• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.367-374
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• 2019

Drying shrinkage in the hardened cement is known to change in volume by decreasing the moisture content in the hardened body, and it is known that the higher the W / C and the higher the content of the paste, the larger the drying shrinkage. In the case of ECC, more drying shrinkage occurs compared to concrete, since it does not contain coarse aggregate. Since ECC is an important material for tensile performance, the effect of restrained tensile stress on mechanical tensile behavior should be considered. The purpose of this study is to analyze the effect of stress caused by restraint on the tensile behavior of ECC. The mechanical properties of the specimens were tested by uniaxial tension tests with different restraints. As a result, the difference of tensile behavior according to restraint stress was observed and the cause was analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1180-1186
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• 2020

One of the Embedded systems Tiny Processing Unit (TPU) usually acts in harsh environments like external shock or insufficient power. In these cases, data could be polluted, and cause critical problems. As a solution to data pollution, many embedded systems are using Error Correcting Code (ECC) to protect and restore data. However, ECC processing in TPU increases the overall processing time by increasing the time of instruction fetch which is the bottleneck. In this paper, we propose an architecture of parallelized ECC block to the reduce bottleneck of TPU. The proposed architecture results in the reduction of time 10% compared to the original model, although memory usage increased slightly. The test is evaluated with a matrix product that has various instructions. TPU with proposed parallelized ECC block shows 7% faster than the original TPU with ECC and was able to perform the proposed test accurately.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.329-332
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• 2006

This paper presents the experimental results for durability of an ECC designed with ground granulated blast furnace slag (BFS) through the test method of chloride ion resistance and freezing-thawing resistance. In order to compare with ECC, normal mortar was also tested. Test results showed that BFS ECC exhibited higher durability performance than ordinary mortar. These results suggest that by adding BFS in ECC, its matrix density is increased which results in decreased of deterioration and it also adds to the fiber bridging that contributes in control of cracking.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.244-247
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• 2003

Recently, construction materials have been quickly advancing. Especially, the rate of development of cement based construction materials is much quicker than steel or composite materials. In order to optimize the ductility and strength of cement based materials, Micro-Mechanics based fiber concrete called Engineered Cement Composite (ECC) has been developed and studied extensively by many researchers in the field due to ECC's remarkable flexural strain and strength capacities, many leading nation (i.e., US, Japan and European countries have reached the point of being able to use ECC in actual constructions. But, due to the belated interest in the field, Korea is lagging behind the leading countries. ECC's ability to use its short fibers to bridge micro-cracks (50-80㎛ in width) allows great ductility and strength. In this study, it is confirmed excellency of ECC through the test of tensile strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.361-366
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• 2003

Recently, construction materials have been guickly advancing. Especially, the rate of development of cement based construction materials is much quicker than steel or composite materials. In order to optimize the ductility and strength of cement based materials, Micro-Mechanics based fiber concrete called Engineered Cement Composite (ECC) has been developed and studied extensively by many researchers in the field due to ECC's remarkable flexural strain and strength capacities, many leading nation (i.e., US, Japan and European countries have reached the point of being able to use ECC in actual constructions. But, due to the belated interest in the field, Korea is lagging behind the leading countries. ECC's ability to use its short fibers to bridge micro-cracks (50-80㎛ in width) allows great ductility and strength. ,In this study, ECC with superior material capacities are manufactured using domestic materials such as cement, silica sand, metal cellulose, etc. Using only domestic products, the optimal W/C ratio and mixing procedures are determined.

