• Title/Summary/Keyword: BFS

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Practical Use of Activated Recycling Water Sludge for Admixture of Concrete (활성도를 부여한 회수수 슬러지의 콘크리트 혼화재 활용)

  • Kim, Ho-Su;Baek, Chul-Woo;Park, Cho-Bum;Jeun, Jun-Young;Ryu, Deug-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.777-780
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    • 2008
  • There were some attempt to reuse water with sludge combinative water for ready mixed concrete. But recycling water consist of cement, aggregate and chemical admixture. So it caused deterioration of concrete. The object of this study was to search for recycling method of the recycling water sludge as mineral admixture. This experiment dealed with the effect of $2.5{\sim}12.5$% range of the recycling sludge which can be used for admixture binder(BFS, FA, BFS+FA) on properties of activated recycling water sludge for admixture of concrete. As a result, Although the slump levels reduced and air contents increased as sludge replacement levels increased, it didn't change highly. The compression strength of concrete slightly increased with an increasing amount of recycling water sludge replacement.

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A Durability Assessment on Complex Deterioration of Concrete with Ground Granulated Blast-Furnace Slag Replacement (복합열화 환경하에서의 고로슬래그미분말 사용 콘크리트의 내구성능 평가)

  • Lee, Seung-Hoon;Kim, Hyung-Doo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.171-175
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    • 2010
  • This paper presents the experimental results of frost durability characteristics including freezing-thawing and de-icing salt scaling of the concrete for gutter of the road and marine structure. Mixtures were proportioned with the three level of water-binder ratio(W/B) and three binder compositions corresponding to Type I cement with 0%, 30% and 50% GGBS(Ground granulated blast furnace slag) replacement. Also, two different solutions of calcium chloride were used to evaluate their effect on the frost durability resistance. Specially, in case of complex of freezing and thawing with salt and carbonation, the deterioration of concrete surface is evaluated. Test results showed that the BFS30 and BFS50 mixture exhibited higher durability and lower mass loss values than those made with OPC mix and the use of GGBS can be used effectively in terms of economy and frost durability of the concrete to be in complex deterioration. Therefore, the resistance to complex deterioration with freezing-thawing was strongly influenced by the strength and the type of cement.

Study of Non Sintered Cement Mortar Using Nanoslag and Alkali Activator (나노슬래그와 알칼리 자극제를 활용한 비소성 시멘트 모르타르에 관한 연구)

  • Jeong, Sung-Wook;Lim, Nam-Gi
    • Journal of the Korea Institute of Building Construction
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    • v.10 no.6
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    • pp.61-66
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    • 2010
  • As global warming has had harmful effects on the environment, the construction industry has made efforts to reduce the amount of $CO_2$ generated in the process of cement production. There is an urgent need for an alternative material that can replace cement. To improve the initial strength and economical efficiency pointed out as problems, this research was conducted for Blast Furnace Slag (BFS), an industrial byproduct. Non-sintering cement (NSC) was used by minimizing the amount of high-priced alkali activators. By using Nano-technology, fineness has been maximized, to enhance the initial strength of BFS. This research is based on non-sintered cement replaced by nano-slag using alkali activators, and the fundamental properties and quality of the non-sintered cement were investigated. A variety of activators were used, up to 10 percent of the slag weight. This research aims to present fundamental data through a comparative analysis of flexural strength, compressive strength, time of setting, diabetic temperature, and rising heat.

Massive Graph Expression and Shortest Path Search in Interpersonal Relationship Network (인물관계망의 대용량 그래프 표현과 최단 경로 탐색)

  • Min, Kyoung-Ju;Jin, Byeong-Chan;Jung, Man-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.4
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    • pp.624-632
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    • 2022
  • Relationship networks such as an interpersonal relationship network or navigation route search can be expressed in graph form. However, as the amount of data increase, there is a problem that it is difficult to search for the desired data when it is displayed on one screen. In this paper, we propose a visualization method for searching for people, searching for the shortest path between people, and using graphs to express an interpersonal relationship network with many nodes. Unlike the search for the shortest path in the routing table, the shortest path in the interpersonal relationship network should be changeable according to the intension or importance of the researcher or user who is analyzing it. To this end, the BFS algorithm was modified to apply the characteristics of the interpersonal relationship network. For the verification of the results, the data in the character relationship information of the Korean Classics DB in the Korean Classics Translation Institute was used.

