• Title/Summary/Keyword: 시야

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A Study on the Hydraulic Characteristics around the Cutter-Head along the Dredging (준설시 커터헤드 주변의 수리특성에 관한 연구)

  • Chae, Dong-Seok;Park, Jae-Hyeon;Kim, Young-Do;Lee, Man-Soo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.588-592
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    • 2008
  • In this study the flow characteristics around the cutter head which makes the dredging soil suspended were measured to evaluate the environmental affect of the dredging action. The PIV was used for measuring the flow characteristics around the cutter head for suction and non-suction cases. As the results, the mean velocity was decreased from the cutter head to outward. The mean velocity decreasing rate of the non-suction case was larger than that of the suction case, but the turbulence intensity decreasing rate of the non-suction case was smaller than that of the suction case because of the suction energy which makes the z-direction flow.

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Adaptive time-delay estimation using median orthogonal FIR filtering in impulse noise envirnment (임펄스 잡음 환경하에서 MO-FIR 필터링을 이용한 적응 시지연 추정)

  • Lee, J.;Jeon, K.S.;Yeo, S.P.;Kim, S.H.
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.3
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    • pp.106-115
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    • 1999
  • 본 연구에서는 충격잡음이 부가되는 비정상 신호 및 잡음 환경하에서 실시간 시지연 추정이 가능한 SLMPTDE와 ZFLMSTDE의 새로운 적응 시지연 추정 방법을 제안하였다. 본 연구에서 제안한 방법은 중간직교 척도를 바탕으로 임의의 SαS 확률과정에 강건하게 적용할 수 있도록 유도된 확률적 경사형적응 추정 알고리즘으로 구성되었으며, SαS 분포를 갖는 다양한 충격잡음을 대상으로 모의 실험하여 알고리즘의 통계적 수렴특성 및 우정 오차에 대해 분석하였으며, 기존의 LMSTDE 방법과 일정시지연의 경우와 시변시지연의 경우에 대해 실시간 시지연 추정능력을 비교, 분석하였다. 실험결과로부터, LMSTDE 방법은 α≥1.9인 가우시안 잡음에 대해서만 시지연 추정이 가능하였고 P=1로 설정한 SLMPTDE 방법은 1〈α≤2인 경우의 SαS 잡음에 대해 정확한 시지연 추정능력을 보였으며, ZFLMSTDE 방법은 0〈α≤2인 모든 경우의 잡음 환경에 대해 그 능력이 입증되었다.

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A Study on the Parasitic Helminths of Domestic Duck (Anas platyrhynchos var. domestica Linnaeus) in Korea (집오리(Anas Pluturhunchos var. domesticu Linnaeus)의 훈충류에 관한 연구)

  • 엄기선;장롸환임한종
    • Parasites, Hosts and Diseases
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    • v.22 no.2
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    • pp.215-222
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    • 1984
  • During February 1982 to September 1983, a total of 105 domestic ducks (Anas platyrhynchos var. domestica Linnaeus) were collected from Ichon Gun, Pusan City, Chunchon City, Yanggu Gun, Taejeon City and unknown areas in Korea. In the results, six trematode and one nematode species of helminth parasites were obtained and described as follows: Amphimerus anatis Yamaguti, 1933, Echinostoma miyagawai Ishii, 1932, Echinochasmus japonicus Tanabe, 1926, Cryptocotyle sp., Notocotylus attenuatus (Rudolphi, 1809) Kossack, 1911, Apatemon sp. and nematode species, Heterakis gallinarum Schrank, 1788. From this collection, Amphimerus anatis Yamaguti, 1933, Echinochasmus japonicus Tanabe, 1926, genus Cryptocotyle Liihe, 1899 and genus Apatemon Szidat, 1928 were firstly recorded in Korea.

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Underwater Acoustic Barrier with Passive Ocean Time Reversal and Application to Underwater Detection (수동형 해양 시역전 수중음향장벽과 수중탐지에의 응용)

  • Shin, Keecheol;Kim, Jeasoo
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.8
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    • pp.551-560
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    • 2012
  • Target detection by acoustic barrier method includes active and passive sonar technique and time reversal process whose theoretical background is already well defined. In this paper, the concept and theory of underwater detection by passive ocean time reversal is established. Also, the reason that this study was conducted was to investigate feasibility of complex mathematical modeling to provide some predictive capability for underwater acoustic barrier with passive time reversal. It may eventually lead to a useful predictive tool when designing underwater acoustic barrier detection system using the passive time reversal concept.

A Study on Binocular Eye Visual Perception Training Program (양안 시지각 훈련 프로그램에 관한 연구)

  • Lee, Seung-Won;Lee, Ok-Jin;Kang, Eun-Kyoung
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.4
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    • pp.95-101
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    • 2008
  • Purpose: The aim of this research was to propose a program that can be used the Binocular Eye Visual Perception Training. Methods: This program can be used as a tool for binocular vision and vision training. The system that was made up of module was available in the stereosis and the vergence training. Results: In case of input module, this program could estimate the distance by using fixation disparity. Also, our margin of erroe is less then 5%. In case of output module, 28 trainers were examined by stereoscopic vision and visual depth perception. Conclusions: Therefore, the system can be used as a tools for the vision training.

