent field tests. This implies that the resistive type is technically more mature than the other types. Bus-bar coupling and transformer feeders were the major application locations. It is of importance that most of the field applications were conducted as R&D projects. A relevant change from the R&D stage to the application stage is shown as recently deployed SFCLs are expected to be under long-term operation and commercial service. Here, we review the installation of these SFCLs by substation. This review also discusses the recent activities for their commercial applications.

Real Time Object Tracking Method using Multiple Cameras (다중 카메라를 이용한 실시간 객체 추적 방법)

  • Jang, In-Tae;Kim, Dong-Woo;Song, Young-Jun;Kwon, Hyeok-Bong;Ahn, Jae-Hyeong
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.4
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    • pp.51-59
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    • 2012
  • Recently, the study about object tracking using image processing has been active in the field of security and surveillance. Existing security and surveillance systems using multiple cameras have been operating independently. Thus, the chase was difficult when the tracking object move to other monitored areas. In this paper, we propose the way to change the control of camera automatically following the moving direction of objects in multiple cameras. The proposed method detects the object and tracks the object using color information and direction information of object. The color information obtains using the hue and the direction information obtains using the optical flow. At this time, the optical flow is detected for the entire image area of an object that is not applied only to reduce the computational complexity makes it possible to track in real time. In addition, it can be solved to inconvenience of security surveillance system to use existing camera by tracking an object automatically.

A Load-Sharing Scheme using SCTP Multi-homing (SCTP 멀티호밍 특성을 활용한 부하 분산 기법)

  • Song Jeonghwa;Lee Meejeong
    • Journal of KIISE:Information Networking
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    • v.31 no.6
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    • pp.595-607
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    • 2004
  • Networks often evolve to provide a host with multiple access points to the Internet. In this paper, we propose a transport layer load distribution mechanism utilizing the multiple network interfaces simultaneously. We specifically propose an extension of Stream Control Transmission Protoco1 (SCTP) to have load sharing over multiple network interfaces. We named the particular service provided by the Proposed load sharing mechanism to be LS (Load Sharing) mode service. LS mode service is based on the following four key elements: (i) the separation of flow control and congestion control, (ii) congestion window based striping, (iii) redundant packet retransmission for fast packet loss recovery, (iv) a novel mechanism to keep track of the receiver window size with the SACKS even if they arrive out-of-order. Through simulations, it is shown that the proposed LS mode service can aggregate the bandwidth of multiple paths almost ideally despite of the disparity in their bandwidth. When a path with a delay of 100% greater is utilized as the second path, the throughput is enhanced about 20%.

Analysis of Open Access Status of Domestic Author's Papers Published in International Journals: Based on Highly Cited Papers (국내연구자가 출판한 국제학술지 논문의 오픈액세스 현황 - 고피인용된 논문 중심 -)

  • Cho, Jane
    • Journal of the Korean Society for Library and Information Science
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    • v.54 no.1
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    • pp.325-341
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    • 2020
  • This study used the Unpaywall API, one of the open tools to track the OA version, to empirically identify the OA of 3,905 papers that have been published by Korean corresponding authors since 2015 in international journals. As a result, the following facts were found. First, less than 30% of papers have been open accessed, and more than half of them were bronze OA. Secondly, the archiving site of the Green OA papers was found not to be domestic but mainly subject repositories or institutional repositories of overseas universities to which co-authors belong. Third, only 19.6% of research fund granted papers were open accessed and half of them were in the medical field. In contrast to the international trends in which the OA papers showed higher citations, the analyzed OA papers showed no higher citations than the non-OA papers.

