• Title/Summary/Keyword: Guidance/Navigation

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A Study on the Construction of Contents for Korean Internet School Library Media Center(KISLMC) (인터넷학교도서관 미디어센터의 컨텐츠구성에 관한 연구)

  • 이명희
    • Journal of Korean Library and Information Science Society
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    • v.32 no.4
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    • pp.303-329
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    • 2001
  • The purpose of this study was to apply internet technology to school library, and to construct the contents of KISLMC(Korean Internet School Library Media Center). The content of KISLMC was composed of three categories, Cyber library, Supporting the materials for teaching and learning, and Guidance and counseling to the students. To develop the user-oriented interface, interface metaphors such as icons and images were used. Also, sitemap, search engine, index were used to avoid to be lost during the navigation.

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무인항공기의 제어기술개발 동향

  • Gang, Yeong-Sin;Park, Beom-Jin;Yu, Chang-Seon
    • Current Industrial and Technological Trends in Aerospace
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    • v.4 no.2
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    • pp.55-67
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    • 2006
  • 20세기에 탄생한 동력비행기는 인간의 이동능력을 비약적으로 향상시켰다. 인류의 미개척지였던 항공분야의 발전은 지속적인 기술개발을 통해 더 빨리, 더 멀리, 더 높이 향하기 위해서 계속 나아가고 있다. 이러한와중에 최근에 괄목할 만한 성장을 이룬 컴퓨터와 소프트웨어 산업의 발전은 비행임무에 따라 위험성이 높거나, 사람이 하기 힘든 반복적이고 지루한 비행을 대신하기위한 로봇 비행체 즉, 무인항공기의 개발을 가능하게 하였다. 무인항공기의 탄생 초기에는 조종사의 희생을 줄이기 위해 군사 분야에서 주로 사용되었으나, 산림감시나 해안정찰, 기상관측, 재난관측, 조난자 수색 등 민수분야의 임무로 점차 활동영역이 넓혀지고 있다. 현재 무인항공기에 탑재된 인공지능의 수준은 안정된 비행이 가능하도록 하는 자동조종(autopilot)과 주어진 비행경로를 추종하기위한 항법유도(Navigation & Guidance)정도이며, 비행 중 발생하는 비상상황에 대처하기 위한 의사판단은 지상의 조종자에 의해 결정된다. 앞으로는 계획되지 않은 상황을 맞이했을 때 무인기 스스로 판단하여 경로를 변경하고, 동시에 여러 무인기들과 협력하여 임무를 수행함으로써 임무효율을 높이는 방향으로 인공지능의 수준이 향상될 것이다. 본 논문에서는 최근의 무인항공기 개발추세와 이들 무인기에 고려되고 있는 제어기에 대해 살펴보고, 향후 무인항공기에 적용될 자율비행 알고리듬과 제어기 시스템의 개발동향에 대해 고찰하였다.

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A Case Study of Unmanned Lunar Lander Design (무인 달 착륙선 설계 사례 분석)

  • Rew, Dong-Young;Ju, Gwang-Hyeok;Kim, Sung-Hoon;Lee, Sang-Ryool
    • Current Industrial and Technological Trends in Aerospace
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    • v.8 no.1
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    • pp.62-76
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    • 2010
  • In this paper, recent researches about the unmanned lunar lander development are studied. Objectives of this study are to derive research trends and to identify key design activities especially in early design phase of unmanned lunar lander. Case study covers SELENE-2 of Japan, LEDA and MoonNEXT of ESA, and small and modular spacecraft approach of NASA. Lunar lander concepts proposed for the International Lunar Network Anchor Nodes are also studied. For each lunar lander program, mission requirements are summarized and mission design results are reviewed. Approaches of safe lunar landing including design of navigation, guidance and control, combination of sensors, derived sensor and propulsion performance requirements are also analyzed.

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The Study about Conditions for Stable Engine Startup on Launch Vehicle (발사체 엔진의 안정적인 시동 조건에 대한 연구)

  • Jung, Young-Suk;Lee, Han-Ju;Oh, Seung-Hyub;Park, Jeong-Joo
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.432-435
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    • 2008
  • Launch vehicle for injecting the satellite into its orbit is composed with propulsion system, guidance and navigation system, telemetry and so on. Among the others, the propulsion system is the most important part, because that is the key factor of failure of launch vehicle. Especially, the most of failures were occurred in time of engine startup. Therefore, the study of the conditions for stable engine startup is needed at the first step of development. The many researches were accomplished for mathematical modeling, stable startup engine and control of liquid propellant rocket engine. But the cavitation problem that can be occurred at an inlet of pump associated with propellant feeding system wasn't considered in these works. In this paper, propulsion system model was integrated with clustered engines and propellant feeding system for the simulations of engine startup. As the results of simulations, the requirements were deduced for the stable engine startup without the cavitation at an inlet of pump.

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Parking Location Control Algorithm for Self-Driving Cars (자율주행 자동차를 위한 주차 위치 제어 알고리즘)

  • Tariq, Shahroz;Park, Heemin
    • KIISE Transactions on Computing Practices
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    • v.22 no.12
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    • pp.654-662
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    • 2016
  • With the advent of autonomous cars, we explored the problems which will soon arise while parking in car parks. These include structure of parking lot suitable for autonomous cars, finding the closest parking slot available, and navigation to the location. We provide an initial solution, wherein we use a central server and the graph of the parking lot to guide cars to the closest parking slots available. Our experiments have shown that the proposed method is effective for the controlled parking for self-driving cars.

