Synthesis of Mesoporous composite Material for UV-blocking Application

Youngjun YANG,Kyoungnam KIM,Kyungho CHOI,Youngjin CHOI,HyunJung NA,Ji Man KIM 한국생물공학회 2012 한국생물공학회 학술대회 Vol.2012 No.4

Electricity modulation of a water motion active transducer <i>via</i> surface functionality control

Yang, YoungJun,Park, Junwoo,Yoon, Sun Geun,Kim, Youn Sang unknown 2017 Nano energy Vol.40 No.-

<P><B>Abstract</B></P> <P>Recently, the water motion active transducer, an electricity generator which uses water contact variations, has attracted much attention as an eco-friendly energy harvesting device. In order to understand the electricity generation induced by ionic behavior in water at the solid-liquid interface of a water motion active transducer accurately and apply it to a wide range of applications, fundamental study of the surface functionalities at the solid-liquid interface of the water motion active transducer is essential. However, most studies in the field of water motion active transducer still remain them for a high power performance. Herein, through an investigation of surface functionality control at a solid-liquid interface, we modulate the generating electricity of a water motion active transducer and successfully demonstrate its potential toward the realization of a novel self-powered pH sensor. For both hydrophobicity and surface functionality control at the solid-liquid interface, we used a self-assembled monolayer technique with APTES ((3-aminopropyl) triethoxysilane) and POTS (1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane). Through control of the surface functionalities at the interface, we show substantial potential for the modulation of the generating electricity. In addition, the unique electric characteristics of this device offer a fundamental understanding of the origin of electricity generation at solid-liquid interfaces induced by water motion and provide a more accurate understanding of the ionic behaviors occurring at solid-liquid interfaces toward the novel ion-functional devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We investigated the water motion transducer performance according to surface functionality. </LI> <LI> The surface functionality of water motion transducer was modified with positive. </LI> <LI> Positive surface functionality was fabricated with APTES and POTS. </LI> <LI> Depending on the types of ions(cation/anion), the electrical signals were reversed. </LI> <LI> Water motion transducer with positive functionality was demonstrated as a novel self-powered pH sensor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Ionovoltaic urea sensor

Yang, YoungJun,Yoon, Sun Geun,Shin, ChaeHo,Jin, Huding,Lee, Won Hyung,Park, Junwoo,Kim, Youn Sang Elsevier 2019 Nano energy Vol.57 No.-

<P><B>Abstract</B></P> <P>Urea detection has been studied extensively because urea is an important indicator in medical, environmental and industrial fields. Despite the considerable body of research in this area, limitations such as the need for an external power source and the complex operation of electrochemical flow cells remain. Herein, we introduce a novel urea sensing method that accomplishes urea detection with a single droplet of an analyte using a pH-sensitive ionovoltaic transducer and an enzyme attached glass probe. An ionovoltaic transducer converts ion dynamic phenomena at the solid-liquid interface directly into electrical signals without an external power source or additional electrochemical flow cells. With a single droplet of an analyte containing urea (140 μL), the output voltage is inverted within two minutes by surface potential changes induced by the urea decomposition depending on urea concentration in the range of 1–50 mM. Furthermore, in a selective experiment with various biomolecules such as glucose, ascorbic acid, and lactic acid, the inversion of the output voltage occurred selectively only in the urea containing analyte, which confirmed the feasibility of the proposed unique biosensor. We believe that the combination of the ionovoltaic transducer and the enzyme attached probe will greatly broaden the scope of applications of this novel biosensor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Detection of urea with the self-powered ionovoltaic transducer and a probe. </LI> <LI> An inversion of the output voltage by the decomposition of urea. </LI> <LI> Urea selectivity for various biomaterials in an ionovoltaic urea sensor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

