• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.858-865
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• 2009

Based on the proven feasibility of bottom ash and tire shred-soil mixtures as lightweight fill materials, tire shred-bottom ash mixtures were suggested as a new lightweight fill material to replace the conventional construction material with bottom ash. Therefore, we carried out the laboratory test, field compaction test and performance test of large scale embankment in order to evaluate their suitability for the use of lightweight fill materials in the before studies. We could verified that the ash, tire-shred and the mixture are able to be the useful materials as light fill materials. In this study, we estimated the long-term compressible settlements for 6 materials such as TA(Tire-Bottom Ash mixture), TBA(Tire-Bottom Ash<5mm) mixture, TWS(Tire-Weathered Soil mixture), Bottom Ash, Bottom Ash(<5mm), Weathered soils.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.164-178
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• 2009

The importance of long-term performance of reinforced earth structures has been gaining its attention as the use of reinforced earth structures as load supporting structures is increasing. When using reinforced earth structures as loading supporting structures the stability as well as serviceability requirements must be met. In that respect the time-dependent long term deformation characteristics should be well understood. In this study the applicability of power law-based creep models for modeling of creep deformation of the components of reinforced earth structures are examined.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.4
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• pp.259-266
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• 2005

This paper presents a therapy that uses a constant drug dosage for leading HIV-infected patient to LTNP (Long-Term Non-Progressor). Based on analysis of CTLp (Cytotoxic T Lymphocyte precursor) concentration at equilibrium point and its bifurcation, we found the therapy with a drug whose efficacy is less than a certain level brings higher CTLp concentration at the equilibrium point. We observed a treatment with constant drug dosage whose efficacy is less than full treatment may lead HIV-infected patient to LTNP. It turns out that the treatment whose efficacy is less than full treatment is better in the point of performance on controllability.

• Journal of Electrochemical Science and Technology
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• v.12 no.3
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• pp.358-364
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• 2021

In this study, an anion exchange membrane water electrolysis (AEMWE) cell was operated for ~1000 h at a voltage bias of 1.95 V. Impedance spectra were regularly measured every ~ 100 h, and changes in the ohmic and non-ohmic resistance were traced as a function of time. While there was relatively little change in the I-V curves and the total cell resistance during the long-term test, we observed various electrochemical phenomena in the cell: 1) initial activation with a decrease in both ohmic and non-ohmic resistance; 2) momentary and non-permanent bubble resistance (non-ohmic resistance) depending on the voltage bias, and 3) membrane degradation with a slight increase in the ohmic resistance. Thus, the regular test protocol used in this study provided clear insights into the performance degradation (or improvement) mechanism of AEMWE cells.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.409-410
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• 2022

This paper proposes a fusion model based on Long-Short Term Memory networks (LSTM) and CNN deep learning methods, and applied to multi-category news datasets, and achieved good results. Experiments show that the fusion model based on deep learning has greatly improved the precision and accuracy of text sentiment classification. This method will become an important way to optimize the model and improve the performance of the model.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.41-48
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• 2005

In this paper, we suggest the scheme combining long-term feedback and short-term feedback in MIMO multi-user system and analyze its system performance. At the beginning of communication, long-term feedback is fed back to transmitter such as the number of active antennas, constellations, and transmission powers which are determined to satisfy the given target symbol error and target data rate for each user. After this, short-term feedback of active antenna index is fed back periodically Simulation results show the proposed scheme outperforms better than long-term feedback or short-term feedback information scheme.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.49-63
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• 2018

This study examines both the announcement effect of corporate real estate acquisitions and sales and long-term stock performance. Also, we analyze long-term stock returns on the basis of the amount and the purpose (business activities, financial activities, etc.) of real estate acquisitions and sales. The major findings are as follow. First, we find that there is no significant announcement effect on the real estate acquisitions. However, the announcement day of real estate sales shows significantly positive abnormal stock returns. Second, we find that both the real estate acquisitions and sales show negative long-term stock performance. We also find the same results from the case where we classify our sample on the basis of the amount and the purpose of real estate acquisitions and sales. Third, the amount of real estate acquisitions is significantly negatively related to long-term stock returns, whereas the relation between firm value and the amount of real estate sales is positive only under the business activities. Overall, long-term stock performance decreases after the announcement day of the real estate acquisitions and sales. This results can be explained by agency theory. Also, we conclude that a decline in stock performance after the real estate sales explain an information signal on financial distress.

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.6
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• pp.121-128
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• 2011

Long-term water treatment performance analysis was conducted for the constructed wetland treating agricultural tailwater. Studied wetland was established in 2001 and operated from June, 2002 to November, 2010. Wetland vegetation cover was shown over 90 % coverage after 2005. According to vegetation development, accumulation of sediment nutrient was observed; Organic Carbon, T-P and T-N. In addition, DO concentration and temperature was decreased in the constructed wetland output. An infiltration rate also significantly decreased due to compaction of wetland soil. A runoff coefficient was increased due to the low infiltration rate after 2005. A T-N, TSS and Chl.a removal rate was maintained constantly. However, the T-P removal rate was slightly decreased along to wetland operation because low DO concentration could increase elution of phosphorus from sediment. After constructing open water, the T-P removal rate was increased. This is because open water could accelerate the reaearation process. Consequently, over three years of vegetation development could be helpful for wetland performance. In addition, DO concentration is important factor to maintain the T-P treatment.

• Nuclear Engineering and Technology
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• v.33 no.1
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• pp.12-24
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• 2001

The post-LOCA long term cooling (LTC) performance of the Korean Standard Nuclear Power Plant (KSNPP) is analyzed for both small break loss-of-coolant accidents (LOCA) and large break LOCA at cold leg. The RELAP5/MOD3.2.2 beta code is used to calculate the LTC sequences based on the LTC plan of the Korean Standard Nuclear Power Plants (KSNPP). A standard input model is developed such that LOCA and the followed LTC sequence can be calculated in a single run for both small break LOCA and large break LOCA. A spectrum of small break LOCA ranging from \ulcorner.02 to 0.5 k2 of break area and a double-ended guillotine break are analyzed. Through the code calculations, the thermal-hydraulic behavior and the boron behavior are evaluated and the effect of the important action including the safety injection tank (SIT isolation and the simultaneous injection in LTC procedure is investigated. As a result, it is found that the sufficient margin is available in avoiding the boron precipitation in the core. It is also found that a further specific condition for the SIT isolation action need to be setup and it is recommended that the early initiation of the simultaneous injection be taken for larger break LTC sequences.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.329-338
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• 2021

This study predicts the amount of wind power generation for rational operation plan of wind power generation and capacity calculation of ESS. For forecasting, we present a method of predicting wind power generation by combining a physical approach and a statistical approach. The factors of wind power generation are analyzed and variables are selected. By collecting historical data of the selected variables, the amount of wind power generation is predicted using deep learning. The model used is a hybrid model that combines a bidirectional long short term memory (LSTM) and a convolution neural network (CNN) algorithm. To compare the prediction performance, this model is compared with the model and the error which consist of the MLP(:Multi Layer Perceptron) algorithm, The results is presented to evaluate the prediction performance.