Effects of Inhalation versus Total Intravenous Anesthesia on Postoperative Pulmonary Complications after Anatomic Pulmonary Resection

  • Lee, Soojin;Cho, Jeong Su;Kim, Eunsoo;Kim, Yeongdae;Lee, Jonggeun
    • Journal of Chest Surgery
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    • v.55 no.1
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    • pp.30-36
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    • 2022
  • Background: No consensus exists regarding whether volatile anesthetics are superior to intravenous anesthetics for reducing postoperative pulmonary complications (PPCs) in patients undergoing general anesthesia for surgery. Studies of this issue focused on anatomic pulmonary resection are lacking. This study compared the effects of total intravenous anesthesia (TIVA) versus volatile anesthesia on PPCs after anatomic pulmonary resection in patients with lung cancer. Methods: This retrospective study examined the medical records of patients with lung cancer who underwent lung resection at our center between January 2018 and October 2020. The primary outcome was the incidence of PPCs, which included prolonged air leak, pneumonia, acute respiratory distress syndrome, empyema, atelectasis requiring bronchofiberscopy (BFS), acute lung injury (ALI), bronchopleural fistula (BPF), pulmonary embolism, and pulmonary edema. Propensity score matching (PSM) was used to balance the 2 groups. In total, 579 anatomic pulmonary resection cases were included in the final analysis. Results: The analysis showed no statistically significant difference between the volatile anesthesia and TIVA groups in terms of PPCs, except for prolonged air leak. Neither of the groups showed atelectasis requiring BFS, ALI, BPF, pulmonary embolism, or pulmonary edema after PSM. However, the length of hospitalization, intensive care unit stay, and duration of chest tube indwelling were shorter in the TIVA group. Conclusion: Volatile anesthetics showed no superiority compared to TIVA in terms of PPCs after anatomical pulmonary resection in patients with lung cancer. Considering the advantages of each anesthetic modality, appropriate anesthetic modalities should be used in patients with different risk factors and situations.

An Experimental Study on the Engineering Characteristics of Ternary Lightweight aggregate Mortar Using Recycling Water (회수수를 사용한 3성분계 경량 골재 모르타르의 공학적 특성에 관한 실험적 연구)

  • Lee, Jae-In;Bae, Sung-Ho;Kim, Ji-Hwan;Choi, Se-Jin
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.10 no.1
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    • pp.48-55
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    • 2022
  • This study uses the recovered water as mixing water and artificial lightweight aggregate pre-wetting water as part of a study to increase the recycling rate and reduce greenhouse gas of the ready-mixed concrete recovered during the concrete transport process, and cement fine powder of blast furnace slag(BFS) and fly ash(FA). The engineering characteristics of the three-component lightweight aggregate mortar used as a substitute were reviewed. For this purpose, the flow, dry unit mass, compressive strength, drying shrinkage, neutralization depth, and chloride ion penetration resistance of the three-component lightweight aggregate mortar were measured. When used together with the formulation, when 15 % of BFS and 5 % of FA were used, it was found to be positive in improving the compressive strength and durability of the mortar.

Mechanical and Electrical Properties of Self-sensing Grout Material with a High-Volume Ultrafine Fly Ash Replacement (초고분말 플라이 애시를 다량 치환한 자기감지형 그라우트재의 역학적 및 전기적 특성)

  • Lee, Gun-Cheol;Kim, Young-Min;Im, Geon-Woo
    • Journal of the Korea Institute of Building Construction
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    • v.24 no.2
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    • pp.215-226
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    • 2024
  • This study presents an experimental investigation into the performance of self-sensing grout formulated with a high volume of ultra-fine fly ash(UHFA). To explore the potential benefits of alternative cementitious materials, the research examined the effect of substituting UHFA with equal parts of blast furnace slag(BFS) fine powder. Both UHFA and BFS are byproducts generated in significant quantities by industrial processes. The evaluation focused on the fresh properties of the grout, including its flow characteristics, as well as the hardened properties such as compressive strength, dimensional stability(length change rate), and electrical properties. The experimental results demonstrated that incorporating UHFA resulted in a substantial reduction in the plastic viscosity of the grout, translating to improved flowability. Additionally, the compressive strength of the UHFA-modified grout surpassed that of the reference grout(without UHFA substitution) at all curing ages investigated. Interestingly, the electrical characteristics, as indicated by the relationships between FCR-stress and FCR-strain, exhibited similar trends for both grout mixtures.

