A Study on the Development of Adaptive Learning System through EEG-based Learning Achievement Prediction

Jinwoo KIM(Jinwoo KIM),Hosung WOO(Hosung WOO) 한국4차산업학회 2023 4차산업연구 Vol.3 No.1

Purpose – By designing a PEF(Personalized Education Feedback) system for real-time prediction of learning achievement and motivation through real-time EEG analysis of learners, this system provides some modules of a personalized adaptive learning system. By applying these modules to e-learning and offline learning, they motivate learners and improve the quality of learning progress and effective learning outcomes can be achieved for immersive self-directed learning Research design, data, and methodology – EEG data were collected simultaneously as the English test was given to the experimenters, and the correlation between the correct answer result and the EEG data was learned with a machine learning algorithm and the predictive model was evaluated.. Result – In model performance evaluation, both artificial neural networks(ANNs) and support vector machines(SVMs) showed high accuracy of more than 91%. Conclusion – This research provides some modules of personalized adaptive learning systems that can more efficiently complete by designing a PEF system for real-time learning achievement prediction and learning motivation through an adaptive learning system based on real-time EEG analysis of learners. The implication of this initial research is to verify hypothetical situations for the development of an adaptive learning system through EEG analysis-based learning achievement prediction.

고 에너지 볼 밀의 회전 속도에 따른 활석의 입도 및 광물학적 특성 변화 연구

김혜원(Hyewon Kim),김희주(Heeju Kim),백성지(Seongji Baek),김동휘(Donghwi Kim),공예림(Yerim Kong),김진우(Jinwoo Kim),김민식(Minsik Kim),김현나(Hyunna Kim) 대한지질학회 2018 대한지질학회 학술대회 Vol.2018 No.10

Performance Validation of a Planar Hall Resistance Biosensor through Beta-Amyloid Biomarker

Jinwoo Kim,Sung Joon Kim,Sri Ramulu Torati,Artem Talantsev,Chang Yeop Jeon,Sung Bae Lee,Cheol Gi Kim 한국자기학회 2020 한국자기학회 학술연구발표회 논문개요집 Vol.30 No.1

PCPP derivatives containing carbazole pendant as hole transporting moiety for efficient blue electroluminescence

Kim, Jinwoo,Jin, Youngeup,Kim, Jaehong,Jung, Jaeyeon,Kim, Sun Hee,Lee, Kwanghee,Suh, Hongsuk Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of polymer science Part A, Polymer chemist Vol.47 No.5

<P>The syntheses and characterization of poly((2,6-(4,4-bis(4-((2-ethylhexyl)oxy)phenyl)-4H-cyclopenta[def]phenanthrene))-co-(2,6-(4,4-bis(4-(((9-carbazolyl)hexyl)oxy)phenyl))-4H-cyclopenta[def]phenanthrene)) (BCzPh-PCPPs) and poly((2,6-(4,4-bis(4-((2-ethylhexyl)oxy)phenyl)-4H-cyclopenta[def]phenanthrene))-co-(2,6-(4-(4-(((9-carbazolyl)hexyl)oxy)phenyl)-4-(4-((2-ethylhexyl)oxy)phenyl)-4H-cyclopenta[def]phenanthrene))) (CzPh-PCPPs), with carbazole unit as pendants, are presented. The carbazole moiety, which can improve the hole injection ability, was introduced as a pendant on the PCPP backbone. The devices of the polymers with the configurations of ITO/PEDOT:PSS/polymers/Ca/Al generate EL emission with maximum peaks at 400–450 nm, CIE coordinates of (x = 0.11–0.29, y = 0.11–0.33), low turn-on voltages of 4–6 V, maximum brightness of 60–810 cd/m<SUP>2</SUP>, and luminescence efficiencies of 0.04–0.22 cd/A. The PL spectra of CzPh-PCPPs films did not show any peak at around 550 nm, which corresponds to keto defect or aggregate/excimer formation, even after annealing for 30 h at 150 °C in air. Out of the series, CzPh-PCPP1 (PCPP derivative with 10% of carbazole moiety as pendant) shows blue emission with the maximum brightness of 810 cd/m<SUP>2</SUP> at 9 V, and the highest luminescence efficiency of 0.22 cd/A at 395 mA/cm<SUP>2</SUP>. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1327–1342, 2009</P> <B>Graphic Abstract</B> <P>The conjugated copolymers of BCzPh-PCPPs and CzPh-PCPPs with carbazole pendant were synthesized by Suzuki reaction. The carbazole moiety, which can improve the hole injection ability, was introduced as a pendant on the PCPP backbone. Their thermal, electrochemical, photoluminescent, and electroluminescent properties were investigated. <img src='wiley_img/0887624X-2009-47-5-POLA23241-gra001.gif' alt='wiley_img/0887624X-2009-47-5-POLA23241-gra001'> </P>

