• Title/Summary/Keyword: concrete flow analysis

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A Study on the Interaction of Single-person Household and Smart Device Based on the Context (컨텍스트 기반 1인가구-스마트 디바이스의 인터랙션 연구)

  • Chang, Mi;Nah, Ken
    • Journal of the HCI Society of Korea
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    • v.13 no.1
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    • pp.21-28
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    • 2018
  • The rapid increase of Sinlge-person household and the increase in the use of smart devices necessitate the context analysis of Sinlge-person household and specific design direction for Sinlge-person household products. Previous studies have analyzed the overall context of smart devices without distinguishing between Sinlge-person household and a household. However, since the number of family members, age distribution, and residential space are different in the case of Sinlge-person household, it is necessary to analyze the different behaviors of smart devices. Therefore, this study limits the use environment of smart device of Single-person household to the scope of investigation, and based on the theoretical background, defines the existing comprehensive context based on user's situation that lasts for a certain interval. For the concrete and empirical research results, Consolidated Flow Model was constructed through Contextual Task through user research. This shows the interaction characteristics such as the guarantee of physical space, efficiency, lifestyle reflection, and safety assurance of Single-person household.

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Modeling the effects of additives on rheological properties of fresh self-consolidating cement paste using artificial neural network

  • Mohebbi, Alireze;Shekarchi, Mohammad;Mahoutian, Mehrdad;Mohebbi, Shima
    • Computers and Concrete
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    • v.8 no.3
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    • pp.279-292
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    • 2011
  • The main purpose of this study includes investigation of the rheological properties of fresh self consolidating cement paste containing chemical and mineral additives using Artificial Neural Network (ANN) model. In order to develop the model, 200 different mixes are cast in the laboratory as a part of an extensive experimental research program. The data used in the ANN model are arranged in a format of fourteen input parameters covering water-binder ratio, four different mineral additives (calcium carbonate, metakaolin, silica fume, and limestone), five different superplasticizers based on the poly carboxylate and naphthalene and four different Viscosity Modified Admixtures (VMAs). Two common output parameters including the mini slump value and flow cone time are chosen for measuring the rheological properties of fresh self consolidating cement paste. Having validated the model, the influence of effective parameters on the rheological properties of fresh self consolidating cement paste is investigated based on the ANN model outputs. The output results of the model are then compared with the results of previous studies performed by other researchers. Ultimately, the analysis of the model outputs determines the optimal percentage of additives which has a strong influence on the rheological properties of fresh self consolidating cement paste. The proposed ANN model shows that metakaolin and silica fume affect the rheological properties in the same manner. In addition, for providing the suitable rheological properties, the ANN model introduces the optimal percentage of metakaolin, silica fume, calcium carbonate and limestone as 15, 15, 20 and 20% by cement weight, respectively.

Development of the Analytic Framework for Dialogic Argumentation Using the TAP and a Diagram in the Context of Learning the Circular Motion (원운동 학습 상황에서 Toulmin의 논의구조(TAP)와 다이어그램을 이용한 대화적 논의과정 분석틀 개발)

  • Shin, Ho Sim;Kim, Hyun-Joo
    • Journal of The Korean Association For Science Education
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    • v.32 no.5
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    • pp.1007-1026
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    • 2012
  • The purpose of this study was to develop analytic framework for dialogic argumentation to show the context and flow visualizing interactions of argumentation, to be able to present quality of argumentation specifically. For this, we formulated a method of the argumentation diagram using feature of diagram simple and structurally visualizing interrelation between argument components, and then quantified quality of argumentation to argument level score on this basis. We have developed the learning material for argumentation about a vertical circular motion and used the obtained translations from applying it in developing the framework. We chose argument statements among full transcript and then coded as Toulmin's argument components, and these codes was effectively arranged and linked to show argumentation diagram. Results by argumentation diagram could be useful understanding of interactive argumentation context and the flow and present frequency, the combination of argument elements, rough qualitative level of argumentation. To quantify argumentation quality, we gave different scores to different link lines reflecting indication of argumentation quality like that diversity of argument component, justification, presence or absence of rebuttals. The process of identification of argument level is very simple, qualitative level of argumentation represented as concrete score could present various and concrete argument level. Developed analytic framework might contribute to argumentation research field, because it can present effectively dialogic argumentation result. Also, various analysis cases might guide designing an effective argumentation practice and circular motion learning.

