• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.9
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• pp.2361-2376
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• 2023

The electrocardiogram (ECG) signal is commonly used to screen and diagnose cardiovascular diseases. In recent years, deep neural networks have been regarded as an effective way for automatic ECG disease diagnosis. The convolutional neural network is widely used for ECG signal extraction because it can obtain different levels of information. However, most previous studies adopt single scale convolution filters to extract ECG signal features, ignoring the complementarity between ECG signal features of different scales. In the paper, we propose a dual-scale network with convolution filters of different sizes for 12-lead ECG classification. Our model can extract and fuse ECG signal features of different scales. In addition, different spatial and time periods of the feature map obtained from the 12-lead ECG may have different contributions to ECG classification. Therefore, we add a spatial-temporal attention to each scale sub-network to emphasize the representative local spatial and temporal features. Our approach is evaluated on PTB-XL dataset and achieves 0.9307, 0.8152, and 89.11 on macro-averaged ROC-AUC score, a maximum F1 score, and mean accuracy, respectively. The experiment results have proven that our approach outperforms the baselines.

• Journal of the Korean Ceramic Society
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• v.51 no.5
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• pp.472-476
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• 2014

In this work, a new method that utilizes L-cysteine salicylaldehyde Schiff-base modified macroporous polystyrene resin (PS-CSC) as an effective sorbent has been developed for preconcentration of trace cadmium and lead in environmental water samples. The effect of pH, the contact time, the elution conditions, the flow rate, the initial concentration of target metal ions, and the effects of interfering ions on the preconcentration of the analytes were investigated. The maximum adsorption capacity of PS-CSC under optimum conditions for cadmium and lead were found to be 6.03 - 18.17 mg/g and 12.58 - 36.13 mg/g when the initial concentration of metal ions between 5.0 - 90 mg/L. The limits of detection for cadmium and lead were 2.46 ng/L and $0.52{\mu}g/L$, with a preconcentration factor of 200. The developed method has been validated by analyzing certified reference material and successfully applied for the enrichment and determination of trace cadmium and lead from environmental water samples.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.377-381
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• 1974

Determination of lead in urine is important in industrial hygiene and toxicology. Dithizone method has been principally used for the determination of lead in urine, which gives accurate results in skilful hands but is usually complex and time-consuming. Atomic absorption spectrophotometry is a new simple method and several procedures have been described. However, the influences of pH and the presence of chelating agents during treatment of lead poisoning are not clear. The purpose of this study was to find out the effect of pH and chelating agents on the determination of lead using Shimadzu atomic absorption/flame spectrophotometer, model AA-610. The results obtained were as follows: 1. The atomic absorption spectrophotometry(AAS) could be applied without prior acid digestion to specimens in the absence of chelating agents. The absorbance at $2,170\;{\AA}$, though more sensitive, was more noisy electronically. Therefore, we selected the wavelength of $2,833\;{\AA}$ plus scale expansion. 2. The optimal pH was in the range from 2 to 3. 3. The sensitivity was $0.075{\mu}g/ml/%$ and detection limit was about $0.2{\mu}g/ml$. 4. In the presence of EDTA, lead could not be completely determined without prior acid digestion. 5. On specimens from patients receiving penicillamine therapy, a comparison was made between the values obtained with dithizone method and AAS method with prior acid digestion. The results of comparison showed a very good agreement.

• 보존과학연구
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• s.30
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• pp.137-147
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• 2009

Mireuk temple site is located in Iksan, on the North Jeolla province in Korea, and confirmed tiles, potteries, metals, glasses and other materials that are remaining between Baekje Kingdom and Joseon period after excavations. It is also detected that production and supply of the materials in this era were started inside the country(domestic) at that time. This is important information for the understanding of the production and circulation systems. In this study, lead isotope ratios of 18 samples includedlead glass, crucibles and glazed rafter tiles excavated from Mireuk Temple Site of Baekje era were analyzed for the provenance study of raw glass material supply and distribution of glass products. The results of lead isotope ratio analysis have shown that all raw materials were located in the distribution area of Baekje region and also confirmed to be accord with the previous research results. As comparing the lead isotope ratios of glass and glass materials excavated from Mireuk Temple Site with Miyajidake tomb from Fukuoka Prefecture in Japan, it is found that the same raw materials were used for glass production. It means that there is the active connection between Mireuk temple site and Miyajidake and that these areas are sharing the same materials at the same period. It also shown that artifacts excavated from Miyajidake were strongly influenced from Baekje culture. And it is estimated that there is a possibility of the use ofsame materials whether the supplies of them are from a specific place of Baekje or not

• Advances in nano research
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• v.13 no.2
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• pp.187-197
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• 2022

The synthesis of organic and hybrid organic-inorganic perovskites directly from solution improves the cost- and energy-efficiency of processing. To date, numerous research efforts have been devoted to investigating the influence of the various solvent parameters for the synthesis of lead halide perovskites, focused on the effects of different single solvents on the efficiency of the resulting perovskites. In this work, we investigated the effect of solvent blends for the first time on the structure and phase of perovskites produced via the Lewis base vapor diffusion method to develop a new synthetic approach for water-stable CsPbBr₃ particles with nanometer-sized dimensions. Solvent blends prepared with DMF and water-miscible solvents with different Gutmann's donor numbers (D_N) affect the Pb ions differently, resulting in a variety of lead bromide species with various colors. The use of a DMF/isopropanol solvent mixture was found to induce the formation of the Ruddlesden-Popper perovskite based on lead bromide. This perovskite undergoes a blue color shift in the solvated state owing to the separation of nanoplatelets. In contrast, the replacement of isopropanol with DMSO, which has a high DN, induces the formation of spherical CsPbBr₃ perovskite nanoparticles that exhibit green emission. Finally, the integration of acetone in the solvent system leads to the formation of lead bromide complexes with a yellow-orange color and the perovskite CsPbBr₃.

