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Reconstruction of old well log data using deep learning imputation
Gian Antariksa,Radhi Muammar,Agung Nugraha,Jihwan Lee 대한산업공학회 2022 대한산업공학회 추계학술대회논문집 Vol.2022 No.11
Well logs are important datasets for interpreting subsurface geology because they represent the physical properties of the logged formations. However, at certain intervals, such information may be missing and/or incorrect due to drilling issues (e.g., significantly larger mud weight than formation integrity, resulting in formation damage), an inefficient logging process, or tool operational concerns. In the case of logging tool faults, such flaws are often identified by the existence of abnormal data spikes or erroneously low log readings in the damaged formation. To solve this issue, a new deep learning-based system was tested to imputate such missing values for sonic log (DT) data. The missing well log values were predicted using data-driven machine learning methods, specifically the GRU and LSTM, given time step sequence inputs from a window. To establish the ideal parameters for achieving the best validation score, an empirical research technique was used. Throughout the training phase, the relative value of various input parameters was analyzed in order to eliminate insensitive measurements and prioritize data with a high connection to the target variables. This paper highlights the study’s important findings, problems, and potential improvements for future studies.
JungYoon Yi,GiAn Lee,YoungYi Lee,JaeGyun Gwag,EunHo Son,HongJae Park 한국자원식물학회 2016 한국자원식물학회지 Vol.29 No.6
Sweet potato (Ipomoea batatas L.) shoot tips grown in vitro were successfully cryopreserved by encapsulationvitrification. Encapsulated explants are very easily manipulated, due to the relatively large size of the alginate beads, and a large number of samples can be treated simultaneously. In this study, the effects of sucrose preculture, cryoprotectant preculture, and post-warm recovery media on regrowth, following liquid nitrogen (LN) exposure, were investigated to establish an efficient encapsulation-vitrification protocol for sweet potato. Shoot tips of plants grown in vitro were precultured in 0.3 M sucrose for 2 d before encapsulation. Encapsulated shoot tips were pre-incubated in liquid MS (Murashige and Skoog) medium containing 0.5 M sucrose for 16 h, before preculturing in sucrose-enriched medium (0.7 M sucrose) for 8 h. Shoot tips were osmoprotected with 35% plant vitrification solution 3 (PVS3) for 3 h, before being dehydrated with PVS3 for 2 h at 25°C. The encapsulated and dehydrated shoot tips were transferred to 2 mL cryotubes, suspended in 0.5 mL PVS3, and plunged directly into liquid N. High levels of shoot formation were obtained for the cv. Yeulmi (65.7%) and Yeonwhangmi (80.3%). The regrowth rates of cryopreserved samples in Yeulmi (78.9%) and Yeonwhangmi (91.3%), following culture on ammonium-free MS medium for 5 d, were much higher than those cultured on standard MS medium (65.7% and 80.3%, respectively). This encapsulation-vitrification is a promising method for the long-term preservation of sweet potato.
Development of large scale Agent Based Modeling Simulator with Microservice architecture
Habtemariam Dugum Yeshitla,Nugraha Agung,Lee Jihwan,Antariksa Gian 한국경영과학회 2023 한국경영과학회 학술대회논문집 Vol.2023 No.5
In the effort to simply and facilitate the ABM simulation process and data analysis, this research utilized Microservice architecture to build services that provide web UI, code generation, simulation running and data storage features. The developed system is deoplyable on HPC resources and can be accessed by multiple users, providing a better utilization of the computing resources. The number of simulation nodes can be increased to provide a better capacity. Future works of this reseach can focus on building a distributed ABM simulator to utilizing multiple Simulation nodes for one model. Additionally the data query process can be further simplfied by depending less on SQL syntax. All in all, the development of this system can help to preserve simulation data privecy by allowing Institutions to utilized their existing HPC resources, which removes the cost burden from individual modelers when running their simulations.
Lwin, May Likha,Dharmaiah, Peyala,Madavali, Babu,Lee, Chul-Hee,Shin, Dong-won,Song, Gian,Lee, Kap-Ho,Hong, Soon-Jik Elsevier 2018 Intermetallics Vol.103 No.-
<P><B>Abstract</B></P> <P>Bismuth antimony telluride based thermoelectric (TE) materials have been intensively developed and synthesized using different mechanisms, for the room temperature TE applications. In particular, bismuth antimony telluride based TE alloys are very sensitive to deviations in their composition, and to contamination during the materials synthesis. Oxygen contamination during Bi-Sb-Te based materials synthesis is one of the critical factors that alters or diminishes thermoelectric-transport properties. Thus, in this study, how the oxide formation mechanism on the powder surface and bulks of p-type Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB> alloys affected the microstructural features and thermoelectric properties were elucidated quantitatively. While applying heat treatment (HT) to Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB> powder, the constituent elements interacted with the ambient atmosphere and formed a new oxide phase which acted as a barrier to carrier transport. At the initial stage (300 °C) of heat treatment, only the powder surface was oxidized due to the reaction of outer surface atoms with atmospheric air and moisture. While increasing in temperature during HT, this surface oxygen contamination diffused further inside the powder through the grain boundaries. More diffusion and spreading occurred throughout the matrix at 450 °C. The increment of oxygen content from 0.05 to 0.82 wt% drastically decreased the electrical conductivity by 67%, and thermal conductivity by 7% at the heat treatment temperature of 450 °C. This reduction behavior is mainly due to severe scattering of the carriers/phonons at the new formation of oxide (Sb<SUB>2</SUB>O<SUB>3</SUB>) phase near grain boundaries and within the matrix. At a glance, a small increase in the oxygen content wouldn't significantly influence the thermoelectric properties; however, at a certain level of oxide formation (0.82 wt%), severe effects could occur due to the intensified scattering or trapping of carriers by the oxide barrier formation at the grain boundaries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Determined the oxygen concentration of different heat-treated GA powder and SPS bulks. </LI> <LI> Elucidation the relation between the mechanism of oxide formation and the thermoelectric properties of Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB> alloys. </LI> <LI> Identified Sb<SUB>2</SUB>O<SUB>3</SUB> phase at the grain boundary and within the grains. </LI> <LI> Demonstrated the thermoelectric performance in Bi<SUB>0.5</SUB>Sb<SUB>1.5</SUB>Te<SUB>3</SUB> alloys with oxygen content. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Development of large scale Agent Based Modeling Simulator with Microservice architecture
Habtemariam Dugum Yeshitla,Nugraha Agung,Lee Jihwan,Antariksa Gian 대한산업공학회 2023 대한산업공학회 춘계학술대회논문집 Vol.2023 No.5
In the effort to simply and facilitate the ABM simulation process and data analysis, this research utilized Microservice architecture to build services that provide web UI, code generation, simulation running and data storage features. The developed system is deoplyable on HPC resources and can be accessed by multiple users, providing a better utilization of the computing resources. The number of simulation nodes can be increased to provide a better capacity. Future works of this reseach can focus on building a distributed ABM simulator to utilizing multiple Simulation nodes for one model. Additionally the data query process can be further simplfied by depending less on SQL syntax. All in all, the development of this system can help to preserve simulation data privecy by allowing Institutions to utilized their existing HPC resources, which removes the cost burden from individual modelers when running their simulations.