• Title/Summary/Keyword: higher mode effect

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A Study on Reducing Rolling Mode Effect in High-Sensitivity Optical Pickup 3-axis Actuator (고감도 3축구동 액츄에이터를 위한 Rolling Mode 저감 연구)

  • 김영중;홍삼열;김진아;최인호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.775-779
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    • 2003
  • Recently, a new type actuator using multi-pole magnet has been developed for high-density and high-speed disk drive, which can be achieved higher sensitivity than a conventional actuator for applying one-pole magnet. However, it is very difficult for the actuator of multi-pole magnet to meet simultaneously the optimal design condition for reducing rolling mode effect and improving driving sensitivity because the force center is different from the mass center In this paper, First We propose the new shape coil for tracking which can reverse moment additionally in tracking motion, Next we achieve the optimal design to reduce phase disturbance and peak gain at the rolling mode frequency. Finally, the validity of the proposed methods is proved from experimental results.

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Design of Housing Structure for the Suppression of Higher­Order Modes in the Microstrip Circuit Packaging (마이크로스트립 회로 패키징의 고차모드 차폐를 위한 하우징 설계)

  • 전중창
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.8
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    • pp.1621-1628
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    • 2003
  • Packaging structures to block the propagation of higher­order modes in the shielded microstrip lines are designed. Packaging for microwave circuits is necessary, basically, to isolate and protect circuits from outside environments both physically and electrically. The drawback of packaging is the possibility of higher­order mode propagation, similar to waveguide modes, as the operating frequency increases. One of Possible choices for the higher­order mode suppression is to insert diaphragms to the housing structure. The shielding effects of diaphragms are analyzed using an FEM code. Several parameters such as dispersion, mode conversion, and higher­order mode transmission and reflection are analyzed. The effect of higher­order mode suppression is eminent as the depth or width of a diaphragm is increased in the air region of the microstrip line. It is shown that inductive diaphragm structure can lower ${S_21}$ for the second­order mode incidence by 30㏈, comparing with the conventional capacitive diaphragm structure. Packaging structure analyzed in this paper can be applied usefully to the design of the microwave system in a package such as transmit/receive modules.

Hysteresis and Mode Transition in Electrodeless Lamp (무전극램프 에서의 Hysteresis와 모드 변환 특성)

  • Lee, Joo-Ho;Yang, Jong-Kyung;Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1560-1561
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    • 2007
  • Electrodeless fluorescent lamp exhibit two modes of operation : a low density mode in which the power is capacitively coupled to the plasma and which is known as the E-mode, and a higher density mode which is an inductive discharge known as the H-mode. The transition between these two(E to H) mode exhibits hysteresis. It is observed that transition currents change at different frequencies and hysteresis exists not only between the starting and minimum maintaining currents of the electromagnetic mode (H mode) discharge but also between the starting and minimum maintaining currents of the electrostatic mode (E mode) discharge. Hysteresis effect can be important role in dimming system.

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大学生在线学习效果的多维度比较研究

  • Lijuan Huang;Xiaoyan Xu
    • Journal of East Asia Management
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    • v.4 no.2
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    • pp.39-62
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    • 2023
  • Online and offline mixed teaching mode has become an important way to promote the connotative development of higher education. Under the background that offline teaching has become mature, in order to further promote the development of online education, and promote the implementation of the mixed teaching mode, to mix and to provide basis for the construction of the mixed teaching mode, this study takes the online learning effect as the evaluation basis, adopts the online questionnaire survey to conduct statistical analysis of the online learning behavior of 2213 college students, and discusses the differentiation phenomenon of online learning groups from the micro, meso and macro perspectives. It is found that there are significant differences in the online learning effect of college students in terms of the type of learning platform, whether the school implements the online offline mixed teaching mode, education background, grade (bachelor's degree), and region. Colleges and universities should strengthen the promotion of online and offline mixed teaching mode; The online learning platform should improve the platform function and strengthen the functional differentiation design of learning resources for students. Education departments pay attention to the learning effect of online learners in different regions, and bridge the gap in regional education.

