• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.3
• /
• pp.15-25
• /
• 2023

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO₂-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm^-1. Such enhancement in ER performance of SiO₂-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

• Journal of Intelligence and Information Systems
• /
• v.29 no.3
• /
• pp.167-183
• /
• 2023

In the recent field of recommendation systems, various studies have been conducted to model sparse data effectively. Among these, GLocal-K(Global and Local Kernels for Recommender Systems) is a research endeavor combining global and local kernels to provide personalized recommendations by considering global data patterns and individual user characteristics. However, due to its utilization of kernel tricks, GLocal-K exhibits diminished performance on highly sparse data and struggles to offer recommendations for new users or items due to the absence of side information. In this paper, to address these limitations of GLocal-K, we propose the GEase-K (Global and EASE kernels for Recommender Systems) model, incorporating the EASE(Embarrassingly Shallow Autoencoders for Sparse Data) model and leveraging side information. Initially, we substitute EASE for the local kernel in GLocal-K to enhance recommendation performance on highly sparse data. EASE, functioning as a simple linear operational structure, is an autoencoder that performs highly on extremely sparse data through regularization and learning item similarity. Additionally, we utilize side information to alleviate the cold-start problem. We enhance the understanding of user-item similarities by employing a conditional autoencoder structure during the training process to incorporate side information. In conclusion, GEase-K demonstrates resilience in highly sparse data and cold-start situations by combining linear and nonlinear structures and utilizing side information. Experimental results show that GEase-K outperforms GLocal-K based on the RMSE and MAE metrics on the highly sparse GoodReads and ModCloth datasets. Furthermore, in cold-start experiments divided into four groups using the GoodReads and ModCloth datasets, GEase-K denotes superior performance compared to GLocal-K.

• Journal of the Daesoon Academy of Sciences
• /
• v.27
• /
• pp.1-34
• /
• 2016

This paper aims to understand how Daesoonjinrihoe perceives the Later World. Daesoonjinrihoe supports to establish an earthly paradise through the re-creation of the real world unlike other religions which tend to relegate ultimate fulfillment to the afterlife. In other words, Daesoonjinrihoe endeavors to achieve their objectives in the human world rather than outside of it in a potential act of escapism. The new religions in Korea have been characterized by ethnocentrism and doctrines which present Koreans as the new chosen people by emphasizing Korea's crucial role in world leadership. However, the doctrine of Daesoonjinrihoe differ with other new religions of Korea in this regard as its purpose is to redeem the whole world. Daesoonjinrihoe proposes an open embrace of the religious diversity found in Korean society. Daesoonjinrihoe argues that the Later World has not come yet, even though the Former World is over and progress towards the Later World has already been set in motion. The meaning of human nobility is akin to anthropocentricity. According to a variety of myths and legends, animals and supernatural often attempt to become human. Moreover, it would not be an overstatement to assert that the re-creation of the real world and the Daesoon concept of human nobility correspond with these myths and legends. There were not definite interpretations regarding heaven in Confucianism historically, yet Daesoonjinrihoe differentiates clearly that heaven and Sangje are cosmic structures. Buddhism perceives that heaven separately exists as a cosmic structure and that Buddha is a transcendental entity, however; that entity is not accessible for intercession. On the contrary, the ways to save the world have been adduced in Daesoonjinrihoe. In addition, the earthly paradise of the Later World has likewise been introduced. Specifically, it is Sangje that opens the door to that paradise. Unresolved issues in the formation of a world view still persist. There are no shortage of studies on the notion of gods or divine beings, however; most of these studies focus on genealogical classification, forms, functions and other such topics. The concept of god, ghost, or soul does not seem to have been clearly defined in these studies nor has the relationship among these entities and humanity been satisfactorily examined. For example, if human beings become either gods or divine beings, questions regarding divine beings who have acted as protectors or guardians of human beings then arises. The Daesoon cosmology should be specifically compared to cosmology in Daoism. By conducting additional studies such as a comparative research with Daoism, it will be possible to interpret mantras and Daoist art as they appear in Daesoonjinrihoe in a thought-provoking way which can in turn be compared with other religions.

