• Title/Summary/Keyword: Scaling factor

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A Study on the Scaling Deterioration and Resistance to Freezing of Concrete by Containing Chlorides (염화물 함유에 의한 콘크리트의 내동해성 및 표면열화에 관한 연구)

  • Park Joo Houn;Kim Gyu Yong;Kim Han Jun;Kwon Yeong Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.372-375
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    • 2004
  • Scaling deterioration and resistance to freezing of port concrete structures due to the combined effects of chemical actions by containning chlorides and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and thaw of concrete by containing chlorides. As a results of this study, it was effective method of scaling deterioration and resistance freewing of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to containing chlorides.

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A Study on the Concrete Scaling Deterioration due to Freezing and Thawing of Sea Water (해수동결융해작용에 의한 콘크리트의 표면열화에 관한 연구)

  • 김규용;박주현;김규동;이승훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.54-57
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    • 2003
  • Scaling deterioration of port concrete structures due to the combined effects of chemical actions by seawater and the freeze-thaw action is also a problem which has not yet been fundamentally solved. Furthermore, deterioration of concrete surface was considered as accelerate factor of concrete durability tended to decrease. Therefore, we considered the scaling measuring method and decreasing influence of durability of concrete according to kind of binders, such as OPC, Slag, Slag+Fa, due to freeze and haw of sea water. As a results of this study, it was effective method of scaling deterioration of concrete, and confirmed the salt deterioration resistance effect to use slag binder against to sea water.

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A Study on a concept of Food Accumulation using Multidimensional Scaling - Comparison between Pyungweesan Questionnaire and Health Related Questionnaires - (다차원척도법을 이용한 식적(食積)의 개념에 관한 고찰 - 평위산(平胃散) 변증(辨證) 설문지와 건강 관련 설문지와의 비교 연구 -)

  • Lee, Cheong-Hee;Park, Young-Jae;Kim, Min-Yong;Lee, Sang-Chul;Park, Young-Bae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.15 no.2
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    • pp.141-148
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    • 2011
  • Objectives: In comparison with functional dyspepsia, food accumulation is known to have wider concept. On this study, we will make a proposal on the concept of food accumulation by a statistical comparison between pyungweesan questionnaire and health related questionnaires. Methods: We studied the similarities between six factors of pyungweesan questionnaire and four health related questionnaires(Rome II criteria of functional dyspepsia, subjective symptoms of fatigue test, beck depression inventory, state-trait anxiety inventory, etc.) using multidimensional scaling. Results and Conclusions: 1. Physical-emotional axis and acute-chronic axis were labelled in a two-dimensional scaling solution. 2. Seup-dam(濕痰) factor and sik-che(食滯) factor of food accumulation were closely related to fatigue. 3. Bi-seup(脾濕) factor of food accumulation was closely related to depression and anxiety. 4. The findings suggest that a concept of food accumulation reflects some aspects of physical fatigue and emotional depression as well as dyspepsia.

Influence of Mechanical Properties and Pore Structure on the Scaling Resistance of Concretes (콘크리트의 역학적 성능 및 공극구조가 스케일링 저항성에 미치는 영향)

  • Lee, Seung-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.1
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    • pp.111-118
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    • 2016
  • The scaling of concrete caused by the combined effects of frost and deicing salt is one of the principle causes of damage to transportation infrastructure in cold-climate regions. In this study, to evaluate the factors affecting scaling resistance of concrete, the relationship between the properties of concrete, such as the mechanical properties and pore structure, and scaling resistance was examined experimentally. The test results showed that the scaling resistance was strongly dependent on the absorption properties of concrete, but not on the compressive strength. Furthermore, it is believed that both the spacing factor and specific surface of the air voids was not a good parameter for evaluating the scaling resistance of concrete. SGC concrete was less durable than OPC and SFC concrete with respect to the scaling resistance in the scope of the present study.

Experimental Study on the Frost Resistance of Concete Product (콘크리트제품의 동결저항성에 관한 실험적 연구)

  • Sugawara, Takashi;Tsukinaga, Yhoichi;Lee, Sanghun
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.91-91
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    • 2011
  • The quality of the surface layer in concrete structures plays an important role in the durability of the concrete. The concrete factory products are made as they improve the appearance of the surface and compressive strength in need. A common criterion to judge the quality of concrete products frequently seen in our daily life appears to be "beauty" in terms of consistent shaping. However, as for most concrete curb in such areas where a large amount of anti-freezing agents(NaCl) and ice and snow melting agents(CaCl2) are spread over roads to ensure road safety during the winter season, since deterioration advances from the surface, scaling is seen on the surface concrete due to deterioration which combined freezing damage and salt damage. Especially, In cold northern districts, the spreading amount of deicing salts increases by regulation of studded tire use, and the scaling of the concrete products, the various parts of concrete structures for roads is increasing in recent years. In this study, L-shape concrete curb were targeted, the permeable form method with the commercial permeable sheet was applied to it and the improvements of the quality were examined. By the permeable form method, surface layers got strengthened, which prevented permeation of the deterioration factor from the outside, and the scaling resistance of the upper surface where the permeable sheet was applied improved exceedingly. It will be expected by applying the permeable form method to various concrete products that frost resistance improves and scaling damage decreases.

