NMR Investigation of the Interaction between the RecQ C-Terminal Domain of Human Bloom Syndrome Protein and G-Quadruplex DNA from the Human c-Myc Promoter

Lee, Sungjin,Lee, Ae-Ree,Ryu, Kyoung-Seok,Lee, Joon-Hwa,Park, Chin-Ju Academic Press 2019 Journal of molecular biology Vol.431 No.4

<P><B>Abstract</B></P> <P>Bloom syndrome protein (BLM) is one of five human RecQ helicases that participate in DNA metabolism. RecQ C-terminal (RQC) domain is the main DNA binding module of BLM and specifically recognizes G-quadruplex (G4) DNA structures. Because G4 processing by BLM is essential for regulating replication and transcription, both G4 and BLM are considered as potential targets for anticancer therapy. Although several studies have revealed the detailed mechanism of G4 unwinding by BLM, the initial recognition of the G4 structure by the RQC domain is unclear. Here, we investigated the interaction between BLM RQC and the G4 DNA from the c-Myc promoter by NMR spectroscopy. While the signals broadened upon reciprocal titrations, the β-wing of RQC had significant chemical shift perturbations and experienced millisecond timescale dynamics upon G4 binding. A point mutation in the β-wing (N1164A) reduced G4 binding affinity. Our hydrogen–deuterium exchange data indicate that imino protons of G4 were exchanged with deuterium much faster in the presence of RQC. We suggest that RQC binds to G4 by using the β-wing as a separating pin to destabilize the G4. By providing information about the RQC–G4 interaction, our study yields insight into potential strategies for preventing G4 processing by BLM.</P> <P><B>Highlights</B></P> <P> <UL> <LI> RecQ C-terminal (RQC) domain of Bloom syndrome protein (BLM) binds to the G-quadruplex with micromolar <I>K</I> <SUB>d</SUB>. </LI> <LI> β-wing and α2 region of the RQC domain play an important role in the G-quadruplex interaction. </LI> <LI> BLM RQC domain destabilizes G-quadruplex without the helicase domain of the protein. </LI> <LI> Our results contribute to the understanding of the initial G4 recognition process of BLM. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Pervasive Network Control Algorithm for Multicamera Networks

Sungjin Lee,Inwoong Lee,Seonghyun Kim,Sanghoon Lee,Bovik, Alan Conrad IEEE 2014 IEEE SENSORS JOURNAL Vol.14 No.4

<P>Owing to the increasingly large volume and complexity of captured videos, renewable energy systems based on solar energy are of particular interest in the design of energy harvesting (EH) wireless visual sensor networks (WVSNs). Since additional energy consumption following image capture occurs owing to image processing, mote operation, data transmission, and reception, the capture rate significantly affects the lifetime of a node. To this end, we explore a novel energy-efficient framework for EH-WVSN design by developing an optimal algorithm named capture rate and pervasive network control for multicamera networks where the quality of service is maximized by obtaining optimal values for the capture rate, allocated energy, and transmit power, based on field of view-based networking in the presence of event and power acquisition patterns. Through simulations, we demonstrate the feasibility of EH-WVSNs in terms of energy consumption, energy allocation, and capture rate in a realistic scenario (parking surveillance).</P>

영어 회화 교육을 위한 예제 기반 대화 시스템

이성진(Sungjin Lee),이청재(Cheongjae Lee),이근배(Gary Geunbae Lee) 한국정보과학회 언어공학연구회 2007 한국정보과학회 언어공학연구회 학술발표 논문집 Vol.2007 No.10

본 논문에서는 영어 회화 교육을 위한 예제 기반 대화 시스템에 대해 논한다. 기존의 획일적인 멀티미디어 영어 학습에서 벗어나 자연어 처리 및 대화 기술을 이용하여 지능적인 일대일 영어 회화 교육 제공을 목적으로 한다. 본 시스템은 미숙한 학습자 발화를 이해할 수 있으므로 불완전한 언어 구사 능력으로도 대화를 참여할 수 있는 체험형 학습을 제공한다. 이를 통해 학습자에게 영어를 배우려는 흥미로운 동기를 부여한다. 또한 학습자의 표현력 향상을 위한 교육적인 도움 기능을 갖추고 있다. 이를 위해 우리는 학습자의 미숙한 표현을 이해하는 통계 기반의 언어 이해 모듈, 도메인 확장성이 뛰어난 예제 기반 대화관리 모듈, 교육 및 평가 기능을 개발하였다.