• (The) Research of the performance art and culture
• /
• no.41
• /
• pp.133-156
• /
• 2020

This is a paper that examines the meaning and changes of how Dalgang Song, a parenting song, is accepted in pansori works and how it plays a role in the narrative of the work. In Chapter 2, Compared the lyrics of Dalgang-Dalgang in actual parenting scene and Dalgang-Dalgang in Pansori's work. As a result, the songs in Pansori, show some differences in lyrics, but most of them kept the narrative structure intact. Among them, Gangreung-maehwa-ga maintained the phrase "Dalgang-Dalgang" in front and back, making the least changes. Simcheong-ga and Jeokbyeok-ga maintained their epic structures, but the the front and the rear phrase turned into a "Uh huh, Doong doong". And Dalgang-Dalgang was sung mostly by its mother or grandmother at the actual parenting scene, but the song in Pansori, was all sung by men. Dalgang song in Pansori, had a mostly Gyemyeon melody due to the genre characteristics of Pansori. Also Dalgang-Dalgang for actual parenting, was sung with a leisurely, soft beat. But Dalgang song in Pansori's works were sung rhythmical with Jungjungmori rhythm or Jajinmori rhythm to maximize joy. In Chapter 3, I discussed the roles and meanings of Dalgang song contained in Pansori. Dalgang-Dalgang of Simcheong-ga appeared in the crucial process of Sim Hak-kyu's return to will of life through Simcheong after the death of his wife. In Jeokbyeok-ga, Dalgang song also appeared as a tool to recall the happy memories with his son. On the other hand, Dalgang-Dalgang of Gangreung-maehwa-ga played a role of expressing affection for relationships between men and women, not between parents and children. This is beyond the original meaning of parenting, which means the hedonistic and excessive affection of Mr. Gol. The desire to change a relationship between a man and a woman into between parents and children is also found in Kim Yeon-soo's Chunhyang-ga. This change is an example of how the role and meaning of Dalgang song has changed dramatically as it was inserted into pansori. And the reason why Dalgang-Dalgang was so important in the narrative of Pansori was because of The lyrics of the song contain the love of the baby.

• Economic and Environmental Geology
• /
• v.55 no.6
• /
• pp.727-736
• /
• 2022

Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.

• Clean Technology
• /
• v.29 no.1
• /
• pp.10-21
• /
• 2023

Hydrogels that are made of natural polymer-based double networks have excellent biocompatibility, low cytotoxicity, and high water content, assuring that the material has the properties required for a variety of biomedical applications. However, hydrogels also have limitations due to their relatively weak mechanical properties. In this study, hydrogels based on an alginate di-aldehyde (ADA) and gelatin (Gel) double network that is reinforced with additional hydrogen bonds formed between the hydroxyl (-OH) groups of the hyperbranched polymer (HPG) and the functional groups present inside of the hydrogels were successfully synthesized. The enhanced mechanical properties of these synthesized hydrogels were evaluated by varying the amount of HPG added during the hydrogel synthesis from 0 to 25%. In addition, magnetite nanoparticles (Fe₃O₄ NPs) were synthesized within the hydrogels and the structures and the magnetic properties of the hydrogels were also characterized. The hydrogels that contained 15% HPG and Fe₃O₄ NPs exhibited superparamagnetic behaviors with a saturation magnetization value of 3.8 emu g^-1. These particular hydrogels also had strengthened mechanical properties with a maximum compressive stress of 1.1 MPa at a strain of 67.4%. Magnetic hydrogels made with natural polymer-based double networks provide improved mechanical properties and have a significant potential for drug delivery and biomaterial application.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.1
• /
• pp.47-56
• /
• 2023

This study describes the successful synthesize strategy for the silica nanoparticles utilizing various water sources, including tap, industrial, and stream waters without using deionized water. Also, as-synthesized silica nanoparticles are employed as dispersive materials for the electro-responsive smart fluid application. Specifically, homogeneous silica nanoparticles with sizes of 500-700nm are successfully prepared in large scale at once (ca. 12.0 g) with the described experimental method and showing similar structural and chemical characteristics with silica nanoparticles synthesized using the deionized water. The size of silica nanoparticles are varied according to the ion conductivity differences of tap, industrial, stream water, and deionized water. The size of silica nanoparticles decresed with the increased ion conductivity, indicating the ion suppression of growth of silica nanoparticles. Moreover, as-synthesized silica nanoparticles from various water sources of electro-responsive characteristic are investigated by the smart fluid application. The smart fluids containing silica nanoparticles synthesized by tap, industrial, and stream water exhibited higher shear stress compared to the deionized water, owing to the more rigid fibril-like structures formed by the smaller silica nanoparticles. Conclusively, uniform silica nanoparticles from various water sources without any purification are able to successfully prepared without usage of deionized water and resulting silica nanoparticles manifested higher electro-responsive performance.

