http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lee, Keon Hwa,Park, Hyun Jung,Kim, Seung Hwan,Asadirad, Mojtaba,Moon, Yong-Tae,Kwak, Joon Seop,Ryou, Jae-Hyun Optical Society of America 2015 Optics express Vol.23 No.16
<P>We study light-extraction efficiency (LEE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs) using flip-chip (FC) devices with varied thickness in remaining sapphire substrate by experimental output power measurement and computational methods using 3-dimensional finite-difference time-domain (3D-FDTD) and Monte Carlo ray-tracing simulations. Light-output power of DUV-FCLEDs compared at a current of 20 mA increases with thicker sapphire, showing higher LEE for an LED with 250-관m-thick sapphire by ~39% than that with 100-관m-thick sapphire. In contrast, LEEs of visible FCLEDs show only marginal improvement with increasing sapphire thickness, that is, ~6% improvement for an LED with 250-관m-thick sapphire. 3D-FDTD simulation reveals a mechanism of enhanced light extraction with various sidewall roughness and thickness in sapphire substrates. Ray tracing simulation examines the light propagation behavior of DUV-FCLED structures. The enhanced output power and higher LEE strongly depends on the sidewall roughness of the sapphire substrate rather than thickness itself. The thickness starts playing a role only when the sapphire sidewalls become rough. The roughened surface of sapphire sidewall during chip-separation process is critical for TM-polarized photons from AlGaN quantum wells to escape in lateral directions before they are absorbed by p-GaN and Au-metal. Furthermore, the ray tracing results show a reasonably good agreement with the experimental result of the LEE.</P>
Who Becomes Exposed to Celebrity Activism on Twitter?
Seulgi Jang,Yujin Kim,Byung Joon Lee,Kyu S. Hahn 한국언론학회 2015 Asian Communication Research Vol.12 No.1
Twitter has significantly amplified celebrity presence on civic affairs. Although celebrities hold little expertise on policy affairs, they can be quite influential since their popularity allows them to reach large audiences. There is an ongoing debate concerning the democratic implications of increasing celebrity influence in policy affairs. In the current study, taking Oisoo Lee as a test case, we investigate the political implications of celebrity following on Twitter. We first compare Lee’s followers with those of ten news outlets, based on the co-following pattern among 1,442,317 Twitter users. We also had access to supplementary survey data on 11,725 members of an online survey panel who had provided their Twitter screen names. For these survey participants, we are able to match their following behavior with individual level attributes. Our results reveal that Lee’s followers are not ideologically skewed in either direction. Indeed, our survey findings confirmed that a vast majority of Lee’s followers identified themselves as independent. On the other hand, survey results show that Oisoo Lee is more likely to attract those lacking the ability to process one-sided information in a balanced manner. This raises a concern that they could be easily misinformed or misled.
이성민,김봉석,송준호,이수훈,이혜진,이문구,송준엽,이창우 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-
Recently, the robustness against daily impact is important according to portablization and downsizing of mobile electronics. Especially, almost parts of cellular phone should undergo drop test when they fall 1.5 m above ground. This test simulates the case when cellular phone slips through user's fingers while he is talking on the phone. This paper studies a drop test of auto focusing (AF) actuator for camera module in cellular phone. This component is composed of voice coil motor (VCM) as an actuator and leaf spring as a guide and suspension. The leaf spring's deformation is essential for the test because its permanent distortion disables the focusing, and then, a high quality photograph cannot be obtained. Up to now the drop test has been carried out after fabricating real AF actuator. We propose a dropt test model which simulates the drop test based on finite element analysis. This model makes us enable investigate the stress acting on the clamping and curved parts of leaf spring. Stress over Von Mises criterion lets the spring deformed permanently, and then AF actuator malfunctioned, It helps us to design and modify AF actuator without manufacturing the real product. And also, it saves the time and cost for the development of new products.
Miscanthus sinensis 와 타 식물과의 친근성에 관한 연구
정일구(Il Koo Lee),이호준(Ho Joon Lee),이경순(Kyung Soon Lee) 한국식물학회 1970 Journal of Plant Biology Vol.13 No.4
Althought allelopathy has been cleary established for Pinus densiflora by Lee-Monsi, the auther suspected that Miscanthus sinensis which grows vigrously in such Korean pine forests might also exhibit the phenomenon. A total of 33 species having an affinity in the Miscanthus group were recorded in the field. Out of these, five species; Patrinia scabiosaefolia, Lespedeza crytobotrya. Oenothera odorata, Raphanus sativus var. acanthiformis, and Zoysia japonica were considered the A group. Five other species which have no affinity to Miscanthus sinensis, Amaranthus patulus, Solanum nigrum, Capsella bursa-pastorris var. triangularis, Chemopodium album var. centrorubrum and Alopeculus amurensis were considered the B group. Extracts of Miscanthus sinensis were applied to determine relative germination and growth. It was found the growth in the B group was promoted by a cold water extract of Miscanthus stems and leaves, but inhibited remarkably by an extract obtained by passing cold water through Miscanthus root. As expected, growth in the A group was promoted by both experimental treatments.
서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)
김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1
In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.
쌍선형 유도기 모델을 위한 최적 안정화 제어기 설계에 관한 연구
李泰基,李五杰,禹靖仁,李浚柝 東義大學校産業技術開發硏究所 1992 産業技術硏究誌 Vol.6 No.-
An optimal Stabilization Technique for a bilinear induction motor model is introduced. This technique includes two parts ; the one is an stabilization control using Lyapunov Function which has the form of a sum of liner and quadratic function of the state variables, and the other is an optimalizing control using the performance index which depends on the choice of the elements of the Lyapunov matrices. Therefore, induction moter is drived with the smaller overshoot of the ones, simulation results are obtained from a digital computer.
염산용액에서 비누화 PC88A에 의한 용매추출로 Gd와 Sm의 분리
이만승,이광섭,이진영,김성돈,김준수 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.5
Solvent extraction experiments have been performed to separate Gd and Sm from chloride solution with PC88A and saponified PC88A. The effects of extraction conditions on the distribution coefficients of Gd and Sm were investigated. The distribution coefficients of Gd were higher than those of Sm in the experimental ranges of experimental conditions of this study. A solvent extraction model was developed to predict the distribution coefficients of metals and separation factor between Gd and Sm from the initial extraction conditions. The measured distribution coefficients of Gd and Sm with PC88A and saponified PC88A showed good agreements with the predicted values. (Received March 3, 2005)
비누화 PC88A에 의한 NdCl₃와 SmCl₃용매추출의 화학모델
이만승,이광섭,이진영,김성돈,김준수 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.10
A chemical model was developed to estimate equilibrium constant for the solvent extraction of Nd and Sm from chloride solution with saponified PC88A. The model could be employed to predict the distribution coefficient of metal from the initial extraction conditions. The model consisted of chemical equilibria, mass balance, charge balance and solvent extraction reaction. By applying the model to the experimental conditions and data, equilibrium constants for the solvent extraction of Nd and Sm were obtained. The effect of the saponification of PC88A on the extraction of Nd was explained in terms of the equilibrium constant obtained in this study and the change of equilibrium pH. The predicted distribution coefficients of Nd and Sm agreed well with those measured. (Received July 14, 2004)