• Title/Summary/Keyword: Pitching type

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A Study on the Influence of Mass Fashion Design Factor in Sportswear (스포츠웨어가 대중 패션디자인 요소에 미친 영향)

  • Park, Kyung-Yeon;Yoo, Thi-Soon
    • Fashion & Textile Research Journal
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    • v.1 no.4
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    • pp.342-348
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    • 1999
  • The purpose of this study taken interest in recent, is a development of the sportswear style fashion design and provision of aid for making a marketing strategy and reasonable purchasing for customer's. Results of this study can be summarized as follows : As baseball boom is revived due to Park, Chan-ho's nice pitching, baseballcap and hood-shirt that printed each team's logo have an effect on mass fashion style. Clothes of mountain c1imbingwear style can personal free coordination, because they are little change of fashion, customers are constantly purchase them. As contemporary women are increase about interest on beauty, leggins and bra-top that aerobic clothes are scoordinated various type and included practice style. Snowboard style is coincide with Hip-hop look that loose fitting style pursues free style, it becomes more popular fashion with street fashion. Golfwear taking root in townwear of the 40, 50 women.

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Visualization Study of Dragonfly Type Wing : Reduced Frequency (잠자리 유형 날개의 가시화 연구 : 무차원 진동수)

  • Kim Song Hak;Chang Jo Won
    • 한국가시화정보학회:학술대회논문집
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    • 2004.11a
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    • pp.14-17
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    • 2004
  • A purpose of this visual experiment is to investigate the effect of reduced frequency qualitatively by examining wake pattern change for insect flying motion. Insect is composed of two pair wing with forewing and hindwing, flying motion of insect is performed pitching and plunging so it makes a separation over the wings. The separation affects at the wake pattern and changed wake pattern has an influence on lift, drag and propulsion. This experiment is conducted by using a smoke wire technique and a camera is fixed at hindwing to take a photograph of wake. An electronic device is mounted below test section to find exact the mean positional angle of wing. The reduced frequency in experiment is 0.15, 0.3 and 0.45. We obtained the result which that reduced frequency is closely related to wake pattern that determines flight efficiency.

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A Study on the Fabrication of a Fiber Optic Gyrocompass for Ships (선박용 광섬유 자이로콤파스의 제작에 관한 연구)

  • 이석정;배정철;홍창희
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.04a
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    • pp.56-63
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    • 1998
  • A fiber optic gyrocompass for ships was made in consideratino of cost, reliability and convenience. In order to reduce the cost a cheaper fiber sensor was used inthis system. The accuracy was increased by replacing a 180ppr-slit disk with a 1000ppr-encoder. The reliability was also increased by improving the signal processing electronics. This system was made as a heading angle display type for convenience. Although more inexpensive FOG than that of the previous system was used , the accuracy of this compass was increased about 0.5$^{\circ}$. Moreover, it has a very fast warm-up time of about 5minutes. Therefore, this compass can show the prospect of proactical use on ships if it is installed ona stabilizer against the dynamic motion such as rolling and pitching.

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Levitation Control Experiment at Standstill in PM LSM Controlled-Repulsive Maglev Vehicle

  • Yoshida, Kinjiro;Takami, Hiroshi;Jozaki, Chiyuki;Kinoshita, Shiauo
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.119-124
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    • 1998
  • This paper proposes a new repulsive-Maglev vehicle in which a vertical type PM linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. A compact control method is developed which is based on the concept of controlling individually the levitation system by armature-current and the propulsion system by mechanical load-angle. The levitation-motion control experiments have carried out successfully together with positioning at standstill. The pitching motion has been compensated for very well by using the zero-phase-current control method proposed here.

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A Study of Ground Reaction Forces During Professional Golfer's Swing with Different Golf Clubs (클럽별 골프 스윙 시 지면 반력 변화에 관한 연구)

  • Hur, You-Jein;Moon, Gun-Pil;Lim, Jung
    • Korean Journal of Applied Biomechanics
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    • v.15 no.2
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    • pp.103-111
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    • 2005
  • The purpose of this study was to analysis golf swing in accordance with each club using ground reaction force data. The subject of this study was current professional golf players in Korea. Golf clubs used for this study were driver, iron4, iron7, and pitching. The ground reaction force for left and right foot was collected by one Kistler and one Bertec force platforms. Also collected visual data by NC high speed camera to check the phase which was composed of address, top of backswing, impact and finish. Sampling rate was 600Hz both ground reaction forces data and visual data. The conclusion are as follows. 1. An aspect of change for ground reaction force was that the weight between the left foot and right foot were contrary to each other in general as the phase. 2. Without regard to the type of golf club, the ratio of necessary ground reaction forces for each phase in accordance with address, top of backswing, impact, and finish was comparatively identical. 3. According to the type of golf club, the tendency of Fy was not varied. In terms of Driver, at the moment of impact, the weight of foot-both right and left-was moved to the movement direction of golf because of the rotation force from swing.

