• The Journal of Internal Korean Medicine
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• v.36 no.1
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• pp.49-57
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• 2015

Objectives : The purpose of this report is to investigate the effect of Taeeumin Cheonghyeolgangki-tang on chronic contact dermatitis caused by cement. Methods : A 52-year-old male patient was diagnosed with contact dermatitis with the Questionnaire for Sasang Constitutional Classification-II (QSCC-II) as well as the four methods of diagnosis (四診), and treated with Taeeumin Cheonghyeolgangki-tang (qīngxuèjiàngqí-tāng). We observed redness and scaling on both palms, and recorded photographs of any changes during the inpatient and outpatient treatment period. Results : The symptoms of contact dermatitis on both palms were significantly improved. Scaling and cracked skin disappeared and the redness almost resolved. Conclusions : Therefore, Taeeumin Cheonghyeolgangki-tang ( qīngxuèjiàngqí-tāng ) is effective on chronic contact dermatitis caused by cement.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.739-752
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• 2018

Purpose: The purpose of this study was to investigate the relationship between kiln processing parameters and NOx emissions that occur in the sintering and calcination steps of the cement manufacturing process and to derive the main factors responsible for producing emissions outside emission limit criteria, as determined by category models and classification rules, using data mining techniques. The results from this study are expected to be useful as guidelines for NOx emission control standards. Methods: Data were collected from Precalciner Kiln No.3 used in one of the domestic cement plants in Korea. Thirty-four independent variables affecting NOx generation and dependent variables that exceeded or were below the NOx emiision limit (>1 and <0, respectively) were examined during kiln processing. These data were used to construct a detection model of NOx emission, in which emissions exceeded or were below the set limits. The model was validated using SPSS MODELER 18.0, artificial neural network, decision treee (C5.0), and logistic regression analysis data mining techniques. Results: The decision tree (C5.0) algorithm best represented NOx emission behavior and was used to identify 10 processing variables that resulted in NOx emissions outside limit criteria. Conclusion: The results of this study indicate that the decision tree (C5.0) can be applied for real-time monitoring and management of NOx emissions during the cement firing process to satisfy NOx emission control standards and to provide for a more eco-friendly cement product.

• Geomechanics and Engineering
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• v.19 no.6
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• pp.543-554
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• 2019

İzmir Bay reserves high amount of residual alluvial deposits generated by Meles River at its stream mouth. These carried sediments with high water content and low bearing capacity are unsuitable in terms of engineering purposes. In-situ soil stabilization with deep soil mixing method is considered to improve properties of soil in this location. This method is widely used especially over Scandinavia, Japan and North America. Basically, the method covers mixing appropriate binder into the soil to improve soil profile according to the engineering needs. For this purpose, soil samples were initially provided from the site, classification tests were performed and optimum ratios of lime and cement binders were determined. Following, specimens representing the in-situ soil conditions were prepared and cured to be able to determine their engineering properties. Unconfined compression tests and vane shear tests were applied to evaluate the stabilization performance of binders on samples with different curing periods. Scanning electron microscope was used to observe time-dependent bonding progress of binders in order to validate the results. Utilization of 4% lime and 4% cement mixture for the long-term performance and 8% lime and 8% cement mixture for short term performance were suggested for the stabilization of Meles Delta soils. Development of CSH and CAH in a gel form as well as CSH crystals were clearly observed on SEM images of treated specimens.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.61-65
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• 2008

This study, having combined and displaced blast furnace slag("BS" hereinafter) known as admixture material that delays hydration reaction with coarse particle cement("CC" hereinafter) collected in particle classification method during ordinary portland cement("OPC" hereinafter), reviewed the hydration heat characteristics affecting the concrete. To reduce hydration heat, the study plain-mixed which used 100% OPC for W/B 50% level 1, displaced CC at level 3 of 25%, 50% and 75% for OPC, and by displacing BS with admixture material at level 5 of 0%, 20%, 40%, 60% and 80% for cement(OPC+CC), experimented totally 16 batches. As a result of experiment, in the case of flow, the more CC displacement rate increased, the more it tended to decrease, and the more BS displacement rate increased, the more it decreased. Also, as for simple adiabatic temperature rise by the CC and BS displacement rates, it decreased as displacement rate increased, and particularly in the case of displaced BS of 80%, It showed temperature reduction effect of about 63% companing with plain. Compressive strength decreased in proportion to displacement rate, however strength reduction increment was shown to decrease with age progress.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.1
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• pp.64-71
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• 2020