Effects of Low Power Laser Irradiation on the Spinal Cord for the Functional Regeneration of Crushed Sciatic Nerve in Rats (흰쥐 좌골신경 압좌손상 후 척수분절의 저강도 레이저 조사가 운동기능 회복에 미치는 영향)

  • Kim, Souk-Boum;Kim, Dong-Hyun;Song, Ju-Min;Nam, Ki-Won;Kwon, Young-Shil;Kim, Jin-Sang
    • The Journal of Korean Physical Therapy
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    • v.13 no.3
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    • pp.569-578
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    • 2001
  • The purpose of the present study was to examine the functional recovery of the crushed sciatic nerve of rats after low-power laser irradiation applied to the corresponding segments of the spinal cord. After a crushed injury on the left sciatic nerve in rats. low-power laser irradiation was applied transcutaneously to corresponding segments of the spinal cord immediately after suture the wound by using 2000 mW, 2000Hz, 830 nm CaAIAs(Gallium-aluminum-arsenide) semiconductor diode laser. The laser treatment was performed with 10 minutes daily for 4 successive weeks. Functional recovery was evaluated per weekly following injury by sciatic function index(SFI),using data obtained by walking track analysis. For four weeks after crush injury, experimental group had significantly greater functional improvement than control group(${\alpha}$=0.05). In a experimental group, SFI was significantly increased for three weeks, but control group not increased for two weeks. This study suggests that low-power laser irradiation applied directly to the spinal cord can improve functional recovery of the crushed sciatic nerve in rats.

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A Study of the Deterioration Restraining Agent Drainage method of Construction (열화억제형 방수공법에 대한 검토)

  • Oh, Dai-Chul;Kim, Eun-Kyum;Kim, Dae-Sang
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1267-1272
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    • 2007
  • In the case of the railway bridge, there are following the progress of works after the drainage method of a bridge surface - vibration proof rubber establishment, track gravel construction and rail construction etc. But these works are not enforced consecutively by the execution and economical reason. This is the reason of the long period of exposure after drainage execution. In many case, from the deterioration phenomenon by long term exposure of surface, there are a lot of occasions that do not keep primitive penetration depth waterproof primitive time. It is the most important that select the drainage method that have durability - it is not fallen in long-term exposure of surface. The major objective of this study is to deduce objective analysis result through examination about the Deterioration Restraining Agent method and to master KNOW-HOW of DRA drainage method. Through the study, minimize economical damage by frequent repair and reinforcement and present the reasonable standard of judgement fot drainage method of construction.

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Robust and Non-fragile $H^{\infty}$ Controller Design for Tracking Servo of Blu-ray disc Drive System (Blu-ray 디스크 드라이브 시스템 트래킹 서보시스템에 대한 견실비약성 $H^{\infty}$ 상태궤환 제어기 설계)

  • Lee, Hyung-Ho;Kim, Joon-Ki;Kim, Woon-Ki;Jo, Sang-Woo;Park, Hong-Bae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.45 no.3
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    • pp.32-41
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    • 2008
  • In this paper, we describe the synthesis of robust and non-fragile $H^{\infty}$ state feedback controllers for linear systems with affine parameter uncertain tracking servo system of blu-ray disc drive, as well as static state feedback controller with polytopic uncertainty Similarity any other control system, the objective of the track-following system design for optical disc drives is to construct the system with better performance and robustness against modeling uncertainties and various disturbances. Also, the obtained condition can be rewritten as parameterized linear matrix inequalities(PLMIs), that is, LMIs whose coefficients are functions of a parameter confined to a compact set. We show that the resulting controller guarantees the asymptotic stability and disturbance attenuation of the closed loop system in spite of controller gain variations within a resulted polytopic region.

An Analysis of Spatial Cognition and Operation in Children's Drawings (아동의 그림을 통해 본 공간인지와 조작능력)

  • Kang, Kyoung-Won
    • Journal of the Korean association of regional geographers
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    • v.6 no.3
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    • pp.83-99
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    • 2000
  • This paper purposes to provide a new perspective for better development of geography texts. For this purpose, we have applied spatial cognition development theory to children's drawings. We have suggested that children's spatial operation ability has three development stages according to their age: topological space, projective space, euclidean space. This study turns out that Piaget and Inhelder's spatial concept development theory is on the right track. However, we make clear that their division according to the age is not always accurate due to children's individual differences. These findings have educational implications as the following: First, it is dubious that most children can understand pictures, pictorial maps and illustrations in the third grader's textbook. Second, current textbooks require pictorial map understanding and drawing to third grade students and map drawing to fourth grade students. However, according to this study, the placement of these tasks are not fit for children's developmental stage because both tasks correspond to euclidean space operation. Therefore, we should remove them from the textbook for children at the age.

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