• Title/Summary/Keyword: 예인 저항

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The Lateral Current Force Coefficient in the Real Ship Towing Test (실선 예인실험을 통한 여객선형의 유압횡력계수 고찰)

  • Jung, Chang-Hyun;Nam, Taek-Kun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.5
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    • pp.373-379
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    • 2016
  • Hydraulic forces on a vessel are changed according to the depth/draft ratio (h/d) during berthing or towing in a lateral direction. It is well known that lateral current force coefficient is dependent on the kinds of vessel in question. However, not much research exists about the characteristics of general ships, except for oil tankers, as suggested by the Oil Companies International Marine Forum (OCIMF). In this paper, lateral current coefficient related to h/d is analyzed in comparison with theoretical values and experiments with a 93m passenger ship. The estimated total resistance on the ship was 14.0 tons under an h/d of 1.6 with a lateral current force coefficient of 1.9. This was found to be similar to the measured value of 13.8 tons on the towing line in actual experiments. Resistances on the ship under an h/d of 3.0 was calculated to be 19.9 tons with a lateral current force coefficient of 1.3. Therefore, the lateral current force coefficient was expected to be 1.3 under an h/d of 3.0, in experiments measured value 20.0 tons. And the discharging currents did not affect the towing force if the towing line was over 30 m, since the towing resistance showed a similar tendency for changes in line length from 30 m to 60 m.

An Experimental Study on Development of the Opening Apparatus for Oil Boom (오일펜스 전개장치 개발에 관한 실험적 연구)

  • Jang Duck-Jong;Na Sun-Chol
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.9 no.1
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    • pp.45-54
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    • 2006
  • The study was to review methods by which a ship can unfold and tow an oil boom by attaching the opening apparatus to an oil boom through experiments. The shape and dimension of the opening apparatus were designed with the measurement value of the towing tension load of the oil boom and the dimension of winch drum of the oil boom installed in the ship considered. For the field experiment to identify the performance of the opening apparatus, opening apparatuses were prepared to have the dimension of $3.0m^2$ and $6.0m^2$ which is 91% and 75% of the calculation value for type B and C respectively. As a result, T(kg), the value of tension in type B oil boom according to the towing speed(v) change when two ships are towed together were proved to be $T=920v^{1.1}\;and\;T=500v^{0.9}$ in case the distance is 100 m and 50 m. Based on the result, the dimension of the opening apparatus for type B and C oil boom was calculated as $3.3m^2$ and $8.0m^2$ respectively. When unfolding and towing by attaching the opening apparatus and 200 m of towing line at both ends of type B and type C oil boom, the maximum width of the opening apparatus was shown as 114 m and 95 m in average(width of opening/total length of oil boom: 33% and 57%) in the towing speed of 1.5 kt. It was evaluated that the opening apparatus could concentrate the spilled oil in a good performance. However as far as the increase rate of oil boom opening width according to the length of the towing line is debatable, the increase rate is remarkably reduced when it is lengthened from 100 m to 150 m and to 200 m although it showed extreme increase of 31% and 40% when the length of the towing line was changed from 50 m to 100 m. Therefore, it is inferred that the towing line should be maintained more or less 100 m to get good spread efficiency of the opening apparatus. Additionally, if the towing speed is faster than 1.5 kt, the opening width was narrowed because of the reduced spread efficiency and the shape of the oil boom can be unstable because of the partial sinking of the oil boom, run over waves, or flap of skirt. Thus the reasonable towing speed can be within 1.5 kt for the operation of the opening apparatus.

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A Basic study on the sea model test techniques for high speed Planing Boat (실 해상모형시험을 이용한 고속 활주정의 선형시험기법 기초연구)

  • Jang, Dong-Won;Park, Chung-Hwan;Jin, Song-Han
    • Journal of Navigation and Port Research
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    • v.34 no.8
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    • pp.623-628
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    • 2010
  • High speed marine vehicle, such as semi-planing, planing craft have been developed recently. These ships paid attention to the resistance characteristics, especially in high speed region. Model test method is divided to two equipment greatly, first 'Towing tank', second 'C.W.C.'. It is difficult to estimate a resistance characteristics for high speed boat. because these are made for low speed ship. This paper suggests a new model test method and system. This is real sea model test and it's comprised of eight part. Firstly, This method is tested at C.W.C that is possible to using in real sea model tes using low speed boat modelt. And then, Real sea model test and CFD calculation are performed and compared with tow way used high speed boat model. It can be a good way to estimate a performance for high speed boat.

