• 제목/요약/키워드: Moving gap

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A Human Enginnering Study on an Original Pattern of Clothing for an Abnormal Type of Figure - with special reference to the of kyphosis - (이상체형의 의복원형의 인간공학적연구 - 척추만곡체형을 중심으로 -)

  • 박정순
    • Journal of the Korean Home Economics Association
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    • v.20 no.3
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    • pp.9-18
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    • 1982
  • In this study, we attempted to make an original pattern of clothing for an abnormal type of figure, especially for the type of kyphosis. We measured the curvature of the spine of a woman with kyphosis with a Martin measuring instrument and a silhouetter in the following ways. First, we counted the rate of shrinkage of the standard lines drawn on the surface of the body according as the body moved. Secondly, placing the front and back darts, the front and back shoulder darts and the side darts according to“Munhwa”pattern, we made cubic cuttings of four moving postures as well as the standing one. Thirdly, we superposed the developed patterns of the standing and the moving postures, measuring the position change and the amount of the chaange of the darts, and compared them. The results are as follows: 1) In the developed pattern of a cubic cutting of the basic pattern and the standing posture, the neckhole became larger than that of the basic pattern, and the waist line was lowered than that of the basic pattern because the center back line was shortened due to the curved backbone. 2) As for the change of the standard line according to the movement, we found that the waist line, the center front line, the center back line, the bust width line, the upper back width line and the back width line became longer. Special consideration must be given to the function of the clothing for an abnormal type of figure. 3) The difference of the measurements between the cubic cutting and the body measurement regardless of the body movement is due to a gap by an acute angle at the jutted place between the developed pattern and the body surface. We found that the body measurement of the upper back width line, the back width line and the bust line became larger. Consequently, in making an original clothing pattern, it is desirable that we must not place the front and the back waist darts at the jutted place on the back from the functional and the aesthetic viewpoint of clothing. It is also desirable that we must widen the neckhole because the shoulder angle is close to a straight line due to a jut of the upper back width line.

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Design of Rotating Moving-Magnet-Type VCM Actuator for Miniaturized Mobile Robot (소형 이동 로봇을 위한 회전형 보이스 코일 구동기 개발)

  • Shin, Bu Hyun;Lee, Seung-Yop;Lee, Kyung-Min;Oh, Dongho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.12
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    • pp.1529-1534
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    • 2013
  • A voice coil actuator with a rotating moving magnet has been developed for a miniaturized mobile robot. The actuator has simple structure comprising a magnet, a coil, and a yoke. Actuator performance is predicted using a linearized theoretical model, and dynamic performance based on the air-gap between the magnet and the coil is predicted using motor constant and restoring constant obtained through finite element simulations. The theoretical model was verified using a prototype with 60 Hz resonance and 80 Hz bandwidth. We found that an input of 1.5 V can make the actuator rotate by $20^{\circ}$ statically. The driving configuration of the proposed actuator can be simplified because of its implementation of open-loop control.

A Theoretical Model of Executive Voluntary Turnover (기업내 임원의 자발적 이직에 관한 이론적 모형)

  • Choi, Dongwon
    • Journal of Digital Convergence
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    • v.19 no.8
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    • pp.173-184
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    • 2021
  • For the current organizations, retaining executive members is one of the most important functions of human resource management. Given that importance, although executives' mobility becomes prevalent, most prior studies tended to focus on involuntary turnover of executive members. To fill this gap, the current theoretical paper suggests a model of executive voluntary turnover, drawing on the lierature of employee mobility and entrepreneurship. First, running a new business as a CEO negatively affects prior-firm performance, but collaboration between two firms mitigate the negative association. Second, spin-off positively affects prior-firm performance, but this is weakened as spin-off firm performance decreases. Finally, moving to a competitor negatively, while moving to a collaborator positively affects prior-firm performance.

Investigation of Electromagnetic Force for Magnetic Contactor of Railway Vehicles (철도차량용 전자접촉기 전자코일의 전자기력 특성 연구)

  • Jung, Jooyoung;Park, Ji-Won;Choi, Jinnil
    • Journal of the Korean Society for Railway
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    • v.19 no.3
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    • pp.324-330
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    • 2016
  • A magnetic contactor is a switching device widely used for electric circuits. For the operation of magnetic contactors, magnetic coils are essential; these coils create and interrupt the electric circuit. In this paper, the finite element analysis model was developed to reflect the experimental data, and was verified through alteration of the applied voltages and the numbers of turns. Effects of electromagnetic force on the geometrical variations of the facing poles for fixed and moving cores of two magnet coils were investigated. In addition, effects of slope and air gap size between two facing poles on the electromagnetic force were explored through the distribution of the magnetic flux density in the magnetic coils of a push-type solenoid. Through this analysis, the characteristics of the electromagnetic force against the facing poles were explored.

