• Title/Summary/Keyword: Resilient design

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Finding-out the Natural Frequency of the Axle Gearbox Suspension System of the High-speed Train (고속전철 액슬 기어박스 현가계의 고유 진동수 측정)

  • 최진욱;차수덕;김용기;이태화
    • Proceedings of the KSR Conference
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    • 2001.10a
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    • pp.163-170
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    • 2001
  • Axle Gearbox of the High Speed Train has rotational degree of freedom centered on the Axle Shaft Center Line, and constrained by the Reaction Arm connected to the Bogie Frame via Resilient Ring made of Rubber. This System is laid on the Power Train and can influence on the Power transmitted from Motor to Axle. The stiffeness of the Resilient Ring have to be selected for the Natural Frequency of this System do not overlap with the Teeth-mating Frequency. To confirm the Design Parameters, Calculation and Experiment were executed and compared.

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Introduction to Leakage-Resilient Authenticated Key Exchange Protocols and Their Applications

  • Imai, Hideki;Shin, Seong-Han;Kobara, Kazukuni
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.18 no.6B
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    • pp.207-217
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    • 2008
  • Secure channels, indispensable to many applications, can be established by using an authenticated key exchange (AKE) protocol where the involving parties authenticate one another and then share authenticated session keys over insecure networks. In this paper, we introduce a new type of AKE protocols that are especially designed to minimize the damages caused by leakages of stored secrets. Such protocols are called Leakage-Resilient AKE (LR-AKE) protocols, whose motivation, design principles, several constructions, security analysis and applications are explained in detail.

Small-size Specimen's Effectiveness That is Used to Mortar Layer of Slab (Heavy-weight Floor Impact Sound) (슬래브 상부 몰탈층에 사용된 작은시편의 유효성 검토(중량충격음을 중심으로))

  • Chung, Jin-Yun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.2
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    • pp.184-191
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    • 2009
  • This study examined small-size specimen's effectiveness that is used to evaluate floor impact sound performance. Floor impact sound level of small-size specimen is higher than full-size. This is due to excessive impact power of Bang machine. Impact hammer that has small impact power relatively can solve this problem. But, according to the size of specimen, mode shape and frequency that influence to structural borne sound is changed. Slab mode of full-size specimen was changed to frequency design of resilient materials. But in case of small-size specimen, there is no change of vibration mode by resilient materials change, Vibration mode of small-size specimen is the same. Therefore, it is not proper that use small-size specimen in floor impact sound estimation.

Highly Accurate Approximate Multiplier using Heterogeneous Inexact 4-2 Compressors for Error-resilient Applications

  • Lee, Jaewoo;Kim, HyunJin
    • IEMEK Journal of Embedded Systems and Applications
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    • v.16 no.5
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    • pp.233-240
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    • 2021
  • We propose a novel, highly accurate approximate multiplier using different types of inexact 4-2 compressors. The importance of low hardware costs leads us to develop approximate multiplication for error-resilient applications. Several rules are developed when selecting a topology for designing the proposed multiplier. Our highly accurate multiplier design considers the different error characteristics of adopted compressors, which achieves a good error distribution, including a low relative error of 0.02% in the 8-bit multiplication. Our analysis shows that the proposed multiplier significantly reduces power consumption and area by 45% and 26%, compared with the exact multiplier. Notably, a trade-off relationship between error characteristics and hardware costs can be achieved when considering those of existing highly accurate approximate multipliers. In the image blending, edge detection and image sharpening applications, the proposed 8-bit approximate multiplier shows better performance in terms of image quality metrics compared with other highly accurate approximate multipliers.

A Design Criterion for the Vibration of a Marine Diesel Generator Set (선박용 디젤발전기의 진동 절연을 위한 설계 기준)

  • Lee, D.C.;Brennan, M.J.;Mace, B.R.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.648-655
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    • 2005
  • The resilient mounts of a diesel engine installed onboard a ship should be designed for both static and dynamic loads. If possible, the resonance frequencies of the six rigid body modes of the installation and the flexible modes of the engine support structure should not lie within the engine operation range. In this paper a design criterion is proposed to evaluate an isolation system which involves the summation of dynamic forces transmitted through the resilient mounts and elastic potential energy index stored in the mounts. A case study is also presented in which a diesel engine generator, which had an elastic foundation and was mounted in a 5500 TEU container vessel, was studied both theoretically and experimentally. The theoretical analysis of the test model was performed by using a single mass 6 degree of freedom system. Actual measurements of mechanical vibration of the Engine and its foundation onboard were carried out, which showed the importance of including the flexibility of the engine support structure in the mode

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A Design Criterion for the Vibration Isolation of a Marine Diesel Generator Set (선박용 디젤발전기의 진동 절연을 위한 설계 기준)

  • Brennan M.J.;Mace B.R.;Lee, D.C.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.4 s.109
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    • pp.329-338
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    • 2006
  • The resilient mounts of a diesel engine installed onboard a ship should be designed for both static and dynamic loads. If possible, the resonance frequencies of the six rigid body modes of the installation and the flexible modes of the engine support structure should not lie within the engine operation range. In this paper a design criterion is proposed to evaluate an isolation system which involves the summation of dynamic forces transmitted through the resilient mounts and elastic potential energy index stored in the mounts. A case study is also presented in which a diesel engine generator, which had an elastic foundation and was mounted in a 5500 TEU container vessel, was studied both theoretically and experimentally. The theoretical analysis of the test model was performed by using a single mass 6 degree of freedom system. Actual measurements of mechanical vibration of the engine and its foundation onboard were carried out, which showed the importance of including the flexibility of the engine support structure in the mode.

