• Title/Summary/Keyword: Pendulum

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A Study on Space in the Moveis of Hirokazu Koreeda (고레에다 히로카즈 감독 영화의 공간 연구)

  • Hwang, Woo-Hyun
    • The Journal of the Korea Contents Association
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    • v.18 no.12
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    • pp.343-363
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    • 2018
  • Classical film narrative fails to reflect the increasing complexity of modern society. In this era of film narrative crisis Hirokazu Koreeda presents a new solution. The director puts an emphasis on neutral valuation over subject matter rather than empathy of audiences which leads to a biased point of view. Thus Hirokazu Koreeda choose space over story as a critical narrative enabler. Two qualitatively opposite spaces are presented and the boundary space of the two are set as a main background where the valuation over the spaces waves up and down. Audiences who get accustomed to a one-sided value judgement led by storytelling can be neutralized by pendulum movement of valuation. The specific methods of using space as a main tool of value neutralization have changed through the director's filmography. Space had been thoroughly designed through the storyboard in early works. Later the director let audiences experience the spaces to evoke a sense of place.

Exploring Structural Stability using Arduino for the Prevention of Tower Cranes' Safety Accident : focused on ardu (타워크레인의 안전사고 예방을 위한 아두이노 기반 구조적 안정성 탐색)

  • Kim, Jun-Seok;Lee, Won-Hee;Kim, Sungae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2019.05a
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    • pp.27-31
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    • 2019
  • Various safety accidents occur frequently at construction sites due to poor operation of construction machines and insufficient safety facilities. Among them, safety accidents on the Tawerkrain have resulted in massive casualties and property damage. Therefore, the purpose of this study is to develop safety devices to prevent safety accidents in the Tower Crane. To this end, the existing safety device was explored and the model of the Tower Crane was constructed using Arduino. The weight of the object, the weight of the pendulum, and the distance from the center axis, as well as the equation of turning and experimentation, suggested mobile weights as a safety device to identify and resolve problems with existing safety devices. This is expected to minimize the limit on the salvage distance of the tower crane, thus providing a safer working environment away from the risk of a safety accident.

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Experimental Study on Response Characteristics of Reinforced Concrete Buildings Due to Waterborne Debris Impact Loads (해일표류물의 충돌에 의한 철근콘크리트 건축물의 응답특성에 관한 실험적 연구)

  • Choi, Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.4
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    • pp.590-595
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    • 2020
  • In this study, the small-scale collision experiments using a pendulum principle were carried out to evaluate the safety of the reinforced concrete building selected as a tsunami evacuation building due to the collision of the waterborne debris represented by ships. The experimental parameters were set as impact velocity, mass and length of the drifted ship. In this paper, the maximum impact force, impact duration, impact waveform and restitution coefficient affecting building response were investigated in detail. As a result, the impact force waveforms were distributed as a triangle in most of the experimental results, but became closer to a trapezoid as the length of the collision specimen increased. This is the very important result in calculating the momentum (impact waveform area) affecting building response, Furthermore, the restitution coefficients were constant regardless of the impact velocity, but they varied depending on the mass and length of the waterborne debris. However, the restitution coefficient for the mass per unit length of the waterborne debris can be evaluated.

The Wave Power Generator on Small Ship for Charging Engine Start-Up Battery (엔진 시동용 소형선 탑재형 파력 발전 시스템)

  • Kisoo, Ryu;Sungjin, Kang;Byeongseok, Yu
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.6
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    • pp.439-446
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    • 2022
  • Efforts to reduce carbon dioxide(CO2) emissions are being carried out due to climate environmental problems. Eco-friendly ships are also being developed, and various energy saving measures have been developed and applied. In ships, researches have been conducted in various fields such as electric propulsion system and energy saving devices. In addition, the development of ships using various renewable energy, such as kite using wind power and wind power generation, has been carried out. This paper proposes a plan to use renewable energy for ships by applying wave generators to small ships. In 2016, 130 small domestic ships drifted by sea due to discharge of starting storage batteries, and discharge cases accounted for the largest portion of the causes of domestic ship accidents. This is due to the excessive use of storage batteries for starting the main engine by departing in a weak storage battery state for small ships. Accordingly, two type wave power generators - opened flow wave power generator and enclosed vibrator type wave power generator - are developed for charging a starting storage battery when the ships are stationary at sea or port. Opened flow wave power generator utilizes the flow of fluid in the ship by using wave induced ship motion. Enclosed vibrator type wave power generator utilizes the pendulum kinetic energy located in a ship due to wave induced ship motion.