• Toxicological Research
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• v.19 no.3
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• pp.217-225
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• 2003

Changes of plasma DNA contents and serum biochemical values were measured in rats administered with lead acetate to investigate the in vivo cytotoxic effects of lead and examine the usefulness of these in vivo cytotoxicity changes as indicators of lead exposure and diagnosis of lead poisoning. Rats were given once intraperitonealy with lead acetate (1.6, 8, 40 and 200 mg/kg b.w) and the changes of plasma DNA contents and serum biochemical values were measured at the time of 2, 4, 8, 24, 48 and 72 hours after the administration of lead acetate. Plasma DNA contents began to increase at 2 hours after the administration of lead acetate in the treatment groups of 8, 40 and 200 mg/kg b.w dose-dependently and significantly compared with control group. These DNA increases of each dosage group were continued until 24, 48 and 72 hours and the maximum levels of DNA (4.02, 10.67 and 14.10 times of control) were arrived at 8, 8 and 4 hours after the each treatment, respectively. Among 10 serum biochemical indicators, the activities of creatine kinase were increased to maximum level (6.55 times of control) at 2 hours after the administration and remained to be significantly higher than that of control by 8 hours in the treatment group of 200 mg, however, after 48 hours, the levels in the treatment groups of 40 mg above were lower than that of control. The values of aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase were higher than that of control from 2 to 24 hours in the treatment group of 200 mg. Maximum levels of these enzymes were 3.34, 3.00 and 3.19 times of control, respectively. Both of alkaline phosphatase and triglyceride values in the treatment groups were decreased compared with control. In the case of alka-line phosphatse, the values were significanly decreased from 24 hours and more severely decreased until 72 hours in the treatment groups of 40 mg above (p<0.01). The minimum value was 0.36 times of control in the 200 mg group. The values of triglyceride were significantly decreased in the tratment groups of 40 mg above (p<0.01), but the values were not different significantly among the treatment groups. This study demonstrates that plasma DNA content and serum biochemical values such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alkaline phosphatase and triglyceride are valuable as biomarkers for exposure assessment and diagnosis of lead poisoning.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1987.10a
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• pp.23-23
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• 1987

• Journal of Energy Engineering
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• v.22 no.4
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• pp.338-346
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• 2013

The conventional lead acid battery is optimized for cranking performance of engine. Recently electric devices and fuel economy technologies of battery have influenced more deep cycle of dynamic behavior of battery. I also causes to reduce battery life-time. This study proposed that aging battery model is focused for increasing of battery durability. The stress factors of battery aging consist of discharge rate, charging time, full charging time and temperature. This paper considers the electrochemical kinetics, the ionic species conservation, and electrode porosity. For prediction of battery life cycle we consider battery model containing strong impacts, corrosion of positive grid and shedding. Finally, we validated that modeling results were compared with the accelerated thermal measurement data.

• Atmosphere
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• v.24 no.1
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• pp.1-15
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• 2014

This study compared ensemble mean and probability forecasts of snow depth amount associated with winter storm over South Korea on 28 December 2012 at five operational forecast centers (CMA, ECMWF, NCEP, KMA, and UMKO). And cause of difference in predicted snow depth at each Ensemble Prediction System (EPS) was investigated by using THe Observing system Research and Predictability EXperiment (THORPEX) Interactive Grand Global Ensemble (TIGGE) data. This snowfall event occurred due to low pressure passing through South Sea of Korea. Amount of 6 hr accumulated snow depth was more than 10 cm over southern region of South Korea In this case study, ECMWF showed best prediction skill for the spatio-temporal distribution of snow depth. At first, ECMWF EPS has been consistently enhancing the indications present in ensemble mean snow depth forecasts from 7-day lead time. Secondly, its ensemble probabilities in excess of 2~5 cm/6 hour have been coincided with observation frequencies. And this snowfall case could be predicted from 5-day lead time by using 10-day lag ensemble mean 6 hr accumulated snow depth distribution. In addition, the cause of good performances at ECMWF EPS in predicted snow depth amounts was due to outstanding prediction ability of forming inversion layer with below $0^{\circ}C$ temperature in low level (below 850 hPa) according to $35^{\circ}N$ at 1-day lead time.

• Journal of Navigation and Port Research
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• v.34 no.2
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• pp.131-136
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• 2010

The aim of the paper is to solve the problem of customer reduction due to the difficulty of parts sourcing which impacts production delay and delivery delay in SC networks. Furthermore, this paper is to suggest the new inventory policy of MTS in order to solve the problem of current inventory policy. In order to compare two policies, a LCD maker is selected as a case study and the real data for 2007 years is used for simulation input. The maker uses MTO policy for parts sourcing which has the problem of lead time even if it has some advantage of inventory cost. Based on current process. The simulation program of AS-IS model and TO-BE model using ARENA 10 version is developed for evaluation. In a result, the order number of two policies shows that MTO is 52 and MTS is 53. However the quantity of order shows big difference such that MTO is 168,460 and MTS is 225,106. Particularly, the lead time of new inventory policy shows much shorter that that of MTO such that MTO 100 is days and MTS is 16 days. In spite of short lead time by MTS policy, new policy has to take burden of inventory cost per year. Total inventory cost per year by MTS policy is US$ 11,254 and each part inventory cost is that POL is US$ 1,807, LDI is US$ 2,166 and Panel is US$ 7,281. The implication of the research is that the company has to consider the cost and the service simultaneously in deciding the inventory policy. In the paper, even if the optimal point of deciding is put into tactical area, the ground of decision is suggested in order to improve the problem in SC networks.