• Title/Summary/Keyword: Resilient layer

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Analysis of Influence Factors on Dynamic Properties of Floor Impact Noise Insulation Materials (바닥충격음 완충재의 동적특성에 영향을 미치는 요인 분석)

  • Kim, Heung-Sik;Joo, Si-Woong;Kim, Dae-Jun;Kim, Byeung-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.946-949
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    • 2005
  • In this paper, influence factors on dynamic properties of floor impact noise insulation materials are suggested. For this purpose measurements on the dynamic stiffness and the loss factor of resilient materials are carried out by Korea standard (KS F 2868) according to the change of density, thickness, design pattern, and composition of materials. As a result the values of dynamic stiffness was decreased at high density and thick thickness, and that of loss factor was increased at low density. For dynamic properties, the pattern of lattice and waffle type material is better than that of plat type, and the mixed composition of materials is better than the composition of double layer materials at same thickness.

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Strength and Deformation Characteristics on Stabilized Pavement Geomaterials(I): Laboratory Test (안정처리된 도로하부 지반재료의 강도 및 변형특성(I): 실내실험)

  • Park, Seong-Wan;Ji, Jong-Keun;Park, Hee-Mun;Ohm, Byung-Sik
    • International Journal of Highway Engineering
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    • v.10 no.3
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    • pp.57-68
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    • 2008
  • The stabilization techniques in the pavement foundations have advantages in increasing pavement performance and reducing pavement thickness. By mixing the geomaterials and stabilizer, the economical and structurally sound layer can be added in the pavement system. Until now, these techniques have been applied in the field empirically and the design criteria for stabilization has not been established. The purposes of this paper are to evaluate the mechanistic properties of stabilizers used for geomaterials and determine the type and optimum amount of stabilizer for each technique. The unconfined compressive testing and repeated load resilient modulus test were conducted on the coarse grained soils mixed with various types of stabilizer to investigate the strength and deformation characteristics of stabilized geomaterials. It is found from the test that the unconfined compressive strength of stabilized geomaterials is more than ten times higher than that of gradation modified geomaterials. The resilient modulus of stabilized geomaterials increases by $6{\times}10$ times compared to the original soils and tends to increase with increase of volumetric and deviatoric stress, and amount of stabilizer.

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Strength and Deformation Characteristics on Stabilized Pavement Geomaterials (II) : Numerical Analysis (안정처리된 도로하부 지반재료의 강도 및 변형특성 (II) : 수치해석)

  • Park, Seong-Wan;Ji, Jong-Keun
    • International Journal of Highway Engineering
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    • v.11 no.2
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    • pp.205-216
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    • 2009
  • As a subsequent study, this paper presents a comparative evaluation of structural responses in asphalt pavements with stabilized foundations. The approach based on a finite element analysis which incorporates non-linear behaviors of pavement geomaterials is used to estimate each performance indicator under standard single axle loading condition. In addition, results from laboratory tests are used to provide physical and mechanical properties of stabilized geomaterials for analyzing various pavement structures. Changes in pavement responses with varying layer thickness and stabilizer contents were investigated. It is found that the effect of layer thickness and stabilizer content is a critical factor in structural response of stabilized pavements. Moreover, a design criterion is proposed for selecting minimum contents of stabilizer of coarse-grained geomaterials based on a result of unconfined compressive strength and proper layer thickness of foundations.

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A Study on Energy Conservative Hierarchical Clustering for Ad-hoc Network (애드-혹 네트워크에서의 에너지 보존적인 계층 클러스터링에 관한 연구)

  • Mun, Chang-Min;Lee, Kang-Whan
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.12
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    • pp.2800-2807
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    • 2012
  • An ad-hoc wireless network provides self-organizing data networking while they are routing of packets among themselves. Typically multi-hop and control packets overhead affects the change of route of transmission. There are numerous routing protocols have been developed for ad hoc wireless networks as the size of the network scale. Hence the scalable routing protocol would be needed for energy efficient various network routing environment conditions. The number of depth or layer of hierarchical clustering nodes are analyzed the different clustering structure with topology in this paper. To estimate the energy efficient number of cluster layer and energy dissipation are studied based on distributed homogeneous spatial Poisson process with context-awareness nodes condition. The simulation results show that CACHE-R could be conserved the energy of node under the setting the optimal layer given parameters.

Analysis of Water Circulation Characteristics for Hydraulic and Water Temperature Investigation in Paldang Reservoir (팔당호의 수리 및 수온 조사를 통한 물순환특성 분석)

  • Choi, Hwang Jeong;Cho, Yong-Chul;Yu, Soonju;Song, Yong Sik;Ryu, Ingu
    • Ecology and Resilient Infrastructure
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    • v.6 no.1
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    • pp.12-22
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    • 2019
  • This study investigated the spatial and temporal water circulation characteristics of Paldang Reservoir by continuous hydraulic and water temperature survey. Due to differences in water temperature and discharge pattern of Ipo Weir and Cheongpyeong Dam, the flow and temperature fluctuations were different in sections of Namhan River and Bukhan River in Paldang Reservoir. At the stratification period, the water temperature of the discharge of Ipo Weir was higher than that of the Cheongpyeong Dam. Therefore, in the surface layer of the downstream of Bukhan River, relatively high temperature water is located and back water phenomenon occurred, and convergence zone is formed. In the downstream section of Namhan River, low-temperature water was distributed in the middle and lower layers, and the upstream flow appeared to be difficult to mix with the surface layer.