Fertility Evaluation of Upland Fields by Combination of Landscape and Soil Survey Data with Chemical Properties in Soil (토양 화학성과 지형 및 토양 조사자료를 활용한 밭 토양의 비옥도 평가)

  • Hong, Soon-Dal;Kim, Jai-Joung;Min, Kyong-Beum;Kang, Bo-Goo;Kim, Hyun-Ju
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.4
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    • pp.221-233
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    • 2000
  • Evaluation method of soil fertility by application of geographic information system (GIS) which includes landscape characteristics and soil map data was investigated from productivities of red pepper and tobacco grown on the fields with no fertilization. Total 131 fields experiments, 64 fields of red pepper and 67 fields of tobacco were conducted from 22 and 23 fields for red pepper and tobacco, respectively, located at Cheangweon and Eumseong counties in 1996, from 20 and 25 fields at Boeun and Goesan counties in 1997, and 22 and 19 fields at Jincheon and Chungju counties in 1998. All the experimental sites were selected on the basis of wide range of distribution in landscape and soil attributes. Dry weights and nutrients (N, P and K) uptakes by red pepper plant and tobacco leaves were considered as basic fertility of the soil (BFS). The BFS was estimated by twenty-five independent variables including 13 chemical properties and 12 GIS data. Twenty-five independent variables were classified by two groups, 15 quantitative variables and 10 qualitative variables, and were analyzed by multiple linear regression (MLR) of REG and GLM models of SAS. Dry weight of red pepper (DWRP) and dry weight of tobacco leaves (DWTL) every year showed high variations by five times in difference plots with minimum yield and maximum yield indicating the diverse soil fertility among the experimental fields. Evaluation for the BFS by the MLR including independent variables was better than that by simple regression showing gradual improvement by adding chemical properties, quantitative variables, and qualitative variables of the GIS. However the evaluation for the BFS by the MLR showed the better result for tobacco than red pepper. For example the variability in the DWTL by MLR was explained 34.2% by only chemical properties, 35.0% by adding quantitative variables, and 72.5% by adding both the quantitative and qualitative variables of the GIS compared with 21.7% by simple regression with $NO_3-N$ content in soil. Consequently, it is assumed that this approach by the MLR including both the quantitative and qualitative variables was available as an evaluation model of soil fertility for upland field.

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A Transformation Military Databases based on the Relational Data model into XML Databases (관계형 데이터 모델 기반 군사용 데이터베이스의 XML 데이터베이스로의 변환)

  • Kim, Chang-Seok;Kim, Eong-Su
    • Journal of National Security and Military Science
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    • s.1
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    • pp.269-310
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    • 2003
  • AS Extensible Markup Language(XML) is emerging as the data format of the Internet era, there are increasing needs to efficiently transform between database and XML documents. In this paper, we propose a schema transformation method from relational database to XML database. To transform the schema, we represent input schema as Entity-Relationship diagram. Entity-Relationship model translator scans the input Entity-Relationship diagram using BFS (breadth First Search) and translates the diagram into hierarchical structure model. The XML Schema generator produces XML Scema code using the transformed hierarchical structure model. The proposed method has a merit that having reusability facility of XML Schema property in comparison with existing researches.

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Units' Path-finding Method Proposal for A* Algorithm in the Tilemap (타일맵에서 A* 알고리즘을 이용한 유닛들의 길찾기 방법 제안)

  • Lee Se-Il
    • Journal of the Korea Society of Computer and Information
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    • v.9 no.3
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    • pp.71-77
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    • 2004
  • While doing games, units have to find goal And according to algorism, there is great difference in time and distance. In this paper the researcher compared and described characteristics of each of the improved algorism and A* algorism by giving depth-first search, breadth-first search and distance value and then argued algorism. In addition. by actually calculating the presumed value in A* a1gorism, the researcher finds the most improved value. Finally, by means of comparison between A* algorism and other one, the researcher verified its excellence and did simple path-finding using A* algorism.

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