• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.200-206
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• 2013

The paper was investigated on the mooring forces(or tension) and motion response characteristics for a 8-point mooring floating dock in regular waves using a commercial code(AQWA). To achieve the aim of the research, a numerical simulation was adapted on an inner port environment condition, which the water depth is 10 meters, significant wave amplitude(1.05 m). wave period(3.85 sec), wind speed(20.21 m/s), wind and current direction ($90^{\circ}$), incident waves(${\chi}=180^{\circ}$, $135^{\circ}$ and $90^{\circ}$). The dimension of the numerical model is length(140 m), breadth(32 m), depth(14.6 m). The maximum length of a mooring line is 120m. We can expected that roll and pitch motions appeared in beam seas better than head sea. the mooring forces also indicated higher in bean seas than in head seas including wind forces.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.847-852
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• 2005

In order to evaluate the safety of navigation at sea and the safety of mooring on berthing, it is necessary that the wave and wind induced ship dynamic motion should be measured in real time domain for the validity of theoretical evaluation method such as sea-keeping performance and safety of mooring. In this paper, the basic design of sensors is discussed and some system configurations were shown. The developed system mainly consists of 4 kinds of sensors such as three-dimensional accelerator, two-dimensional tilt sensor, azimuth sensor and two displacement sensors. Using this measuring system, it can be obtained the 6 degrees of freedom of ship dynamic motions at sea and on berthing such as rolling, pitching, yawing, swaying, heaving, surging under the certain external forces.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.661-666
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• 2005

Recent warnings indicate that there is a potential risk of massive earthquake. These earthquakes could produce large-scale tsunamis. Consideration of the effect of Tsunami to the moored ship is very important bemuse it brings the loss of life and vast property damage in a viewpoint of ship operations within a harbor. If a tsunami occurs, a ship in a harbor may begin drifting in case of ship entering and departing harbor, and breakage of mooring rope and drifting of moored ship are happened. And extremely serious accident, such as stranding and collision to a quay, might occur. On the other hand, since the tsunami consists of approximately component waves of several minutes, there is a possibility of resonance with the long period motion of mooring vessel. As the speed of Tsunami is much faster than tidal current in a harbor, a strong resisting force might act on the moored ships. In this paper, the numerical simulation procedure in the matter of ship motions due to the attack of large-scale tsunamis are investigated and the effects on the ship motions and mooring loads are evaluated by numerical simulation.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.2
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• pp.48-59
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• 1992

In this paper, the effects of a skirt deformation on the responses of an Air Cushion Vehicle in waves are investigated. The air in the bag and in the plenum chamber is assumed to be compressible and to have a uniform instantaneous pressure distribution in each volume. The free surface deformation is determined in the framework of linear potential theory by replacing the cushion pressure with the pressure patch moving uniformly with an oscillating strength. And the bag-finger skirt is assumed to be deformed due to the pressure disturbance while its surface area remained constant. The restoring force and moment due to the deformation of bag-finger skirt from the equilibrium shape is included in the equations of hearse and pitch motions. The numerical results of motion responses due to various ratios of the bag and cushion pressure or bag-to-finger depth ratios are shown.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.69-74
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• 2005

In order to evaluate the safety of navigation at sea and the safety of mooring on berthing, it is necessary that the wave and wind induced ship dynamic motion should be measured in real time domain for the validity of theoretical evaluation method sum as sea-keeping performance and safety of mooring. In this paper, the basic design of sensors is discussed and some system configurations were shown. The developed system mainly consists of 4 kind of sensors sum as three dimensional accelerator, two dimensional tilt sensor, two displacement sensors and azimuth sensor. Using this measuring system(MMS), it can be obtained the 6 degrees of freedom of ship dynamic motions at sea and on berthing sum as rolling, pitching, yawing, swaying, heaving, surging under the certain external forces.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.31-37
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• 1990

To obtain the values of linear stability derivatives, both analytical and experimental methods are now proposed and in use. The experimental method is well known as the planar motion mechanism(PMM) test. Its concept is to drive the model with a prescrived frequency and amplitude of the motion and pick up the hydrodynamic forces. But this kind of method is inconvenient in case we want to know the stability derivatives in wider range of the frequencies. So a different method is attempted that with one test run, we can get the derivatives in wider range of the frequencies. This technique forces the impulsive motion on the model, using the power of the oil pressure pump. This kind of method was originated by Scragg, C.A., Cummins, W.E, or Frank, T., This resarch is a further development of such preceding works. Todd's series 60(Cb=0.7) 2.00M model is chosen for the test and the results are compared with Van Leeuwen's famous PMM test results.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.39-45
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• 1993

In order to analyze the rolling motion of a ship in random beam waves we have used the equivalent linearization method. The quadratic nonlinear damping, the cubic and quintic nonlinear restoring moments were added to a single degree of freedom linear equation of roll motion. The irregular excitation moment was assumed to be the Gaussian white noise. The statistical characteristic of the response by the equivalent linearization method was compared with the simulation result.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1031-1037
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• 2021

The frequency of marine accidents of vessels in Korea is steadily increasing and it is concentrated on small vessels with less than 10 tons of gross tonnage. Therefore, preventing capsizing accidents in small vessels is important to reduce the cost in terms of human and property damage due to such accidents. However, research on the seakeeping performance of small vessels has been insufficient, and there are no domestic and international regulations on seakeeping performance. Therefore, in this study, capsizing accidents caused by poor loading conditions were investigated by examining the adjudications of the small vessels in which the capsizing accidents occurred. Hydrostatic calculations and seakeeping performance analysis were performed for a representative vessel. A vessel generally performs a six-degree-of-freedom motion during operation. In this study, the response amplitude operator and response spectrum of a representative vessel were calculated to determine the roll motion. Moreover, a short-term statistical analysis of the vessel according to the loading conditions was performed for the wave stationary status for 3 h. From the results, it was estimated that, when the loading condition of a small vessel is poor, its roll motion increases, greatly reducing its stability.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1991.06a
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• pp.11-12
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• 1991