Effect of Virtual Reality Based Ring Fit Adventure Core Exercise on the Thickness of the Transverse Abdominis, Internal Oblique and External Oblique Muscle (가상현실 기반의 링 피트 어드벤처 코어 운동이 배가로근, 배속빗근, 배바깥빗근의 두께에 미치는 영향)

  • Yoon, Sam-Won;Yoon, Sung-Young;Park, Han-Kyu
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.4
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    • pp.93-102
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    • 2022
  • Purpose : The purpose of this study was to analyze the change in thickness of transvers abdominis, internal oblique, and external oblique when virtual reality based ring fit adventure is applied to young adults in order to investigate the effect of ring fit adventure on core stabilization. Methods : 30 subjects participated in the experiment. Subjects were randomly assigned to two groups. 15 subjects performed ring fit adventure core exercise (experimental group) and 15 subjects bridge and dead bug exercise (control group). The ring fit adventure core exercise program consists of 6 types, 1) bow pull, 2) overhead lunge twist, 3) pendulum bend, 4) seated ring raise, 5) plank, 6) warrior III pose. Each exercise was performed for 5 minutes, for a total of 30 minutes. The bridege and dead bug exercise were performed for 15 minutes each for a total of 30 minutes. All interventions were performed 3 times a week for 4 weeks. Thickness of the abdominal muscles was measured with a ultrasound. The paired t-test was used to compare the thickness of the transverse abdominis, internal oblique, and external oblique before and after intervention, and the comparison between groups was analyzed using the independent t-test. Results : As a result, in the experimental group, thickness of transverse abdominis and internal oblique increased significantly (p<.05), but external oblique decreased significantly (p<.05), and in the control group, thickness of transverse abdominis, internal oblique, and external oblique increased significantly (p<.05). There was a significant difference in external oblique in the difference between groups (p<.05). Conclusion : These study results showed that core exercise using ring fit adventure can reduce external oblique and increased selective muscle activity of transverse abdominis and internal oblique of the deep abdominal muscles, so it is meaningful as an effective intervention for core stabilization.

Seismic response of a high-rise flexible structure under H-V-R ground motion

  • We, Wenhui;Hu, Ying;Jiang, Zhihan
    • Earthquakes and Structures
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    • v.23 no.2
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    • pp.169-181
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    • 2022
  • To research the dynamic response of the high-rise structure under the rocking ground motion, which we believed that the effect cannot be ignored, especially accompanied by vertical ground motion. Theoretical analysis and shaking table seismic simulation tests were used to study the response of a high-rise structure to excitation of a H-V-R ground motion that included horizontal, vertical, and rocking components. The use of a wavelet analysis filtering technique to extract the rocking component from data for the primary horizontal component in the first part, based on the principle of horizontal pendulum seismogram and the use of a wavelet analysis filtering technique. The dynamic equation of motion for a high-rise structure under H-V-R ground motion was developed in the second part, with extra P-△ effect due to ground rocking displacement was included in the external load excitation terms of the equation of motion, and the influence of the vertical component on the high-rise structure P-△ effect was also included. Shaking table tests were performed for H-V-R ground motion using a scale model of a high-rise TV tower structure in the third part, while the results of the shaking table tests and theoretical calculation were compared in the last part, and the following conclusions were made. The results of the shaking table test were consistent with the theoretical calculation results, which verified the accuracy of the theoretical analysis. The rocking component of ground motion significantly increased the displacement of the structure and caused an asymmetric displacement of the structure. Thus, the seismic design of an engineering structure should consider the additional P-△ effect due to the rocking component. Moreover, introducing the vertical component caused the geometric stiffness of the structure to change with time, and the influence of the rocking component on the structure was amplified due to this effect.

