• Title/Summary/Keyword: WMA

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A Study on the Performance Evaluation Method of Warm-mix Asphalt Mixture by the Analysis of Bonding Properties between Asphalt Binder and Aggregate (중온 아스팔트 혼합물의 성능 평가를 위한 아스팔트 바인더와 골재 사이의 접착물성분석 방법에 관한 연구)

  • Yoo, In Sang;Cho, Dong-Woo;Hwang, Sung Do;Rhee, Suk Keun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.6D
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    • pp.803-810
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    • 2011
  • The public interest of global warming and energy shortage is gradually increased, and the related industries also have become interested in developing eco-friendly material and technology. Warm-mix asphalt (WMA) is a result of the developments to alleviate global warming and energy problems. This WMA is produced at lower temperatures than the temperature at which hot mix asphalt (HMA) is produced. Because most tests in Superpave are developed only for the performance and maintenance of HMA produced by hot temperatures, it is difficult for the tests to identify properly the material properties and then evaluate the performances between HMA and WMA. This study deals with the development of a new protocol to differentiate HMA and WMA performance, and especially the interfacial properties between asphalt and aggregate are targeted as the performance indicator; thus, an evaluation method and guideline are suggested. The concept and idea of the test method applied in this study were modified from the DSR moisture damage test protocol. In addition, TSR test was performed to affirm the relation between the asphalt-aggregate interface and the asphalt-aggregate mixture performances. The followings are the results of this study. Shear stress at 85% linear visco-elastic complex modulus (LVE $G^*$) can be a better parameter than LVE $G^*$, which can assess the interfacial or bonding performance between asphalt and aggregate. Moreover, measuring the bonding performance in thinner film thicknesses will be a better way to evaluate the real and field situation between asphalt and aggregate. The interfacial properties' criteria to apply the newly developed test and parameter should be developed, after the asphalt mixture criteria relating to the interfacial properties are completed.

Feasibility Evaluation of Number of Gyration for HMA and WMA Mixtures (HMA와 WMA 혼합물의 선회 다짐횟수 적정성 검토 연구)

  • Lee, Moon-Sup;Yoon, Chun-Joo;Kwon, Soo-Ahn;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.133-142
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    • 2011
  • The objective of this study is to validate the number of gyrations of Superpave gyratory compactor(SGC) for compaction of hot-mix asphalt (HMA) and warm-mix asphalt(WMA) mixtures. Marshall compaction was also used for comparison purpose. The 13mm and 19mm aggregates of 1st class quality shape were used. A PG64-22 and a PG76-22 for HMA and a PG70-22 for WMA. Four compaction temperatures based on the suggested value were used for each binder using 100 gyrations for SGC and 75 blows per side for Marshall compactor. It was found that SGC compaction was somewhat better than Marshall compaction. The analysis of variance showed that two compactors were significantly different in air voids of 19mm mixtures at ${\alpha}=0.05$ level. The 13mm mixture did not show a significant statistical difference. When compacted at the temperature below a certain level, however, the compaction of two compactors were fond to be proor. Therefore, observing compaction temperature above the minimum level is important to secure proper compaction work. If the minimum temperatures were maintained, 100 gyrations, which was given for HMA of arterial road pavement by the Korean Guide, was found to be appropriate compaction, showing similar or better compaction work than 75 blows per side of Marshall compaction.

A Study of Warm-Mix Asphalt's Bonding Properties on the Change of Asphalt Film Thicknesses (아스팔트 피막두께 변화에 따른 중온 아스팔트의 접착성질에 관한 연구)

  • Yoo, In-Sang;Cho, Dong-Woo;Hwang, Sung-Do;Rhee, Suk-Keun
    • International Journal of Highway Engineering
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    • v.13 no.4
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    • pp.29-40
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    • 2011
  • Warm-Mix Asphalt(WMA) technologies have been developed since 15 years ago, which are internationally and domestically concerned with energy-saving and environmental-friendly technologies in public and private sectors of highway engineering. The performance of asphalt mass is traditionally evaluated by the penetration, viscosity, or Superpave tests. This research, however, is focused more on the properties depending on asphalt film thicknesses instead of evaluating asphalt mass behaviors by those tests. For this approach, a new testing protocol and analysis method are described by the bonding properties on each film thickness. This testing method and analysis tool are borrowed from those of DSR Moisture Damage test and applied by using ARES. The analysis results indicate that there is a limit film thickness between $200{\mu}m$ and $400{\mu}m$, which causes significant changes of the properties. In addition, the results show that the property changes of Hot-Mix Asphalt(HMA) and WMA on the limit film thickness are also different. Therefore, it is suggested that the properties on thin film thicknesses between $200{\mu}m$ and $400{\mu}m$ should be considered in order to evaluate WMA properly.

Estimation of Forest Growing Stock by Combining Annual Forest Inventory Data (연년 산림자원조사 자료를 이용한 임목축적 추정)

  • Yim, Jong Su;Jung, Il Bin;Kim, Jong Chan;Kim, Sung Ho;Ryu, Joo Hyung;Shin, Man Yong
    • Journal of Korean Society of Forest Science
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    • v.101 no.2
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    • pp.213-219
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    • 2012
  • The $5^{th}$ national forest inventory (NFI5) has been reorganized to annual inventory system for providing multi-resources forest statistics at a point in time. The objective of this study is to evaluate statistical estimators for estimating forest growing stock in Chungcheongbuk-Do from annual inventory data. When comparing two estimators; simple random sampling (SRS) and double sampling for post-stratification (DSS), for estimating mean forest growing stock ($m^3/ha$) at each surveyed year, the estimate for DSS in which a population of interest is stratified into three sub-population (forest cover types) was more precise than that for SRS. To combine annual inventory field data, three estimators (Temporally Indifferent Method; TIM, Moving Average; MA, and Weighted Moving Average; WMA) were compared. Even though the estimated mean for TIM and WMA is identical, WMA-DSS is preferred to provide more smaller variance of estimated mean and to adjust for catastrophic events at a surveyed year (so-called "lag bias") by annual inventory data.