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Simplified 2-Dimensional Scaled Min-Sum Algorithm for LDPC Decoder

  • Cho, Keol;Lee, Wang-Heon;Chung, Ki-Seok
    • Journal of Electrical Engineering and Technology
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    • v.12 no.3
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    • pp.1262-1270
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    • 2017
  • Among various decoding algorithms of low-density parity-check (LDPC) codes, the min-sum (MS) algorithm and its modified algorithms are widely adopted because of their computational simplicity compared to the sum-product (SP) algorithm with slight loss of decoding performance. In the MS algorithm, the magnitude of the output message from a check node (CN) processing unit is decided by either the smallest or the next smallest input message which are denoted as min1 and min2, respectively. It has been shown that multiplying a scaling factor to the output of CN message will improve the decoding performance. Further, Zhong et al. have shown that multiplying different scaling factors (called a 2-dimensional scaling) to min1 and min2 much increases the performance of the LDPC decoder. In this paper, the simplified 2-dimensional scaled (S2DS) MS algorithm is proposed. In the proposed algorithm, we figure out a pair of the most efficient scaling factors which multiplications can be replaced with combinations of addition and shift operations. Furthermore, one scaling operation is approximated by the difference between min1 and min2. The simulation results show that S2DS achieves the error correcting performance which is close to or outperforms the SP algorithm regardless of coding rates, and its computational complexity is the lowest comparing to modified versions of MS algorithms.

Vehicle Detection Using Optimal Features for Adaboost (Adaboost 최적 특징점을 이용한 차량 검출)

  • Kim, Gyu-Yeong;Lee, Geun-Hoo;Kim, Jae-Ho;Park, Jang-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.8
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    • pp.1129-1135
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    • 2013
  • A new vehicle detection algorithm based on the multiple optimal Adaboost classifiers with optimal feature selection is proposed. It consists of two major modules: 1) Theoretical DDISF(Distance Dependent Image Scaling Factor) based image scaling by site modeling of the installed cameras. and 2) optimal features selection by Haar-like feature analysis depending on the distance of the vehicles. The experimental results of the proposed algorithm shows improved recognition rate compare to the previous methods for vehicles and non-vehicles. The proposed algorithm shows about 96.43% detection rate and about 3.77% false alarm rate. These are 3.69% and 1.28% improvement compared to the standard Adaboost algorithmt.

Static Compressive Strength of Thick Unidirectional Carbon Fiber - Epoxy Laminate (두꺼운 일방향 탄소섬유-에폭시 적층판의 정적 압축 강도 연구)

  • Lee, J.;Soutis, C.;Gong, Chang-Deok
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.61-65
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    • 2005
  • Existing test methods for thick-section specimens ( 4mm) have not provided precise compressive properties to date for the analysis and design of thick structure. A survey of the failure behaviour of such thick specimens revealed that the failure initiated at the top corner of the specimen and propagated down and across the width of the specimen as premature failure, not typically reported for thin compression specimens. In the current study, the premature failure was successfully avoided during compressive testing and the failure mode was quite similar regardless of increasing specimen thickness and specimen volume. Failure mode was similar regardless of increasing specimen thickness and specimen volume, i.e. brooming failure mode combined with longitudinal splitting, interlaminar cracking, fibre breakage and kinkband formation (fibre microbuckling). Nevertheless, average failure strengths of the specimens decreased with increasing specimen thicnkiness from 2mm to 8mm with the T800/924C system (36% strength reduction) and specimen volumes from scaling factor I to scaling factor 4 with the IM7/8552 system (46% strength reduction). It was revealed from the literature$^{11}$ that the thickness effect and scaling effect arc caused by manufacturing defects such as void content and fibre waviness.

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Feasibility Study on Similarity Principle in Discrete Element Analysis (이산요소법을 이용한 수치해석에서의 상사성 이론의 적용성 검토)

  • Yun, Taeyoung;Park, Hee Mun
    • International Journal of Highway Engineering
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    • v.18 no.2
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    • pp.51-60
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    • 2016
  • PURPOSES : The applicability of the mechanics-based similarity concept (suggested by Feng et al.) for determining scaled variables, including length and load, via laboratory-scale tests and discrete element analysis, was evaluated. METHODS: Several studies on the similarity concept were reviewed. The exact scaling approach, a similarity concept described by Feng, was applied in order to determine an analytical solution of a free-falling ball. This solution can be considered one of the simplest conditions for discrete element analysis. RESULTS : The results revealed that 1) the exact scaling approach can be used to determine the scale of variables in laboratory tests and numerical analysis, 2) applying only a scale factor, via the exact scaling approach, is inadequate for the error-free replacement of small particles by large ones during discrete element analysis, 3) the level of continuity of flowable materials such as SCC and cement mortar seems to be an important criterion for evaluating the applicability of the similarity concept, and 4) additional conditions, such as the kinetics of particle, contact model, and geometry, must be taken into consideration to achieve the maximum radius of replacement particles during discrete element analysis. CONCLUSIONS : The concept of similarity is a convenient tool to evaluate the correspondence of scaled laboratory test or numerical analysis to physical condition. However, to achieve excellent correspondence, additional factors, such as the kinetics of particles, contact model, and geometry, must be taken into consideration.