Interfacial Friction Factor in Arrested Saline Wedge (정상염수(定常塩水)쐐기에 있어서의 계면저항계수(界面低抗係數)의 평가(評價))

  • Lee, Moon Ock;Murota, Akira
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.9 no.1
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    • pp.53-62
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    • 1989
  • In order to determine the form and the length of saline wedge, it is necessary to evaluate interfacial friction factor. Hetherto one dimensional two-layer flow model which assumed pressure as the hydrostatic pressure distribution has been well used to the calculation of saline wedge form, it just then stands in need of relevant interfacial friction factor. For example, in the case where we calculate back to interfacial friction factor out of saline wedge form obtained at a laboratory open channel with comparatively narrow width, it is needed to correct the side-wall effect of a channel, if generally negligible in the river. In this study, we confirmed the influence of a side-wall upon the lateral velocity distributions at laboratory channel and then examined in detail the value of interfacial friction factor in the case where it was corrected by the side-wall effect and not corrected. And then we make clear the influence of a side-wall upon the arrested saline wedge and interfacial faction factor from these results.

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Representation of History and Resistance - Focused on and ('일제 강점기 영화'의 역사와 저항의 재현 -<암살>과 <동주>를 중심으로)

  • Kwon, Eunsun
    • The Journal of the Convergence on Culture Technology
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    • v.5 no.3
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    • pp.185-190
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    • 2019
  • Historically, the representation of the colonial period has responded closely to the policies and political conditions of the time. The Korean blockbuster , which links the genealogy of Manchuria Western, adopts a safe nationalism frame, upgrading the genre's narrative typology to colorful action and spectacle, including the Japanese army, the Liberation Army, the good and evil, and the confusion of identity. On the other hand, , which deals with the friendship of the poet and the warrior, treats the mental and internal struggles implied by the power of poetry, without resorting to familiar nationalism and heroism. is a thorough genre of rules. If the visual and sensual pleasures of imaginative resilience beyond the bounds of the law are provided within the Rules, inevitably seeks resistance within the colonial empire's legal system. Political, diplomatic, and economic conflicts between Japan and Korea, which have been continuing until recently, reaffirm the framework of nationalism on the screen.

The Effect of Low-Frequency Repetitive Transcranial Magnetic Stimulation on Treatment-Resistant Tourette's Syndrome among Children and Adolescents : An Open-Label Study (치료저항성 뚜렛장애를 가진 소아청소년에서 저빈도 반복적 경두개자기자극술의 효과 : 오픈 라벨 연구)

  • Lee, Young-Ji;Chae, Jin Hyuk;Seo, Wan Seok
    • Journal of the Korean society of biological therapies in psychiatry
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    • v.24 no.3
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    • pp.239-246
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    • 2018
  • 목 적 : 본 연구의 목적은 치료저항성 뚜렛장애를 가진 소아 청소년들에 대해서 보조운동영역을 표적으로 한 저빈도 반복적 경두개자기자극술의 효과를 평가하는 것이다. 방 법 : 이 연구는 미국정신의학회 진단기준 및 통계편람, 제 4판을 기준으로 뚜렛장애로 진단받은 10명의 소아 청소년(평균연령 $12.56{\pm}1.04$세)을 대상으로 하였다. 모든 참가자들은 1년 이상 지속적으로 충분한 용량의 약물치료를 받았음에도 불구하고 한국판 예일 틱 증상 평가척도(YGTSS) 20점 이상, 임상인상척도(CGI-TS) 4점 이상을 받았다. 참가자들은 보조운동영역을 표적으로 1 Hz 반복적 경두개자기자극 치료를 매일 20분간 받았으며, 총 20회 치료를 받았다. YGTSS, CGI-TS 및 이상반응 체크리스트는 연구 시작 전과 연구 시작 후 4, 8, 12주에 시행되었다. 결 과 : 틱 증상은 연구 12주차까지 호전된 상태로 지속되었으며, YGTSS와 CGI-TS가 통계적으로 유의하게 감소하였다. 특히 음성 틱 점수의 감소가 운동 틱 점수의 변화보다 전체 YGTSS 점수의 감소에 큰 역할을 한 것으로 나타났다. 그리고 전체 10명의 참가자 중 9명이 심각한 부작용 없이 연구를 끝까지 완료하였다. 결 론 : 본 연구는 보조운동영역을 표적으로 한 저빈도 반복적 경두개자기자극술이 치료 저항성 뚜렛장애를 가진 소아 청소년들에게 효과적이고 안전한 치료도구가 될 수 있음을 시사한다. 이러한 반복적 경두개자기자극술의 치료효과를 확정하기 위해서는 보다 많은 환자를 대상으로 한 잘 통제된 연구가 필요할 것이다.

Anatomic Classification of Ventricular Septal Defects and Clinical Review of 99 Cases (심실중격 결손증의 해부학적 분류 및 임상적 고찰)

  • Lee, Cheol-Joo;Lee, Dong-Hyup;Chung, Tae-Eun;Kang, Myeun-Shick
    • Journal of Yeungnam Medical Science
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    • v.3 no.1
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    • pp.221-227
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    • 1986
  • Ventricular septal defect is most common congenital cardiac anomaly in Korea and worldwide. And its clinical spectrum is well known. The anatomic classification had been undertaken by several authors, but recently Dr. Soto and Anderson's classification is widely used instead of Dr. Kirklin's it. From April. 1984 to December 1986, 99 cases of ventricular septal defects had been taken surgical repair under direct vision using conventional cardiopulmonary bypass technique at Yeungnam university hospital. The clinical spectrum was similar to other hospital, and the postoperative mortality was 2%, The most common associated anomaly was patent foramen ovale, and the most common postoperative complication was incomplete or complete right bundle branch block. The rank of defects was as followings: 45 perimembranous inlet type, 21 doubly commited subarterial type, 17, perimembranous trabecular type, and 16 perimembranous outlet type. There was no muscular and mixed type.

