• 제목/요약/키워드: Seesaw

검색결과 39건 처리시간 0.026초

Design of aerodynamic stabilizing cables for a cable-stayed bridge during construction

  • Choi, Sung-Won;Kim, Ho-Kyung
    • Wind and Structures
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    • 제11권5호
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    • pp.391-411
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    • 2008
  • A design procedure of stabilizing cable is proposed using buffeting analysis to stabilize the seesaw-like motion of the free cantilevered structure of a cable-stayed bridge during its construction. The bridge examined is a composite cable-stayed bridge having a main span length of 500 m. Based on the buffeting analysis, the stress in bare structure exceeded the allowable limit and a set of stabilizing cable was planned to mitigate the responses. The most efficient positions of the hold-down stabilizing cables were numerically investigated by means of an FE-based buffeting analysis and the required dimensions and pretension of the stabilizing cables were also calculated. The proposed stabilizing measure would be expected to secure the aerodynamic safety of a cantilevered structure under construction with considerable mitigation of buffeting responses.

신경회로망을 이용한 동적 시스템의 상태 공간 인식 모델 (The State Space Identification Model of the Dynamic System using Neural Networks)

  • 이재현;탁환호;이상배
    • 한국지능시스템학회논문지
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    • 제10권5호
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    • pp.442-448
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    • 2000
  • 전통적인 동적 시스템의 제어에는 제어대상의 정확한 수학적 모델링이 필요하다. 그러나 동적 시스템의 모델링은 복잡한 상태방정식과 많은 제어파라메터들에 의해 매우 복잡한 계산과정을 필요로 한다. 그러므로, 본 논문에서는 신경회로망을 이용한 동적 시스템의 상태 공간 인식 모델을 제안하였으며, 제안된 신경회로망을 학습시키기 위하여 가우스-뉴턴 방법을 사용하였다. 본 논문에서 제안된 신경회로망 모델은 시소 시스템 인식문제를 컴퓨터 모이실험을 통해 효과적임을 보였다.

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화상처리용 마이크로 미러의 동특성 측정기술 (Dynamic Characteristics Measurement of Micro Mirror for Image Display)

  • 이은호;김규로
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1997년도 춘계학술대회 논문집
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    • pp.371-376
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    • 1997
  • A 100*100.mu.m$^{2}$ aluminum micro mirror is designed and fabricated using a thick photoresist as a sacrificial layer andas a mold for nickel electroplating. The micro mirror is composed of aluminum mirror plate, two nickel support posts, two aluminum hinges, two address eletrodes, and two landing electrodes. The aluminum mirror plate,which is supported by two nickel support posts, is overhung about 10.mu.m from the silicon substrate. THe aluminum mirror plate is actuated like a seesaw by electrostatic force generated by electic potential difference applied between the mirror plate and the address electrode. This paper presents some methods to measure the optical and the dynamic characteristics of the fabricated micro mirror.

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Neutrino Oscillation and S4 Flavor Symmetry

  • Park, Jong-Chul
    • Applied Science and Convergence Technology
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    • 제27권5호
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    • pp.86-89
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    • 2018
  • Observations of neutrino oscillations are very strong evidence for the existence of neutrino masses and mixing. From recent experimental results on neutrino oscillation, we find that neutrino mixing angles are quite consistent with the so-called tri-bi-maximal mixing pattern, but the deviation from observational results is non-negligible. However, the tri-bi-maximal mixing pattern is still useful as a leading order approximation and provides a good guideline to search for the flavor symmetry in the neutrino sector. We introduce the $S_4$ permutation symmetry as a flavor symmetry to the standard model of particle physics with additional particle contents of heavy right-handed neutrinos and scalar fields. Finally, we obtain the tri-bi-maximal mixing pattern as a mixing matrix in the lepton sector within the suggested model. To derive the required unitary mixing matrix for the neutrino sector, the double seesaw mechanism is utilized.

The Effect of the Aging of Red Blood Cells on Rheological Properties and Hemolysis

  • Tomioka, Jun;Motokubo, Kazuhiro;Watanabe, Hisayoshi
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.371-372
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    • 2002
  • It is well known that red blood cells (RBCs) are suffered from chronic stresses in systemic circulation. The objective of this study is to clarify the effect of the aging of RBCs on rheological properties and hemolysis. Initially, RBCs age fractionation was performed by using a high-speed centrifugation (15[min] at 1500[G]), then young and aged RBCs were suspended in plasma to adjust the hematocrit level of 40[%]. After this pretreatment, the viscosity was measured by using a capillary type and a cone-plate type viscometers, respectively, and the hemolysis test was carried out by a seesaw type shaker. Results from these experiments showed that the viscosity of the aged RBCs measured by the capillary viscometer was increased by 10[%] as compared with that of the young RBCs. Under the condition of all shear zones, the viscosity of the aged RBCs was increased in case of using the cone-plate type viscometer. And the hemolytic level was increased twice as the aging. The data obtained in this study indicated that the ability of aggregation of RBCs was increased and the deformability of RBCs membrane got lower with the aging. Furthermore, it was exhibited that the fragility of RBCs ’ membrane was increased with the aging.