Location Effect of Tuned Mass Dampers on the Response of Buildings (TMD의 위치변화에 따른 건물의 응답효과)

  • Min, Kyung-Won;Hong, Sung-Mok;Hwang, Jae-Seung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.95-99
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    • 1993
  • Conventional tuned mass dampers are located on the top floor of tall buildings, which reduce the fundamental mode response of buildings. Higher modes may have a greater contribution toward the acceleration response of tall buildings. To reduce this, additional tuned mass dampers are required and could be substituted as building equipments. This paper shows, with a numerical ezample, how the lecate tuned mass damper in order to reduce the higher mode response effectively

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A Study on the Conspicuous Consumption Characteristic Expressed in the Modern Fashion (현대 패션에 나타난 과시적 소비 특성)

  • Lee, Ji-Hyoun;Yang, Sook-Hi
    • The Research Journal of the Costume Culture
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    • v.18 no.1
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    • pp.177-189
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    • 2010
  • The purpose of this study is to research the conspicuous consumption characteristic expressed in the modern fashion. The conspicuous consumptions are classified with 2 parts as follows as: 1. The motive of conspicuous consumption, 2. The effect of conspicuous consumption. And the motive of conspicuous consumption is 1) conspicuous consumption, 2) conformity consumption, 3) compensatory consumption. The effect of conspicuous consumption is 1) veblen effect, 2) bandwagon effect, 3) snob effect. The veblen effect is caused either by the belief that higher price means higher quality, or by the desire for conspicuous consumption to be seen as buying an expensive, prestige item. The bandwagon effect is people tend to follow the crowd without examining the merits of a particular thing. The snob effect refers to the desire to own unusual, expensive or unique goods. The conspicuous consumption has produced conflicting results of the homogeneous imitation and the different scarcity. Consequently conspicuous consumption characteristic expressed in the modern fashion refers to the conformable imitation and the different scarcity. The conformable imitation is pursuit of first lady look and imitation. The different scarcity refers to the desire to own exclusive or unique goods. The unique value is pursuit of limited edition and art mode.

Experimental study on moonpool resonance of offshore floating structure

  • Yang, Seung-Ho;Kwon, Sun-Hong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.2
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    • pp.313-323
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    • 2013
  • Offshore floating structures have so-called moonpool in the centre area for the purpose of drilling, installation of subsea structures, recovery of Remotely-Operated Vehicle (ROV) and divers. However, this vertical opening has an effect on the operating performance of floating offshore structure in the vicinity of moonpool resonance frequency; piston mode and sloshing mode. Experimental study based on model test was carried out. Moonpool resonance of floating offshore structure on fixed condition and motion free condition were investigated. And, the effect of cofferdam which is representative inner structure inside moonpool was examined. Model test results showed that Molin's theoretical formula can predict moonpool resonance on fixed condition quite accurately. However, motion free condition has higher resonance frequency when it is compared with that of motion fixed. The installation of cofferdam moves resonance frequency to higher region and also generates secondary resonance at lower frequency. Furthermore, it was found that cofferdam was the cause of generating waves in the longitudinal direction when the vessel was in beam sea.

Hybrid Component Mode Synthesis Considering Residual Dynamic Flexibility Attachment Mode (잔여 동연성 부가 모드를 고려한 혼합 부분 모드 합성법)

  • Cha Hyun Joo;Kim Jin Ho;Lee Shi Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.5 s.236
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    • pp.716-725
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    • 2005
  • The method of substructure synthesis o. component mode synthesis(CMS) provides an effective means of dynamic analysis of very large and/or complex structures. In this study, residual dynamic flexibility attachment modes in hybrid component mode synthesis are considered for the purpose of exactly compensating the effect of higher order truncated modes. Following this way, the analysis accuracy of the synthesized structure can be improved effectively with less computational effort. In order to show the accuracy and effectiveness of the proposed hybrid component mode synthesis(HCMS), numerical experiments were carried out for the models of a clamped-clamped beam. The results verified the effectiveness of the proposed method.