AJAX와 .NET 리모팅을 기반으로 한 서버 중심의 인터넷 어플리케이션

양영준(Youngjun Yang),이인환(Inhwan Lee) 한국정보과학회 2009 한국정보과학회 학술발표논문집 Vol.36 No.2D

인터넷 통신 기술의 발전으로 사용자들은 PC에 설치형 프로그램인 전형적인 데스크탑 어플리케이션보다 웹 브라우저를 통하여 다양한 서비스들을 이용한다. 현재 웹 기술의 발전으로 사용자의 브라우저와 웹 서버간의 비동기 통신이 가능하여 동적 서비스가 가능하게 되었지만, 다른 시스템과의 통신 기술 및 스레딩 기술 등 기술적으로 전형적인 데스크탑 어플리케이션에 비해 부족한 부분이 많이 있다. 현재 이러한 문제를 해결 하기 위하여 ActiveX, Flex, Java Applet, Sliverlight등을 이용하고 있다. 이 방법들은 클라이언트 자원으로 동작하게 되며, 전형적인 데스크탑 어플리케이션의 기능을 대신 할 수 있다는 장점이 있다. 그러나 시스템이 정상적으로 작동하기 위해서는 필수적으로 사용자가 플러그인을 설치를 해야 하는 불편함이 있으며, 플랫폼 종속적과 브라우저 종속적이라는 단점이 있다. 본 논문에서는 플러그인 설치 없이 모든 브라우저에서 동일하게 작동하기 위해서 기존에 클라이언트에 플러그인 되어 동작하던 기능들을 서버 측에서 서버 어플리케이션이 대체 해주는 방법으로 접근하는 서버 중심의 인터넷 어플리케이션을 제안한다. 그리고 제안한 방법을 사용하여 프로토타입 시스템을 구현해보고, 기존 방법들과 비교 분석해 본다. 결과적으로 사용자들은 플러그인 설치 없이 위의 문제를 해결 할 수 있었으면, 사용자 플랫폼 독립성을 얻을 수 있다.

GIS 웹사이트 기반 실시간 X-band 레이더 응용연구

양영준(Youngjun Yang),이유경(Yukyung Lee) 한국항해항만학회 2022 한국항해항만학회 학술대회논문집 Vol.2022 No.2

본 연구에서는 속초해수욕장 행정복지센터 옥상, 울릉도에 설치된 X-band 레이더를 통해 실시간으로 해양환경을 계측, 해석한다. 이후 해석결과를 Client PC로 전송하는 것을 목표로 한다. 계측결과를 전자지도, 전자해도를 활용하여, GIS(공간정보시스템)에 오버레이하고, 웹사이트를 통해 실시간 자료를 공유하고 웹서버를 통해 정보를 표출한다. 현재 웹사이트 상에는 CCTV정보 및 해양환경정보가 표출되지만, 향후 Open API활용 등 다양한 응용연구를 수행할 예정이다. In this study, the marine environment is measured and analyzed in real time through the X-band radar installed on the rooftop of the Sokcho Beach administrative Welfare Center and Ulleungdo. Afterwards, the goal is to transmit the analysis results to the client PC. Using electronic maps and electronic navigational charts, the measurement results are overlaid on GIS (spatial information system), real-time data are shared through a website, and information is displayed through a web server. Currently, CCTV information and marine environment information are displayed on the website, but various application studies such as the use of Open API will be conducted in the future.

朝鮮醫書『增補萬病回春』에 대한 硏究

양영준(Yang YoungJun),안상우(Ahn SangWoo) 한국의사학회 2006 한국의사학회지 Vol.19 No.2

Man-Byeong-Hoi-Chun(萬病回春) is a representative writing of Gong Zhongxian (龔廷賢). It was generally used by Koreans in Joseon(朝鮮) era and issued many times in the latter period of Joseon dynasty. We investigated the Jeung-Bo-Man-Byeong-Hoi-Chun (增補萬病回春, An enlarged edition of the Man-Byeong-Hoi-Chun), which is published in the 17th century, coming to a conclusion like the followings. 1. In Joseon(朝鮮), there was the Jeung-Bo-Man-Byeong-Hoi-Chun which was made through revision and enlargement of the Man-Byeong-Hoi-Chun written by Gong Zhongxian(龔廷賢) of China. 2. There are two versions of the Jeung-Bo-Man-Byeong-Hoi-Chun pressed in Joseon, which are written by Kim Yuk(金堉) in 1656 and by Kim Seok-ju(金錫胄) in 1679. 3. The representative medical books of Joseon such as Eui-Rim-Chual-Yo-Sok -Jip (醫林撮要續集), Dong-Eui-Bo-Gam (東醫寶鑑), Je-Jung-Sin-Pyeon(濟衆新編) contained quotations from the Jeung-Bo-Man-Byeong-Hoi-Chun(增補萬病回春), not from the Man-Byeong-Hoi-Chun (萬病回春). 4. The Jeung-Bo-Man-Byeong-Hoi-Chun(增補萬病回春) contained not only the essence of the Chinese medicine but also new medical systems reflecting actual circumstances of Joseon at that time. So, it can be recognized as the foundation of the Joseon medicine in the latter period of the dynasty.

