• Title/Summary/Keyword: Lee Sam

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The Analysis of the Correlation between the Sustain-Electrode Gap of an AC-PDP and Address Discharge Characteristics (AC-PDP의 유지방전 전극사이의 간격과 어드레스 방전 특성과의 상관성 분석)

  • Lee, Young-Jun;Choi, Su-Sam;Park, Se-Kwang;Kim, Yong-Duk
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.5
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    • pp.239-244
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    • 2006
  • To drive the high-image quality plasma displays of XGA and/or full-HD, we must effectively improve the driving waveform, which get the reset period for the stabilized control of wall charges, the address period to select discharge or non-discharge, and sustain period for luminance in 1 TV-frame, and also the display quality. To accomplish them, the development of the technology for the fast address discharge is required. In this paper, the correlation between the sustain-electrode gap and address discharge characteristics for the high-speed addressing was analyzed using the measurements of dynamic voltage margins. Results showed that the narrower the gap between the sustain electrodes, the narrower the with of the scan pulse became and a dynamic margin of data voltage of 29.2 V was obtained at scan pulse width of $1.0{\mu}s\;and\;V_{ramp}$ of 240 V for driving 4-inch test penal, which the gap between sustain electrodes was $65{\mu}m$.

Design of a Stereoscopic Image Display System Using a LCD Shutter (LCD 셔터를 이용한 입체 영상 디스플레이 시스템의 설계)

  • Lee, Ki-Jong;Kim, Nam-Jin;Moon, Jeong-Sueng;Kim, Ju-Young;Park, Gwi-Tae;Seo, Sam-Joon
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.511-513
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    • 1998
  • This paper describes a full color stereoscopic video display system using a LCD shutter. Human apprehends the world with a natural stereo vision. The left eye sees through a slightly different perspective from the right eye; proposed vision system combines two images into a single image that has stereo depth. That is, when the left image is on the screen, the left shutter opens and the right shutter closes - and vice versa. The LCD shutter channels the left image to the left eye, and the right image to the right eye. The brain then fuses the stereo pair into a single high-resolution, flicker-free 3D image. The designed vision system is a real-time system that shows stereoscopic images without the loss of image information from video cameras.

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Path Planning of Autonomous Mobile Robot (자율 이동 로봇의 경로 계획)

  • Lee, Joo-Ho;Seo, Sam-Joon;Park, Gwi-Tae
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.866-870
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    • 1995
  • To make a mobile robot to get to a goal point, path which connects the mobile robot and the goal point is needed and a path planning is necessary. There are various kinds of a path planning. Well known methods are skeleton method, cell decomposition method and potential field method. But each method has both fortes and defects. In this paper, we propose a new method of path planning to find a path for mobile robot. It is obtained by modifying a Voronoi diagram. An original Voronoi diagram can make a safe path but its result is not satisfied. First defect of path, finded by the original Voronoi diagram, is sulplus of safty which make a path longer. Second defect is that the original Voronoi diagram method has a problem of connecting the Voronoi daigram with start/goal point of mobile robot. These defects are removed in proposed algorithm in this paper. We define a function to show the quality of paths. And by computer simulation, paths are compared and its result are shown.

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Spalling Properties of High Performance Concrete Designed with the Various Blaine of Cement, Mineral Admixture Types and Fiber Contents (시멘트 입도, 혼화재 종류 및 PP섬유 혼입률 변화에 따른 고성능 콘크리트의 폭렬특성)

  • Song, Yong-Won;Shin, Jae-Kyung;Lee, Jae-Sam;Hann, Chang-Pyung;Yang, Seong-Hwan;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.11a
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    • pp.103-106
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    • 2006
  • This study investigates spalling properties of 60MPa class, high performance concrete, made with the various influential parameters, such as, blaine of cement, mineral admixture and polypropylene(PP) fiber contents. Totally 21 parameters of ${\phi}100{\times}200mm$ in size was fabricated; three specimens for variance in blaine of cement, 4 specimens for combination of mineral admixture type, along with 0.05, 0.1, 0.15% of fiber adding ratio. After that, one hour unloading fire test was conducted, and then spalling appearance and spalling degree of specimens was examined. Test showed that a specimen made with high blaine of cement(H) improved early strength but exhibited similar value to a specimen made with low blaine(L) at the age of 28 days, thus indicating comparable spalling appearance. In conclusion, spalling easily occur in higher strength and smaller particle shape of cement and mineral admixture.