전력수요예측을 위한 딥러닝 모델의 성능 비교 연구

이환수(Hwan-su Lee),기송도(Song-Do Ki),김대경(Dae-Kyong Kim) 대한전기학회 2022 대한전기학회 학술대회 논문집 Vol.2022 No.7

영어 회화 교육을 위한 예제 기반 대화 시스템

이성진(Sungjin Lee),이청재(Cheongjae Lee),이근배(Geunbae Lee) 한국정보과학회 2010 정보과학회논문지 : 소프트웨어 및 응용 Vol.37 No.2

본 논문에서는 영어 회화 교육을 위한 예제 기반 대화 시스템에 대해 논한다. 기존의 획일적인 멀티미디어 영어 학습에서 벗어나 자연어 처리 및 대화 기술을 이용하여 지능적인 일대일 영어 회화 교육제공을 목적으로 한다. 본 시스템은 미숙한 학습자 발화를 이해할 수 있으므로 불완전한 언어 구사 능력으로도 대화를 참여할 수 있는 체험형 학습을 제공한다. 이를 통해 학습자에게 영어를 배우려는 흥미로운 동기를 부여한다. 또한 학습자의 표현력 향상을 위한 교육적인 도움 기능을 갖추고 있다. 이를 위해 우리는 학습자의 미숙한 표현을 이해하는 담화 상황 고려 발화의도 인식 모델, 도메인 확장성이 뛰어난 예제기반 대화 관리 모델, 교육 및 평가 기능을 개발하였다. 실험 결과 학습자의 발화에 에러가 많아도 높은 발화의도 인식 성능을 보였으며 대화 상황에 적합한 피드백을 제공하여 학습자가 회화 연습을 끝까지 마치도록 도와 교육 효과에 이바지함을 알 수 있었다. In this paper, we present an Example-based Dialogue System for English conversation tutoring. It aims to provide intelligent one-to-one English conversation tutoring instead of old fashioned language education with static multimedia materials. This system can understand poor expressions of students and it enables green hands to engage in a dialogue in spite of their poor linguistic ability, which gives students interesting motivation to learn a foreign language. And this system also has educational functionalities to improve the linguistic ability. To achieve these goals, we have developed a statistical natural language understanding module for understanding poor expressions and an example-based dialogue manager with high domain scalability and several effective tutoring methods.

Exploiting Sequential and Temporal Localities to Improve Performance of NAND Flash-Based SSDs

Lee, Sungjin,Shin, Dongkun,Kim, Youngjin,Kim, Jihong Association for Computing Machinery 2016 Acm transactions on storage Vol.12 No.3

<P>NAND flash-based Solid-State Drives (SSDs) are becoming a viable alternative as a secondary storage solution for many computing systems. Since the physical characteristics of NAND flash memory are different from conventional Hard-Disk Drives (HDDs), flash-based SSDs usually employ an intermediate software layer, called a Flash Translation Layer (FTL). The FTL runs several firmware algorithms for logical-to-physical mapping, I/O interleaving, garbage collection, wear-leveling, and so on. These FTL algorithms not only have a great effect on storage performance and lifetime, but also determine hardware cost and data integrity. In general, a hybrid FTL scheme has been widely used in mobile devices because it exhibits high performance and high data integrity at a low hardware cost. Recently, a demand-based FTL based on page-level mapping has been rapidly adopted in high-performance SSDs. The demand-based FTL more effectively exploits the device-level parallelism than the hybrid FTL and requires a small amount of memory by keeping only popular mapping entries in DRAM. Because of this caching mechanism, however, the demand-based FTL is not robust enough for power failures and requires extra reads to fetch missing mapping entries from NAND flash. In this article, we propose a new flash translation layer called LAST++. The proposed LAST++ scheme is based on the hybrid FTL, thus it has the inherent benefits of the hybrid FTL, including low resource requirements, strong robustness for power failures, and high read performance. By effectively exploiting the locality of I/O references, LAST++ increases device-level parallelism and reduces garbage collection overheads. This leads to a great improvement of I/O performance and makes it possible to overcome the limitations of the hybrid FTL. Our experimental results show that LAST++ outperforms the demand-based FTL by 27% for writes and 7% for reads, on average, while offering higher robustness against sudden power failures. LAST++ also improves write performance by 39%, on average, over the existing hybrid FTL.</P>

