Bowen`s disease associated with esophageal cancer

( Dongkyun Hong ),( Nam Ji Jeong ),( Myung Im ),( Young Lee ),( Young Joon Seo ),( Jeung Hoon Lee ) 대한피부과학회 2012 대한피부과학회 학술발표대회집 Vol.64 No.1

다상 인터리빙 부스트 컨버터의 효율 향상을 위한 커플드인덕터 설계방안

홍석민(Seokmin Hong),홍성용(Seongyong Hong),김동균(Dongkyun Kim),이재범(Jaebum Lee),김백(Baik Kim) 전력전자학회 2022 전력전자학술대회 논문집 Vol.2013 No.11

Passive Duplicate Address-Detection Schemes for On-Demand Routing Protocols in Mobile Ad Hoc Networks

Dongkyun Kim,Hong-Jong Jeong,Toh, C.K.,Sutaek Oh IEEE 2009 IEEE Transactions on Vehicular Technology VT Vol.58 No.7

<P>Internet protocol (IP) auto-configuration in mobile ad hoc networks (MANETs) has attracted much attention. Efficient duplicate address detection (DAD) schemes should be devised to provide each node with its unique address in the network. Generally, DAD schemes can be categorized into two classes: 1) active DAD and 2) passive DAD (PDAD). In this paper, we focus on PDAD schemes over on-demand ad hoc routing protocols. Specifically, we have three goals: 1) improving the accuracy of detecting address conflicts; 2) improving the successful detection success ratio; and 3) reducing the time taken to detect these conflicts. Unlike current approaches, we propose several schemes that exploit additional information, such as sequence number, location, and neighbor knowledge. Simulation results show that our approaches achieve better accuracy and shorter time to detect conflict addresses when compared with existing schemes.</P>

Effect of pre-drying treatments on solution-coated organic thin films for active-matrix organic light-emitting diodes

Shin, Dongkyun,Hong, Ki-Young,Park, Jongwoon Elsevier 2017 The Journal of physics and chemistry of solids Vol.111 No.-

<P><B>Abstract</B></P> <P>Due to capillary rise, organic thin films fabricated by solution coating exhibit the concave thickness profile. It is found that the thickness and emission uniformities within pixels vary depending sensitively on the pre-drying treatment that has been done before hard bake. We investigate its effect on the film quality by varying the temperature, time, pressure, fluid flow-related solute concentration, and evaporation-related solvent. To this end, we carry out spin coatings of a non-aqueous poly(N-vinylcarbazole) (PVK) for a hole transporting blanket layer. With a low-boiling-point (BP) organic solvent, the pre-drying makes no significant impact on the thickness profiles. With a high-BP organic solvent, the PVK films pre-dried in a vacuum for a sufficient time exhibit very uniform light emission in the central region, but non-emission phenomenon near the perimeter of pixels. It is addressed that such a non-emission phenomenon can be suppressed to some extent by decreasing the vacuum pressure. However, the rapid evaporation by heat conduction during the pre-drying degrades the thickness uniformity due to a rapid microflow of solute from the edge to the center. No further enhancement in the thickness uniformity is obtained by varying the solute concentration and using a mixture of low- and high-BP solvents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The concave thickness profile appears in solution coating due to capillary action. </LI> <LI> Pre-drying treatments are applied to solution-coated organic films. </LI> <LI> Pre-drying in a vacuum with a high-boiling-point solvent is desirable. </LI> <LI> It leads to shrinkage of light emission area within pixels. </LI> <LI> The vacuum pressure is the most critical parameter that enhances the film quality. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Slot-die coating of organic thin films for active-matrix organic light-emitting diode displays

Shin, Dongkyun,Lee, Jin-Young,Hong, Ki-Young,Park, Jongwoon,Seo, Yu-Seok Elsevier 2016 THIN SOLID FILMS - Vol.619 No.-

