• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.236-241
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• 2024

Due to the recent emphasis on carbon neutrality and environmental regulations, the global electric vehicle (EV) market is experiencing rapid growth. This surge has raised concerns about the recycling and disposal methods for EV batteries. Unlike traditional internal combustion engine vehicles, EVs require unique and safe methods for the recovery and disposal of their batteries. In this process, predicting the lifespan of the battery is essential. Impedance and State of Charge (SOC) analysis are commonly used methods for this purpose. However, predicting the lifespan of batteries with complex chemical characteristics through electrical measurements presents significant challenges. To enhance the accuracy and precision of existing measurement methods, this paper proposes using a Long Short-Term Memory (LSTM) model, a type of deep learning-based recurrent neural network, to diagnose battery performance. The goal is to achieve safe classification through this model. The designed structure was evaluated, yielding results with a Mean Absolute Error (MAE) of 0.8451, a Root Mean Square Error (RMSE) of 1.3448, and an accuracy of 0.984, demonstrating excellent performance.

• International Journal of Advanced Culture Technology
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• v.12 no.3
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• pp.466-470
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• 2024

This study proposes a deep learning-based LSTM model to predict the state of charge (SOC) of lithium-ion batteries. The model was trained using data collected under various temperature and load conditions, including measurement data from the CS2 lithium-ion battery provided by the University of Maryland College of Engineering. The LSTM model effectively models temporal patterns in the data by learning long-term dependencies. Performance evaluation by epoch showed that the predicted SOC improved from 14.8400 at epoch 10 to 12.4968 at epoch 60, approaching the actual SOC value of 13.5441. The mean absolute error (MAE) and root mean squared error (RMSE) also decreased from 0.9185 and 1.3009 at epoch 10 to 0.2333 and 0.5682 at epoch 60, respectively, indicating continuous improvement in predictive performance. This study demonstrates the validity of the LSTM model for predicting the SOC of lithium-ion batteries and its potential to enhance battery management systems.

• Smart Structures and Systems
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• v.32 no.5
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• pp.297-308
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• 2023

Dynamic deflection is important for evaluating the performance of a long-span cable-stayed bridge, and its continuous measurement is still cumbersome. This study proposes a dynamic deflection monitoring method for cable-stayed bridge based on Bi-directional Long Short-term Memory (BiLSTM) neural network taking advantages of the characteristics of spatial variation of cable acceleration response (CAR) and main girder deflection response (MGDR). Firstly, the relationship between the spatial and temporal variation of the CAR and the MGDR is described based on the geometric deformation of the bridge. Then a data-driven relational model based on BiLSTM neural network is established using CAR and MGDR data, and it is further used to monitor the MGDR via measuring the CAR. Finally, numerical simulations and field test are conducted to verify the proposed method. The root mean squared error (RMSE) of the numerical simulations are less than 4 while the RMSE of the field test is 1.5782, which indicate that it provides a cost-effective and convenient method for real-time deflection monitoring of cable-stayed bridges.

• Korean Journal of Acupuncture
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• v.35 no.3
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• pp.139-148
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• 2018

Objectives : This study was performed to examine the toxicity on the long term procedure of Aconitum ciliare Decaisne pharmacopuncture(ADP) solution. Methods : To evaluate the long term toxicity of 3 different repeated doses, 60, 150, and 300 mg/kg/day for 13 weeks were injected into BALB/c mice, respectively. The ADP solution was injected into near ST36 of the right leg and normal saline of the same volume was used for the vehicle control group. To evaluate the toxicity of 60, 150, and 300 mg/kg of repeated doses for 13 weeks, toxic symptoms, weight measurement, hematological test, blood biochemical test, visual examination and weight measurement of major organs, and histopathological test were conducted. Results : No significant changes in toxic symptoms, weight measurement, hematological test, blood biochemical test, visual examination and weight measurement of major organs, and histopathological test were observed in different doses of ADP solution treated groups compared to vehicle control group. Conclusions : As a result, repeated dose at a concentration of 300 mg/kg or less is considered to be not harmful for clinical treatment.

• Journal of Korea Technology Innovation Society
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• v.8 no.3
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• pp.1087-1116
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• 2005

This research examines performance evaluatees' opinions regarding the institutional performance evaluation systems of Government S&T Research Institutes (GRI). Research methodology is as follows: first, four perspectives of Kaplan & Norton (1992) Balanced Scorecard Model are revised into six perspectives suitable to GRI's characteristics. Second, experts classify current performance evaluation measures into the six perspectives. This enables different evaluation systems of three GRI evaluation groups to be compared under the same evaluation measures. Third, GRI's evaluatees are asked to allocate ideal weights on the performance measures. The evaluatees' weights are compared with the weights of current performance measures, and the characteristics of evaluatees' opinions about current performance evaluation systems are analyzed. Results are as follows; first, six perspectives for Korean GRIs are financial, long-term outcome, short-term outcome, strategic direction, project management, human resources perspectives. second, GRI evaluation systems put the most weights on the long- and short-term outcome perspectives and the least weights on the financial perspective. This result complies with theoretical model: in performance evaluation of GRIs, the customer perspective is the most important one while the financial perspective is the least important one. Third, evaluatees think that the long-term outcome perspective of the Basic-technology GRI group and the short-term outcome perspective of the Applied-technology GRI Group needs more weight. Fourth, it is found that the current systems have more weights on the project management and strategic direction perspectives than evaluatees think. The possible explanation of this result would be that since the measures of these perspectives are relatively easier to set up than those of other perspectives, the current systems contains larger number of measures and, accordingly more weights.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.201-202
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• 2023