Effect of Curing Conditions on the ASR of Lightweight Aggregate Concrete (양생조건이 경량골재 콘크리트의 ASR에 미치는 영향)

  • 성찬용;김성완;민정기
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.4
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    • pp.38-46
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    • 1993
  • This study is to analyze effect of exposure environment and mode of ASR on the engineering properties of synthetic lightweight aggregate concrete, such as dynamic modulus of elasticity and ultrasonic pulse velocity. The results of this study are summarized as foflows ; 1. The expansion rate of each exposure environment in 380$^{\circ}$C and NaCI 4% solution was shown higher than in 20$^{\circ}$C and normal water. The expansion rate of each exposure mode was largely shown in order of fjill immersion, wetting/drying, half immersion. 2. The dynamic modulus of elasticty and ultrasonic pulse velocity of each exposure environment in 38$^{\circ}$C and NaCl 4% solution was shown less than in 20$^{\circ}$C and normal water. The dynamic modulus of elasticity and ultrasonic pulse velocity of each exposure mode was shown smaller in order of full immersion, wetting/drying, half imersion.3. The relation between dynamic modulus of elasticity and ultrasonic pulse velocity was highly significant. The dynamic modulus of elasticity was increased with increase of ultrasonic pulse velocity. The decreasing rate of the dynamic modulus of elasticity was shown 2.1~3.4 times higher than the ultrasonic pulse velocity at each age, exposure environment and mode, respectively. 4. The expansion of each exposure environment and mode was increased with increase of curing age. The dynamic modulus of elasticity and ultrasonic pulse velocity of those concrete was increased with increase of curing age. At the curing age 28 days, the highest properties was showed at each type concrete, it was gradually decreased with increase of curing age. Specially, at the curing age 98 days of full immersion, the rate of expansion of type D was shown 3.95 times higher than the type A. But the dynamic modulus of elasticity and ultrasonic pulse velocity was decreased 17% and 8.3%.

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A Study Comparing the Effects of Burst Mode and High Rate Mode Transcutaneous Electrical Nerve Stimulation on Experimental Pain Threshold and Skin Temperature (Burst형과 고빈도형 경피신경전기자극치료가 실험적 동통역치와 체온에 미치는 영향 비교)

  • Kim, Suhn-Yeop;Choi, Houng-Sik;Kwon, Oh-Yun
    • Journal of Korean Physical Therapy Science
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    • v.2 no.2
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    • pp.465-479
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    • 1995
  • We randomly assigned 61 healthy subjects(male 14, female 47) to compare the experimental pain threshold and skin temperature between high mode TENS and burst mode TENS. In this study, 61 subjects were divided into three groups ; high mode TENS(n=20), burst mode TENS (n=20), and control group(n=21). Experimental pain thresholds and skin temperatures were measured before, immediately after cessation of stimulation, and at 30 minutes post stimulation. Stimulation was applied to the dorsal surface of the forearm(L14, LI10). Pain thresholds were measured by chronaxie meter. Skin temperature were measured by electrical digital thermometer. The results are as follows ; 1. There were no statistical difference in the pain threshold and skin temperature at before TENS stimulation among the three groups(p>0.05). 2. The pain threshold and skin temperature in burst mode TENS group was significantly higher and longer effect than that in high mode TENS group and control group(p<0.01). 3. The pain threshold in burst mode TENS group decreased to prestimulation levels by 30 minutes poststimulation. 4. The skin temperature in burst mode TENS group decreased to prestimulation levels by 20 minutes poststimulation. 5. The skin temperature was significantly difference among three group at immediately after, and at 30 minutes poststimulation and the skin temperature in burst mode TENS group was significantely higher than that in two groups(p<0.001). 6. The increasing rate of pain threshold in high mode TENS group after immediately cassation of stimulation was 24.3%(p<0.001). 7. The increasing rate of pain threshold in burst mode TENS group after immediately cessation of stimulation was 93.5% (p<0.001).

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