Temperature Dependency Affecting the Properties at Early Age of the Concrete Containing High Volume Blast Furnace Slag (고로슬래그 미분말을 다량 치환한 콘크리트의 초기품질에 미치는 온도의존성)

  • Han, Cheon-Goo;Lee, Jang-Hwa;Koh, Kyung-Taek;Han, Min-Cheol;Lee, Ju-Sun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.1
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    • pp.74-80
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    • 2009
  • This study analysis the fundamental properties of temperature-dependence corresponding the change of curing temperature classified by the replacement ratio of BS, and the results are summarized as following. As the properties of flow, plain satisfied with the target slump, and as the replacement ratio of BS increased, the flow increased, but the air content slightly decreased. The time of set delayed as the replacement ratio of BS increased, but the curing temperature $35^{\circ}C$, even with 80% BS replaced concrete, the time of set was faster than $5^{\circ}C$, $20^{\circ}C$ plain, so the temperature-dependence was much greater. The compressive strength was decreased as the replacement ratio of BS increased, especially as the curing temperature lower, the compressive strength was lower comparatively. Also as the age increased, the plain developed more strength, therefore it show the temperature-dependence is much larger.

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Ratiocination for evaluation of mental image -Evaluation leafing to characteristic position of associate image and product elements- (Mental Image의 평가를 위한 추론 -연상이미지에 의한 제품평가를 중심으로-)

  • 송창호
    • Archives of design research
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    • v.16 no.3
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    • pp.59-70
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    • 2003
  • The consumer's feelings toward products is each evaluated and appears in different way that is to say there are various types of motives for deciding a purchase for example, there might be an interesting function and emotional reaction. How is the product image that induces motives like this metaphorized and evaluated to be existing in the mental image. This study inquired into, it by presenting problems conscious of both sides indicated above, the major points associated with image of the product, characteristic positions of product elements and evaluation of the product. To draw out a clear conclusion, first three hypotheses were established and case a study was performed as part of conclusive research for verification of this. The collected data was made, by simple tabulation to represent the overall flow, and based on this, concrete analysis was conducted on the three reserch items. The analysis method weighted on quantitative analysis with consideration to consumer's psychological aspect. As the result, three important conclusions could be drawn out or ratiocination for evaluation of mental image formation.

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CASE STUDY ON SEVERELY-DAMAGED REINFORCED EARTH WALL WITH GEO-TEXTILE IN HYOGO, JAPAN Part II: Numerical simulation into causes and countermeasures

  • Hur, Jin-Suk;Kawajiri, Shunzo;Jung, Min-Su;Shibuya, Satoru
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.11-17
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    • 2010
  • Numerical analysis was carried out in order to simulate the development of the large deformation that took place on the reinforced earth wall, a part of the Tottori expressway planned to pass Hyogo, Japan. Since this reinforced earth wall had experienced unexpected deformation of the wall during construction, the wall was re-constructed twice. However, the wall deformation showed no sign to cease even at the final stage of the construction. Countermeasures to re-stabilize the wall were demanded. In part I of this paper, it was manifested that subsidence of a 3-meter weak soil due to seepage flow was responsible for the large deformation. A part of concrete panel wall was severely damaged due to extremely large pulling force of geotextile induced by the hammock state. As for the countermeasures, "grouting with slag system" was applied to fill voids of the backfill, and also to prevent further development of settlement in the weak soil layer. "Ground anchor" was also considered to achieve the prescribed factor of safety.

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Carbonation Behavior of Fly Ash with Circulating Fluidized Bed Combustion (CFBC)

  • Bae, Soon Jong;Lee, Ki Gang
    • Journal of the Korean Ceramic Society
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    • v.52 no.2
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    • pp.154-158
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    • 2015
  • This paper investigates the reaction rates of $CO_2$ that stores carbonation through comparing the carbonation behavior between $Ca(OH)_2$ and fly ash with circulating fluidized bed combustion (CFBC) containing a large amount of free CaO. Because fly ash with CFBC contains abundant free CaO, it cannot be used as a raw material for concrete admixtures; hence, its usage is limited. Thus, it has been buried until now. In order to consider its reuse, we conduct carbonation reactions and investigate its rates. X-ray diffraction (XRD), thermogravimetric/differential thermal analysis (TG/DTA), and X-ray fluorescence (XRF) are conducted for the physical and chemical analyses of the raw materials. Furthermore, we use a PH meter and thermometer to verify the carbonization rates. We set the content of the fly ash of CFBC, $Ca(OH)_2$, $CO_2$ flow rate, and water to 100 ~ 400 g, 30 ~ 120 g, 700 cc/min, and 300 ~ 1200 g, respectively, based on the content of the free CaO determined through the TG/DTA analyses. As a result, the carbonization rate of the fly ash with CFBC is the same as that of $Ca(OH)_2$, and it tends to increase linearly. Based on these results, we investigate the carbonization behavior as a function of the free CaO content contained in the raw material.