Magnetic mesoporous materials for removal of environmental wastes

Kim, Byoung Chan,Lee, Jinwoo,Um, Wooyong,Kim, Jaeyun,Joo, Jin,Lee, Jin Hyung,Kwak, Ja Hun,Kim, Jae Hyun,Lee, Changha,Lee, Hongshin,Addleman, R. Shane,Hyeon, Taeghwan,Gu, Man Bock,Kim, Jungbae Elsevier 2011 Journal of hazardous materials Vol.192 No.3

<P><B>Highlights</B></P><P>• Iron oxide particle embedded mesoporous silica and carbon are synthesized. • Both mesoporous materials are separated easily under aqueous condition using magnet. • Mercury or fluorescein is removed by using magnetic mesoporous material. • Tyrosinase is immobilized in magnetic mesoporous silica and reused after reaction. • Magnetic mesoporous materials are applicable to removal of environmental wastes.</P> <P><B>Abstract</B></P><P>We have synthesized two different magnetic mesoporous materials that can be easily separated from aqueous solutions by applying a magnetic field. Synthesized magnetic mesoporous materials, Mag-SBA-15 (magnetic ordered mesoporous silica) and Mag-OMC (magnetic ordered mesoporous carbon), have a high loading capacity of contaminants due to high surface area of the supports and high magnetic activity due to the embedded iron oxide particles. Application of surface-modified Mag-SBA-15 was investigated for the collection of mercury from water. The mercury adsorption using Mag-SBA-15 was rapid during the initial contact time and reached a steady-state condition, with an uptake of approximately 97% after 7h. Application of Mag-OMC for collection of organics from water, using fluorescein as an easily trackable model analyte, was explored. The fluorescein was absorbed into Mag-OMC within minutes and the fluorescent intensity of solution was completely disappeared after an hour. In another application, Mag-SBA-15 was used as a host of tyrosinase, and employed as recyclable catalytic scaffolds for tyrosinase-catalyzed biodegradation of catechol. Crosslinked tyrosinase in Mag-SBA-15, prepared in a two step process of tyrosinase adsorption and crosslinking, was stable enough for catechol degradation with no serious loss of enzyme activity. Considering these results of cleaning up water from toxic inorganic and organic contaminants, magnetic mesoporous materials have a great potential to be employed for the removal of environmental contaminants and potentially for the application in large-scale wastewater treatment plants.</P>

Optimization of Electropolishing on NiTi Alloy Stents and Its Influence on Corrosion Behavior

Kim, Jinwoo,Park, Jun-Kyu,Kim, Han Ki,Unnithan, Afeesh Rajan,Kim, Cheol Sang,Park, Chan Hee American Scientific Publishers 2017 Journal of Nanoscience and Nanotechnology Vol.17 No.4

<P>Nitinol or NiTi alloys are well-known as an attractive biomedical material due to their unique properties such as the shape memory effect, super-elasticity and biocompatibility. These characteristics enable them to be best candidates for implant materials such as stent. One of the major factors that strongly affect the performance of nitinol stent is its unique surface properties. In this study, the influence of electropolishing on nitinol stents and its corrosion behavior were observed. Electropolishing is an effective method for surface treatment, which not only controls the surface state but also helps to produce uniform surface layers. Therefore, to improve the surface quality of nitinol stents, we conducted an electropolishing under various conditions from 30-40 V and 10-30 s as a post heat treatment for nitinol stent manufacturing process. In order to find the optimal surface state of NiTi stents, various electropolished samples were explored using various characterization techniques. Furthermore, the potentiodynamic polarization tests were also performed to determine the corrosion resistance. The electropolished nitinol stents under the condition of 40 V for 10 s exhibited the best corrosion performance as well as surface quality.</P>

Prototype for the Weather Monitoring System with Web - Based Data Management - Construction and Operation

Kim, Jinwoo,Kim, Jin-Young,Oh, Jai-Ho,Kim, Do-Yong Korean Meteorological Society 2010 大氣 Vol.20 No.2

In this paper, an attempt has been made to build and test self-configuring weather sensor networks and internet based observation system to gather atmospheric data. The aim is to provide integrated or real-time weather information in standard form using network data access protocol. This system was successfully developed to record weather information both digital as well as visual using sensor network and web-enabled surveillance cameras. These data were transformed by network based data access protocol to access and utilize for public domain. The competed system has been successfully utilized to monitor different types of weather. The results show that this is one of the most useful weather monitoring system.