Primary Glioblastoma of the Cerebellopontine Angle : Case Report and Review of the Literature

  • Lee, Ji-Hye;Kim, Jong Hyun;Kwon, Taek-Hyun
    • Journal of Korean Neurosurgical Society
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    • v.60 no.3
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    • pp.380-384
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    • 2017
  • Glioblastoma multiforme (GBM) is located most frequently in the cerebral hemispheres. Glioblastoma presenting as an extraaxial mass of cerebellopontine angle (CPA) is very rare in adults. We report a rare case of GBM arising in the CPA. The patient was a 71-year-old female, who complained of progressive gait disturbance and poor memory. Initial magnetic resonance imaging (MRI) revealed a $1.4{\times}1.3cm$ mass in the left CPA, with broad base to the petrous bone, showing homogenous enhancement. Follow-up MRI showed a rapid increase in size of mass ($2.7{\times}2.2cm$) with a necrotic portion. A stereotactic biopsy was done under the guidance of navigation system, and the histopathologic diagnosis was GBM, World Heath Organization grade IV. Further surgical resection was not performed considering her general condition, and the patient underwent concurrent chemotherapy with radiation therapy. Although rare, the possibility of glioblastoma should be included in the differential diagnosis of atypical CPA tumor.

All-Fiber Optic Gyroscope (전광파이버형 광파이버 자이로)

  • Kim, In-Soo S.;Kim, Yo-Hee
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1840-1842
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    • 1998
  • Gyroscope is a very important core sensor, as a rotation sensor in inertial space, in inertial guidance and navigation system on aeronautics, plane, vessel and so on for civilian and millitary applications. Mechnical gyroscopes, adopting a principle of spinning a top, have been used in many application system. These mechnical gyroscopes need high power consumption, long warming time and complicated peripheral devices. But fiber-optic gyroscopes, based on the Sagnac effect, have novel advantages as small volume. simple scheme, low power consumption and high reliability. So we have developed a Intermediate grade All-fiber Optic Gyroscope, which has open-loop and minimum reciprocal configuration scheme. We have designed feedback circuits for stability of amplitude and phase using four lock-in amplifier(LIA) circuits and also used for noise limitation. This paper describes the scheme of optical part and electronic part and also test results of this all-fiber optic gyroscope. The performance have been achieved as long-term bias drift of $9.54^{\circ}/h$, random walk of $0.0317^{\circ}/\sqrt{h}$ and dynamic range of ${\pm}150\;deg/s$.

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Visual Tracking of Objects for a Mobile Robot using Point Snake Algorithm

  • Kim, Won;Lee, Choon-Young;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.30-34
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    • 1998
  • Path Planning is one of the important fields in robot technologies. Local path planning may be done in on-line modes while recognizing an environment of robot by itself. In dynamic environments to obtain fluent information for environments vision system as a sensing equipment is a one of the most necessary devices for safe and effective guidance of robots. If there is a predictor that tells what future sensing outputs will be, robot can respond to anticipated environmental changes in advance. The tracking of obstacles has a deep relationship to the prediction for safe navigation. We tried to deal with active contours, that is snakes, to find out the possibilities of stable tracking of objects in image plane. Snakes are defined based on energy functions, and can be deformed to a certain contour form which would converge to the minimum energy states by the forces produced from energy differences. By using point algorithm we could have more speedy convergence time because the Brent's method gives the solution to find the local minima fast. The snake algorithm may be applied to sequential image frames to track objects in the images by these characteristics of speedy convergence and robust edge detection ability.

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A Study on Technique of Development Test by an Aircraft Captive Flight Test in Weapon System (무기체계의 항공기 탑재비행시험을 통한 개발시험 기법 연구)

  • Yeom, Hyeong-Seop;Oh, Jong-Hoon;Sung, Duck-Yong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.10
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    • pp.1010-1016
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    • 2009
  • In this paper, we have described an aircraft captive flight test for the development test of weapon systems. We have conducted a captive flight test for the development of core onboard parts and sensors of airborne weapons and guided missiles. We have used KTX-1/XKO-1 aircraft as a platform for the captive flight test. In order to perform a captive flight test, we have made a captive test pod as a shape of external fuel tank in the XKO-1 and have modified XKO-1 aircraft for a system interface. We have taken a development test about all kinds of seekers, navigation & guidance systems, and core part of guided missile through the aircraft captive flight test.

Intracranial Metastases of Cervical Intramedullary Low-Grade Astrocytoma without Malignant Transformation in Adult

  • Jang, Se-Youn;Kong, Min-Ho;Song, Kwan-Young;Frazee, John G.
    • Journal of Korean Neurosurgical Society
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    • v.45 no.6
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    • pp.381-385
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    • 2009
  • The first case of intracranial metastases of a cervical intramedullary low-grade astrocytoma without malignant transformation in adult is presented in this report. Seven years ago, a 45 year-old male patient underwent biopsy to confirm pathologic characteristics and received craniocervical radiation and chemotherapy for a grade II astrocytoma in the cervical spinal cord. Two years later, posterior fusion was necessary for progressive kyphosis in the cervical spine. He was well for approximately 7 years after the primary surgery. Two months ago, he presented with partial weakness and incoordination with gait difficulty. MRI Scan demonstrated multiple small lesions in the cerebellar vermis and left hemisphere. After suboccipital craniectomy and posterior cervical exposure, the small masses in the cerebellar vermis and hemispheres were excised to a large extent by guidance of an intraoperative navigation system. The tumor at the cervical and brain lesions was classified as an astrocytoma (WHO grade II). When a patient with low-grade astrocytoma in the spinal cord has new cranial symptoms after surgery, radiaton, and chemotherapy, the possibility of its metastasis should be suspected because it can spread to the intracranial cavity even without malignant transformation as shown in this case.