Low-latency low-complexity heap-based extended min-sum algorithms for non-binary low-density parity-check codes

Youngjun Hwang,Kyeongcheol Yang,Kyungwhoon Cheun IET 2015 IET COMMUNICATIONS Vol.9 No.9

<P>The extended min-sum (EMS) and improved EMS (I-EMS) algorithms for non-binary low-density parity-check codes over GF(<I>q</I>) significantly reduce the decoding complexity with an acceptable performance degradation, but they suffer from high latency because of many serial computations, including a sorting process. On the other hand, the trellis-based EMS algorithm can greatly reduce the latency, but it does not solve the complexity problem in high-order fields (<I>q</I> ≥ 64). To improve the latency problem with low-complexity advantages, the authors propose heap-based EMS (H-EMS) and heap-based I-EMS (HI-EMS) algorithms that are modifications of the EMS and I-EMS algorithms, respectively. The authors also propose double H-EMS and double HI-EMS algorithms trading off the latency against the performance by heaping messages twice. Numerical results show that the H-EMS algorithm has 2.74-9.52 times lower latency than the EMS algorithm with a negligible performance degradation over a wide range of code rates, whereas the HI-EMS algorithm has 1.20-1.62 times lower latency than the I-EMS algorithm. Furthermore, the proposed algorithms may be employed regardless of the decoding schedules.</P>

60-3: High-Performance MoS₂ Thin-Film Transistors for Flexible OLED display

Woo, Youngjun,Hong, Woonggi,Yang, Sang Yoon,Kang, Taegyu,Choi, Sung-Yool Wiley (John WileySons) 2018 Society for Information Display International Symp Vol.49 No.1

비이진 터보 부호를 사용하는 SM-MIMO 시스템의 채널용량 및 성능

황영준(Youngjun Hwang),조성혜(Sunghye Cho),이태교(Tae-Kyo Lee),전경훈(Kyungwhoon Cheun),양경철(Kyeongcheol Yang) 한국통신학회 2015 한국통신학회 학술대회논문집 Vol.2015 No.06

Additive-Free Hollow-Structured Co₃O₄ Nanoparticle Li-Ion Battery: The Origins of Irreversible Capacity Loss

Kim, Youngjun,Lee, Jung-Hyun,Cho, Sungeun,Kwon, Yongwoo,In, Insik,Lee, Jihoon,You, Nam-Ho,Reichmanis, Elsa,Ko, Hyungduk,Lee, Kyu-Tae,Kwon, Hyun-Keun,Ko, Doo-Hyun,Yang, Heesun,Park, Byoungnam American Chemical Society 2014 ACS NANO Vol.8 No.7

<P>Origins of the irreversible capacity loss were addressed through probing changes in the electronic and structural properties of hollow-structured Co<SUB>3</SUB>O<SUB>4</SUB> nanoparticles (NPs) during lithiation and delithiation using electrochemical Co<SUB>3</SUB>O<SUB>4</SUB> transistor devices that function as a Co<SUB>3</SUB>O<SUB>4</SUB> Li-ion battery. Additive-free Co<SUB>3</SUB>O<SUB>4</SUB> NPs were assembled into a Li-ion battery, allowing us to isolate and explore the effects of the Co and Li<SUB>2</SUB>O formation/decomposition conversion reactions on the electrical and structural degradation within Co<SUB>3</SUB>O<SUB>4</SUB> NP films. NP films ranging between a single monolayer and multilayered film hundreds of nanometers thick prepared with blade-coating and electrophoretic deposition methods, respectively, were embedded in the transistor devices for <I>in situ</I> conduction measurements as a function of battery cycles. During battery operation, the electronic and structural properties of Co<SUB>3</SUB>O<SUB>4</SUB> NP films in the bulk, Co<SUB>3</SUB>O<SUB>4</SUB>/electrolyte, and Co<SUB>3</SUB>O<SUB>4</SUB>/current collector interfaces were spatially mapped to address the origin of the initial irreversible capacity loss from the first lithiation process. Further, change in carrier injection/extraction between the current collector and the Co<SUB>3</SUB>O<SUB>4</SUB> NPs was explored using a modified electrochemical transistor device with multiple voltage probes along the electrical channel.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2014/ancac3.2014.8.issue-7/nn500218m/production/images/medium/nn-2014-00218m_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn500218m'>ACS Electronic Supporting Info</A></P>