Improvement of the Performance Based Seismic Design Method of Cable Supported Bridges with Resilient-Friction Base Isolation Systems (I- Analysis of Field Testing of Cable Supported Bridge) (마찰복원형 지진격리장치가 설치된 케이블교량의 성능 기반 내진설계법 개선(I-실 교량 실험 결과 분석))

  • Gil, Heungbae;Park, Sun Kyu;Han, Kyoung Bong;Yoon, Wan Seok
    • Journal of the Earthquake Engineering Society of Korea
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    • v.24 no.4
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    • pp.157-167
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    • 2020
  • In this study, a field bridge test was conducted to find the dynamic properties of cable supported bridges with resilient-friction base isolation systems (R-FBI). Various ambient vibration tests were performed to estimate dynamic properties of a test bridge using trucks in a non-transportation state before opening of the bridge and by ordinary traffic loadings about one year later after opening of the bridge. The dynamic properties found from the results of the tests were compared with an analysis model. From the result of the ambient vibration tests of the cable supported bridge with R-FBI, it was confirmed that the dynamic properties were sensitive to the stiffness of the R-FBI in the bridge, and the seismic analysis model of the test bridge using the effective stiffness of the R-FBI was insufficient for reflecting the dynamic behavior of the bridge. In the case of cable supported bridges, the seismic design must follow the "Korean Highway Bridge Design Code (Limit State Design) for Cable supported bridges." Therefore, in order to reflect the actual behavior characteristics of the R-FBI installed on cable-supported bridges, an improved seismic design procedure should be proposed.

Study on Establishing the Subgrade Compaction Control Methods Based on the In-situ Elastic Modulus (현장 탄성계수에 근거한 노상 다짐관리방안 연구)

  • Choi, Jun-Seong;Han, Jin-Seok;Kim, Jong-Min
    • International Journal of Highway Engineering
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    • v.14 no.3
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    • pp.49-58
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    • 2012
  • In many countries including Korea, the design concept of pavement structure has been converted from empirical method to mechanisticempirical method since the advent of compaction control based on resilient modulus proposed by AASHTO in 1986. Studies of last decades indicates that the classical compaction control method based on relative compaction and plate bearing test(PBT) will necessarily move to the methods taking advantage of light falling weight deflectometer(LFWD) and dynamic cone penetrometer(DCP) in addition to PBT. In this study, the validity of resilient modulus prediction equation proposed by Korean Pavement Design Guide is verified by comparison with physical properties of subgrade soil and the results of structural analysis. In addition, correlational equations between elastic modulus measured by various field tests and resilient modulus estimated by empirical model are proposed. Finally, a field test-based compaction control procedure for subgrade is suggested by using proposed correlational equations.

Research on Landscape Design by Flexibly Using Resilient Theory - Focused On 'New York High Line Park'- (리질리언트 이론을 활용한 경관 디자인에 관한 연구 - 'The High Line' 를 중심으로 -)

  • Chen, Wen-Li;Hong, Kwan-Seon
    • The Journal of the Korea Contents Association
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    • v.20 no.1
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    • pp.644-657
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    • 2020
  • As the development of urbanization has cause some environmental problems and natural disasters such as natural earthquakes and floods have brought about impact, designers have turned their attention to the independent prevention ability of urban ecosystems in face of environmental pollution and natural disasters, as well as its ability to adapt to the future. This study introduces 'elasticity theory' to discuss the practical application of elasticity design in landscapes and to solve the problem of lack of elasticity in space, which can provide more scientific reference meaning to create economic, cultural, and social values for space. After selecting 'The High Line' as the object, this paper investigates the previous theories and practical cases, and infers ecology, sustainability, diversity, and adaptability. And then this paper applies five components and analyzes the specific application of these five components of the landscape spatial elasticity strategy, and summarizes the application characteristics and influencing factors of elasticity design in 'The High Line' landscape planning. It can be known from the research that elasticity strategy which is reflected in the design process is the systematic management of landscape space. Elasticity design itself can strengthen environment quality and satisfy the requirements of the environment to defense external shocks so as to adapt to environment changes. Therefore, the elasticity design can strengthen the sustainable development of the city and establish a periodic recycle system.

Establishment of Resilient Infrastructures for the Mitigation of an Urban Water Problem: 1. Robustness Assessment of Structural Alternatives for the Problem of Urban Floods (도시 물 문제 저감을 위한 회복탄력적 사회기반시설 구축: 1. 도시 홍수 문제 구조적 대안의 내구성 평가)

  • Lee, Changmin;Jung, Jihyeun;An, Jinsung;Kim, Jae Young;Choi, Yongju
    • Ecology and Resilient Infrastructure
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    • v.3 no.2
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    • pp.117-125
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    • 2016
  • Current cities encounter various types of water problems due to rapid urbanization and climate change. The increasing significance of urban water problems calls for the establishment of resilient alternatives to prevent and minimize social loss that results from these phenomena. As a background research for establishing resilient infrastructures for the mitigation of urban water problems, we evaluated the robustness of structural alternatives for urban flood as a representative case. Combining the robustness index (RI) and the cost index (CI), we suggested the robustness-cost index (RCI) as an indicator of the robustness of structural alternatives, and applied the index to assess the existing infrastructures and structural alternatives (i.e., sewer network expansion, additional storage tank construction, and green roof construction) at a site prone to floods located around Gangnam-station, Seoul, Korea. At a rainfall intensity frequency range of 2 to 20 years, the usage of a storage tank and a green roof showed relatively high RCI value, with a variation of an alternative showing greater RCI between the two depending on the size of design rainfall. For a rainfall intensity frequency of 30 years, installing a storage tank with some green roofing was the most resilient alternative based on the RCI value. We proposed strategies for establishing resilient infrastructures for the mitigation of urban floods by evaluating the robustness of existing infrastructures and selecting optimal structural alternatives with the consideration of scales of design disaster.