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A Study on Inter-event Time with the Time-resolution (시간단위 변화를 고려한 각 지점별 적정 무강우시간 연구)

  • Song, Hyun-Keun;Joo, Kyungwon;Jung, Jinseok;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.167-167
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    • 2016
  • 일반적으로 빈도해석은 강우의 연 최대 강우자료들을 통해 지속기간별 확률강우량을 산정한다. 하지만 강우자료들은 관측기간이 상대적으로 짧은 편이라 지점 별 강우특성을 고려한 확률강우량 산정은 쉽지 않다. 각 지점 별 강우특성을 고려하기 위해서 연속적인 시계열로 기록되어 있는 강우자료를 독립 강우사상으로 분리하여 강우사상간의 시간, 즉, 무강우시간을 결정하는 것이 선행되어야 한다. 연속강우자료를 독립 강우사상으로 분리하기 위해서는 강우사상 간의 기준이 필요하다. 기존의 연구에서는 강우사상을 분리하기 위한 기준으로 무강우시간(Inter-Event Time, IET)을 사용하고 있다. 국내의 경우에는 무강우시간을 10시간부터 12시간까지 다양하게 적용하고 있다. 따라서 본 연구에서는 기상청 산하 강우관측소의 우기(4월~10월) 자료를 이용하여 시간 단위를 각각 1분, 5분 그리고 1시간으로 분리하였다. 강우분리방법은 자기상관계수와 포아송분포(Poisson distribution)를 고려한 지수분포(exponential distribution)의 변동계수를 이용하여 무강우시간 결정 방법(Inter-Event Time Definition, IETD)을 적용하였다. 각 지점별로 추출된 1분, 5분 그리고 1시간의 무강우시간을 비교 및 분석하였고, 이를 통해 각 지점의 시간단위 특성에 의한 적절한 무강우시간 및 강우사상시간을 제시할 수 있을 것으로 판단된다.

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The Healing Properties of English Poetry In a Digital Age (디지털 시대 영시의 치유적 속성)

  • Kim, Kyoung-Soon
    • Journal of Digital Convergence
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    • v.13 no.10
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    • pp.437-444
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    • 2015
  • In this age of digital technology, we often experience overwhelming and inescapable feelings of weakness, vulnerability, loneliness and fear that propel us into a state of gloom or frustration. Poetry can also serve as a therapeutic medium for overcoming them because it provides unique opportunities for self-discovery and is a catalyst for healing and self-integration. This study examines the healing properties in English poetry. First, Poetry has expressed innermost feelings, which can serve as a catharsis the emotional release. Therefore it can nurture and strengthen the human capacity. Poetic language heals our soul and mind. Rhythm which comes in many forms and poetic form also are important components of the therapeutic value of poetry. So we can say English poetry can be used as a therapeutic means for healing and personal growth.

Studies on the Leaching of the Constituents In Paddy Soil -II. Effects of Organic Matter (논 토양성분의 용탈에 관한 연구 -II. 논 토양성분의 용탈에 미치는 유기물(有機物)의 영향(影響))

  • Kim, Kwang-Sik;Kim, Yong-Woon
    • Korean Journal of Soil Science and Fertilizer
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    • v.16 no.2
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    • pp.162-167
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    • 1983
  • These studies were carried out to investigate the effects of organic matter on the leaching of chemical constituents in paddy soil. Rice plants were cultured in paddy soil to which rice straw and compost were applied and then chemical properties of percolated water were analysed. The results were as follows: In the paddy soil cultured with rice plants, the pH value of soil was higher in the compost plot than in the rice straw plot. The leaching of iron, managanese, calcium, magnesium and phosphate was increased by cultivation of rice plant, but that of potassium, ammonium, and silica was decreased. When rice straw was applied in the paddy soil, the leaching of iron, managanese, phosphate and silica was increased during the growing periods, while that of calcium, magnesium, potassium and ammonium was increased by application of compost.

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Influences of Security Oractitioners' Organizational Learning on Organizational Performances (시큐리티 종사자의 조직학습이 조직성과에 미치는 영향)

  • Kim, Pyong-Soo;Lee, Kwang-Ryeol;Lee, Young-Suk
    • Korean Security Journal
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    • no.10
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    • pp.79-102
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    • 2005
  • This study aims to present implications to the basic directions according to organization's own objectives, roles, physiology and changes, etc for private security being activated. The change in organization can lead to foster the foundation for coping with sharp social environmental changes. The fundamental factors leading organizational changes should include intentional, planned and future-oriented activities. This is because organizational changes can be achieved by organizational learning. Besides, organizational learning is indeed important in terms of improvement in business methods and security services, but it should be also much more examined than in any other organization, since business particularity lies in getting in most sensitive contact with customers on the spot. Therefore, this study aims to propose the developmental directions of organizational learning by positively exploring the basic learning directions according to the influences of organizational learning, focusing the organizational efficientization strategies coping with environmental changes on the organizational learning.

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Study on Developing the Equipment of the Time Division System for Rehabilitation in People with Homonymous Hemianopia (동측성 반맹시 환자의 재활치료용 시분할 장치 개발에 관한 연구)

  • Seo, Jae-Myoung;Park, Gune-Ho;Heo, Min-Young;Jung, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.3
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    • pp.407-412
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    • 2014
  • Purpose: It is investigated whether the time division system can extend the field without diplopia for people with homonymous hemianopia. Methods: The time division system was manufactured by a modified mini fan and a black cardboard. In order to verify the effectiveness of the equipment, subjects with and without the equipment took part in the experiment to bisect the space and to recognize letters. Results: Subjects with and without the equipment showed +8.91 and +18.14 degrees in the experiment to bisect the space. In the experiment reading the letters and numbers with the equipment, there were 9 percentage point increase in $4{\times}4$ charts and 15 percentage point increase in $6{\times}6$ charts. It turned out that there was a remarkable improvement for the worst group for reading the charts. Conclusions: The time division system is effective in the mobility and orientation for people with homonymous hemianopia.