• Title/Summary/Keyword: Lee Sam

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Evolution of Phase Morphology During Compounding of Ternary Blends in a Twin Screw Extruder (이축 압출기를 이용한 혼련에서 삼성분계 블렌드의 상구조 형성과정)

  • Kim, Hyungsu;Lee, Shi-Choon;D .Y. Yu;C. G. Gogos
    • The Korean Journal of Rheology
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    • v.10 no.4
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    • pp.247-255
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    • 1998
  • The morphological changes during melt compounding of ternary blends containing various combinations of acrylonitrile-butadiene-styrene(ABS), methyl methacrylate-butadiene-ethyl acrylate(MBE), styrene-acrylonitrile(SAM) copolymers, and poly(methyl methacrylate)(PMMA) as dispersed components in a fixed matrix of polycarbonate(PC) have been investigated. Depending on the composition of the blend, MBE particles and PMMA phase appear to locate at the PC-SAN interface under the influence of interfacial tensions and motion induced coalescence. The interfacial viscosity is found to be a critical factor that affects the amount of coalescence.

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High Resolution Electrodes Fabrication for OTFT Array by using Microcontact Printing and Room Temperature Process

  • Jo, Jeong-Dai;Choi, Ju-Hyuk;Kim, Kwang-Young;Lee, Eung-Sug;Esashi, Masayoshi
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.186-189
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    • 2006
  • The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and room temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing process. The OTFT array with dielectric layer and organic active semiconductor layer formed at room temperature or at a temperature lower than $40^{\circ}C$. The microcontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a big dielectric.

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A Study on Stamp Process Life Time in Thermal NIL (Thermal NIL 용 스탬프 공정 수명에 관한 연구)

  • Cho, Cheon-Soo;Lee, Moon-Jae;Oh, Ji-In;Lim, O-Kaung;Jeong, Myung-Yung
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.2
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    • pp.239-244
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    • 2011
  • Nano Imprint Lithography(NIL) is technique for copying a pattern from stamp with nano size pattern in order to replicated the materials. It is very important to demold in order to make NIL process effectively. Self Assembled Monolayers(SAM) coater is manufactured by means of decreasing surface energy with the stamp surface treatment to improve release characteristics. Manufactured device contains tilting and rotation option for increasing process life time by coating on the sidewall of the pattern in stamp. The stamp coated with optimized tilting angle $30^{\circ}$ and rotation speed of 10rpm has more imprinting cycles than the stamping coated without tilting and rotation. Effective SAM coating on the sidewall of the pattern in stamp will improve by 50% of process life time.

Onset time analysis of solar proton events

  • Hwang, Jung-A;Cho, Kyung-Suk;Lee, Jae-Jin;Kocharov, Leon;Krucker, Sam;Kim, Yeon-Han;Park, Young-Deuk
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.45.2-45.2
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    • 2010
  • We analyzed onset times of the largest six solar proton events during 1997-2006 of solar cycle 23, as observed at 1AU by two satellites of GOES/SEM (Geostationary Operational Environmental Satellites/the Space Environment Monitor) and SOHO/ERNE (Solar and Heliospheric Observatory/the Energetic and Relativistic Nuclei and Electron). We adopted the time shifted method suggested by Leon Kocharov and determined the path length by Sam Krucker's fitting method. We found some problems of those methods and tried to improve those. In this presentation, we will give details of the energy spectra of the 6 SPE events from the ERNE/HED, and onset time comparison among the SPE, flare, type II burst, and CME.

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Estimation of the History of "The Old House at No'eun-ri" and its Original Structure (홍성 "노은리 고택"의 건축 시기와 가구(架構)의 원형 고찰)

  • Lee, Jong-Seo
    • Journal of architectural history
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    • v.25 no.1
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    • pp.33-46
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    • 2016
  • The old house at No'eun-ri, located in Hongseong-gun Hongbuk-myeon of the Chungcheong Nam-do province, really seems like the old house of late Seong Sam-mun who died in 1456. The original structure of the house seems to have been symmetrical, in terms of its left and right sides, and the females' chamber(Anchae) as well as the guest quarters(Haeng'rang-chae) would have featured a Matbae(맞배) fashion. The flank chamber and corridor would have displayed a multi-storied shape, and people would have been able to traverse the inside of the house all the way to the second story of the residence. We can see such shapes and dispositions from other 'ㅁ'-shaped houses - found in Chungnam and Gyeongbuk regions - which are now considered as distinct characteristics of certain residences constructed before the war with the Japanese in the 1590s, confirmed from extant vestiges and historical records of that time period. It can be concluded that the old house at No'eun-ri does harbor the traits and elements that resembled the upper class residences of the Joseon dynasty's early half period.

A Study of Power Inductor for Slim Mobile Communication Set (휴대용 이동 통신기기의 슬림화를 위한 전력용 인덕터의 연구)

  • Kim, Du-Il;Seo, Jong-Go;Kim, Sung-Il;Uhm, Jae-Hyun;Jung, Jin-Hwee;Lee, Hea-Jong
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.48-50
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    • 2005
  • As technology is developed, customers want to use many functions in one system. Manufacturers want to reach the customer's needs, make systems more small, thin, light-weight. To make them real, it is necessary to make components to be small and thin. But components of power stage are big, thick and heavy-weighted yet. especially power inductor is the most significant component. This paper proposed a novel chip-type power inductor I-type inductor. Inductor that proposed has 3225-size, 5.6uH and 1.3A of max saturation current. And it has $R_{DC}$ of $0.25{\Omega}$ which is smaller than $0.45{\Omega}$ of chip-type inductor and $0.9{\Omega}$ of coil-type inductor.

