• Title/Summary/Keyword: RAP

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Physical Properties and Low Temperature Resistance of Recycled Binder (재생 아스팔트 바인더의 물리적 특성과 저온균열 저항성 연구)

  • Lee, Young-Gwan;Kim, J.E.;Do, Young-Soo;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.6 no.4 s.22
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    • pp.1-12
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    • 2004
  • This study evaluated the asphalt binder characteristics for the hot-recycled asphalt mixture in which RAP was added in ambient temperature for surface course as well as for base course. RAPs were collected from four sources and their physical properties were evaluated. Mix designs were performed using 10 and 20% RAP contents for surface courses and 10, 20 and 30% for base courses. A virgin asphalt with the penetration grade of 60-80 was used for mixing recycled mixtures. Physical properties of recycled binders, including penetration, absolute viscosity, GPC, BBR and penetration after TFO were measured. From the results, regression analysis of absolute viscosity versus LMS in GPC showed $R^2$ being over 0.95, showing that GPC results estimate the absolute viscosity with relative accuracy. In BBR test, the resistance of recycled mixtures at low service temperature was inferior to the control, because the low temperature PG of recycled binder was one grade higher than that of the control binder.

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The I/LWEQ Domain in RapGAP3 Required for Posterior Localization in Migrating Cells

  • Lee, Mi-Rae;Kim, Hyeseon;Jeon, Taeck J.
    • Molecules and Cells
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    • v.37 no.4
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    • pp.307-313
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    • 2014
  • Cell migration requires a defined cell polarity which is formed by diverse cytoskeletal components differentially localized to the poles of cells to extracellular signals. Rap-GAP3 transiently and rapidly translocates to the cell cortex in response to chemoattractant stimulation and localizes to the leading edge of migrating cells. Here, we examined localization of truncated RapGAP3 proteins and found that the I/LWEQ domain in the central region of RapGAP3 was sufficient for posterior localization in migrating cells, as opposed to leading-edge localization of full-length Rap-GAP3. All truncated proteins accumulated at the leading edge of migrating cells exhibited clear translocation to the cell cortex in response to stimulation, whereas proteins localized to the posterior in migrating cells displayed no translocation to the cortex. The I/LWEQ domain appears to passively accumulate at the posterior region in migrating cells due to exclusion from the extended front region in response to chemoattractant stimulation rather than actively being localized to the back of cells. Our results suggest that posterior localization of the I/LWEQ domain of RapGAP3 is likely related to F-actin, which has probably different properties compared to newly formed F-actin at the leading edge of migrating cells, at the lateral and posterior regions of the cell.

Performance Evaluation of 100% RAP Asphalt Mixtures using Rapid-Setting Polymer-Modified Asphalt Emulsion for Spray Injection Application (스프레이 패칭 긴급보수용 개질 유화 아스팔트와 100% 순환골재를 사용한 상온 아스팔트 혼합물의 성능 평가)

  • Lim, Jeong-un;Kwon, Bong Ju;Kim, Doo Youl;Lee, Sang Yum;Rhee, Suk Keun
    • International Journal of Highway Engineering
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    • v.18 no.2
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    • pp.61-71
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    • 2016
  • PURPOSES: The objective of this study was to determine the optimum ratio of mix design, for a reclaimed asphalt pavement (RAP) content of 100%, for spray injection application. METHODS: A literature review revealed that spray injection is an efficient and cost-effective application for fixing small defective regions of an asphalt pavement. Rapid-setting polymer-modified asphalt mixtures prepared from two types of rapid-setting polymer asphalt emulsion were subjected to Marshall stability and wet track abrasion tests, in order to identify the optimum mix designs. RESULTS and CONCLUSIONS : Different mix designs of type A and type B emulsions were prepared using RAP and virgin aggregates, in order to compare the performance and determine the optimum mix design. The performance of mixtures prepared with RAP was superior to that of mixtures containing virgin aggregates. Moreover, for optimum ratio of the design, the binder content prepared from RAP was set to 1~2% lower than that consisting of virgin aggregates. Compared to their Type A counterparts, type B mixtures consisting of a reactive emulsion performed better in the Marshall stability and wet track abrasion tests. The initial results confirmed the advantages associated with using RAP for spray injection applications. Further studies will be performed to verify the difference in the optimum mix design and performance obtained in the lab-scale test and tests conducted at the job site by using the spray injection machine.