Fast Response Time in IPS Mode Using LC mixtures with High Elastic Constant

  • Lim, C.S.;Lee, J.H.;Choi, H.C.;Oh, C.H.;Yeo, S.D.;Lee, Seung-Eun;Jin, Min-Ok;Kang, Doo-Jin;Klasen-Memmer, M.;Tarumi, K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.843-846
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    • 2004
  • For the fast growing Liquid Crystal Display (LCD) TV market, it is essential to make the LCD panels to show moving images without any visual difficulties such as blurring or tailing. Owing to reduction of the cell gap and the improved Liquid Crystal (LC) mixtures with low viscosity, it is possible that our S-IPS TFT-LCDs feature a response time (R/T) as fast as 1-frame time (16ms) for a white-black operation and less than a 16rns in all gray levels without Over Driving Circuit (ODC) technology. Currently, mass production of the large size IPS panels with high speed has been successfully achieved. In order to achieve faster response time, new LC mixtures have been developed, optimizing the physical properties of rotational viscosity (${\gamma}$1) and elastic constants (Kii). Also, the LC mixtures with high elastic constant allow us to increase the cell gap. In this paper, realization of fast switching time in IPS mode with optimized '${\gamma}$1/Kii' parameter in the LC mixtures forms the core of this paper.

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PDMS-based pixel-wall bonding technique for a flexible liquid crystal display (플렉서블 액정 디스플레이를 위한 PDMS 기반 pixel-wall bonding 기술)

  • Kim, Young-Hwan;Park, Hong-Gyu;Oh, Byeong-Yun;Kim, Byoung-Yong;Paek, Kyeong-Kap;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04a
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    • pp.42-42
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    • 2008
  • Considerable attention has been focused on the applications of flexible liquid crystal (LC)-based displays because of their many potential advantages, such as portability, durability, light weight, thin packaging, flexibility, and low power consumption. To develop flexible LCDs that are capable of delivering high-quality moving images, like conventional glass-substrate LCDs, the LC device structure must have a stable alignment layer of LC molecules, concurrently support uniform cell gaps, and tightly bind two flexible substrates under external tension. However, stable LC molecular alignment has not been achieved because of the layerless LC alignment, and consequently high-quality images cannot be guaranteed. To solve these critical problems, we have proposed a PDMS pixel-wall based bonding method via the IB irradiation was developed for fasten the two substrates together strongly and maintain uniform cell gaps. The effect of the IB irradiation on PDMS with PI surface was also evaluated by side structure configuration and a result of x-ray photoelectron spectroscopic analysis of PDMS interlayer as a function of binder with substrates. large number of PDMS pixel-walls are tightly fastened to the surface of each flexible substrate and could maintain a constant cell gap between the LC molecules without using any other epoxy or polymer. To enhance the electro-optical performance of the LC device, we applied an alignment method that creates pretilt angle on the PI surface via ion beam irradiation. Using this approach, our flexible LCDs have a contrast ratio of 132:1 and a response time of about 15 ms, resulting in highly reliable electro-optical performance in the bent state, comparable to that of glass-substrate LCDs.

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Numerical Study on the Pulse Heating Type Infinitesimal Liquid Mass Flow Meter (단속가열식 액체용 극소질량유량 계측기에 관한 수치해석적 연구)

  • Kim, Taig Young
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.2
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    • pp.119-124
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    • 2015
  • Numerical study on the new design of the liquid mass flow meter in infinitesimal flow rate for semiconductor production is performed. The heater and thermistor are wired on the circular tube about 0.3mm inner diameter with designed gap between them. After the time interval from the single pulse heating the thermistor reaches its peak temperature and this time interval is almost inversely proportional to the liquid mass flow rate. The axial conduction in tube wall and convection through the flow is combined. As a result, the peak temperature moving velocity is much smaller than flow mean velocity and there is no linear relationship between them. In this study, the effects of design parameters such as the tube inner/outer diameter, wired heater width, and the gap between heater and thermistor are investigated and the trends of optimization in these parameters are discussed.