Direct molecular interaction of CO₂ with KTFSI dissolved in Pebax 2533 and their use in facilitated CO₂ transport membranes

Lee, Sungjin,Park, Seul Chan,Kim, Tea-Yon,Kang, Sang Wook,Kang, Yong Soo Elsevier 2018 Journal of membrane science Vol.548 No.-

<P><B>Abstract</B></P> <P>Polymer electrolyte membrane containing potassium bis(trifluoromethanesulfonyl)imide (KTFSI) dissolved in a polymeric solvent of Pebax 2533 demonstrated facilitated transport for effective CO<SUB>2</SUB> separation. Reversible interactions of CO<SUB>2</SUB> with both K<SUP>+</SUP> and TFSI<SUP>-</SUP> dissolved in Pebax 2533 were directly observed by both solid state <SUP>39</SUP>K and <SUP>13</SUP>C NMR and FT-IR spectroscopy for the first time, inducing the CO<SUB>2</SUB> carrier activity for the facilitated transport. Additionally, through comparing the CO<SUB>2</SUB> separation performance of LiTF<SUB>2</SUB>N, NaTF<SUB>2</SUB>N and KTF<SUB>2</SUB>N, it was concluded that alkali cation has play an important role in helping to interact with CO<SUB>2</SUB> for the CO<SUB>2</SUB> carrier activity and that K<SUP>+</SUP> was the best as a CO<SUB>2</SUB> carrier among alkali metals used. Consequently, the KTFSI/Pebax 2533 polymer electrolyte membrane showed significant improvement of the CO<SUB>2</SUB> separation performance due to the carrier action of both K<SUP>+</SUP> and TFSI<SUP>-</SUP> in the solid state with long-term stability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The interactions of CO<SUB>2</SUB> with KTFSI have been directly observed for the first time. </LI> <LI> KTFSI have been utilized as CO<SUB>2</SUB> carriers in facilitated CO<SUB>2</SUB> transport membrane. </LI> <LI> Separation performance of the KTFSI membrane have been improved significantly. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Intelligent Corrective Feedback for Communicative Computer-Assisted Language Learning

Sungjin Lee(이성진) 한국HCI학회 2011 한국HCI학회 학술대회 Vol.2011 No.1

A middleware platform for the validation and utilization of short-term weather forecast data for office buildings

Lee, Junghun,Lee, Sungjin,Kim, Jonghun,Song, Doosam,Jeong, Hakgeun Elsevier 2017 Energy and buildings Vol.149 No.-

<P><B>Abstract</B></P> <P>Simulations are widely used to calculate the thermal environment and energy consumption of buildings. The results of these simulations are affected by weather data, thus making the selection of appropriate weather data essential. Typical weather data are used to analyze a building’s thermal performance, but this is not appropriate for analyzing the performance of an actual building controlled by a building energy management system, which responds to real-time weather conditions. Such a building needs short-term weather forecast data to calculate the energy consumption. However, an evaluation of the validity of weather forecast data has not been performed. This study quantitatively analyzes the validation of real-time weather forecast data. A middleware platform was developed to combine weather forecast data and the EnergyPlus software using Grasshopper software. In addition, weather forecast data and actual weather data were compared to evaluate the forecast validation and a predictive control method using weather forecast data was devised. The application of real-time control was found to reduce the electricity costs incurred for cooling by 10% relative to there being no control, and by 2% relative to fixed temperature control.</P>

Backbone Assignment of the N-terminal Domain of Human Replication Protein A 70 kDa

Lee, Sungjin,Park, Chin-Ju Korean Magnetic Resonance Society 2016 Journal of the Korean Magnetic Resonance Society Vol.20 No.4

Replication Protein A (RPA) is the eukaryotic single-stranded DNA binding protein. It involves in DNA replication, repair, and damage response. Among three subunits, RPA70 has a protein-protein binding domain (RPA70N) at the N-terminal. It has known that the domain recruits several damage response proteins to the damaged site. Also, it is suggested that there are more candidates that interact with RPA70N. Even though several studies performed on the structural aspects of RPA70N and its ligand binding, the backbone assignments of RPA70N is not available in public. In this study, we present the backbone assignments of RPA70N.