A Creative Apparel Up-cycling Design Development Using Creative Thinking Methodology

  • Minji Kim
    • Journal of Fashion Business
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    • v.27 no.6
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    • pp.147-159
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    • 2023
  • Fashion is the second most polluting industry. We must strive to transition to a form of industry that does not cause environmental pollution. These efforts drive may fashion brands to produce and sell products with redesigned methods that delight the inventory flow. Accordingly, it is necessary to develop creative apparel up-cycling design using the creative thinking method. This study aims to produce clothing redesign works by introducing design idea types for systematic redesign creation. In this research, we conducted a literature review on the concept of up-cycling design and employed heterotopa spacial concept reflected fashion design creation methodology types. The RE;CODE, a leading domestic up-cycling design brand, was used in case analysis. According to the command of shape transformation, it is spreading, stacking, dropping, inverting and crossing, from the creative thinking method reflecting heterotopia spacial concepts, showing designers a concrete way to transform form into new apparel. Seven works of apparel up-cycling design were developed by conducting process of RE;CODE. Also, to establish an apparel up-cycling design creation process for creating works. In this study, we proposed a systematic method for apparel up-cycling design, including a method for reorganizing two or more different materials to create something new and ultimately reversing the structure. The value and significance of this study is that it proposes a systematic method for apparel up-cycling design to make it new.

Study on Characteristics of Fine Bottom Ash Based Geopolymer Mortar (미분쇄 바텀애시 기반 지오폴리머 모르타르 특성에 관한 연구)

  • Lim, Gwi-Hwan;Lee, Jeong-Bae;Jeong, Hyun-Kyu;Kim, Seong-Soo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.4
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    • pp.418-424
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    • 2016
  • This study is an experimental study on the recycling of bottom ash in coal ash discharged from a thermal power plant. Bottom ash has limited research on recycling because it has more porous and higher water absorption ratio than fly ash. In this paper, the bottom ash was pulverized to a specific surface area of $4,000cm^2/g$ in order to use as a binder, and the flow, compressive strength test and microstructure analysis of the bottom ash based geopolymer mortar were performed. The flow measurement results of the geopolymer mortar showed that the flow rate was improved by increasing mixing water as the molar concentration of activator was increased. Compressive strength increased with increasing curing temperature and molar concentration. Through the microstructure analysis, we could confirm the geopolymer gel produced by the reaction of the condensation polymerization. It is considered that it is possible to make the bottom ash based geopolymer concrete through proper molar concentration of activator and high temperature curing.

Modeling the Effect of Water, Excavation Sequence and Reinforcement on the Response of Tunnels

  • Kim, Yong-Il
    • Journal of the Korean Geotechnical Society
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    • v.15 no.3
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    • pp.161-176
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    • 1999
  • A powerful numerical method that can be used for modeling rock-structure interaction is the Discontinuous Deformation Analysis (D D A) method developed by Shi in 1988. In this method, rock masses are treated as systems of finite and deformable blocks. Large rock mass deformations and block movements are allowed. Although various extensions of the D D A method have been proposed in the literature, the method is not capable of modeling water-block interaction, sequential loading or unloading and rock reinforcement; three features that are needed when modeling surface or underground excavation in fractured rock. This paper presents three new extensions to the D D A method. The extensions consist of hydro-mechanical coupling between rock blocks and steady water flow in fractures, sequential loading or unloading, and rock reinforcement by rockbolts, shotcrete or concrete lining. Examples of application of the D D A method with the new extensions are presented. Simulations of the underground excavation of the \ulcornerUnju Tunnel\ulcorner in Korea were carried out to evaluate the influence of fracture flow, excavation sequence and reinforcement on the tunnel stability. The results of the present study indicate that fracture flow and improper selection of excavation sequence could have a destabilizing effect on the tunnel stability. On the other hand, reinforcement by rockbolts and shotcrete can stabilize the tunnel. It is found that, in general, the D D A program with the three new extensions can now be used as a practical tool in the design of underground structures. In particular, phases of construction (excavation, reinforcement) can now be simulated more realistically.

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