Standard Auctions with Security Bids

Jinwoo Kim 한국계량경제학회 2013 JOURNAL OF ECONOMIC THEORY AND ECONOMETRICS Vol.24 No.1

Peter DeMarzo, Ilan Kremer and Andrzej Skrzypacz (2005) study auctions where bidders compete in securities. As the main results, they show that: a steeper security generates a higher revenue for the seller; the revenue ranking between the first-price and second-price auction depends on the steepness of security; and the first-price auction combined with call option achieves the highest revenue among a general set of auction mechanisms. As pointed out by Che and Kim (2010), using steeper securities can cause the adverse selection problem and reduce the seller's revenue, in case a bidder who expects a higher return must incur a higher investment cost. While the analysis of Che and Kim (2010) focuses on the second-price auction, this paper analyzes the first-price auction to show that it is plagued by the same problem and in fact more vulnerable than the second-price auction to the adverse selection problem, which may lead to a reversal of the DKS's revenue ranking between the two auctions.

Parametric study and performance evaluation of an organic Rankine cycle (ORC) system using low-grade heat at temperatures below 80°C

Kim, Dong Kyu,Lee, Ji Sung,Kim, Jinwoo,Kim, Mo Se,Kim, Min Soo Elsevier 2017 APPLIED ENERGY Vol.189 No.-

<P>A parametric study and performance evaluation of an organic Rankine cycle (ORC) system that uses low-grade heat at a temperature below 80 degrees C and with a cycle power of less than 10 kW was undertaken to analyze the effects of the operating conditions on the performance and efficiency. R245fa was used as the working fluid, and a scroll expander as the power generation device. A model of the system was developed and its predictions were verified by the results of experiments, which were also used to determine the appropriate charge of the working fluid for maximizing the system power output. Owing to the difference between the variations of the power generated by the expander and the power consumed by the pump, the performance of the system was found to initially increase and then decrease with increasing refrigerant charge. The parametric investigation of the ORC system was conducted by varying the pressure ratio and mass flow rate of the working fluid. Increases in both parameters were found to increase the system performance by improving the torque generation and expander speed. The variation of the system performance with the heat sink temperature, which was varied between 20 and 35 degrees C, was also examined. The system power and efficiency were observed to decrease with increasing heat sink temperature owing to the decrease in the pressure ratio resulting from the increased condensation temperature. Based on the study findings, we propose a performance map for a low-temperature low-cycle-power ORC. The power and efficiency are shown to be proportional to the heat source temperature and capacity, which varies in a manner similar to the expander performance. The findings of this study highlight the feasibility of an ORC system that uses low-grade heat at a temperature below the boiling point. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Design, synthesis, and biological evaluation of novel pyrrolo[1,2-<i>a</i>]pyrazine derivatives

Kim, Jinwoo,Park, Mikyung,Choi, Jiwon,Singh, Dileep Kumar,Kwon, Ho Jeong,Kim, Seong Hwan,Kim, Ikyon Elsevier 2019 Bioorganic & medicinal chemistry letters Vol.29 No.11

<P><B>Abstract</B></P> <P>A pyrrolo[1,2-<I>a</I>]pyrazine-based chemical territory was expanded via construction of new chemical library with distinctive substitution patterns, which was made possible by regiodivergent electrophilic acylation followed by aldol condensation. Biological screening of the compounds in this class revealed that the viability of human lymphoma U937 cells was strongly inhibited by <B>6b</B> with a methoxy group at the <I>o</I>-position of the aromatic ring, but not by compounds <B>6t-w</B> bearing a halogen at the <I>o</I>-position. Furthermore, <B>6x</B> having a 2,4-dimethoxyphenyl group inhibited the survival of U937 cells more potently than <B>6b</B>. In contrast, <B>6y</B> possessing a 2,5-dimethoxyphenyl moiety did not show effective inhibition, implying the importance of orientation of the substituent(s) around the benzene ring. The anticancer action of <B>6x</B> with safe therapeutic window could be associated with the FTase-p38 signaling axis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> New pyrrolo[1,2-<I>a</I>]pyrazine-based chemical space via regiodivergent acetylation/formylation followed by aldol condensation. </LI> <LI> Installation of a chalcone unit around the basic pyrrolo[1,2-<I>a</I>]pyrazine in a different orientation. </LI> <LI> Anticancer screening of the synthesized pyrrolo[1,2-<I>a</I>]pyrazine-chalcone hybrids. </LI> <LI> Identification of structural requirement of pyrrolo[1,2-<I>a</I>]pyrazine-chalcone skeleton to inhibit human lymphoma U937 cells. </LI> <LI> Anticancer activity of <B>6x</B> via the caspase-dependent apoptosis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>