<P><B>Abstract</B></P> <P>We investigate solution coating of organic thin films for the fabrication of active-matrix organic light-emitting diode (AMOLED) displays. For blanket layers, an aqueous polymer-based hole injection layer (HIL) and non-aqueous polymer-based hole transport layer (HTL) are fabricated by slot-die coating and also by spin coating for comparison. Thin organic films coated on a substrate with a pixel-defining layer (bank) exhibit the concave profile due to capillary rise. With an attempt to suppress it and thus obtain thin films with high conformity, we carry out solution coating by varying the pixel size, solvent, and drying condition. As the pixel size increases, the overall film thickness increases by an enhancement in the filling of a solution into the cells. We have found that spin coating provides more conformal thin films for the aqueous polymer HIL. When a high-boiling-point solvent and vacuum drying are used for the non-aqueous polymer HTL, however, the film conformity by slot-die coating is higher than that by spin coating. It is attributed that an evaporation-induced convective flow (microflow) occurs from the pixel edge to the center. It also enables the formation of homogeneous light distribution over the emission area of OLED pixels.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Coating was performed by varying the pixel size, solvent, and drying condition. </LI> <LI> Evaporation-induced convective flow occurs from the pixel edge to the center. </LI> <LI> A high-boiling-point solvent and vacuum drying provide high-conformity thin films. </LI> <LI> The emission uniformity of pixels can be enhanced to a great extent. </LI> </UL> </P>

IPv6 코어 망에서의 IPv4 노드 이동성 지원 방안

정홍종 ( Hong-jong Jeong ),김동균 ( Dongkyun Kim ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.1

IPv6 는 풍부한 주소공간, 이동성 지원, 보안기 강화, QoS 지원, 주소자동 생성 등 다양한 기능을 제공하며 IPv4 를 대신할 표준 인터넷 프로토콜로 개발되었다. 하지만 현재까지 많은 수의 IPv4 노드들이 사용되고 있어, IPv6 네트워크에서 기존의 IPv4 노드의 지원은 필수적이다. 본 논문에서는 IPv6 코어 망에서 이동성 기능이 없는 IPv4 노드의 이동성을 지원하기 위한 방안을 제안한다.

MicroRNA-34a Modulates Cytoskeletal Dynamics through Regulating RhoA/Rac1 Cross-talk in Chondroblasts

Kim, Dongkyun,Song, Jinsoo,Kim, Sunhyo,Park, Hyang Mi,Chun, Churl-Hong,Sonn, Jongkyung,Jin, Eun-Jung American Society for Biochemistry and Molecular Bi 2012 The Journal of biological chemistry Vol.287 No.15

<P>MicroRNAs (miRNAs) have been implicated in various cellular processes, such as cell fate determination, cell death, and tumorigenesis. In the present study, we investigated the role of miRNA-34a (miR-34a) in the reorganization of the actin cytoskeleton, which is essential for chondrocyte differentiation. miRNA arrays to identify genes that appeared to be up-regulated or down-regulated during chondrogenesis were applied with chondrogenic progenitors treated with JNK inhibitor. PNA-based antisense oligonucleotides and miRNA precursor were used for investigation of the functional roles of miR-34a. We found that, in chick chondroprogenitors treated with JNK inhibitor, which suppresses chondrogenic differentiation, the expression levels of miR-34a and RhoA1 are up-regulated through modulation of Rac1 expression. Blockade of miR-34a via the use of PNA-based antisense oligonucleotides was associated with decreased protein expression of RhoA (a known modulator of stress fiber expression), down-regulation of stress fibers, up-regulation of Rac1, and recovery of protein level of type II collagen. miR-34a regulates RhoA/Rac1 cross-talk and negatively modulates reorganization of the actin cytoskeleton, which is one of the essential processes for establishing chondrocyte-specific morphology.</P>

HIMALIS-VI: Fast and Secure Mobility Management Scheme Based on HIMALIS for V2I Services in Future Networks

Jeong, Hong-Jong,Kafle, Ved P.,Yoo, Hongseok,Kim, Dongkyun Springer-Verlag 2014 WIRELESS PERSONAL COMMUNICATIONS Vol.78 No.4