Analytical Solution of Magnetic Field in Permanent-Magnet Eddy-Current Couplings by Considering the Effects of Slots and Iron-Core Protrusions

  • Dai, Xin;Liang, Qinghua;Ren, Chao;Cao, Jiayong;Mo, Jinqiu;Wang, Shigang
    • Journal of Magnetics
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    • v.20 no.3
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    • pp.273-283
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    • 2015
  • In this study, we propose an analytical model for studying magnetic fields in radial-flux permanent-magnet eddy-current couplings by considering the effects of slots and iron-core protrusions on the eddy currents. We focus on the analytical prediction of the air-gap field by considering the influence of eddy currents induced in conducting bars. In the proposed model, the permanent magnet region is treated as the source of a time-varying magnetic field and the moving-conductor eddy current problem is solved based on the resolution of time-harmonic Helmholtz equations. The spatial harmonics in the air gap and in slots, as well as the time harmonics are all considered in the analytical calculation. Based on the proposed field model, the electromagnetic torque is computed by using the Maxwell stress tensor method. Nonlinear finite element analysis is performed to validate the analytical model. The proposed model can be used for permanent-magnet eddy-current couplings with any slot-pole combination.

Flow Near the Meniscus of a Pressure-Driven Water Slug in Microchannels

  • Kim Sung-Wook;Jin Song-Wan;Yoo Jung-Yul
    • Journal of Mechanical Science and Technology
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    • v.20 no.5
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    • pp.710-716
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    • 2006
  • Micro-PIV system with a high speed CCD camera is used to measure the flow field near the advancing meniscus of a water slug in microchannels. Image shifting technique combined with meniscus detecting technique is proposed to measure the relative velocity of the liquid near the meniscus in a moving reference frame. The proposed method is applied to an advancing front of a slug in microchannels with rectangular cross section. In the case of hydrophilic channel, strong flow from the center to the side wall along the meniscus occurs, while in the case of the hydrophobic channel, the fluid flows in the opposite direction. Further, the velocity near the side wall is higher than the center region velocity, exhibiting the characteristics of a strong shear-driven flow. This phenomenon is explained to be due to the existence of small gaps between the slug and the channel wall at each capillary corner so that the gas flows through the gaps inducing high shear on the slug surface. Simulation of the shape of a static droplet inside a cubic cell obtained by using the Surface Evolver program is supportive of the existence of the gap at the rectangular capillary corners. The flow fields in the circular capillary, in which no such gap exists, are also measured. The results show that a similar flow pattern to that of the hydrophilic rectangular capillary (i.e., center-to-wall flow) is always exhibited regardless of the wettability of the channel wall, which is also indicative of the validity of the above-mentioned assertion.

A study of pants pattern for bowlegged females in their twenties (O자형 다리 20대 여성의 팬츠 패턴 연구)

  • Seo, Yoo Ra;Kim, Hyo Sook
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.2
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    • pp.79-91
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    • 2021
  • This study aims to rectify the disfigurement of bowlegged, (which means they have a gap between knees due to knee joint problems) females in their twenties through the development of pants patterns. The contents of the study are as follows: First, two types of basic pattern-making methods were selected. Two mock-ups, which were made by using these pre-selected basic patterns, were worn by three bowlegged participants and evaluated with a fit test. A basic pattern, which had good body fit was selected, which had a bubble or a wedge at in crotch area and roomy or snug upper thigh. Second, the mock-up, which was made by using the selected basic pattern, led to the outward movement of crease lines. Two types of patterns that were adjusted were evaluated through a fit test. As a result, an effective adjustment for moving the crease line to the outside or to the center was to cut along the slash line of a horizontal balance line to, but not through the crotch seam to spread the pattern at the hip. Third, three patterns were readjusted using the chosen alteration pattern, and the crotch seam and spread patterns of 1 cm, 2 cm, and 3 cm at the hip were applied. As a result of the evaluation of the fit test, three participants-the majority-showed a better fit when the spread amount in the pattern was 2 cm, although every participant did have a different gap between the knees. This study has significance in which rectifies the disfigurement of bowlegged individuals through the development of patterns for females in their twenties who are bowlegged.