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Soyasaponins from Soybean Flour Medium for the Liquid Culture of Ganoderma applanatum

  • Lee, So-Young;Kim, Ju-Sun;Shim, Sang-Hee;Kang, Sam-Sik
    • Bulletin of the Korean Chemical Society
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    • v.32 no.10
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    • pp.3650-3654
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    • 2011
  • Two new unusual soyasaponins named 6"-O-methyldehydrosoyasaponin I(7) and desglucosylsoyasaponin $A_1$ (10) along with eight known saponins, dehydrosoyasaponin IV (1), dehydrosoyasaponin III (= impatienoside A) (2), soyasaponin III (3), dehydrosoyasaponin II (= soyasaponin Bg) (4), soyasaponin II (5), dehydrosoyasaponin I (= soyasaponin Be) (6), soyasaponin I (8), and kudzusaponin $SA_3$ (9), were isolated as their methyl esters and identified from the liquid culture of G. applanatum. Their structures were determined by chemical and spectroscopic analyses including 1D- and 2D-NMR as well as by comparison of their spectroscopic data with those of the reported in literatures. Although dehydrosoyasaponin IV was identified by LC-MS/MS method from soy protein isolate, this is the first report of the isolation of this compound. Dehydrosoyasaponin III (2) and kudzusaponin $SA_3$ (9) were also isolated for the first time from soybean. The presence of soyasaponins in Ganoderma species seems to be unusual feature. Thus, we presumed that compounds 1-10 might all be derived from the defatted soybean flour which was added to the culture medium as a nitrogen source.

Relationship between Olfactory Preferences and Olfactory Event-Related Potentials

  • Lee, Gil-Hyun;Yoon, Hae-Gyung;Kim, Young-Sam;Hyun, Kyung-Yae
    • Biomedical Science Letters
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    • v.26 no.1
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    • pp.14-21
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    • 2020
  • Quantitative evaluation of the sense of smell is done by the olfactory event-related potential (OERP) test. OERP consists of N1, P1, N2, P2, and P3, of which N1 and P1 latency are known to be affected by the concentration of odor stimuli associated with the pre-sensory phase and P2 and P3 are the stages at which odors are perceived and are known to change by subjective evaluation of the stimulus. The purpose of this study was to clarify the correlation between the expression of OERP and the subjective evaluation of the object on the fragrance stimulus using various fragrances. Therefore, the study examined the relative waveform power ratio, preference for each scent stimulus, and finally the amplitude and latency change of the components of OERP, N1 and P2. In contrast, it was found that the late P2 response waveform was an effective aroma stimulus recognition waveform in OERP compared to the initial response waveforms.

A Study on the Construction of Women's Excavated Jangui in 17th Centuries -Mainly on the Jangui from KyungJu Lee's Tomb in Young-am- (17세기 여자 출토 장의의 구성법에 관한 연구 -영암출토 경주 이씨~1684) 장의를 중심으로-)

  • An, Myung-Sook
    • Journal of the Korean Society of Costume
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    • v.57 no.7
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    • pp.45-52
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    • 2007
  • This study is based on the observation of women's Jangui in 17th centuries. As we observed, Jangui in seventeenth century was shown the same style. They were not headdress but coat. The characteristics of shape are Mokpankit, double-seop, straight sleeve, triangle moo, sam-su(which is attached to the end of sleeves) and a little coat string etc. There is no specific mode difference with the change of times. However, the straight sleeve is shown straight line in the early Chosun dynasty. Jangui in seventeen century are all oblique line sleeve except Jangui of Jin-ju Ha's family. Jangui put on coat do not seem clear-cut difference with the change of times. From Jangui of Yang-chun Hu's family in 14th centuries till An-dong Kim's family, the special features of Jangui are the same style. In addition, The double-seop in 17th centuries was not completely symmetry. However, after 19th centuries, Jangui for headdress was shown perfectly symmetry.