• Journal of IKEEE
• /
• v.27 no.1
• /
• pp.116-121
• /
• 2023

In this paper, we develop a deep learning structure for a complex microbial incubator that applies deep learning prediction result information. The proposed complex microbial incubator consists of pre-processing of complex microbial data, conversion of complex microbial data structure, design of deep learning network, learning of the designed deep learning network, and GUI development applied to the prototype. In the complex microbial data preprocessing, one-hot encoding is performed on the amount of molasses, nutrients, plant extract, salt, etc. required for microbial culture, and the maximum-minimum normalization method for the pH concentration measured as a result of the culture and the number of microbial cells to preprocess the data. In the complex microbial data structure conversion, the preprocessed data is converted into a graph structure by connecting the water temperature and the number of microbial cells, and then expressed as an adjacency matrix and attribute information to be used as input data for a deep learning network. In deep learning network design, complex microbial data is learned by designing a graph convolutional network specialized for graph structures. The designed deep learning network uses a cosine loss function to proceed with learning in the direction of minimizing the error that occurs during learning. GUI development applied to the prototype shows the target pH concentration (3.8 or less) and the number of cells (10⁸ or more) of complex microorganisms in an order suitable for culturing according to the water temperature selected by the user. In order to evaluate the performance of the proposed microbial incubator, the results of experiments conducted by authorized testing institutes showed that the average pH was 3.7 and the number of cells of complex microorganisms was 1.7 × 10⁸. Therefore, the effectiveness of the deep learning structure for the complex microbial incubator applying the deep learning prediction result information proposed in this paper was proven.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.1
• /
• pp.252-264
• /
• 2023

This paper proposes a design of a dual-band band-pass filter that integrates a λg/2 open SIR structure, a transmission line, and a fork-type structure with symmetric and asymmetric open stubs. To obtain the dual-band effect, the proposed filter uses the SIR structure and adjusts the impedance ratio of the SIR structure. Therefore, the position of the harmonics of the filter is shifted through the adjustment of the impedance ratio, and this can obtain a double-band effect. In order to obtain the dual-band characteristics, the dual-band effect is obtained by inserting a open stub between the SIR structures with the SIR structure divided in half. In addition, the second frequency response is obtained by adjusting the length of the open symmetrical stub in the fork-shaped structure. The asymmetrical open stub in the fork form achieves optimum bandwidth by adjusting the length. Therefore, the first center frequency of the proposed band-pass filter is 5.896 GHz and the bandwidth is 13.6 %. At this time, the measurement results are 0.13 dB and 33.6 dB. The second center frequency is 5.906 GHz and the bandwidth is 13.6 %. At this time, the measurement results are 0.15 dB and 19.8 dB. The reason is that when the impedance ratio (Δ) is higher than 1, the position of the harmonic is shifted to a lower frequency band. However, if the impedance ratio (Δ) is lowered by one step, the position of harmonics will move to a higher frequency band. The function of the filter designed using these characteristics can be obtained from the measurement result. The proposed band-pass filter has no coupling loss and no via energy concentration loss because there is no coupling structure of input/output and no via hole. Therefore, system integration is possible due to its excellent performance, and it is expected that dedicated short-range communication (DSRC) system applications used in traffic communication systems will be possible.

• Geophysics and Geophysical Exploration
• /
• v.26 no.2
• /
• pp.52-61
• /
• 2023

The use of ultra-high-resolution (UHR) seismic surveys to preceisly characterize coastal and shallow structures have increased recently. UHR surveys derive a spatial resolution of 3.125 m using a high-frequency source (80 Hz to 1 kHz). A digital streamer system is an essential module for acquiring high-quality UHR seismic data. Localization studies have focused on reducing purchase costs and decreasing maintenance periods. Basic performance verification and application tests of the developed streamer have been successfully carried out; however, a comparative analysis with the existing benchmark model was not conducted. In this study, we characterized data obtained by using a developed streamer and a benchmark model simultaneously. Tamhae 2 and auxiliary equipment of the Korea Institute of Geoscience and Mineral Resources were used to acquire 2D seismic data, which were analyzed from different perspectives. The data obtained using the developed streamer differed in sensitivity from that obtained using benchmark model by frequency band.However, both type of data had a very high level of similarity in the range corresponding to the central frequency band of the seismic source. However, in the low frequency band below 60 Hz, data obtained using the developed streamer showed a lower signal-to-noise ratio than that obtained using the benchmark model.This lower ratio can hinder the quality in data acquisition using low-frequency sound sources such as cluster air guns. Three causes for this difference were, and streamers developed in future will attempt to reflect on these improvements.