• Title/Summary/Keyword: 김영기

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Ground Vibration Test for Korea Sounding Rocket - III (KSR-III의 전기체 모달 시험)

  • 우성현;김영기;이동우;문남진;김홍배
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.441-447
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    • 2002
  • KSR-III(Korea Sounding Rocket - III), which is being developed by Space Technology R&D Division of KARI(Korea Aerospace Research Institute) will be launched in late 2002. It is a three-stage, liquid propellant rocket which can reach 250 km altitude and will carry out observation of ozone layer and scientific experiments, such as microgravity experiment, and atmospheric measurement. KSR-III is believed to be an intermediate to the launch vehicle capable of carrying a satellite to its orbit. Space Test Department of KARI performed GVT(Ground Vibration Test) fer KSR-III EM at Rocket Test Building of KARI. GVT is very important for predicting the behavior of rocket in its operation, developing flight control program and performing aerodynamic analysis. This paper gives an introduction of rocket GVT configuration and information on test procedures, techniques and results of It. In this test. to simulate free-free condition, test object hung in the air laterally by 4 bungee cords specially devised. For the excitation of test object, pure random signal by two electromagnetic shakers was used and total 22 frequency response functions were achieved. Polyreference parameter estimation was performed to identify the modal parameters with MIMO(Multi-Input-Multi-Output) method. As the result of the test, low frequency mode shapes and modal parameters below 60Hz were identified

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A Potential-Based Panel Method for the Analysis of Resistance Characteristics of a High Speed Catamaran (포텐셜기저 패널법에 의한 고속쌍동선의 저항성능 해석)

  • Kim, Y.G.;Rhyu, S.S.;Yoo, J.H.;Lew, J.M.;Hong, S.K.
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.4
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    • pp.12-20
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    • 1997
  • A potential-based panel method has been developed to investigate the resistance characteristics of a high speed catamaran advancing on the free surface. Normal dipoles and sources are distributed on the body surface while sources are distributed on the free surface. Linearised free surface conditions are used in the present analysis. To avoid the instabilities due to the velocity difference between inner and outer flow of a high speed catamaran, Kutta condition has been applied at the stern. Model test has been carried out not only to validate the numerical results but to confirm the capabilities of a CWC(Circulating Water Channel). It is believed that we can obtain the qualitatively reasonable results in the CWC. Computed results are compared with those of experiments and Insel's experimental values. Since the Kutta condition is applied at the stern, stable solutions are obtained at the high speed range. The present method, using linearised free surface conditions at the high speed range, seems to be a useful tool in the hull form design of a high speed catamaran.

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Diagnostic Laparoscopic Biopsy in Dogs and Cats (개와 고양이에서 복강경을 이용한 생검 증례)

  • Park, Se-Jin;Lee, Seung-Yong;Jin, So-Young;Kim, Min-Hyang;Seok, Seong-Hoon;Kim, Young-Ki;Lee, Hee-Chun;Jung, Dong-In;Hong, Il-Hwa;Yeon, Seong-Chan
    • Journal of Veterinary Clinics
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    • v.33 no.1
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    • pp.21-24
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    • 2016
  • Four dogs and two cats received laparoscopic or laparoscopic-assisted biopsy of abdominal organs for definite diagnosis of illness. Patients were presented with a chief complaint of acute or chronic vomiting excluding case 5 (seizure). Two patients needed the liver biopsy (case 1 and 5), and others did stomach and small intestine biopsy excluding case 2 (small intestine biopsy only). Surgical procedure was performed with modified standard methods. All patients recovered uneventfully and did not require any hospitalization without complications. Laparoscopic and laparoscopic-assisted biopsy could offer benefits of reduced incision length and rapid postoperative recovery.

