• Computers and Concrete
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• v.19 no.3
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• pp.275-282
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• 2017

The aim of this study is to build Machine Learning models to evaluate the effect of blast furnace slag (BFS) and waste tire rubber powder (WTRP) on the compressive strength of cement mortars. In order to develop these models, 12 different mixes with 288 specimens of the 2, 7, 28, and 90 days compressive strength experimental results of cement mortars containing BFS, WTRP and BFS+WTRP were used in training and testing by Random Forest, Ada Boost, SVM and Bayes classifier machine learning models, which implement standard cement tests. The machine learning models were trained with 288 data that acquired from experimental results. The models had four input parameters that cover the amount of Portland cement, BFS, WTRP and sample ages. Furthermore, it had one output parameter which is compressive strength of cement mortars. Experimental observations from compressive strength tests were compared with predictions of machine learning methods. In order to do predictive experimentation, we exploit R programming language and corresponding packages. During experimentation on the dataset, Random Forest, Ada Boost and SVM models have produced notable good outputs with higher coefficients of determination of R2, RMS and MAPE. Among the machine learning algorithms, Ada Boost presented the best R2, RMS and MAPE values, which are 0.9831, 5.2425 and 0.1105, respectively. As a result, in the model, the testing results indicated that experimental data can be estimated to a notable close extent by the model.

• Computers and Concrete
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• v.19 no.2
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• pp.153-159
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• 2017

In this study, the strength properties of alkali-activated silica fume (SF) mortars were investigated. The crushed limestone sand with maximum size of 0-5 mm and the sodium meta silicate ($Na_2SiO_3$) used to activate the binders were kept constant in the mortar mixtures. The mortar specimens using the replacement ratios of 0, 25, 50, 75 and 100% SF by weight of cement together with $Na_2SiO_3$ at a constant rate were produced in addition to the control mortar produced by only cement. Moreover, the mortar specimens using the replacement ratio of 4% titanium dioxide ($TiO_2$) by weight of cement in the same mixture proportions were produced. The prismatic specimens produced from eleven different mixtures were de-moulded after a day, and the wet or dry cure was applied on the produced specimens at laboratory condition until the specimens were used for flexural strength ($f_{fs}$) and compressive strength ($f_c$) measurement at the ages of 7, 28 and 56 days. The $f_{fs}$ and $f_c$ values of mortars applied the wet or dry cure were compared with the results of control mortar. The findings revealed that the $f_c$ results of the alkali activated 50% SF mortars were higher than that of mortar produced with Portland cement only. It was found that the $f_{fs}$ and $f_c$ of alkali-activated SF mortars cured in dry condition was averagely 4% lower than that of alkali-activated SF mortars cured in wet condition.

• Journal of Korean Medical classics
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• v.24 no.6
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• pp.101-110
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• 2011

There are not a few cases in Oriental medicine where a different prescription should be given to some of the patients whose symptoms are similar to each other. In other words, there might happen a misdiagnosis due to an extremely delicate difference in symptoms of the same diseases, causing a patient's condition to get worse or to be even on the brink of death. In such a context, the records in "WooJam JabJeo(愚岑雜著)" are worthwhile to do in-depth research on. Jang-Taegyung described his first-hand experience in major medical treatment very vivaciously during his ages between 25 and 42. Particularly, most of the prescriptions recorded in this book include not only his empirical prescriptions on the patients who life was almost on the brink of death but it also so plentifully contained the process of overcoming the side effect caused by other clinics' misdiagnosis; thus, that this book is drawing attention in that it could be indispensable materials not only in the research on medical history but also for clinical treatment. Particularly, as regards two cases of insanity, this book mentions the reason for using totally different prescription on one case from the other case even though the two cases had a similar symptom, through which we can acquire somewhat concrete experience in curing scenes though indirectly during the period of the Joseon Dynasty. We were able to get the result from the analysis of the two cases of insanity as follows: 1. WooJam, in treating the two cases of insanity due to the severe exacerbation of yang energy, managed to treat the one case by inducing a bowel movement and the other case by inducing urination. Such a different treatment seems to be greatly attributable to the constitutional factor of the two patients. Such an Oriental-medicine-based method of diagnosis and prescription as WooJam's is rarely found in Western medicine-i.e., that's why more thorough research on Oriental medicine is deeply required. 2. In case of the second patient, the patient arrived at insanity due to another clinic's treatment on perspiration on the patient with severe mouth thirst. This medical story once again highlights the importance of a diagnosis in today's Oriental medicine and at the same time it's a good example showing how big the side effect caused by the abuse of medicinal herbs is. The second patient's body fluids ran dry and finally his yang energy got exacerbated all the more due to the treatment by perspiration.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.349-356
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• 2016