A Parameter Study of Stuctural Respanse Model in Flexible Pavement Substucture Layers (아스팔트 포장하부구조 층모델 결정에 관한 연구)

  • Choi, Jun-Seong;Seo, Joo-Won
    • International Journal of Highway Engineering
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    • v.5 no.4 s.18
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    • pp.13-22
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    • 2003
  • Several design methods from overseas are employed without considering different conditions such as material properties, climate, and traffic condition in this country. Therefore, there are limitations in application. Therefore, new pavement analysis system which is able to design a pavement efficiently and economically should be set up. In this study, 243 probable sections are classified depending on values of layer thickness and elastic modulus, and the effect of load types for the probable sections are analyzed. The section showing larger load distribution is chosen for analysis. As a result of sensitivity, a layer thickness has more influence on pavement than an elastic modulus does. The stress distribution of FWD test load is larger than that of circular load. This study compares outputs between nonlinear elastic model and linear elastic model. Based on the result, this study finds nonlinear elastic model considering stress condition in the ground is recommended for subbase.

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Evaluation of Impact Sound Insulation Properties of Light-Framed Floor with Radiant Floor Heating System

  • Nam, Jin-Woo;Park, Joo-Saeng;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.30 no.3
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    • pp.75-84
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    • 2002
  • In order to find out impact insulation properties, various types of current radiant floor heating systems and light-framed floors that are used in light-framed residential buildings were evaluated for two types of impact sources at the same time. Sound Pressure Level (SPL) was different from each impact sources for those spectrum patterns and peaks. In case of light-framed floor framework, the excitation position and the assumed effective vibrating area have effects on sound pressure level but it is not considerable, and Normalized SPL was reduced for each frequency by increasing the bending rigidity of joist. The mortar layer in the radiant heating system had relatively high density and high impedance, therefore, it distributed much of the impact power when it was excited, and reduced the Normalized SPL considerably. Nevertheless, Increasing a thickness of mortar layer had little influence on SPL. Ceiling components reduced the sound pressure level about 5~25 dB for each frequency. Namely, it had excellent sound insulation properties in a range from 200 to 4,000 Hz frequency for both heavy and lightweight impact sources. Also, there was a somewhat regular sound insulation pattern for each center frequency. The resilient channel reduced the SPL about 2~11 dB, irrelevant to impact source. Consequently, current radiant floor heating systems which were established in light-framed residential buildings have quite good impact sound insulation properties for both impact sources.

A study of Mechanical Properties of Hot Mix Asphalt for Developing of Quiet Pavement (저소음 포장체 개발을 위한 아스팔트 혼합물의 역학적 특성 연구)

  • Lee, Kwan-Ho;Jeong, Tae-Hyun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.1
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    • pp.49-55
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    • 2009
  • Our domestic economy has been developed very rapidly after 1960's. Also, it is dramatically increasing traffic on road and surround environmental issues. Especially, rapid economic growth has been induced large construction of pavement, and bigger and higher traffic for transportation. These are making air pollution, traffic noise and vibration. The social requirement against the revealed road environment and traffic sound reduction is being demanded. Traffic noise of city zone is showed over the environmental specification more than 57%. In order to overcome these situations, the social attention is being increased. The quiet pavement is the same format of permeable pavement, but is not same for functional performance. In this research, it has been carried out to evaluate the fundamental-mechanical properties of hot mix asphalt for quiet pavement. Especially, couple of laboratory tests are conducted like marshall stability, resilient modulus, indirect tensile test, and compaction energy analysis with gyratory compaction curve. Also, two-layer pavement system has been adopted for developing of quiet pavement. The basic performance of hot mix asphalt of quiet pavement show a satisfaction of specification of hot mix asphalt.

Multiple Description Video Coding Using Rate-Distortion Optimized DCT Coefficient Splitting (비트율-왜곡 최적화된 DCT 계수 분할을 이용한 다중 표현 동영상 압축 방법)

  • Kim, Il-Koo;Cho, Nam-Ik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.6
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    • pp.565-574
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    • 2002
  • We propose an algorithm for the robust transmission of video in error prone environment based on multiple description (MD) scheme and simple rate-distortion operators. The redundancy rate-distortion (RRD) criteria is used to split a one-layer compressed video stream into two correlated descriptions. The proposed algorithm can find more candidate points on the RRD curve than the conventional RRD based methods. A new distortion measure is also defined in this paper, which considers more realistic error environments. Since the proposed MD video coder is based on the standard H.263 coder, each description can be decoded independently by the standard H.263 decoder. Also, several descriptions can be decoded into a single stream by additional merge stage and the H.263 decoder. Simulation results show that the proposed MD video coder yields better performance than the conventional MD splitting algorithm at all bitrates both in single and two description cases.

Planning of Neighborhood Parks for the Disaster Prevention in Jecheon City (제천시의 방재형 도시 근린공원 조성 계획)

  • Lee, Ai-Ran
    • Ecology and Resilient Infrastructure
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    • v.2 no.4
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    • pp.296-304
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    • 2015
  • The rapid increase in the number of climate disasters combined with the scale of change and the diversification of natural disasters require a radical solution. In particular, the urban space is more complex, therefore we need to establish measures for disaster response and how to react to damaged infrastructure based on the phenomenon of an increase in the urban population and the impermeable layer being extended. The social problems related to the economic burden of land purchase and the securing of a disaster prevention system can be solved simultaneously by introducing the park system for disaster reduction into the public land of the green space in the city. The local government has recently adapted diverse systems of disaster mitigation and carried out pioneer projects according to the guidelines for the construction of the urban park for disaster prevention published by the Ministry of Land, Infrastructure and Transport. The purpose of this study is to propose a composition model for neighborhood parks to prevent disaster through urban green spaces which has the functions of water management and biotope conservation. The result of this study will contribute to utilize the climate change adaptation model for living area neighborhood parks in the existing urban structure.