• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.311-318
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• 2000

In this paper, the process of development of resilient sleepers, which improves the train safety, passenger comport and reduces the noise and vibration, is discussed. To determine the required material properties of elastic pad, static and dynamic simulations are performed and is applied in manufacturing. From the experiment results, it is investigated that the displacement is less for sleeper with elastic pad than that in ordinary PC form. The rate of displacement is also shown In be less for the sleeper with elastic pad. These results indicate that the elastic pad can reduce possibility of rail-corrugations and thus resulting in the reduction of maintenance costs.

• 대한치과의사협회지
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• 제55권1호
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• pp.72-81
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• 2017

Regardless of the type of impression being made, the tray is the most important part of the impression-making procedure for completely edentulous patients. Dentists have to make use of a combination of rigid, thermoplastic, and resilient materials and control step-by-step procedure from irreversible hydrocolloid impression to definitive cast fabrication. For successful edentulous impression, some considerable clinical tips were guided.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.805-814
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• 2008

This study focused on the resilient modulus prediction model, which is the functions of mean effective principal stress and axial strain, for three types of railroad trackbed materials such as crushed stone, weathered soil, and crushed-rock soil mixture. The model is composed with the maximum Young's modulus and nonlinear values for higher strain in parallel with dynamic shear modulus. The maximum values is modeled by model parameters, $A_E$ and the power of mean effective principal stress, $n_E$. The nonlinear portion is represented by modified hyperbolic model, with the model parameters of reference strain, ${\varepsilon}_r$ and curvature coefficient, a. To assess the performance of the prediction models proposed herein, the elastic response of a test trackbed near PyeongTaek, Korea was evaluated using a 3-D nonlinear elastic computer program (GEOTRACK) and compared with measured elastic vertical displacement during the passages of freight and passenger trains. The material types of sub-ballasts are crushed stone and weathered granite soil, respectively. The calculated vertical displacements within the sub-ballasts are within the order of 0.6mm, and agree well with measured values with the reasonable margin. The prediction models are thus concluded to work properly in the preliminary investigation.

• 한국지반공학회논문집
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• 제23권3호
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• pp.15-24
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• 2007

본 논문은 도로기초 입상재료의 응력의존적인 특성을 고려한 응력의존적 재료 상수의 적용을 통하여 층 변형예측을 수행하는 간편한 방식을 소개한다. 이 방법은 Unbound지반재료에 대하여 회복변형과 영구변형을 구분하여 고려하며 두 변형의 상호작용을 적용하지 않는 방식이다. 그 결과 회복변형 탄성계수와 포와송비를 포함한 해석모형은 상호작용이 고려되지 않아도 현장에서의 도로기초 변형을 예측할 수 있음을 잘 보여주고 있다. 또한 응력의존 탄성계수와 응력의존 포와송 비 모형에서 가장 영향을 많이 미치는 계수를 찾기 위하여 민감도분석을 실시하였다. 이러한 분석결과를 토대로 응력의존에 의하여 변형 예측시 나타나는 경향을 살펴보았다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.227-228
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• 2023

A floating floor generally consists of mortar bed separated from the structural RC slab by a continuous resilient layer. It is known that the floating floors are a type of vibration-isolation system to improve the impact sound insulation performance. However, some researchers have demonstrated that the amplification of vibration response at a specific range of frequencies results in an increase in the impact sound level. This study carried out the forced vibration tests to obtain the frequency response function (FRF) of a floating floor compared with a bare RC slab. Test results shows that the additional peak occur in vibrational spectrum of the floating floor except natural vibration modes of the bare RC slab. This is because the relatively flexible resilient material and mass of the mortar bed offer an additional degree of freedom in the structural system. Therefore, it could be efficient for reduction of floor impact vibration and noise to control the additional mode frequency and response of floating floors.