5MW Class Gas Turbine Engine Test Cell (5MW급 발전용 가스터빈 엔진 성능시험 설비)

  • Nam, Sam-Sik;Song, Ju-Young;Kim, Sung-Hyun;Lee, Ki-Hoon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.339-342
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    • 2010
  • Doosan Heavy Industries & Construction Co., Ltd. constructed a gas turbine engine test cell to verify operating characteristics and design parameters of 5MW class gas turbine engine for power generation under developing. Engine test cell was designed to satisfy critical requirements to scrutinize all performance parameters of the engine with safe and reliability in accordance with design specification. As the test cell developed can effectively reproduce engine operation conditions covering from start-up to maximum power condition, it can be utilized to make a continuing design improvement of the engine based on practical test data at full stretch. Moreover, it is expected to be serviceable to develop derivative engines and be utilized to put them into serial production and contribute to a competitiveness reenforcement as a gas turbine engine manufacturer.

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Flow structure of wake behind a finite circular cylinder (자유단이 있는 원주의 후류 유동특성에 관한 실험적 연구)

  • Lee, Sang-Jun;Jeong,Yong-Sam
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.6
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    • pp.2014-2022
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    • 1996
  • Flow characteristics of the wake behind a finite circular cylinder(FC) mounted on a flat plate was experimentally investigated. Three finite cylinder models having aspect ratio (length to diameter ratio, L/D) of 6,10 and 13 were tested in this study. Wake velocity was measured by a hot-wire anemometry at Reynolds number of 20,000, and the results were compared with those of two-dimensional circular cylinder. As a result, the free-end effect on the wake structure becomes more dominant with decreasing the aspect ratio(L/D) of the finite cylinder. Invisid flow entrained into the wake region decreases the turbulence intensity and periodicity of the vortex shedding due to existence of the free end. From spectral analysis and cross correlation of the velocity signals, vortices having 24Hz frequency characteristics are found in the down wash flow just behind the free end. There exists very complicated flow near the free end due to interaction between the entrained flow and streamwise vortices. Vortex formation region is destroyed significantly in the near wake and shows quite different wake structures from those of 2-D cylinder.

The Influence of Temperature on Low Cycle Fatigue Behavior of Prior Cold Worked 316L Stainless Steel (I) - Monotonic and Cyclic Behavior - (냉간 가공된 316L 스테인리스강의 저주기 피로 거동에 미치는 온도의 영향 (I) - 인장 및 반복 거동 -)

  • Hong, Seong-Gu;Yoon, Sam-Son;Lee, Soon-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.4
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    • pp.333-342
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    • 2004
  • Tensile and low cycle fatigue (LCF) tests on prior cold worked 316L stainless steel were carried out at various temperatures from room temperature to 650$^{\circ}C$. At all test temperatures, cold worked material showed the tendency of higher strength and lower ductility compared with those of solution treated material. The embrittlement of material occurred in the temperature region from 300$^{\circ}C$ to 600$^{\circ}C$ due to dynamic strain aging. Following initial cyclic hardening for a few cycles, cycling softening was observed to dominate until failure occurred during LCF deformation, and the cyclic softening behavior strongly depended on temperature and strain amplitude. Non-Masing behavior was observed at all test temperatures and hysteresis energy curve method was employed to describe the stress-strain hysteresis loops at half$.$life. The prediction shows a good agreement with the experimental results.