• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
• /
• pp.377-380
• /
• 2008

경량콘크리트는 자중을 경감할 수 있다는 특징을 활용하여 다양한 용도로 건축 및 토목 구조물에 적용할 수 있다. 그러나 경량콘크리트의 성능은 사용된 경량골재의 물리적 특성에 의해 크게 좌우되어진다. 따라서 본 연구에서는 일반적인 콘크리트의 물결합재비부터 고강도 영역의 낮은 물결합재비까지의 콘크리트 배합범위를 대상으로 하여 국내외에서 제조 생산되고 있는 대표적인 구조용 인공경량골재 3종류의 품질 특성에 따른 경량콘크리트의 프레쉬 및 경화성상의 검토를 하였다. 그 결과 보통콘크리트에 비해 경량골재를 사용한 콘크리트의 경우가 슬럼프 로스가 다소 큰 것을 알 수 있었으며 재령별 강도발현은 보통콘크리트에 비해 경량콘크리트가 다소 낮은 것을 알 수 있으나 큰 차이를 나타내지는 않았다. 경량골재의 비조립형 및 조립형 골재에 따라서는 조립형 경량골재를 사용한 경우 비조립형 보다 양호한 콘크리트 성상을 나타냈으며 향후 철근부착 및 철근정착 등의 구조 부재성능 차원의 검토를 통해 판단될 필요가 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제8권3호
• /
• pp.1119-1143
• /
• 2014

Lightweight trust mechanism with lightweight cryptographic primitives has emerged as an important mechanism in resource constraint wireless sensor based mobile devices. In this work, outlier detection in lightweight Mobile Ad-hoc NETworks (MANETs) is extended to create the space of reliable trust cycle with anomaly detection mechanism and minimum energy losses [1]. Further, system is tested against outliers through detection ratios and anomaly scores before incorporating virtual programmable nodes to increase the efficiency. Security in proposed system is verified through ProVerif automated toolkit and mathematical analysis shows that it is strong against bad mouthing and on-off attacks. Performance of proposed technique is analyzed over different MANET routing protocols with variations in number of nodes and it is observed that system provide good amount of throughput with maximum of 20% increase in delay on increase of maximum of 100 nodes. System is reflecting good amount of scalability, optimization of resources and security. Lightweight modeling and policy analysis with lightweight cryptographic primitives shows that the intruders can be detection in few milliseconds without any conflicts in access rights.

• 한국염색가공학회지
• /
• 제31권4호
• /
• pp.312-322
• /
• 2019

The mechanical properties of developed fabrics which were composed of soluble yarns and stretch fibers were analyzed using the Kawabata Evaluation System. The following findings were obtained from this investigation. Fabrics woven with lightweight yarns can be easily deformed by external forces. But when the fabric were woven using thick lightweight yarns reduced the slippage between the fibers, which makes it difficult to deform due to external force, thereby maintaining a certain space from the human body. As for the weight of the fabric per unit thickness, it was found that fabrics were compose of lightweight spun yarn was lightweight relatively. Lightweight yarns were more flexible than regular yarns because of the reduced bending and shear properties that greatly affect the lattice pattern. smoother, more flexible, and the better the bend was recovered. As fabrics increased content of using of lightweight spun yarn was increased flexible and smooth, and bending recovery.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 춘계 학술발표회 논문집
• /
• pp.383-393
• /
• 2006

This paper investigates strength characteristics and stress-strain behaviors of geogrid mixing reinforced lightweight soil. The lightweight soil was reinforced with geogrid in order to increase its compressive strength. Test specimens were fabricated by various mixing conditions including cement content, initial water content, air content and geogrid layer and then unconfined compression tests were carried out. From the experimental results, it was found that unconfined compressive strength as well as stress-strain behavior of lightweight soil were strongly influenced by mixing conditions. The more cement content that is added to the mixture, the greater its unconfined compressive strength. However, the more initial water content or the more air foam content, the less its unconfined compressive strength. It was observed that the strength of geogrid reinforced lightweight soil was increased due to reinforcing effect by the geogrid for most cases except cement content less than 20%. In reinforced lightweight soil, secant modulus $(E_{50})$ was increased as the strength increased due to the inclusion of geogrid.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2009년도 추계 학술논문 발표대회
• /
• pp.127-131
• /
• 2009

The purpose of this study is to provide fundamental data on chloride diffusion from lightweight aggregate concrete by utilizing crushed stone-powder. Accordingly, the study performed experiments using concrete aggregates of Crushed Aggregate (CG), Single-sized Lightweight Aggregate (SLG), Continuous Graded Lightweight Aggregate (CLG), and using water-binder ratio of 0.4, 0.5, 0.6, and using binder of FA and BFS. The chloride diffusion coefficient is calculated after experiment based on NT BUILD 492. Diffusion coefficient of SLG and CLG were little bit higher than CG Concrete, but the difference is meaningless. Also, chloride diffusion coefficient indicates that it is highly affected by water-binder ratio, and it decreases with the decrease in water-binder ratio. The admixture substitution indicates decrease only with water-binder ratio of 0.4 for FA15% case, but admixture substitution indicates decrease with all levels of ratio for FA10 + BFS20% which means more appropriate. According to the analysis result of chloride diffusion from lightweight aggregate concrete, crushed stone-powder utilized lightweight aggregate concrete indicates higher chloride diffusion coefficient than CG concrete, which is not a significant difference, and can improve resistance through water-binder ratio and admixture substitution.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
• /
• pp.257-264
• /
• 2002