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The Surface Modification of Electrode with Solid Electrolyte Interphase for Hybrid Supercapacitor

  • Choi, Min-Geun;Kang, Soo-Bin;Yoon, Jung Rag;Lee, Byung Gwan;Jeong, Dae-Yong
    • Journal of Electrical Engineering and Technology
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    • v.10 no.3
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    • pp.1102-1106
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    • 2015
  • A hybrid supercapacitor (HS) is an energy storage device used to enhance the low weight energy density (Wh/kg) of a supercapacitor. On the other hand, a sudden decrease in capacity has been pointed out as a reliability problem after many charge/discharge cycles. The reliability problem of a HS affects the early aging process. In this study, the capacity performance of a HS was observed after charge/discharge. For detailed analysis of the initial charge/discharge cycles, the charge and discharge curve was measured at a low current density. In addition, a solid electrolyte interphase (SEI) layer was confirmed after the charge/discharge. A HC composed of a lithium titanate (LTO) anode and active carbon cathode was used. The charge/discharge efficiency of the first cycle was lower than the late cycles and the charge/discharge rate was also lower. This behavior was induced by SEI layer formation, which consumed Li ions in the LTO lattice. The formation of a SEI layer after the charge/discharge cycles was confirmed using a range of analysis techniques.

An Hybrid Probe Detection Model using FCM and Self-Adaptive Module (자가적응모듈과 퍼지인식도가 적용된 하이브리드 침입시도탐지모델)

  • Lee, Seyul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.3
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    • pp.19-25
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    • 2017
  • Nowadays, networked computer systems play an increasingly important role in our society and its economy. They have become the targets of a wide array of malicious attacks that invariably turn into actual intrusions. This is the reason computer security has become an essential concern for network administrators. Recently, a number of Detection/Prevention System schemes have been proposed based on various technologies. However, the techniques, which have been applied in many systems, are useful only for the existing patterns of intrusion. Therefore, probe detection has become a major security protection technology to detection potential attacks. Probe detection needs to take into account a variety of factors ant the relationship between the various factors to reduce false negative & positive error. It is necessary to develop new technology of probe detection that can find new pattern of probe. In this paper, we propose an hybrid probe detection using Fuzzy Cognitive Map(FCM) and Self Adaptive Module(SAM) in dynamic environment such as Cloud and IoT. Also, in order to verify the proposed method, experiments about measuring detection rate in dynamic environments and possibility of countermeasure against intrusion were performed. From experimental results, decrease of false detection and the possibilities of countermeasures against intrusions were confirmed.

A Case of Congenital Hypothyroidism Due to Organification Defect Associated with Huerthle Cell Adenoma (Organification장애(障碍)에 의한 선천성(先天性) 갑상선기능저하증(甲狀線機能低下症)과 $H\"{u}rthle$ 세포선종(細胞線腫)이 병발(竝發)된 1예(例))

  • Kim, Byung-Tae;Lee, Kee-Sang;Chung, Soon-Il;Kim, Sam-Yong;Cho, Kyung-Sam;Cho, Bo-Yeon;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.15 no.1
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    • pp.37-43
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    • 1981
  • Congenital hypothyroidism due to organification defect was first reported by Haddad and Sidbury in 1959. The organification defect is easily proved by perchlorate discharge test. We experienced a patient who had large goiter, growth and mental retardation, and revealed positive reponse to perchlorate discharges test, and the surgical biopsied specimen showed Huerthle cell adenoma, which was probably due to chronic stimulation of thyroid stimulating hormone, or coexisted incidentally. Described here a case of congenital hypothyroidism due to organification defect associated with Huerthle cell adenoma, with review of some literatures.

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IMPURITY SEGREGATION ON CRACKED GRAIN BOUNDARIES IN LLCC SOLDER JOINTS DURING THERMAL CYCLING (온도 변화에 지배되는 LLCC Solder접합부에서 균열이 일어난 계면에 대한 불순물 편석)

  • Lee, Seong-Min
    • Korean Journal of Materials Research
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    • v.4 no.3
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    • pp.329-333
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    • 1994
  • A large number of grain boundaries were seen to crack in near-eutectic solder joints of leadless ceramic chip carriers (LLCC's) during thermal cycling at temperature ranges from -$35^{\circ}C$ to +$125^{\circ}C$ with lhr time period. One potential explanation for this type of cracking might be the presence of embrittling species on the boundary. Although there do not appear to be any instances reported in the literature of solders being embrittled by small amounts of contaminating species, the possibility of such an occurrence exists. The potential presence of impurities located at crack surfaces was inspected using Scanning Auger Microprobe(SAM) and it was found that intergranular cracking could be accomplished by the oxidation of the grain boundary. A physical model for fatigue crack growth was introduced, in which grain boundary separation took place under oxidation facilitated by sliding.

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