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The Signal Distortion Due to the Electromagnetic Induction Inside a Cable (전선의 전자기유도 현상에 의한 신호 왜곡)

  • Jeong Ji-Min;Choi Seong-Jun;Kim Jung-Ho;Song Young-Soo
    • Geophysics and Geophysical Exploration
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    • v.7 no.4
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    • pp.251-255
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    • 2004
  • Electric cables such as multi-interphone cables and ribbon cab]os are commonly used for data aquisition in the DC resistivity survey. In general, electromagnetic induction may occur in the electric cables when electric current flows through them. In case of using multi-interphone cables in the DC resistivity survey, electromagnetic induction could take place due to the entangled wires of the multi-interphone cables, when the current flows through them. Then, the electromagnetic induction may cause measured DC resistivity data to be distorted. In this study, a monitoring system with PXI (PCI Extention for Instrumentation) was constructed to examine signal distortion on the DC resistivity data, attributed to the electromagnetic induction. Common electric cables used in the DC resistivity survey were tested to observe the waveforms of the electric voltages. The waveforms measured were compared to examine signal distortion due to the electromagnetic induction. The results may provide information on the resistivity data obtained using different electric cables in the DC resistivity survey. The distortion of waveforms attributed to the electromagnetic induction wat not observed when using ribbon cables for DC resistivity data aquisition, while the distortion were observed when using multi-interphone. Therefore, the ribbon cables provide better quality of data than other cables in the DC resistivity data aquisition.

Comparison of Geometrical Factors of Dielectric Resonators Prepared for the Surface Resistance of Superconductor Films: Field Analysis vs. Computer Simulation (초전도체 박막의 표면저항 측정용 유전체 공진기에 대한 Geometrical factor의 비교 : 전자기장 해석 대 시뮬레이션)

  • Yang, Woo-Il;Jung, Ho-Sang;Kim, Myung-Su;Cho, Man-Soon;Choo, Kee-Nam;Lee, Sang-Young
    • Progress in Superconductivity
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    • v.13 no.2
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    • pp.97-104
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    • 2011
  • In the dielectric resonator method, which has been widely used for measuring the microwave surface resistance of superconductors, accuracies in the geometrical factors (G-factors) affect the uncertainty in the measured surface resistance. We compare the G-factors of short-ended sapphire resonator as obtained by using field analysis with those by using computer simulations: The former is obtained by using the analytic expressions for the electric and the magnetic field components inside the resonator, and the latter by using computer software. The G-factors as obtained by using the latter appear to be closer to those obtained by using the former as the resonator space is divided into larger number of sub-space, i.e., a tighter mesh, with a difference of ~8 % observed for a mesh of 14400 sub-spaces reduced to ~2 % for 114996 sub-spaces. Variations in the relative uncertainty in the surface resistance of typical $YBa_2Cu_3O_{7-\delta}$ superconductor films with those in the G-factors are studied, which provides an upper limit of the relative uncertainty in the G-factors required for realizing the target uncertainty in the surface resistance. These results could be useful in estimating the optimum number of meshes for obtaining the G-factors through computer simulations.

An Evaluation Method for Sesame (Sesamum indicum L.) Resistance to Phytophthora nicotianae var. parasitica (참깨발병 품종저항성 검정방법 연구)

  • Seong Ho, Choi;Eui Kyoo, Cho;Young Am, Chae
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.2
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    • pp.173-180
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    • 1987
  • Symptom development and disease severity of Phytophthora blight in the sesame plants varied depending upon age of the plants tested, inoculation method, watering method, and inoculum density in both susceptible Suweon 9 and Suweon 26 and moderately resistant B-67 and IS 103 sesame lines to Phytophthora nicotianae var. parasitica when inoculated. However, successful differentiation of the sesame lines for varietal resistance was possible using 20-day old seedling, inoculation by soil infestation, saturated soil water condition by half immersion of pots in water tank, and 200 sporangia per one ml of inoculum. Spraying or soil inoculation to 70-day old plants also was effective in differentiating the varietal resistance. By the screening method Suwon 26 showed 100% diseased plants and symptom severity index 9.0, while B-67 showed 20% diseased plants and symptom severity index 1.7. The rating scale given was from 0 through 9. For example, the scale 0 signified no symptom development, 5 signified discoloration of basal part of stem, and 9 signified discoloration of stem more than 10 cm high above the soil surface with blighted leaves. Differentiation in symptom severity also was made by percentage of the lesion area. Results evaluated using both parameters were well corresponded in varietal reaction of sesame to Phytophthora blight.

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