• Title/Summary/Keyword: labyrinth

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Changes in Excitability of Neurons in Rat Medial Vestibular Nucleus Following Vestibular Neurectomy

  • Chun, Sang-Woo;Choi, Jeong-Hee;Lee, Shin-Hyung;Park, Byung-Rim
    • The Korean Journal of Physiology and Pharmacology
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    • v.6 no.6
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    • pp.287-291
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    • 2002
  • Intrinsic excitabilities of acutely isolated medial vestibular nucleus (MVN) neurons of rats with normal labyrinth and with undergoing vestibular compensation from 30 min to 24 h after unilateral vestibular deafferentation (UVD) were compared. In control rats, proportions of type A and B cells were 30 and 70%, respectively, however, the proportion of type A cells increased following UVD. Bursting discharge and irregular firing patterns were recorded from 2 to 12 h post UVD. The spontaneous discharge rate of neurons in the ipsilesional MVN increased significantly at 2 h post-UVD and remained high until 12 h post-UVD in both type A and type B cells. After-hyperpolarization (AHP) of the MVN neurons decreased significantly from 2 h post-UVD in both types of cells. These results suggest that the early stage of vestibular compensation after peripheral neurectomy is associated with an increase in intrinsic excitability due to reduction of AHP in MVN neurons.

Design of the Dasan Children's Park (다산 어린이 공원설계)

  • 김성균
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.5
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    • pp.51-59
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    • 2001
  • This paper presents a design of the Dasan Children\`s Park which is located Shindang- dong, lung-gu, Seoul which has an area of about 3,678$m^2$. Objectives for the design were to make nature-friendly space, learning space, interesting play space, space for every child, adventure play space, traditional play space, sense of place, and recycle space. For the space compositions a children\`s garden, a traditional play space, and a science play space were located around the S shaped main route. Facilities relating nature, science, culture. environment and adventure play were arranged in the 3 main spaces. The Children\`s Garden is a green space for learning and playing with natural elements. It is composed of a ecological learning space, a children\`s story garden, a children\`s song road, an environmental labyrinth, and a pall space leer handicap children. The Science Play Place is a place space for learning scientific theories through plays to which scientific theories were applied. It is composed of a total play structure, a math experience playground, a \"Keojunggi\" play space, a sound reflecting experience space, arid an infant playground. The Traditional Play Madang(space) is a space for traditional plays. It is composed of a traditional play pattern, a sun dial, and a floor fountain. The Recycle Road is a dragon shaped road fort learning about resource recycling and conservation. It is composed of a dragon head, body, tail space and a dragon bead(cint mani).int mani).

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GMR in Multilayers with an Alternating In-plane and Perpendicular Anisotropy

  • Stobiecki, F.;Szymanski, B.;Lucinski, T.;Dubowik, J.;Urbaniak, M.;Roll, K.;Kim, J.B;Kim, K.W;Lee, Y.P
    • Journal of Magnetics
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    • v.9 no.2
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    • pp.40-46
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    • 2004
  • The magnetic properties of sputtered ($Ni_{83}Fe_{17}/Au/Co/Au$) multilayers with various thicknesses of Au (0.5 {\leq} t_{Au} {\leq} 3 nm), Ni-Fe ($1{\leq}t_{Ni-Fe}{\leq}4nm$) and Co ($0.2{\leq}t_{co}{\leq}1.5nm$) layers were characterized. An alternating in-plane and out-of-plane anisotropy of the ferromagnetic layers was achieved for the structures ($t_{Au}{\geq}1.5nm$) showing a weak coupling between the Ni-Fe layers with an in-plane anisotropy and the Co layers ($0.3{\leq}t_Co{\leq}1.2nm$) with a perpendicular anisotropy. For such a structure, a detailed discussion on the GMR effect is presented, relating to the magnetization reversal from a mutually perpendicular magnetic configuration at the remanence to a parallel one at the saturation. An influence of the dense labyrinth domain structure on the magnetoresistance effect is also addressed.