Evaluation of the added mass for a spheroid-type unmanned underwater vehicle by vertical planar motion mechanism test

  • Lee, Seong-Keon;Joung, Tae-Hwan;Cheon, Se-Jong;Jang, Taek-Soo;Lee, Jeong-Hee
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.3 no.3
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    • pp.174-180
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    • 2011
  • This paper shows added mass and inertia can be acquired from the pure heaving motion and pure pitching motion respectively. A Vertical Planar Motion Mechanism (VPMM) test for the spheroid-type Unmanned Underwater Vehicle (UUV) was compared with a theoretical calculation and Computational Fluid Dynamics (CFD) analysis in this paper. The VPMM test has been carried out at a towing tank with specially manufactured equipment. The linear equations of motion on the vertical plane were considered for theoretical calculation, and CFD results were obtained by commercial CFD package. The VPMM test results show good agreement with theoretical calculations and the CFD results, so that the applicability of the VPMM equipment for an underwater vehicle can be verified with a sufficient accuracy.

Analysis of Aerodynamic Characteristics for Guided Gliding Type Ammunition Using Computational Analysis and Wind Tunnel Test (전산해석 및 풍동시험을 이용한 유도형 활공탄약의 공력해석)

  • Bang, Jae Won
    • Journal of the Korea Society for Simulation
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    • v.28 no.1
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    • pp.49-56
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    • 2019
  • In this study aerodynamic characteristics of guided gliding type ammunition were investigated by using a computational analysis and wind tunnel test. Missile DATCOM, a semi-empirical method, and a FLUENT, a computational fluid dynamics analysis program, were used for computational analysis. For a guided gliding type ammunition, aerodynamic characteristics were investigated by calculating lift force, drag force, pitching moment and etc. Aerodynamic characteristics of guided gliding type ammunition are completely different from those of conventional ammunition. The results obtained from the computer analysis are similar to those obtained from the wind tunnel test. Although the pitch moment values obtained by the semi-empirical method were slightly different from the wind tunnel test results, the overall computer analysis results showed trends and values similar to the test results. In this study, aerodynamic characteristics of guided gliding type ammunition were identified and it found that semi-empirical method can be applied to analyze the aerodynamic characteristic in the initial design of guided gliding ammunition.

Evaluation of Wind Force Coefficients of a Box-Type Girder Bridge with Noise Barriers (방음벽의 유무에 따른 박스형 거더교의 풍력계수 평가)

  • Jeong, Seung Hwan;Lee, Youngki
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.5
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    • pp.627-634
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    • 2018
  • In the study, computational fluid dynamics analysis was performed to estimate wind force coefficients for a box-type concrete girder bridge under the influence of wind. The drag, lift and pitching moment coefficients were obtained for the bridge section without noise barrier and compared with those of the bridge section with noise barriers of various heights. The shear stress transport $k-{\omega}$ turbulence model was employed to estimate the wind force coefficients, and the contribution of the friction drag force to the total drag force was investigated. It was found from the study that the drag force coefficients increased as the height of noise barrier increased when a wind blew horizontally, and that the contribution of the friction drag force was highest for the bridge section without noise barrier. It is concluded that the impact of the height of noise barriers should be considered in the design of bridges, and the friction force played an important role in evaluating wind forces on bridges.

Design and Control of 6 D.O.F(Degrees of Freedom) Hovering AUV (6자유도 호버링 AUV의 설계 및 제어)

  • Jeong, Sang-Ki;Choi, Hyeung-Sik;Seo, Jung-Min;Tran, Ngoc Huy;Kim, Joon-Young
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.9
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    • pp.797-804
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    • 2013
  • In this paper, a study of a new hovering six dof underwater robot with redundant horizontal thrusters, titled HAUV (hovering AUV), is presented. The results of study on the structure design, deployment of thrusters, and development of the developed control system of the AUV was presented. For the HAUV structure, a structure design and an analysis of the thrusting system was performed. For navigation, a sensor fusion board which can proceed various sensor signals to identify correct positions and speeds was developed and a total control system including EKF (Extended Kalman Filter) was designed. Rolling, pitching and depth control tests of the HAUV have been performed, and relatively small angle error and depth tracking error results were shown.

Force Characteristics Analysis to Improve Actuating Performance in Extruded Lens Type Optical Pickup Actuator (렌즈 돌출형 광 픽업 액츄에이터의 구동 성능 향상을 위한 Force 특성 분석)

  • Choi, In-Ho;Hong, Sam-Nyol;Kim, Young-Joong;Suh, Min-Suk;Ahn, Young-Woo;Kim, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1555-1560
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    • 2000
  • Recently, optical pickup actuators have been designed to have structures that extruded lens to decrease their height, because they are used in very thin drive for notebook computers. However, because of discordant and undesirable of forces that are supposed to happen in this design feature, subsidiary resonance such as rolling and pitching mode exert bad influence on actuator. In this paper, we presented force constituents to clarify the cause of subsidiary resonance and proposed new finite element analysis method to calculate force precisely, and performed frequency response analysis to evaluate characteristics of actuators. As a result, we could find out design parameters to diminish the influence of subsidiary resonance. Sample actuators designed with appropriate parameters were fabricated and put to practical tests. Comparing analysis with experimental results, we verified the accuracy of the analysis and the effectiveness of the method presented.

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