초등학교 교사의 사회과 학생평가에 대한 인식 및 전문성 분석

홍서영(Hong, SuhYoung),한동균(Han, DongKyun) 한국사회과교육연구학회 2017 사회과교육 Vol.56 No.3

본 연구는 초등학교 교사들을 대상으로 초등 사회과의 학생평가 실태 및 인식을 조사하고, 사회과 학생평가의 전문성 정도와 이에 영향을 미치는 요인을 분석하였다. 그 결과 초등학교 교사들은 사회과 학생평가의 방법으로 서답형 지필검사가 가장 적합하다고 생각하며, 현재 이를 가장 많이 활용하고 있었다. 또한 사회과 학생평가 방법의 선정 기준으로 평가의 목적을 가장 많이 고려하고 있으며, 평가활동 시 서답형 채점의 일관성 유지와 평가문항의 타당도와 신뢰도 확보에 어려움을 나타내고 있었다. 그리고 사회과 교수 . 학습에서 학생평가를 교육활동의 중요한 요소라고 인식하고 있으며, 현재의 선다형 평가방식의 질을 개선하는 것이 필요하다고 생각하고 있었다. 또한 사회과 학생평가에 있어서 교사에게 가장 중요한 능력으로 평가방법에 대한 이해 및 문항 개발 능력을 지목하고 있었다. 한편, 초등학교 교사들은 전반적으로 사회과 학생평가에 대한 전문성을 가지고 있는 것으로 조사되었지만 평가도구의 개발 등에 대한 전문성은 다른 영역에 비해 부족한 것으로 나타났다. 그리고 교사의 배경 변인에 따라 사회과 학생평가 전문성의 차이가 있는지를 분석한 결과, 성별과 평가 관련 연수 이수 여부는 사회과 학생평가 전문성과 관련 있는 것으로 나타났으나, 심화전공, 교사 경력, 평가 과목 수강, 학력 등에 따라서는 사회과 학생평가 전문성의 차이가 거의 나타나지 않았다. 사회과 학생평가에 영향을 미치는 요인은 교사의 성별, 경력, 평가관련 연수 이수 여부였으며, 그 외 대학에서의 심화전공이나 평가 관련 과목 수강 및 교사의 학력은 사회과 학생평가 전문성에 영향을 미치지 못했다. This study investigated current situations and awareness of student assessment in social studies in elementary schools among teachers and analyzed degree of professionality of student assessment in social studies and influencing factors. This study observed that elementary school teachers perceive short-answer examinations as the most appropriate form for evaluation in social studies and this form has been widely adopted. In addition, the objective of evaluation was commonly considered for selection criterion as the evaluation method for social studies. It also found that consistent grading of short answer questions and guarantee of validity as well as reliability in evaluation questions are challenging. Student assessment is a crucial element in an educational activity for instruction and learning of social studies. They also perceived that the quality of current multiplechoice examinations should be upgraded. In addition, they selected understanding of evaluation methods and development of questions as the most crucial skills required for teachers in terms of evaluation in social studies. Meanwhile, this study demonstrated that elementary school teachers are generally specialized in student assessment in social studies, while they are less proficient in development of evaluation tools compared to other areas. This study explored if there is a difference in evaluating professionality in social studies depending on variables of teachers’ backgrounds. Gender and training completion are associated with evaluating professionality in social studies; whereas, there is no significant difference in intensive major, teacher career, attending evaluation courses, and academic degrees. Influencing factors on student assessment in social studies include teacher gender, career, and completion of evaluation training. However, intensive major in university, attending evaluation-related courses, and academic degrees did not affect student performance in social studies.

점탄성 댐핑 물질을 이용한 하드 디스크 드라이브의 NRRO 저감

김동균(Dongkyun Kim),장건희(Gunhee Jang),홍선주(Seonju Hong),한재혁(Jeahyuk Han),이창조(Changjo Lee),정대현(Deahyun Jung),박일웅(Iloong Park) 한국소음진동공학회 1999 한국소음진동공학회 학술대회논문집 Vol.1999 No.6