A Study on the Methodology to Ensure Long-Term Durability of Low and Intermediate Level Radwaste Disposal Concrete Structure (${\cdot}$저준위 방사성폐기물 처분 콘크리트 구조물의 장기적 내구성 확보를 위한 방안 검토)

  • Kim Young-Ki;Lee Byung-Sik;Lee Yong-Ho
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.06a
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    • pp.211-220
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    • 2005
  • The concrete structure is being considered for the main engineered barrier of low and intermediate level radwaste disposal facility. Concrete of low permeability can minimize infiltration of water and effectively prevent release of nuclide to ecosystem. But if concrete degrades, structural stability of disposal structure will decrease while permeability increase, resulting in increased possibility of nuclide release due to water infiltration. Therefore disposal concrete structure degradation shall be minimized to maintain capacity of nuclide isolation. The typical causes of concrete structure degradation are sulfide attack, reinforcement corrosion due to chloride attack, leaching of calcium hydroxide, alkali-aggregate reaction and repeated freezing-thawing. The common cause of these degradation processes is infiltration of water or adverse chemicals into concrete. Based on the study of these degradation characteristics and mechanisms of concrete structure, the methodology of design and service life evaluation of concrete structure as an engineered barrier are reviewed to ensure its long-term durability.

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Evaluation of Durability and Self-clearing in Concrete Impregnated with Photocatalyst-colloidal Silica (광촉매-분산 실리카 함침 콘크리트의 내구성 및 정화성능 평가)

  • Kim, Hyeok-Jung;Kim, Young-Kee;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.5
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    • pp.47-54
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    • 2018
  • Concrete undergoes various deterioration on surface. Impregnant with silicate is usually applied to concrete surface and forms insoluble hydrates, which can provide many engineering advantages. In the work, concrete impregnated with colloidal silicate is used for durability enhancement in surface and self-clearing performance is evaluated with photocatalyst-$TiO_2$ spraying. For the work, various tests are performed both for strength evaluation and durability evaluation such as absorption ratio, drying shrinkage, chloride penetration, sulfate resistance, and freezing/ thawing action. Furthermore, removal and self-clearing performance are evaluated with Acetaldehyde decomposition and Methylene blue decolorization. Through silicate impregnation and photocatalyst spraying, the impregnated concrete can have not only durability enhance but also self-clearing performance.

The Geometric Analysis of Fractures near the Yangsan Fault in Eonyang Area (언양지역(彦陽地域) 양산단층(梁山斷層) 부근(附近) 단열(斷裂)의 기하(幾何) 분석(分析))

  • Chang, Tae Woo;Chang, Chun Joong;Kim, Young Ki
    • Economic and Environmental Geology
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    • v.26 no.2
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    • pp.227-237
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    • 1993
  • Lineaments in the Kyungsang basin most intensely develop in the East coast domain including the Yangsan fault, which dominantly run in NNE direction. The geometry of small fault population near or along the Yangsan fault represents the dominant strikes of N35E, high angle dips and shallowly plunging rakes with dextral movement sense. Stereographic solution on the Yangsan fault geometry gives the dip of 88SE, the slip direction of 17,024 and the slip rake of 18, which were determined from the strike (N23E) of the fault measured on map, and the average attitude (N35E, 84SE) and fault striation (16, 037) of small fault population considered as Riedel shears. It is judged from the geometry of small fault population to the main Yangsan fault and dragging features of bedding attitude near the fault that the Yangsan fault was produced from dextrally strike-slip movement. The movement of the Yangsan and the adjacent parallel faults is thought to be taken place much later than the other fault sets in the Kyungsang basin. It might occur during the geologic age from Eocence to early Miocene according to the consideration of K-Ar ages of the igneous rocks near the fault. The estimated paleostress state indicates ENE shortening and NNW extension. The displacement of the Yangsan fault in the study area is not constant along the fault but decreases from the south to the north. Taking the northern end of the study area as a separating point the whole extension of the Yangsan fault may be divided into southern and northern segments.