A Study on Real-Time Autonomous Travelling Control of Two-wheel Driving Robot Based Ultrasonic Sensors (초음파센서기반 2휠구동로봇의 실시간 자율주행제어에 관한연구)

  • hwang, Won-Jun;Park, In-Man;Kang, Un-Wook;Han, Sung-Hyun
    • Journal of the Korean Society of Industry Convergence
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    • v.17 no.3
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    • pp.151-169
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    • 2014
  • We propose a new technique for autonomous navigation and travelling of mobile robot based on ultrasonic sensors through the narrow labyrinth that leave only distance of a few centimeters on each side between the guides and the robot. In our current implementation the ultrasonic sensor system fires at a rate of 100 ms, that is, each of the 8 sensors fires once during each 100 ms interval. This is a very good firing rate, implemented here for optimal performance. This paper presents an extensively tested and verified solution to the problem of obstacle avoidance. Our solution is based on the optimal placement of ultrasonic sensors at strategic locations around the robot. Both the sensor location and the associated navigation algorithm are defined in such a way that only the accurate radial sonar data is used for accurate travelling.

Spontaneous Vertigo (자발현훈)

  • Choi, Kwang-Dong;Kim, Ji Soo
    • Annals of Clinical Neurophysiology
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    • v.9 no.1
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    • pp.1-4
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    • 2007
  • Vertigo is an illusion of rotation, which results from an imbalance within the vestibular system. This review focuses on two common presentations of spontaneous vertigo: acute prolonged spontaneous vertigo and recurrent spontaneous vertigo. Common causes of acute prolonged spontaneous vertigo include vestibular neuritis, labyrinthitis, and brainstem or cerebellar stroke. The history and detailed neurological/neurotological examinations usually provide the key information for distinguishing between peripheral and central causes of vertigo. Brain MRI is indicated in any patient with acute vertigo accompanied by abnormal neurological signs, profound imbalance, severe headache, and central patterns of nystagmus. Recurrent spontaneous vertigo occurs when there is a sudden, temporary, and largely reversible impairment of resting neural activity of one labyrinth or its central connections, with subsequent recovery to normal or near-normal function. Meniere's disease, migrainous vertigo, and vertebrobasilar insufficiency (VBI) are common causes. The duration of the vertigo attack is a key piece of information in recurrent spontaneous vertigo. Vertigo of vascular origin, such as VBI, typically lasts for several minutes, whereas recurrent vertigo due to peripheral inner-ear abnormalities lasts for hours. Screening neurotological evaluations, and blood tests for autoimmune and otosyphilis are useful in assessment of recurrent spontaneous vertigo that are likely to be peripheral in origin.

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Characterising the dynamic seals used in absorber rod drive mechanisms in Indian FBR

  • Kaushal, Nihal;Patri, Sudheer;Kumar, R. Suresh;Meikandamurthy, C.;Sreedhar, B.K.;Murugan, S.;Raghupathy, S.
    • Nuclear Engineering and Technology
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    • v.53 no.10
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    • pp.3438-3448
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    • 2021
  • Dynamic seals are one of the critical components of Absorber Rod Drive Mechanism of Fast Breeder Reactors, requiring separate experimental development. Their significance can't be overemphasized considering that the availability and re-usability of Control Rod Drive Mechanisms of Fast Breeder Test Reactor is governed by the failure rate of dynamic seals (bellows). For prototype and subsequent Fast Breeder Reactors in India, choice of the dynamic seal is changed to an in-house designed & developed labyrinth type V-ring seal. The present work is related to the numerical investigations carried out to gain insights into the sealing mechanism and the thermal behaviour of these seals. The results indicate that the seal geometry is very important for obtaining optimum performance. By changing the geometry of the present seal, performance enhancement by more than 50% in important indices is obtained. Further, the results point out that caution shall be exercised when the seal material & its operating temperature are changed. Also, the numerical model developed in this study will be useful for developing more robust dynamic seals in future.