편측 성대마비의 음성개선을 위하여 현재까지 알려진 치료방법은 teflon 또는 silicone 주입술, 외과적 성대 내전술, 갑상연골 성형술, 신경재식술, 등이 있으며, 근래까지는 Teflon 또는 Gelform 주입술이 제일 효과적인 방법이라 알려져 있으나, 이는 음의 높낮이 조절능력의 한계가 있고, 신경재식술의 결과 역시 만족스럽지 못한 경우가 많다. 따라서 저자는 발성기능의 생리학적인 측면에서, 보다 효과적인 음성개선의 방법을 찾기 위하여, 사람의 후두와 비교적 유사한 특성을 가진 개를 사용하여 실험을 하였다. 반회신경을 절단하여 편측 성대 마비를 유발한 뒤, 동측의 유일한 외전근인 후윤상피열근을 절제후 절단된 신경을 문합하여, 성대의 외전근 작용의 소실과, 발성시에 주로 작용하는 내전근만의 작용을 유도하여, 공동운동의 차단과, 내전운동의 향상을 기대하였다. 본 실험에 앞서, 임의적으로 신경을 자극시킬 수 있는 신경자극기와, 주위조직으로부터 신경만을 분리하여 자극할 수 있는 전극을 개발하여 사용하였으며, 또한 성대의 발성음을 임의대로 유발시킬 수 있는 생체 내 후두발성 모형(in vivo laryngeal phonation model)을 Moore(1987, 1988)등이 발표한 모형을 토대로 자체 개발하여 사용하였다. 실험은 13마리의 개를, 반회신경 절단군(3 마리), 반회신경 절단 및 후윤상피 열근 절제군(3 마리), 후윤상피열근 절제군(3 마리), 반회신경 문합 및 후윤상피 열근 절제군(4 마리)등으로 나누어 실험하였으며, 3 개월 후, 현수후두경, 후두 내시경, videolaryngoscopy, 신경자극 검사 등으로 성대의 내전운동 및 위치 변화의 관찰, 발성음의 음향분석 및 갑상피열근의 형태학적 변화를 관찰하여 다음과 같은 결과를 얻었다. 1. 반회신경 절단군과 반회 신경 절단 및 후윤상피열근 절제군은, 수술후 3 개월에 성대의 움직임이나 각도의 변화가 없었으며, 음향분석 결과 발성음이 아닌 잡음만이 포착되었다. 즉, 절단된 신경의 문합 없이 후윤상피열근 절제 만으로는 음성개선은 기대할 수 없었다. 2. 후윤상피열근 절제군에서는 수술 후 3 개월에 정상적인 성대의 내전운동이 관찰되었으며, 음향분석상 기본주파수 동요율 및 발성음의 강도는 약간의 증가를 보였다. 즉, 반회신경이 절단되지 않은 상태에서 후윤상피 열근 만을 절제하면, 발성음의 변화는 거의 없었다. 3. 반회신경을 절단후 문합하고 후윤상피열근을 절제한군 에서는 수술후 3 개월에, 성대의 정상적인 내전운동을 보였고, 음향분석상 수술직후에는 잡음만이 포착되었으나, 3 개월 후에는 잡음이 아닌 발성음을 들을 수 있었으며, 이 발성음의 기본주파수 및 강도는 수술전보다 감소되어 있었으나, 기본주파수 동요율은 증가되어 있었다. 즉 이 술식으로 인한 뚜렷한 발성음의 향상이 있었다. 이상의 결과로 미루어, 편측 신경 절단으로 인한 성대마비시, 절단된 신경을 봉합하고 성대의 유일한 외전근인 후윤상피열근을 절제하면, 공동운동의 차단과, 내향운동의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다.

• Journal of Korea Entertainment Industry Association
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• v.15 no.2
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• pp.35-46
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• 2021

The purpose of this research is to analyze Soon Chul Jung's children's songs, who is one of the four great children's songwriters in Korea along with Geuk Young Yoon, Nan Pa Hong and Tae Jun Park. Soon Chul Jung has contributed by actively participate into children's movement at Japanese colonial period through writing self-composed children's songs. Since children's songs are made for the age group without the sense of sound, children's songs necessitate 'easy to sing-along' melody writing process. Like so, when writing the melody that are easy to be sang along, utilization of development technique using a unit called motive can be the potent way. This method has an advantage of being sang more with ease if actively implemented, and can be done by utilizing the smallest unit of the melody called motive, especially by lightly transform and repeat the unit, consequently structuring the song altogether. To investigate and analyze this motive-based development technique of Soon Chul Jung's songs, 38 out of 40 written songs considered eligible for the research were confirmed and chosen from 'Soon Chul Jung's bibliography and choreography' and each songs were analyzed based on 17 different development techniques which were standardized in the textbook 'Melody in Songwriting' adopted as a textbook of the Berklee college of Music, and also compared these song-writing pipelines with other great songwriters' representatives mentioned above. As a result, it was almost linear that the song's pitch variation in combination with thinning or extension were used frequently and repeatedly, otherwise implicating melody duplication for more than 2 bars and motive repetition were not in his favor, while these methods were often used when writing children's songs. This finding could be viewed as a character of his songwriting.