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Open-source robot platform providing offline personalized advertisements (오프라인 맞춤형 광고 제공을 위한 오픈소스 로봇 플랫폼)

  • Kim, Young-Gi;Ryu, Geon-Hee;Hwang, Eui-Song;Lee, Byeong-Ho;Yoo, Jeong-Ki
    • Journal of Convergence for Information Technology
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    • v.10 no.4
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    • pp.1-10
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    • 2020
  • The performance of the personalized product recommendation system for offline shopping malls is poor compared with the one using online environment information since it is difficult to obtain visitors' characteristic information. In this paper, a mobile robot platform is suggested capable of recommending personalized advertisement using customers' sex and age information provided by Face API of MS Azure Cloud service. The performance of the developed robot is verified through locomotion experiments, and the performance of API used for our robot is tested using sampled images from open Asian FAce Dataset (AFAD). The developed robot could be effective in marketing by providing personalized advertisements at offline shopping malls.

A Study on Patent Valuation for the Activation of IP Finance (IP 금융 활성화를 위한 특허가치평가에 관한 연구)

  • Park, Seong-Taek;Kim, Young-Ki
    • Journal of Digital Convergence
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    • v.10 no.11
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    • pp.315-321
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    • 2012
  • Since technological innovation is such an important factor that it can determine a company's economic growth and competitive enhancement, all the companies make lots of investments and efforts for technological innovation. As outcomes of technological innovation, there are patents, trademark and copyrights, etc. and they are mostly approved as a legal right called 'Intellectual Property Right'. To activate such an intellectual property right, financing techniques are needed for enterprises to raise funds through collaterals, such as technological and intellectual patents. In reality, however, any IP-related financial system is not really activated due to the lack of surety-related regulations in Korea. Thus, on the premise that it is important to carry out an objective and reliable valuation on IP as a collateral for the activation of IP finance, this study intends to investigate various different methods of patent valuation needed for IP finance.

A Study of Heat Transfer Characteristics of P.C.M. in a Latent Heat Storage Tank(Cubic Type) (직육면체형 잠열축열조내 상변화물질의 열전달특성에 관한 연구)

  • Yim, C.S.;Choi, K.K.;Kim, J.K.;Kim, Y.K.;Kim, I.G.;Kim, D.C.
    • Solar Energy
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    • v.15 no.3
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    • pp.15-27
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    • 1995
  • This study presents experimental and numerical results of the temperature characteristics, the heat transfer phenomema, and the heat storage quantity during the heat storage process with sodium phyrophosphate decahydrate($Na_4P_2O_7{\cdot}10H_2O$)-Phase Change Material(PCM) in a latent heat storage tank(cubic type). It was proved that heat transfer by conduction was dominant because PCM($Na_4P_2O_7{\cdot}10H_2O$) during heating processes was gel phase, not liquid phase The gap ratio(rate of air content) of PCM became smaller, the thermal capacity of PCM became larger, therefore the temperature distribution of PCM slowly increased than that of large gap ratio. There was maximum 15% difference between measured temperatures and calculated temperatures.

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Jindo Dog's Ethogram Revealed by Behavioral Test (진도개의 행동 테스트에 의한 에소그램)

  • Kim, Young-Ki;Lee, Scott-S.;Oh, Seok-Il;Lee, Gye-Woong;Kim, Jong-Seok;Chang, Hong-Hee;Suh, Euy-Hoon;Lee, Hee-Chun;Lee, Hyo-Jong;Yeon, Seong-Chan
    • Journal of Veterinary Clinics
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    • v.26 no.3
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    • pp.238-245
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    • 2009
  • This study was performed to develop ethogram of the Jindo dog's temperament categories under various conditions. A set of 12 behavioral tests were developed to investigate temperament categories expressed by the dogs. Fourty-three adult Jindo dogs(24 males, 19 females) from three different farms located in Jindo island were tested in 12 different behavioral tests. All test procedures and dog's behaviors responded to the tests were recorded using two digital video cameras and one digital still camera. A single observer reviewed all of the videotapes focused on dog's vocalization, movement, head, ears, eyes, mouth, and tail-positions. After all of the behavioral variables expressed throughout the testing period were described in detail, an ethogram of four temperament categories of 'sociability', 'aggression', 'fearfulness', and 'submission' revealed by 12 behavioral tests was developed.