Rut Resistance of LDPE-modified Warm-Mix Asphalt Mixtures (LDPE 개질 준고온 아스팔트 혼합물의 소성변형 저항성)

  • La, Il-Ho;Kim, Kwang-Woo;Choi, Chan-Yong
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.1208-1213
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    • 2011
  • The objective of this study is to analyze rut resistance and moisture susceptibility of warm mix asphalt(WMA) mixture. The deformation strength ($S_D$), which is known to have high correlations with the high-temperature deformation resistance of dense grade mixture, was used as a tool, together with wheel tacking (WT) test, for evaluating warm mix asphalt mixture's rut resistance.

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Stability Analysis of Networked Control Systems with Packet Dropouts (패킷 손실을 고려한 네트워크 제어 시스템의 안정성 분석)

  • Kim, Jae-Man;Park, Jin-Bae;Choi, Yoon-Ho
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1731_1732
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    • 2009
  • This paper presents a stability analysis of networked control systems with packet dropouts. The packet dropouts are modeled as a linear function of the stochastic variable satisfying Bernoulli random binary distribution and weighted moving average (WMA). The observer based controller scheme is designed to exponentially mean square stabilize the NCS. Simulation results is provided to show the applicability of the proposed method.

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Insights into the Incidence of Watermelon chlorotic stunt virus Causing Yellowing Disease of Watermelon in Western and Southwestern Regions of Saudi Arabia

  • Ahmad, M.H.;Shakeel, M.T.;Al-Shahwan, I.M.;Al-Saleh, M.A.;Amer, M.A.
    • The Plant Pathology Journal
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    • v.34 no.5
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    • pp.426-434
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    • 2018
  • During the spring season of 2014, a total of 148 melon and watermelon leaf samples were collected from symptomatic and asymptomatic plants in the western and southwestern regions of Saudi Arabia and were tested for the presence of Watermelon chlorotic stunt virus (WmCSV) and other suspected cucurbit viruses by double antibody sandwich enzyme-linked immunosorbent assays. Ninety-eight samples were found to be positive for the presence of WmCSV, nine samples were positive for the presence of Cucurbit yellow stunting disorder virus (CYSDV), and 22 showed a mixed infection with both WmCSV and CYSDV. No other cucurbit viruses were detected in any of the samples. Host range experiments revealed that eight out of fourteen tested plant species were susceptible to WmCSV. PCR products of approximately 1.2 kb were obtained after amplification using primers specifically targeting the coat protein region of WmCSV. Positive PCR results were confirmed by dot blot hybridization. Coat protein gene sequences from eleven WmCSV isolates indicated that the highest identity was between the 104WMA-SA isolate from the Wadi Baish location and a previously reported isolate from the AL-Lith location in Saudi Arabia. The lowest identity was observed between the 42WMA-SA isolate and an isolate from Palestine.

Construction of Korean Experiance Life Table (한국인의 경험생명표 작성 및 통계적 해석)

  • Hong, Yeon-Woong;Lee, Jae-Mann;Cha, Young-Jun
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.153-161
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    • 1997
  • A Korean exporience life table(male) is constructed by using a mixture of weighted moving average(WMA) model and Gompertz' parametric survival model based on 25,000,000 insured of major 6 life insurance companies from 1988 to 1992. The graduated values are taken as those which minimize the composite measure of fittness and smoothness. Moreover, we propose closed form estimators for three parameters of Gompertz' model.

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A Unique Identification hiding technique for Internet Broadcast service of Digital Audio (디지털 오디오의 인터넷 방송 서비스를 위한 저작물 식별 코드 은닉 기술)

  • 신승원;김종원;최종욱
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2001.11b
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    • pp.163-168
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    • 2001
  • 본 논문은 인터넷을 이용한 방송 서비스에서 저작권 보호 및 저작물 식별을 위한 고유 식별 정보(unique identification)를 삽입, 추출하는 기술을 제안한다. 인터넷을 통한 방송 서비스의 활성화를 위해서는 저작권의 보호와 저작물의 불법 사용 방지, 저작물에 대한 저작권료 지불, 그리고 차후에 불법 사용자의 적발 등을 할 수 있는 기술이 필요하다. 본 논문에서 제안하는 기술은 디지털 음악을 소비자에게 서비스할 때, 사용자의 아이디(ID)와 신상 정보를 이용해서 생성된 정보와 음악의 식별 정보를 같이 저작물에 삽입하여 다운로드 받은 음악 파일이나 또는 청취 중에 녹음한 음악 파일을 불법으로 유통시킬 경우에 유통된 음악 파일에서 삽입된 식별코드를 추출하여 음악 파일의 불법 유통경로를 추적하여 불법 사용자를 적발할 수 있는 기능을 갖고 있다. 이러한 기능을 만족시키기 위해서 인터넷 서비스에서 널리 이용되는 MP3, AAC, WMA 등과 같은 손실 압축을 거친 이후에도 삽입된 워터마크를 검출할 수 있으며, 일반 사용자들이 손쉽게 접할 수 있는 여러 신호처리에도 강인한 특성을 갖는 기술을 제안한다.

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