• Title/Summary/Keyword: 조종힘

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An Experimental Study on Flow Characteristic around a Flap rudder (플랩러더 주위의 유동특성에 관한 실험적 연구)

  • Gim, Ok-Sok;Cho, Dae-Hwan;Lee, Gyoung-Woo;Ko, Jae-Yong
    • Proceedings of KOSOMES biannual meeting
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    • 2006.11a
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    • pp.277-282
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    • 2006
  • The purpose in having a control surface on a ship is to control the motion of the ship. The control surface may be composed entirely of a single movable surface or of a combination of fixed and movable portion A control surface has one sole function to perform in meeting its purpose, and that is to develop a control force in consequence of its orientation and movement relative to the water. The forces and moments generated as a result of this rotation and angle of attack then determine the maneuvering characteristics of the ship. In this paper the study of flapped rudder's 2-dimensional section was accomplished. Model tests had been carried out with different angles of attack of a main foil and flap's deflection angles to predict the performance of the flapped rudder and the 2 frame particle tracking method had been used to obtain the velocity distribution in the flow field $Re=2.8\times10^4$ had been used during the whole experiments and measured results had been compared with each other.

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Estimation of Hydrodynamic Derivatives of Submarine Model by Using VPMM Test (VPMM 시험을 이용한 잠수함 모형의 유체력 미계수 추정)

  • Jung, Jin-Woo;Jeong, Jae-Hun;Kim, In-Gyu;Lee, Seung-Keon
    • Journal of Navigation and Port Research
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    • v.38 no.2
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    • pp.97-103
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    • 2014
  • In these days, the world has been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic derivatives were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic derivatives of the submarine are provided through the Fourier analysis of the forces and moments in this paper.

Experimental Investigation on Hydrodynamic Coefficients of Submarine Model by VPMM Test (VPMM 시험을 이용한 수중 잠수함 모형의 동유체력 계수 추정에 관한 연구)

  • Jung, Jin-Woo;Jeong, Jae-Hun;Kim, In-Gyu;Lee, Seung-Keon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.117-118
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    • 2013
  • In these days, the world have been increasing navy forces such as aircraft carriers and high-tech destroyers etc. and the importance of submarines is being emphasized. Therefore, accurate values of the derivatives in equations of motion are required to control motion of the submarines. Hydrodynamic coefficients were measured by the vertical planar motion mechanism(VPMM) model test. VPMM equipment gave pure heave and pitch motion respectively to the submarine model and the forces and moments were acquired by load cells. As a result, the hydrodynamic coefficients of the submarine are provided through the fourier analysis of the forces and moments in this paper.

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EEG Analysis Following Change in Hand Grip Force Level for BCI Based Robot Arm Force Control (BCI 기반 로봇 손 제어를 위한 악력 변화에 따른 EEG 분석)

  • Kim, Dong-Eun;Lee, Tae-Ju;Park, Seung-Min;Ko, Kwang-Eun;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.2
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    • pp.172-177
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    • 2013
  • With Brain Computer Interface (BCI) system, a person with disabled limb could use this direct brain signal like electroencephalography (EEG) to control a device such as the artifact arm. The precise force control for the artifact arm is necessary for this artificial limb system. To understand the relationship between control EEG signal and the gripping force of hands, We proposed a study by measuring EEG changes of three grades (25%, 50%, 75%) of hand grip MVC (Maximal Voluntary Contract). The acquired EEG signal was filtered to obtain power of three wave bands (alpha, beta, gamma) by using fast fourier transformation (FFT) and computed power spectrum. Then the power spectrum of three bands (alpha, beta and gamma) of three classes (MVC 25%, 50%, 75%) was classified by using PCA (Principal Component Analysis) and LDA (Linear Discriminant Analysis). The result showed that the power spectrum of EEG is increased at MVC 75% more than MVC 25%, and the correct classification rate was 52.03% for left hand and 77.7% for right hand.