This study presents a life-cycle cost (LCC) effectiveness of a concrete with lightweight aggregate. A number of researchers have made their efforts to develop a lightweight concrete, since it is difficult to apply conventional concrete using general aggregate to heavy self-weight structures such as long span bridges. In this study, an optimum design for minimizing the life-cycle cost of concrete slab bridges is performed to evaluate the life cycle cost effectiveness of the lightweight concrete relative to conventional one from the standpoint of the value engineering. The data of physical properties for new concrete can be obtained from basic experimental researches. The material properties of conventional one are acquired by various reports. This study presents a LCC effectiveness of newly developed concrete, which is made by artificial lightweight aggregate. A number of researchers have made their efforts to develop a lightweight concrete, since it is difficult to apply conventional concrete using general aggregate to heavy self-weight structures such as long span bridges. From the results of the numerical investigation, it may be positively stated that the new concrete lead to, the longer span length, the more economical slab bridges compared with structures using general concrete.

• 한국IT서비스학회지
• /
• 제8권1호
• /
• pp.203-215
• /
• 2009

This paper illustrates the application of co-occurrence theory to generate lightweight ontologies semi-automatically. The proposed model includes three steps of a (Semi-) Automatic creation of Ontology; (they are conceptually named as) the Syntactic-based Ontology, the Semantic-based Ontology and the Ontology Refinement. Each of these three steps are designed to interactively work together, so as to generate Lightweight Ontologies. The Syntactic-based Ontology step includes generating Association words using co-occurrence in web documents. The Semantic-based Ontology step includes the Alignment large Association words with small Ontology, through the process of semantic relations by contextual terms. Finally, the Ontology Refinement step includes the domain expert to refine the lightweight Ontologies. We also conducted a case study to generate lightweight ontologies in specific domains(news domain). In this paper, we found two directions including (1) employment co-occurrence theory to generate Syntactic-based Ontology automatically and (2) Alignment large Association words with small Ontology to generate lightweight ontologies semi-automatically. So far as the design and the generation of big Ontology is concerned, the proposed research will offer useful implications to the researchers and practitioners so as to improve the research level to the commercial use.

• 한국산업융합학회 논문집
• /
• 제24권6_2호
• /
• pp.819-825
• /
• 2021

In the industry, the use of lightweight bearings is increasing to minimize motor power loss, and in particular, the application of next-generation systems such as robots and drones is increasing. Bearing manufacturers are producing lightweight bearings by changing the bearing material, but related researches is insufficient. In this paper, life test and structural analysis were performed for lightweight bearings, and shape parameters and scale parameters were derived based on the life test results. It was confirmed that the shape parameter was 2.52 and the scale parameter was 164 hours. As a result of calculating the dynamic load rating based on the B₁₀ life, it was confirmed that the dynamic load rating of the lightweight bearing was 7% compared to the formula suggested by ISO 281. The reason is that the material of the retainer, which is a major failure part, is a polyamide 66 series that reacts sensitively to heat, so It is judged to show a lot of difference from the ISO 281 calculation formula.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2012년도 추계 학술논문 발표대회
• /
• pp.89-91
• /
• 2012

The purpose of this study is to investigate the mechanical property and carbonation resistance of concretes using surface treated lightweight aggregate. In order to evaluate mechanical property and carbonation resistance, slump, compressive strength, and carbonation depth are tested. Slump of concretes using surface treated lightweight aggregate measured 120~125mm, which are lower than slump of NWAC. Compared to compressive strength of NWAC, compressive strength of concretes using surface treated lightweight aggregate showed a level of 82.8~95.9%. In carbonation resistance test, carbonation depth of concretes using surface treated lightweight aggregate measured 10.2~11.3mm, which are lower than carbonation depth of NWAC. As a result, it is found that compressive strength is decreased slightly but carbonation resistance is improved, in case of using surface treated lightweight aggregate.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
• /
• pp.271-272
• /
• 2010

본 논문은 경량콘크리트의 깊이에 따른 수축을 일반콘크리트와 비교하여 연구하였다. 경량콘크리트는 사전흡수수가 20%인 인공경량골재를 사용하였다. 물-결합재비가 30%일 때의 경량콘크리트는 일반콘크리트보다 단면의 평균 수축률은 감소하였지만 부등수축률은 다소 증가하는 현상이 나타났다. 물-결합재비가 40&일 때는 경량콘크리트는 일반콘크리트보다 단면 평균 수축률, 부등수축률 모두 감소한 것으로 나타났다.