• Title/Summary/Keyword: Kyung-Rak

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LED transceivers with beehive-shaped reflector for visible light communication

  • Sohn, Kyung-Rak;Kim, Min-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.2
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    • pp.169-174
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    • 2014
  • This paper proposes a novel beehive-shaped reflector for application to light-emitting diode (LED) transceivers for illumination and bi-directional visible light communication (VLC). By using a diffuse propagation model extended to line-of-sight and direct signals, the distribution of illuminance and the path loss of the transceiver are investigated to evaluate the performance of the beehive-shaped reflector. To verify bi-directional communication, a VLC-based image capture system, comprising a complementary metal-oxide semiconductor (CMOS) image sensor and video processor unit, is demonstrated. Real-time images captured by the CMOS camera are successfully transmitted to the monitoring system via a free-space channel at a rate of 115.2 kbps.

Novel Long-period Fiber Grating devices for Monitoring the Deformation of Ship Hull (선체의 변형을 감지하기 위한 새로운 형태의 장주기 광섬유 격자 소자)

  • Sohn, Kyung-Rak
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.6
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    • pp.761-767
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    • 2007
  • We have developed novel optical-fiber sensors based on strain-induced long-period fiber gratings for monitoring the deformation of a hull. They have no external pressure for sustaining the mechanical formed gratings. The pressure, which provides a force to form the periodic grating along the single mode fiber, was realized by the bonding strength of a photopolymer. To reduce the polarization dependency of the sensors caused by the asymmetry structure of gratings, a Faraday Rotator Mirror (FRM) was utilized in this experiment. We have realized the polarization-insensitive function of the proposed sensors. The change of an external strain are measured by an optical spectrum analyzer. When the external stain increases. the attenuation at the resonant wavelength decreases and the loss peak was slightly shifted to the shorter wavelength.

Multipoint Pressure-detection Sensors using Microbanding-induced Long-period Fiber Gratings (마이크로밴딩 장주기 광섬유 격자를 이용한 다중위치 압력감지 센서)

  • Sohn, Kyung-Rak;Choi, Young-Gill;Jang, Se-In;Choi, Jae-Yun;Shim, Joon-Hwan
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.3
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    • pp.449-454
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    • 2006
  • We present a pressure sensor based on the mechanically induced long-period fiber gratings (LPFG) for detecting the multi-location strain variation. The theoretical analysis is performed using a graphic method for a weakly guiding step-index fiber. The calculated results are in good agreement with the experimental results. In this study, from the fact that the optical parameters of a single-mode fiber slightly differ from manufacturing company to manufacturing company, the multipoint pressure-detection sensor systems composed two identical LPFGs are realized. When the pressure is applied two LPFG sensors at once, the resonance peaks are separated as much as about 40 nm. These types of sensor systems are well suited as a multipoint monitoring of strain or temperature in the ship or the smart structure.

Cloning and Overexpression of Methylcatechol 2, 3-Dioxygenase Gene from Toluene-Degrading Pseudomonas putida mt-2(pWWO)

  • Lee, Jeong-Rai;Min, Kyung-Rak;Kim, Young-Soo
    • Archives of Pharmacal Research
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    • v.15 no.4
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    • pp.360-364
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    • 1992
  • Methylcatechol 2, 3-dioxygenase encoded in pWWO megaplasmid of Pseudomonas putida mt-2 has been cloned and overexpressed in Escherichia coli. This enzyme gene has been localized inside 2. 3-kb XhoI fragment derived from the pWWO megaplasmid. Analysis of enzyme activity and SDS-PAGE showed that the cloned methylcatechol 2, 3-dioxygenase gene in E. coli was about 100 fold overexpressed compared with the parental gene in P. putida mt-2 (pWWO). The cloned enzyme exhibited higher ring-fission activity to catechol than catechol derivatives including 3-methylcatechol, 4-methylcatechol, and 4-chlorocatechol.