• Biomedical Science Letters
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• v.7 no.1
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• pp.7-15
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• 2001

Although extracorporeal circulation (ECC) has been routinely used for cardiovascular surgery, hyperoxemia during ECC may produce oxygen toxicity and cellular injury. This study was performed to investigate the clinical influences of hyperoxemic ECC during cardiovascular operation. 40 adult patients scheduled for elective cardiovascular surgery were classified into normoxemic (arterial oxygen tension: 115 mmHg, n＝20) and hyperoxemic (arterial oxygen tension: 380 mmHg, n＝20) ECC. At preoperative and postoperative period, total leukocyte and neutrophil counts, platelet counts, iron, glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine in peripheral arterial blood, malondialdehyde (MDA) and troponin-T concentration (TnT) in coronary sinus blood, pulmonary vascular resistance (PVR), and postoperative blood loss volume (BLS) were measured and compared between groups. Hyperoxemic group had postoperatively higher total leukocyte and neutrophil counts, MDA, TnT, PVR total BLS, iron, glucose, AST, ALT, BUN, and creatinine than normoxemic group (p<0.05).0 conclusion, hyperoxemic ECC results in greater inflammatory response and oxidative damaging effects on the heart lung, liver and kidney, probably being adverse to postoperative patient recovery. For reducing these deleterious effects and improving postoperative outcomes, management lowering oxygen tension during ECC is recommended.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.199-202
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• 2008

The purpose of this study is to obtain the fundamental fire resistance performance of engineered cementitious composites(ECC) under fire temperature in order to use the fire protection material in high-strength concrete structures. The present study conducted the experiment to simulate fire temperature by employing of ECC and investigated experimentally the explosion and cracks in heated surface of these ECC. In the experimental studies, 3 HSC specimens are being exposed to fire, in order to examine the influence of various parameters(such as depth of layer=20, 30, 40mm; construction method=lining type) on the fire performance of HSC structures. Employed temperature curve were ISO 834 criterion(3hr), which are severe in various criterion of fire temperature in building structures. The numerical regressive analysis and proposed equation to calculate ambient temperature distribution is carried out and verified against the experimental data. By the use of proposed equation, the HSC members subjected to fire loads were designed and discussed.

• Journal of Korean society of Dental Hygiene
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• v.14 no.4
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• pp.571-576
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• 2014

Objectives : The purpose of this study was to investigate the relationship between early childhood caries(ECC) and breastfeeding. Methods : Data of 670 children were derived from the Forth Korean National Health and Nutrition Examination Survey from 2007 to 2009. Demographic and socioeconomic data, oral health related behavior, and breastfeeding practice data were collected as independent variables. The ECC was used as a dependent variable. The chi-square test and logistic regression analysis were performed to identify the relationship between ECC and the other variables. Results : Multiple logistic regression analysis revealed that ECC was related with age, tooth brushing frequency, and breastfeeding practice. Conclusions : This study confirmed various risk indicators of ECC in Korean children, using Korean national survey data. Parents should begin an early and consistent mouth care regime to decrease the risk of ECC.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.9
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• pp.1689-1694
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• 2009

In a previous paper, the characteristics of ECC (earth continuity conductor) have been analysed for reducing the level of induced sheath voltage considering the dimension and position of ECC, the spacing between ECC and three phase cables, and the use of two ECC conductors at the single point boned section of underground power cable system. From these results, the study conditions for optimal installation has been selected such as installation section, conductor size and etc. In this paper, 5 cases which are set by possible installation conditions are tested based on previous research results. Finally, the optimal installation method of ECC is selected on underground power cable systems.

• Earthquakes and Structures
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• v.26 no.4
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• pp.269-283
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• 2024

When a reinforced concrete (RC) structure is exposed to a corrosive environment for an extended period of time, the material qualities deteriorate, resulting in a loss in seismic performance. Engineered Cementitious Composites (ECC) have been used to reinforce the corroded RC structure, which can achieve reinforcement effectiveness for a small change in cross-section size. In this work, finite element models of unjacketed RC pier and ECC jacketed pier were established and verified by experimental tests, with the buckling effect of longitudinal reinforcement considered. Compared with the unjacketed pier, the displacement of the pier top of the ECC jacketed pier was reduced by about 9.52% under earthquake action. In the case of moderate and major earthquakes, the probability of exceedance of ECC jacketed pier is significantly reduced. For the case of rare earthquake loading, with the ECC jacket, the e of the pier experiencing serious damage and complete damage states is reduced by 10.29% and 29.78%, respectively.