Performance Comparison Analysis of a Bridge Installed with Anti-seismic Devices using PVDF/MgO Friction Material According to Friction Analysis Models (마찰해석모델에 따른 PVDF/MgO 마찰재 적용 면진 장치가 설치된 교량의 성능 비교 분석)

  • Hye-Ri Park;Sung-Jo Kim;Tong-Seok Han
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.2
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    • pp.105-112
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    • 2023
  • In this study, structural analyses were conducted to analyze the performance of a bridge to which friction pendulum systems (FPSs) were applied using different friction models. A Coulomb friction model and a rate dependent friction model were constructed using the friction coefficient of a PVDF/MgO friction material to analyze the effect of different friction analysis models. The Coulomb friction model uses a single friction coefficient regardless of friction velocity, while the rate dependent friction model can reflect the change in the friction coefficient with friction velocity. Nonlinear time history and seismic fragility analyses were conducted to confirm responses of the bridge. The seismic responses of a deck and a column were used to evaluate the performance of the base isolated bridge, and a friction model that can effectively evaluate the performance of isolated bridges was analyzed.

Development of Laminated Blade Based Shock Absorber Using Viscoelastic Adhesive Tape (점탄성 테이프를 적용한 적층형 블레이드 기반 충격저감장치)

  • Jae-Seop Choi;Yeon-Hyeok Park;Hyun-Ung Oh
    • Journal of Aerospace System Engineering
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    • v.17 no.2
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    • pp.86-93
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    • 2023
  • Pyrotechnic separation devices have been widely used as holding and release mechanism for deployable appendage. However, pyro-shock can cause temporal or permanent damage on shock sensitive components such as electronics, mechanism, and brittle components. This study proposed a low-stiffness blade based passive shock absorber using a multi-layered stiffener laminated with viscoelastic acrylic tapes for reducing transmitted pyro-shock upon explosion of pyrotechnic separation devices. The multi-layered structure with viscoelastic tape has high-damping characteristics to effectively secure structural integrity of low-stiffness blades under the launch environment. The design effectiveness was verified through a shock test by dropping a pendulum. The structural integrity of the shock absorber under a launch environment was evaluated through structural analysis under load conditions with a deployable payload.

A Study on Base Isolation Performance and Phenomenological Model of E-Shape Steel Hysteretic Damper (E-Shape 강재이력댐퍼의 수치모델과 기초격리구조물의 지진응답)

  • Hwang, Inho;Ju, Minkwan;Sim, Jongsung;Lee, Jong Seh
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5A
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    • pp.685-690
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    • 2008
  • Recently, as large structures become lighter and more flexible, the necessity of structural control for reducing excessive displacement and acceleration due to seismic excitation is increased. As a means to minimize seismic damages, various base isolation systems are adopted or considered for adoption. In this study, a base isolation system using hysteretic damper is shown to effectively protect structures against earthquakes. A mechanical model is determined that can effectively portray the behavior of a typical E-shape device. Comparison with experimental results for a hysteretic damper indicates that the model is accurate over a wide range of operating conditions and adequate for analysis. The seismic performance of hysteretic dampers are studied and compared with the conventional systems as a base isolation system. A five-story building is modeled and the seismic performance of the systems subjected to three different earthquake is compared. The results show that the hysteretic damper system can provide superior protection than the other systems for a wide range of ground motions.

Design of a Neuro-Fuzzy System Using Union-Based Rule Antecedent (합 기반의 전건부를 가지는 뉴로-퍼지 시스템 설계)

  • Chang-Wook Han;Don-Kyu Lee
    • The Transactions of the Korea Information Processing Society
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    • v.13 no.2
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    • pp.13-17
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    • 2024
  • In this paper, union-based rule antecedent neuro-fuzzy controller, which can guarantee a parsimonious knowledge base with reduced number of rules, is proposed. The proposed neuro-fuzzy controller allows union operation of input fuzzy sets in the antecedents to cover bigger input domain compared with the complete structure rule which consists of AND combination of all input variables in its premise. To construct the proposed neuro-fuzzy controller, we consider the multiple-term unified logic processor (MULP) which consists of OR and AND fuzzy neurons. The fuzzy neurons exhibit learning abilities as they come with a collection of adjustable connection weights. In the development stage, the genetic algorithm (GA) constructs a Boolean skeleton of the proposed neuro-fuzzy controller, while the stochastic reinforcement learning refines the binary connections of the GA-optimized controller for further improvement of the performance index. An inverted pendulum system is considered to verify the effectiveness of the proposed method by simulation and experiment.