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어린이 놀이터 놀이시설의 안전도에 관한 조사 (An Actual Measurement on Safety of Play Equipments in the Outdoor Playground)

  • 석주영;안옥희;박인전
    • 한국주거학회논문집
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    • 제13권2호
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    • pp.47-53
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    • 2002
  • The purposes of this study actually measure to the dimension and the quality of material play equipment's examine whether they meet safety standards or not, and intend to offer basic data to present proper safety standards concerning the dimension of play equipment in the end. The subjects for this study were 59 outdoor playgrounds, 30 among them located in apartment sites and the remainder did in residential districts. The time of actual measurement was in June 1999, and June 2000. Data were analyzed into frequency, percentage, mean, and standard deviation by using SPSSWIN program. The main results were as follows.: First, more than half of playgrounds were assessed for being traffic hazards due to the adjacent streets. And they were hardly equipped with the toilet and drinking water facilities, but were almost equipped with the shade of a tree and benches. Second, it was caused in inconvenience of children's use and difficulty of play equipments'management, since the quality of play equipments materials was consisted of wood or metal. Third, the standards for swing and slide were established in detail and actual measurement's results were suitable to standards'value as well, whereas the standards for seesaw and climber were not in detail and they did not design or install suitably.

드라마 제작산업의 가격 결정 메커니즘 (Pricing Mechanism of Production Factors in the Broadcasting Industry)

  • 노동렬
    • 한국콘텐츠학회논문지
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    • 제16권2호
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    • pp.618-632
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    • 2016
  • 드라마 제작산업의 가격결정 방식은 다중가격 체계를 형성하고 있다. 생산요소 가격은 방송사업자별, 제작주체별, 드라마 장르별로 차별화가 이루어지고 있다. 다중가격 체계에서 가격결정에 영향을 미치는 요인들은 생산요소의 희소성과 대체재의 유무, 제작비 규모, 명성 효과, 경쟁의 정도, 생산요소를 선택하는 주체 등이다. 스타 연기자에게 가격은 자신의 역량을 평가받는 기준으로 작용하는 동시에 자존심이라는 명성과 직결되는 기준으로 인식되고 있다. 이로 인해, 연기자 가격은 기존의 최고 가격을 경쟁자가 뛰어넘으며 경쟁하는 시소효과를 나타내고 있는 반면, 작가 가격은 최고 대우를 받고 있는 특정 작가의 가격 이하에서 제한적으로 상승하는 사다리 효과를 나타내고 있다. 현재는 제작비 규모의 상승 속도가 생산요소 가격의 상승 속도를 따라가지 못하는 상황이기 때문에 런닝개런티 제도를 적용하여 합리적인 시장 가격 형성을 위한 기준이 마련되어야 할 시점이다.

북한 호위사령부의 경호요원 체육교육에 관한 연구 (A Study on the Physical Training for the Security Agents of the Security Headquaters in the North Korea)

  • 김정현
    • 시큐리티연구
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    • 제8호
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    • pp.45-64
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    • 2004
  • The pivotal emphasis of the physical training for the security agents of the security headquarters in the North Korea is to inspire them with the defense physical training-centered ideology and the war spirit. Their special martial arts is the protectee-centered offensive arts rather than the self-centered arts. It puts emphasis on training black belt-holders in diverse martial arts rather than in a certain martial art. Thus, the physical training for security agents in the South Korea should be also developed into the ways to rear them as black belt-holders in diverse martial arts rather than to foster them as high grade-holders in a certain martial art. And also, professors majoring in security and physical science have to develop jointly the measures to improve the physical and mental agility and the basic physical strength to inspire rapid handling and perseverance, to develop the physical training program to reduce mental and physical stress of security guards, to develop the standard for the examination of physical strength suitable for the body figures of Korean people and the regular evaluation with the standard and to apply traditional folk-games such as the swing and the seesaw to the physical training for security guards.

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회전모멘트 힌지 설계에 따른 캔틸레버형 횡방향 구동 Fast Tool Servo 연구 개발에 관한 고찰 (A Study on the Development of a Cantilever & Swing-Type Fast Tool Servo with Rotational Moment Hinge Design)

  • 이승준;정재호
    • 한국기계가공학회지
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    • 제19권8호
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    • pp.43-49
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    • 2020
  • The growth of the AR/VR market due to the advent of the 4th Industrial Revolution begins with the development of the display industry. The development of OLED and flexible displays is further accelerated by the development of R2R technology. Micro-processing technology using a fast tool servo (FTS), the core technology in R2R processes, is making technological progress in increasingly diverse ways. This paper proposes a method to develop an FTS for horizontal driving and presents this method through experiments and analyses. To develop a swing-type FTS based on a seesaw motion, a rotational moment hinge structure was designed for each type, and research was conducted to determine an effective design method. A cantilever-based swing-type FTS was developed in two variations: one with single-side hinges and another with dual-side hinges. The parameters in the design of the swing-type FTS are rotational moment, natural frequency, and material selection. In conclusion, an FTS with a single-side hinge demonstrates the high performance required for micro processing.

차량용 델타샤시의 프로그레시브 공정 설계 (Progressive Process Design for Delta Sash in Vehicles)

  • 고영준;곽효서;배준호;김철
    • 한국정밀공학회지
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    • 제31권12호
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    • pp.1161-1170
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    • 2014
  • Delta sash is an important part of automobile door, which has the functions of supporting and guiding seesaw of car's window, preventing dust and air from outside. In previous manufacturing process, each part of the delta sash was independently formed by tandem processes, and rubber is bonded to steel by poisonous glue. So, the previous processes, including roll forming process and toxic gases, had low production rate and high failure rate. In this study, progressive process design of the delta sash was proposed in order to increase productivity and high utilization of the materials. And instead of the poisonous glue used for adhesion of rubber in the previous tandem process, embossing and piercing processes were designed in the new guide to help the rubber to adhere well to steel. And the optimal piercing distance was designed to ensure structural safety, and prototypes were manufactured for verifying reliability of the processes.