Relationship between Restoring Force and Typical Stroke with SMA Coil Spring in Electrosurgical Knee Wand (슬관절 수술용 전기소작완드에 적용되는 형상기억합금 코일스프링의 회복력 및 행정거리의 관계)

  • Yang, Young-Gyu;Han, Gi-Bong;Kim, Cheol-Woong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.12
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    • pp.1301-1307
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    • 2011
  • Electrosurgical knee wand (EKW) is a high-frequency thermocautery instrument and is often used for coagulation, ablation, excision, and extirpation of knee ligaments and tissues. In order to maximize the success rate, ease, and safety of knee surgery using EKW and radiofrequency ablation, it is necessary to ensure that the EKW selectively approaches the lesion with utmost accuracy and safety. The key feature of this instrument is its excellent maneuverability. Hence, the authors constructed a tensile spring model based on a shape memory alloy (SMA), which exhibits the shape memory effect. This model can be used in knee surgery as it is considered the most biocompatible femorotibial surgical actuator. The changes in external temperature with current and the thermoelectric characteristics of the SMA were investigated. The relationship between the restoring force and the typical stroke (TS) in response to the conditions in the SMA tensile spring design were evaluated. In conclusion, as the diameter of the SMA tensile spring decreased, the maximum temperature increased. The strain in the actuator caused a stable and proportional increase in the force and induced current for up to 15s, but this increase became very unstable after 30s. Moreover, the relationship between the current and the TS was more stable than that between the current and the restoring force.

The Response of Hadley Cell and Jet Stream to Earth's Rotation Rate (지구 자전속도에 따른 해들리 순환과 제트의 반응)

  • Cho, Chonghyuk;Kim, Seo-Yeon;Son, Seok-Woo
    • Journal of the Korean earth science society
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    • v.40 no.3
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    • pp.203-211
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    • 2019
  • The two key factors controlling the atmospheric general circulation are the equator-to-pole temperature difference and the Coriolis force driven by Earth's rotation. Although the former's role has been extensively examined, little has been reported about the latter's effect. To better understand the atmospheric general circulation, this study investigates the responses of Hadley Cell (HC) and westerly jet to the rotation faster or slower than the present Earth's rotation rate. It turns out that the HC edge and jet position tend to move equatorward and become weaker with increasing rotation rate. In most cases, the HC edge is quasi-linearly related with the jet position except for the extremely slow or fast rotating cases. The HC edge is more inversely proportional to the root of rotation rate than the rotation rate in the range of 1/8 to 8 times of the current Earth's rotation rate. However, such a relationship does not appear in the relationship between HC strength and jet intensity. This result highlights that while the latitudinal structure of atmospheric general circulation can be, to some extent, scaled with the Earth's rotation rate, overall intensity cannot be simply explained by the Earth's rotation rate.

The View of Life and Death in Jeon-gyeong (『전경』에 나타난 대순사상의 생사관)

  • Cheng, Chihming
    • Journal of the Daesoon Academy of Sciences
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    • v.27
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    • pp.79-132
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    • 2016
  • The view of life and death in Daesoonjinrihoe includes all the gods of Heaven and Earth, and the human heart is taken as the foundational key. Practitioners can realize their value according to how much they have cultivated themselves. This is regarded as the mythical use of a singularly focused mind (full dedication of one's heart). In other words, it focuses on the potentiality of humans who are able to enter a transcendental area of divinity through their self-cultivation. This view of life and death in Daesoonjinrihoe was established by the religious mission known as "Samgye Gongsa (the Reordering of Three Realms of Heaven, Earth, and Humanity)." Samgye Gongsa indicated a new opening of the Three Realms of Heaven, Earth, and Humanity. This new opening is a return to the original principle of Heavenly operation and also a new order for the universe. Heaven and Earth have their own underlying principle by which they operate. This act was directly initiated and manifested from Dao. Daesoonjinrihoe diagnoses that the underlying principle by which Heaven operates was damaged by human misconduct, and as a result, the human observance of that principle fell out of common usage. Therefore, Daesoonjinrihoe gives priority to the reestablishment of Dao as it existed originally and tries to bring about reconciliation between Heaven and Earth and Humanity. In short, it resolves the grievances accrued since time immemorial by correcting the order of Sindo (Divine Law). Furthermore, it shows that the Dao of Sangsaeng (mutual beneficence) was created by reordering the arrangement of Heaven and Earth so that human beings and divine beings could reach a state of perfection through self-realization. Humans not only communicate with Heaven and Earth, but also communicate with divine beings. Divine beings are transcendent living beings capable of communicating with humans through their heart-minds. In Daesoon thought, human beings are not swayed by the power of divine beings, but instead are able to control divine beings through the transcendent power of their heart-minds. Given this view, the aim of Daesoonjinrihoe lies in participating in the harmony of Heaven and Earth through the cultivation of the human heart. Also, it sees that the human heart-mind can be united with the universal Dao, and thus it is able to be united with the deities of Heaven and Earth. In order to actualize this, one does not rely on exterior rituals or magic but has to focus instead on cultivating the moral ethics of the heart-mind to reach perfection. In other words, one can reach a transcendent level in one's heart-mind through the cultivation of a singularly focused mind and be free from the contradiction of life and death and other such torments. Life and death is an inevitable process for humans. So they do not have to be happy for life and sad for death. They can rather be free from the fear of death by fulfilling the energetic zenith of the human heart-mind via training themselves to transcend their physical bodies. No aging and no death is not a pursuit of radical longevity or immortality for the physical body, but rather a pursuit of the essence of life and the realization of eternity on a spiritual level. Daesoonjinrihoe pursues the state of being unified with Dao by developing "Jeong·Gi·Sin (精·氣·神 the internal energies of essence, pneuma, and spirit)" and trying to reach the transcendent state of non-aging and radical longevity by spurring the practice of self-realization and the discovery one's own innate nature. Through the practice of human ethics, they can access the creative functions of Heaven and Earth and become one with Heavenly Dao thereby achieving harmony between temporal existence and eternity. In this way, humans transcend the life and death of their physical bodies. When "Doins (trainees of Dao)" reach the true state of unification with Dao through singularly focused cultivation, they not only realize self perfection as human beings, but also enable themselves the means to do away with all disasters and forms of suffering. They thereby attain ultimate happiness in their lives.