The purpose of this study was to evaluate the North Korea cement industry and technology status by comparing and analyzing the cement standards and properties of South and North Korea. In the literature study, data on North Korea's cement industry and standards were collected and analyzed through the Ministry of Unification's North Korea Data Center and other agency. The facilities, classification, and quality standards of South and North Korea cements were compared. In an experimental study, a survey on the quality of cement in North Korea was carried out through physical and chemical analysis experiments by obtaining a small amount of cement from North Korea, and compared with domestic cement. As a result, North Korea cement was of lower quality than South Korean cements. North Korea cement had lower C₃S and higher C₂S than South Korea cement, especially the residue content was much higher. In addition, North Korea cement had about 50% of the compressive strength of cement in South Korea because the clinker was not fired at a sufficient temperature due to the poor performance of the cement facilities in North Korea.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.329-330
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• 2009

This study is to investigate the effect of the combined use of fly ash(FA) and coarse particle cement(CC) collected in particle classification process of ordinary Portland cement(OPC) manufacturing on the hydration exothermic and strength development in the field application.

• Journal of the Korea Institute of Building Construction
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• v.15 no.4
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• pp.367-373
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• 2015

In this study, fundamental properties of cement were reviewed to apply high fineness cement at low temperature environment. The classified high fineness cement has large proportion of particles below $10{\mu}m$ which affects early hydration: an overall reaction of cement hydration faster. As a result of using high fineness cement, setting time of concrete was reduced and compressive strength was higher than OPC at all ages. Especially, compressive strength was more than double its value compared with OPC after three days curing in low temperature. Faster reaction and higher heat of hydration was verified by calorimetry early and maximum heat of hydration was analyzed by adiabatic temperature raising test. The analysis of this study confirmed that high fineness cement can be suitable to be used in low temperature environment.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.122-127
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• 1998

This paper presents the neuro-fuzzy classifier derived from the generic model of a 3-layer fuzzy perceptron and developed the classification software based on the neuro-fuzzl model. Also, a comparison of the neuro-fuzzy and maximum-likelihood classifiers is presented in this paper. The Airborne Multispectral Scanner(AMS) imagery of Tae-Duk Science Complex Town were used for this comparison. The neuro-fuzzy classifier was more considerably accurate in the mixed composition area like "bare soil" , "dried grass" and "coniferous tree", however, the "cement road" and "asphalt road" classified more correctly with the maximum-likelihood classifier than the neuro-fuzzy classifier. Thus, the neuro-fuzzy model can be used to classify the mixed composition area like the natural environment of korea peninsula. From this research we conclude that the neuro-fuzzy classifier was superior in suppression of mixed pixel classification errors, and more robust to training site heterogeneity and the use of class labels for land use that are mixtures of land cover signatures.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.997-1000
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• 2008

Strength development of concrete subjected to cold weather is generally delayed due to its low temperature. In case of soil nailing method, it is necessary to apply the shotcrete. However, the shotcrete placement under low temperature experiences retardation of strength development due to delayed hydration reaction. Therefore, in this paper, the use of fine particle cement which is produced through particle classification in cement manufacturing process, is discussed to enhance the strength development of the shotcrete under low temperature. According to the results, the concrete containing 100% of fine particle cement had excellent strength development even at $-9^{\circ}C$ of temperature and at 5days, it reached design strength with PE film curing. It is thought that more than 70% of fine particle cement can secure required strength of the shotcrete even at low temperature condition.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.139-145
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• 2009

This study presents an estimation of the strength development of concrete considering the equivalent age using fine particle cement (FC), which is manufactured according to the classification process. Contents and W/B were considered as experimental parameters. The strength considering the equivalent age is gradually increased, and the deviation of the strength according to W/C is increased with decrease of W/C in accordance with the replacement of the fine particle cement. For estimating the apparent activation energy (Ea) considering setting time and blame fineness of cement, Ea of the FC based on setting time is calculated with $27.6{\sim}28.9$ KJ/mol, which is somewhat similar to that of OPC, while by applying Ea based on blame fineness, Ea is increased with increase of FC contents, and is calculated with $40{\sim}56$ KJ/mol. Good agreement is obtained by applying Ea based on setting time, while there was remarkable variation between calculated value and measured value when Ea based on blame fineness. Therefore, it is necessary to add influencing factors in existing Ea to enhance the accuracy of the estimation.