• 한국철도학회논문집
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• 제15권6호
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• pp.623-630
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• 2012

궤도하부층의 지지강성을 확보하기 위하여 설치하는 강화노반은 통상 일정 입도분포의 쇄석재료로 구성된다. 이러한 강화노반은 통과톤수의 누증 즉, 과도한 열차하중이 반복적으로 가해질 경우 영구변형이 발생할 수 있으며 이러한 영구변형은 궤도틀림의 한 원인이 될 수 있다. 또한 강화노반 재료의 적정두께를 확정하기 위해서는 이러한 영구변형 특성을 파악하는 것이 중요하다. 본 연구에서는 국내 강화노반 재료로 사용될 가능성이 높은 M-40 쇄석재료를 선정하여 대형반복삼축시험을 실시하여 재료의 회복탄성 특성과 영구변형 특성을 분석하였다. 시험으로부터 임의 전단응력비 및 반복재하횟수에 따른 회복탄성계수 특성과 영구변형 발생특성을 분석하였으며 M-40 쇄석강화노반 재료의 영구변형에 영향을 미치는 인자(반복재하횟수, 구속압, 전단응력비, 탄성계수 등)를 함께 고려할 수 있는 영구변형 예측모델을 제시하였다.

• The Journal of Advanced Prosthodontics
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• 제3권1호
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• pp.33-36
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• 2011

In process of fabrication of a fixed partial denture, dies are trimmed to expose margins of the preparations. The need for the soft tissue cast is quite evident as the soft tissue emergence profile that surrounds the prepared tooth is destroyed in the process of fabrication. This article describes a modified technique to fabricate the soft tissue cast for the conventional fixed partial denture. The impression made with the polyvinylsiloxane was first poured to prepare the die cast. After retrieval of the cast, the same impression was poured second time with the resin based resilient material to cover the facial and proximal gingival areas. The remaining portion of the impression was poured with the gypsum material. This technique does not require additional clinical appointment, second impression procedure, technique sensitive manipulations with impression, or cumbersome laboratory procedures. The simplicity of this technique facilitates and justifies its routine use in fabrication of the fixed partial denture.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.256-256
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• 2006

The design and synthesis of novel biomolecular materials, based on mimicking the properties of molecules found in nature, is providing materials with unusual properties. Resilin serves as an energy storage material in insects and facilitates flight, jumping (in fleas, froghoppers etc) and sound production (cicadas, etc). Resilin is initially produced as a soluble protein and in its mature form is crosslinked through formation of dityrosine units into a very large insoluble polymer. In the present study, we have synthesized a recombinant form of resilin that can be photochemically cross-linked into a resilient, rubber-like biomaterial that may be suitable for spinal disc implants. This material is almost perfectly elastic and its fatigue lifetime in insects must be >500 million cycles.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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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.

• International Journal of Concrete Structures and Materials
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• 제10권3호
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• pp.271-295
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• 2016

In this study, an extensive literature review has been conducted on the material characterization of UHPC and its potential for large-scale field applicability. The successful production of ultra-high performance concrete (UHPC) depends on its material ingredients and mixture proportioning, which leads to denser and relatively more homogenous particle packing. A database was compiled from various research and field studies around the world on the mechanical and durability performance of UHPC. It is shown that UHPC provides a viable and long-term solution for improved sustainable construction owing to its ultrahigh strength properties, improved fatigue behavior and very low porosity, leading to excellent resistance against aggressive environments. The literature review revealed that the curing regimes and fiber dosage are the main factors that control the mechanical and durability properties of UHPC. Currently, the applications of UHPC in construction are very limited due to its higher initial cost, lack of contractor experience and the absence of widely accepted design provisions. However, sustained research progress in producing UHPC using locally available materials under normal curing conditions should reduce its material cost. Current challenges regarding the implementation of UHPC in full-scale structures are highlighted. This study strives to assist engineers, consultants, contractors and other construction industry stakeholders to better understand the unique characteristics and capabilities of UHPC, which should demystify this resilient and sustainable construction material.