Now, there are many cases where materials are maintained at construction sites or standard construction prices are not in accordance with the applicable regulations, resulting in a lot of fine dust. Therefore, a particulate matter measurement system is applied not only to manage particulate matter at construction sites but also to reduce particulate matter .This study aims to evaluate the applicability of this particulate matter measurement system to the construction site through long-term measurement experiments using a light scattering method particulate matter measurement instrument at the construction site.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.67-80
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• 2014

Long-term stability and delayed failure of granite were evaluated through the laboratory test based on Wilkins method and Brazilian disc test (BDT) which yields tensile strength, mode I fracture toughness and subcritical crack growth parameters. Then, the long-term strength of granite was estimated by using analytical models and long-term stability of compressed air-energy storage (CAES) pilot cavern pressurized up to 5 ~ 6 MPa was evaluated using numerical code, FRACOD with the determined subcritical crack growth parameters. The results of test and analyses showed that the subcritical crack growth index, n was determined as 29.39 and the inner pressure of 5 ~ 6 MPa had an insignificant effect on the long-term stability of pilot cavern. It was also found that the measurement and analysis of acoustic emission events can describe the accumulation of damage due to subcritical crack growth quantitatively. That is, AE monitoring can provide the current status of rock under loading if we make an identical installation condition in the field with that of the laboratory test.

• Journal of the Korean Society of Food Culture
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• v.16 no.5
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• pp.431-441
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• 2001

To develop the low-temperature and long-term fermented kimchi, kimchi was prepared according to the recipe of a specific ratio of major and minor ingredients and adjusted its salinity to 3.7%. Prepared kimchi fermented at $15{\pm}1^{\circ}C$ for 24 hours and transferred and fermented in a refrigerator only used to make low-temperature and long-term fermented kimchi at $-1{\pm}1^{\circ}C$ for 30 weeks. During 30 weeks of fermentation the changes in physicochemical and microbiological properties of low-temperature and long-term fermented kimchi were studied. The initial pH of 6.47 decrease gradually and dropped to pH 4.0 after 14 weeks of fermentation, and then it maintained at same level. Acidity increased to 0.49% on 2 weeks of fermentation and kept at 0.47 $\sim$0.50% during 2 to 30 weeks fermentation. Salinity was slightly increased at early stage and started to decrease on 4 weeks of fermentation, and then it did not change. The change of reducing sugar content was closely related to the trend of pH change with a very high correlation coefficient(r =0.912). Lactic acid, citric acid, malic acid, succinic acid and acetic acid were major organic acids contained in low-temperature and long-term fermented kimchi. Vitamin C content decreased at initial stage of fermentation and then slightly increased up to the maximum of 22.3 mg% on 8weeks of fermentation. In color measurement, L value continued to increase during the fermentation and reached at the highest of 55.45 on 22 weeks of fermentation, and a and b values of 3.62 and 4.54 also increased to 31.26 and 37.32 on 30 weeks of fermentation, respectively. Total microbial count increased slowly from beginning and was the highest on 4 weeks of fermentation, and then began to decrease slowly. Count of Lactobacillus spp. was highest after 6weeks, but count of Lactobacillus spp. was highest on 2 weeks of fermentation, and then both showed a slow decrease. Yeast count wasn't increased until 4 weeks of fermentation and then increased rapidly to get the highest on 10 weeks of fermentation.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.149-155
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• 2022

This study conducted a descriptive research to compare the degree of patient safety culture awareness among general hospitals and long-term care hospital nurses. The subjects of this study were 150 nurses who worked for more than 6 months at 2 general hospitals and 4 long-term care hospitals located in 3 cities, the data has collected from October to December 2021. To Measure patient safety culture, the patient safety culture measurement tool developed by Soon Gyo Lee was used. Data were analyzed by 𝑥²-test, ANOVA, and t-test using SPSS 20.0 program. As a result of the study, the variables with high patient safety culture were the nurse's age(F=44.17, p=.000), clinical career(F=62.86, p=.000), and current workplace career(F=26.27, p=.000). Among the subdomains of patient safety culture, leadership(t=2.07, p= .040) and patient safety priorities(t=2.18, p=.031) were found to be higher in long-term care hospital nurses than general hospital nurses. Based on this result, we expected that it can be used as data in developing programs to raise the level of patient safety culture in hospitals and long-term care hospitals.

• Korean Journal of Animal Reproduction
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• v.24 no.3
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• pp.249-254
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• 2000

This study was carried out to investigate the possibility of dehydroepiandrosterone sulphate(DHEAS) as a stress hormone. Experiment 1) We evaluated the variation of DHEAS levels of long-term(30minutes a day fur 3 weeks) 37$^{\circ}C$ thermal stressed mice compared with that of cortisol. Serum concentrations of cortisol and DHEAS were measured by radioimmunoassay(RIA). Cortisol levels were not significantly altered both LW(Long-term stressed group, mice were killed without rest) and LR(Long-term stressed group, mice were killed after 4 days' rest) compared with control group, but DHEAS levels were decreased in LW compared with control group(p<0.05), and it kept a sustained difference after 4 days' rest(LR)(p<0.05). Experiment 2) We evaluated the changes of DHEAS levels on term of stress and rest. As stress term was longer, serum DHEAS levels were decreased and also kept a sustained difference after 10 days' rest compared with control group(p<0.05). These results suggest that cortisol has difficulty in taking an accurate measurement after extinction of stimuli, whereas DHEAS is more accurate and stable. Thus, this study implies that DHEAS is a stress-related hormone.