Research on the Application of Rap Music and Music Expression of Popular Songs in the 2020 Melon Chart (2020년 멜론차트 내 대중가요의 랩 음악 적용 현황과 음악표현 연구)

  • Shim, In-Sup
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.4
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    • pp.101-111
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    • 2021
  • This paper is a study that analyzes the use and techniques of rap in music that entered Melon Chart, one of the major music sites in Korea, during 2020. Among the songs that entered the chart, reflecting the public's preference, the trend of rap music, an important element of hip-hop music, is analyzed and musical features such as representative artists or frequently used rhythm patterns are analyzed. Through this paper, characteristics of rap music favored by the public and artists in recent popular music have been organized and formalized, and based on this, the elements of etude development for technical polishing are summarized. Through this, it is hoped that just like the long-time analyzed and structured performance techniques such as vocals and instruments, various styles of rap music can develop into a systematic and step-by-step technique system for students who want to learn and practice it.

Investigating meso-scale low-temperature fracture mechanisms of recycled asphalt concrete (RAC) via peridynamics

  • Yuanjie Xiao;Ke Hou;Wenjun Hua;Zehan Shen;Yuliang Chen;Fanwei Meng;Zuen Zheng
    • Computers and Concrete
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    • v.33 no.5
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    • pp.605-619
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    • 2024
  • The increase of reclaimed asphalt pavement (RAP) content in recycled asphalt concrete (RAC) is accompanied by the degradation of low-temperature cracking resistance, which has become an obstacle to the development of RAC. This paper aims to reveal the meso-scale mechanisms of the low-temperature fracture behavior of RAC and provide a theoretical basis for the economical recycling of RAP. For this purpose, micromechanical heterogeneous peridynamic model of RAC was established and validated by comparing three-point bending (TPB) test results against corresponding numerical simulation results of RAC with 50% RAP content. Furthermore, the models with different aggregate shapes (i.e., average aggregates circularity (${\bar{C_r}}=1.00$, 0.75, and 0.50) and RAP content (i.e., 0%, 15%, 30%, 50%, 75%, and 100%) were constructed to investigate the effect of aggregate shape and RAP content on the low-temperature cracking resistance. The results show that peridynamic models can accurately simulate the low-temperature fracture behavior of RAC, with only 2.9% and 13.9% differences from the TPB test in flexural strength and failure strain, respectively. On the meso-scale, the damage in the RAC is mainly controlled by horizontal tensile stress and the stress concentration appears in the interface transition zone (ITZ). Aggregate shape has a significant effect on the low-temperature fracture resistance, i.e., higher aggregate circularity leads to better low-temperature performance. The large number of microcracks generated during the damage evolution process for the peridynamic model with circular aggregates contributes to slowing down the fracture, whereas the severe stress concentration at the corners leads to the fracture of the aggregates with low circularity under lower stress levels. The effect of RAP content below 30% or above 50% is not significant, but a substantial reduction (16.9% in flexural strength and 16.4% in failure strain) is observed between the RAP content of 30% and 50%. This reduction is mainly attributed to the fact that the damage in the ITZ region transfers significantly to the aggregates, especially the RAP aggregates, when the RAP content ranges from 30% to 50%.

A Variable Neighbourhood Descent Algorithm for the Redundancy Allocation Problem

  • Liang, Yun-Chia;Wu, Chia-Chuan
    • Industrial Engineering and Management Systems
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    • v.4 no.1
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    • pp.94-101
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    • 2005
  • This paper presents the first known application of a meta-heuristic algorithm, variable neighbourhood descent (VND), to the redundancy allocation problem (RAP). The RAP, a well-known NP-hard problem, has been the subject of much prior work, generally in a restricted form where each subsystem must consist of identical components. The newer meta-heuristic methods overcome this limitation and offer a practical way to solve large instances of the relaxed RAP where different components can be used in parallel. The variable neighbourhood descent method has not yet been used in reliability design, yet it is a method that fits perfectly in those combinatorial problems with potential neighbourhood structures, as in the case of the RAP. A variable neighbourhood descent algorithm for the RAP is developed and tested on a set of well-known benchmark problems from the literature. Results on 33 test problems ranging from less to severely constrained conditions show that the variable neighbourhood descent method provides comparable solution quality at a very moderate computational cost in comparison with the best-known heuristics. Results also indicate that the VND method performs with little variability over random number seeds.