Surrealism in Labyrinth: Marcel Duchamp's Mile of String for "First Papers of Surrealism" (1942) (미로 속의 초현실주의: 1942년 ${\ll}$초현실주의의 1차서류${\gg}$ 전시와 마르셀 뒤샹의 <1마일의 끈>에 관한 연구)

  • Jung, Eun Young
    • The Journal of Art Theory & Practice
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    • no.15
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    • pp.167-198
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    • 2013
  • This paper explores rich and complex implications of Marcel Duchamp's Mile of String which he created for "First Papers of Surrealism," the Surrealist international exhibition in New York in 1942. Part of a larger project devoted to investigating Duchamp's role in Surrealist exhibitions and his relation to the avant-garde group, this paper focuses on Duchamp's exhibition installation in the 1942 show. Under the title of "g$\acute{e}$n$\acute{e}$rateur-arbitre" Duchamp played an important role as installation and exhibition designer in a series of major Surrealist exhibitions in the 1930's-1960's. The "First Papers of Surrealism" was held by Surrealists who exiled in New York during World War I, and Duchamp created a labyrinthine installation of string for the exhibition, which physically blocked the spectator and optically hindered his or her contemplative view. Unraveling the intricately related meanings of Mile of String as an independent work of art and an installation for a specific exhibition, I examine the work on two levels: first, how the work was situated in the context of Duchamp's oeuvre, particularly his earlier work employing string or thread; second, how and in what way the installation rendered a critique on Surrealism as a group and an avant-garde movement. More specifically, by exploring the concepts of 'pataphysics' and voluntary 'nomadism' implicated in Duchamp's work, I suggest that his Mile of String asserted a critical stance against nationalism and collective identity of Surrealism and manifested a radical individualism founded upon what he called the spirit of 'expatriation.'

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A optimized structural design of piston on moving in gas spring elevation working (가스 스프링 Elevation 동작에의 최적화된 피스톤 구조 설계)

  • Lee, Jeong-Ick
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8274-8283
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    • 2015
  • Gas springs of the television is to control the piston speed when operating under along stroke(200~300 mm, television elevation)is possible. User by this principle is capable of elevation adjustment. First carried out a flow analysis of the piston. A piston speed adjustment technique for precise pipe type cross-section was examined. The piston structure for flow rate control and elevation action is proposed. This study is the development of a gas spring of more than 50 inch television with a large television stand. Hollow piston rod for optimal control(the outer diameter 19.9 mm, the inner diameter 13.9 mm) was injected into the nitrogen gas(0.3 mm/s) in. As a result, the flow rate the pressure drop of the piston rod as the increase was increased without any change of the external force. As a result, control of the displacement via the gas spring is possible.

A Case of Vestibulopathy With Vertigo (전정 신경병증 환자 치험 1례에 대한 고찰)

  • Yu, Mi-Kyung;Choi, Jung-Hwa;Kim, Jong-Han;Park, Su-Yeon;Park, Yong-Ho
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.18 no.2
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    • pp.93-98
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    • 2005
  • Vertigo occurs when there is conflict between the signals sent to the brain by various balance- and position-sensing systems of the body. Injury to or diseases of the inner ear can send false signals to the brain indicating that the balance mechanism of the inner ear (labyrinth) detects motion. Inner ear disorders, such as benign paroxysmal positional vertigo (BPPV), Meniere's disease, vestibular neuronitis, or labyrinthitis. Vestibular neuronitis is an inflammation of the vestibular nerve, which is located in your inner ear. In this case, She has vertigo occured suddenly and continued even when the person lies completely still. It may be accompanied by nausea and vomiting. She has taken herbal medication and treated by acupunture. Her symptoms become disappeared after 3 days and All most symptoms were disappeard. In conclusion, It is required to classify vestibulopathy into vestibular neuronitis or labyrinthitis. In this case we diagnosed her case as vestibular neuronitis. Her symptoms of vestibulopathy recovered fast by Korean traditional medical therapy.

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Analysis of Identity of Meta Game - A Focus on Games about Games - (메타 게임의 정체성 연구 - 게임에 대한 게임을 중심으로 -)

  • Kim, So-Yeon;Han, Hye-Won
    • Journal of Korea Game Society
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    • v.18 no.2
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    • pp.99-108
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    • 2018
  • With the development of the game industry, 'games about games,' which examine the identity of game itself through a form of the game, emerged with a variety of shapes. Thus, this paper aims to suggest a definition, characteristics, and meaning of 'meta game.' Firstly, meta games strengthen the artificiality of the games and suggest procedurality through a form of the game play. Meta games also utilize the external context as a part of the games, and use the metaphor of 'labyrinth' to identify a feature of the game space. Furthermore, they emphasize intertextuality and prove that the fantasy and the reality can merge within the game world. In conclusion, meta games prove themselves to be independent expressional arts and experimental content, and suggest the potential for an alternative medium beyond formality.