This report presents the results of an investigation on the early strength development of pastes high volume slag cement (HVSC) activated with different concentration of sodium carbonate ($Na_2CO_3$). The ordinary Portland cement (OPC) was replaced by ground granulated blast furnace slag (GGBFS) from 50% to 90% by mass, the dry powders were blended before the paste mixing. The $Na_2CO_3$ was added at 0, 2, 4, 6, 8 and 10% by total binder (OPC+GGBFS) weight. A constant water-to-binder ratio (w/b)=0.45 was used for all mixtures. The research carried out the compressive strength, ultrasonic pulse velocity (UPV), water absorption and X-ray diffraction (XRD) analysis at early ages(1 and 3 days). The incase of mixtures, V5 (50% OPC + 50% GGBFS), V6 (40% OPC + 60% GGBFS) and V7 (30% OPC + 70% GGBFS) specimens with 6% $Na_2CO_3$, V8 (20% OPC + 80% GGBFS) and V9 (10% OPC + 90% GGBFS) specimens with 10% $Na_2CO_3$ showed the maximum strength development. The results of UPV and water absorption showed a similar tendency to the strength properties. The XRD analysis of specimens indicated that the hydration products formed in samples were CSH and calcite phases.

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.120-126
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• 1978

Comparative studies have been carried out to elucidate effects of 3 types of Japanese hardening agents and cement on the compressive and tensil strength of solidified briquette ashes with different ages, when various mixing ratio were applied. 1. The hardening agent, especially type C, were appeared to be better than the cement to obtain higher compressive and tensil strength of the products. 2. The compressive strength when mixing ratio of 1 : 3 applied were : $177.6kg/cm^2$. for type C; $168.6kg/cm^2$ for type A; and $155.94kg/cm^2$ for type B. 3. The tensil strength when mixing ratio of 1 : 3 applied were: $24.63kg/cm^2$ for type C ; $23.14kg/cm^2$ for type B; and $22.45kg/cm^2$ for type A. 4. Although the solidified briquette ashes were found to be not as strong as cement mortar, it is (considered that they could be used instead of low-strength concrete, and that they could contribute to reduce the amount of terminal city-wastes then to reduce pollutions caused by the wastes.

• Journal of Aquaculture
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• v.20 no.4
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• pp.270-277
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• 2007

White spot syndrome virus (WSSV) which is the most serious threat to cultured shrimp around the world has given enormous economic damages to shrimp culture industry every year since it was found from the shrimp ponds in the west coast of the South Korea in 1993. WSSV has strong infectivity as well as virulence and it can be rapidly transmitted among shrimps in ponds by cannibalism of infected ones. Polyculture of shrimps with carnivorous fish has been applied in commercial shrimp farms to suppress or delay the viral outbreak because the fish may selectively eat the moribund shrimps infected by virus. To determine the selective predatory effect of a carnivorous fish, river puffer Takifugu obscurus on white shrimp Litopenaeus vannamei, polyculture trials in laboratory scale of WSSV-infected and non-infected shrimps with river puffer were conducted in concrete round tanks of $28.26\;m^2$ in surface area as followings: 1) juvenile shrimps (B. W. 0.62 g) with 5 months old puffer (B. W. 11.60 g) cultured for 8 days, and 2) sub-adult shrimps (B. W. 6.84 g) with 16 months old puffer (B. W. 85.82 g) cultured for 5 days in order to know the effects according to size difference of cultured animals. In polyculture of juvenile shrimp with 5 months old puffer, survival rates of infected and non-infected shrimps were 46.0% and 89.1% respectively and in that of sub-adult shrimp with 16 months old puffer those were4% and 48% respectively. The results showed that puffer tends to selectively prey on virus infected shrimps among infected and non-infected ones in a limited space with although there is difference in predatory rate with age and density of animals. Regardless of different densities and ages of animals as well as health condition of shrimps, however, there were low differences in daily biomass of shrimp consumed per kg body weight of puffer. This finding suggests that puffer preys on healthy shrimps when moribund shrimps were not sufficient. Therefore, farmers should consider the total biomass of puffer as well as density and stocking time when they stock puffer into shrimp ponds for polyculture.