Classification of Product Safety Management Target by RAP and Cluster Analysis for Consumer Safety (소비자안전을 위한 RAP 및 군집분석을 통한 제품안전 관리대상 유형분류 연구)

  • Suh, Jungdae
    • Journal of the Korean Society of Safety
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    • v.33 no.6
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    • pp.128-135
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    • 2018
  • Currently, the government selects products that are likely to cause harm to consumers as safety management targets and classifies them into three types: safety certification, safety confirmation, and supplier conformity verification. In addition, the government conducts safety surveys on products in circulation or accident products, and recalls products that are of great concern to consumer risks. In this paper, we have developed RAP (Risk Assessment method based on Probability), which is a probability based product risk assessment method, for the classification of safety management type of product and safety investigation, and have shown an application example. In this process, information is used for the CISS (Consumer Injury Surveillance System) of the Korean Consumer Agency. In addition, we apply the cluster analysis to classify the current supervised children products into three groups. Then, we confirm the effectiveness of RAP by comparing the result of RAP application, cluster analysis result and current safety management classification type. Also, we recognize the need to review the current safety management classification criteria for classifying products into three types.

A Study on the fashion culture of Teenager influenced Dance Music - focused on Rap Music and Hiphop Fashion - (댄스음악이 10대 패션문화에 끼친 영향에 관한 연구 - 랩음악과 힙합패션을 중심으로 -)

  • 도규희
    • Archives of design research
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    • v.12 no.3
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    • pp.93-103
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    • 1999
  • This study is investigated the formative characteristics of Rap Music and Hiphop fashion, and I try to comprehend about the fashion mind and fashion culture of teenager 1. Teenager's Hiphop Fashion is subcultures, the fashion culture of teenager reflects their unique identity. 2. The formative characters of Rap Music and Hiphop Fashion are the incompatibility ignored their body size and the popularity caused street fashion imitation, the unbalance ignored a principle of fashion design. 3. Hiphop Fashion is consist of jump-style jacket, hood -shirt, stripe T-shirt and drum pants, baggy pants, snowboard pants and so on. 4. The characters of Hiphop Fashion is the breaking of rule and the destruction. 5. They select something which they like, even though the price is high, so they is tendency to editing coordinate 6. Fashion business for teenager, it needs an ideal conversion not for 'company' but for 'individual' As this results, fashion culture of teenager came out to the surface of water, because of Hiphop Fashion.

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A Study on the printability of the paper prepared from red algae pulp(RAP) (홍조류 종이의 인쇄적성에 관한 연구)

  • Lim, Soo-Man;Lee, Young-Se;Yoo, Jae-Hyeon;Youn, Jong-Tae
    • Proceedings of the Korean Printing Society Conference
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    • 2007.11a
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    • pp.45-57
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    • 2007
  • Properties of newly developed paper from Red Algae Pulp (RAP) were examined. The paper samples were prepared according tomixing RAP fiber with wood fibers, HwBKP and SwBKP, to form a paper with 60 g/$m^{2}$ in weight. It was prepared in three to four different levels of refining degree and pressure so that it can reveal different bulk level in order to clearly compare the opacity at equivalent bulk for each furnish compositions. printability of RAP fiber revealed superior effect on print through repression and initial ink absorption. Those properties are expected to improve further if printability improvement effect due to smoothness improvement is added.

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Liquefaction Remediation by Rammed Aggregate Piers(RAP) on Soft Ground (쇄석다짐말뚝에 의한 연약지반의 액상화 저감효과에 관한 연구)

  • An, Dong-Seok;Bae, Kyung-Tae;Park, Seong-Wan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.1030-1035
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    • 2008
  • Dynamic numerical analyses were performed to investigate the response of liquefaction remediation of rammed aggregate piers(RAP) on soft ground under free strain conditions. The safe factors of the soft ground reinforced by RAP during seismic loading of magnitude 6.5 were calculated. The results of simulation showed that factors of safety were affected various area replacement ratios, surcharge loads and depth of RAP systems.

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