A review on the transmission aspect of Sangjwa chum and Omjung chum in Yangju Byeolsandae Nori (양주별산대놀이 상좌·옴중춤의 전승양상 고찰)

  • Park, In-Soo;Kim, Ji-Hoon
    • (The) Research of the performance art and culture
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    • no.41
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    • pp.285-320
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    • 2020
  • This study aims to examine the processes of changes of the two main roles, Sangjwa(the young Buddist monk) chum and Omjung(the monk with a boil on his face) chum, performed in Yangju Byeolsandae Nori, on the basis of Chumsawi (dance-movement). Above all, having studied many artistic remains performed by Jo jong sun, Jung han gyu, Park jun seup, Kim sung tae from 1929 to 1942, two main roles, in which Geodeureum chum is now an essential part in almost all performances, were then played only in Kkaekki chum to Taryong Jangdan without performances of Geodeureum chum. In case of Sangjwa chum, players had performed ad libitum and without restraint only on the basis of five sorts of Kkaekki chum's movements. In Omjung chum, witty remarks along with the drama had become more important factors than dances. Let alone two main roles, other parts then also showed no big changes in dance performance. Performers just tried to maintain its slender existence within stifling atmosphere because of oppressions and restraints during the Japanese imperialism. After the restoration of independence in 1945, Kim sung tae and his disciples made a great effort on the restoration of Talnori. During the Korean war, many players also endeavored to keep a good track of Talnori, teaching and training their young followers. Especially performers such as Park jun seup, Park sang hwan, Kim sung tae, and Lee jang sun put much more efforts on restoring Talnori. From that time, Geodeureum chum began to appear in two main roles' performances. In Sangjwa's performances, Byeogsa ritual dance, which was performed to Taryong Jangdan, changed into performances to Yeombul Jangdan, and Kkaekki chum -originally slow and ritual dance, became very fast and active one. Geodeureum chum, called Yongteulim, was added in Omjung chum, so that dance had more important role in performance. Even at this time, dance movements were not clearly and completely organized and arranged, because Geodeureum chum's performance was not clearly defined as orderly dance movements but was regarded as just a movement. After Geodeureum chum being designated as a cultural treasure, Lee byeong kwon took over the task from Park sang hwan, Sangjwa chum's performer, so Geodeureum chum became much more well organzied, arranged and orderly. Geodeureum chum played by Sangjwa had almost the same order of scenes and movements as Geodeureum chum played by Yeonnip. Based on this performance, the order of dances and movements was consistently arranged and settled. Following Park jun seup's performances, Jangsam was more widely applied and used in Omjung chum than ever before, so Omjung chum became much more organized and arranged. Well-arranged Omjung chum had also almost the same dances and movements as Nojang chum's. Yeonnip and Nojang's performances were not directly and intentionally studied and applied to two main roles in Yangju Byeolsandae Nori. Players seemed to borrow those parts naturally through many times of performances. Through their persistent efforts, Jangdan and dance movements have more clearly and completely been organized, establied, and improved through many years' performances. And dance movement can be performed exactly to Jangdan, so we have more complete and orderly types of dance movements. Thanks to many performers' efforts, Sangjwa chum has been established as one that only top performer can play, and Omjung chum has become an integral part in Yangju Byeolsandae Nori.