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A study on Batch-processing in Performing Design-changes of Robot-links using Parametric Method (파라메트릭 기법을 사용한 로봇링크 설계변경의 일괄처리 적용연구)

  • Park Tae Won;Moon Ha Kyung;Jung Il Ho;Seo Jong Hwi;Kim Hyuk;Choi Yong Won;Choi Jae Rak
    • Journal of the Korea Society for Simulation
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    • v.14 no.1
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    • pp.43-53
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    • 2005
  • We developed the module of the software that robot designers can perform their work faster and more easily. The parametric modeler is founded on the virtual robot design program. The virtual robot design program is the powerful software which may be used to solve various problems of robot kinematics and dynamics. The parametric modeler in the software we developed is that all the positions of joints and links are changed automatically when the designer changes one joint or one link in the robot system. Without parametric method, robot-designers must change all the positions of connected joints and links. It might become time-consuming. However, it is very efficient for designers to use the method of batch-processing in performing design-changes of robot-links using the parametric modeler.

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Optimum SIL System Design with High NA and Large Tolerance

  • Won, Ki-Tak;Choi, Na-Rak;Kim, Jai-Soon;Lee, Ji-Yeon;Lee, Kyung-Eon;Shin, Yun-Sup
    • Proceedings of the Optical Society of Korea Conference
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    • 2007.02a
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    • pp.277-278
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    • 2007
  • Even though high NA, Hyper SIL system easily decline the optical performance even a little alignment error. Not only to overcome this instability but to maintain the high NA gain, we suggest a new system (Optimum SIL) which is a combination of each advantage of Hyper SIL and Hemi SIL. Simulation results shows that Optimum SIL system has much higher tolerance to various performance-lowering factors than Hyper SIL system even with a relatively small NA resignation.

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Characteristics silicon pressure sensor using dry etching technology (건식식각 기술 이용한 실리콘 압력센서의 특성)

  • Woo, Dong-Kyun;Lee, Kyung-Il;Kim, Heung-Rak;Suh, Ho-Cheol;Lee, Young-Tae
    • Journal of Sensor Science and Technology
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    • v.19 no.2
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    • pp.137-141
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    • 2010
  • In this paper, we fabricated silicon piezoresistive pressure sensor with dry etching technology which used Deep-RIE and etching delay technology which used SOI(silicon-on-insulator) wafer. We improved pressure sensor offset and its temperature dependence by removing oxidation layer of SOI wafer which was used for dry etching delay layer. Sensitivity of the fabricated pressure sensor was about 0.56 mV/V${\cdot}$kPa at 10 kPa full-scale, and nonlinearity of the fabricated pressure sensor was less than 2 %F.S. The zero off-set change rate was less than 0.6 %F.S.

A Case of Segniliparus rugosus Pulmonary Infection in an Immunocompetent Patient with Non-cystic Fibrosis

  • Lee, Jung Yeon;Chon, Gyu Rak;Jung, Tae-Young;Sung, Heungsup;Shim, Tae Sun;Jo, Kyung-Wook
    • Tuberculosis and Respiratory Diseases
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    • v.77 no.5
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    • pp.227-229
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    • 2014
  • Segniliparus species is a novel genus that is reported to be the new emerging respiratory pathogens. Here, we report a very rare case of S. rugosus pulmonary infection in an immunocompetent patient with non-cystic fibrosis. The organism was identified by 16S rRNA gene sequencing. The patient was successfully treated with antibiotics.

Development of Automatic Resistance Measuring System for Aluminum Connector (금구류 히트사이클 시험용 자동 저항측정 시스템 개발)

  • Park, Sung-Kyun;Son, Hwa-Young;Ryu, Jae-Nam;Kim, Kyung-Hwan;Park, Byung-Rak;Park, Choong-Yeol;Kim, Oun-Seok
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.161-163
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    • 1997
  • Heatcycle testing for aluminum connector is very important. But because of connecting or disconnecting the test circuit, measuring resistance is difficult. Also the previous measuring resistance instrument is analog type. So measuring method is difficult. And four measuring points for one test circuit cause difficulty in automation. In this paper we developed the automatic system for measuring resistance. Automation will allow more information to be gathered, which will lead to the connector aging process being better understood and controlled.

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The ras oncogenes in aflatoxin B$_{1}$-induced rat liver carcinomas

  • Kim, Youngsoo;Min, Kyung-Rak;Gerald N.Wogan
    • The Microorganisms and Industry
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    • v.16 no.1
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    • pp.7-17
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    • 1990
  • In summary, the nature of the amino acid changes that impart oncogenicity in either the focus formation or tumorigenicity assay can be inferred by analysis of PCR-amplified DNA from tumor-derived NIH3T3 transformants and confirmed by analysis of primary liver tumors. Putative activating mutations in the c-K-ras genetic locus have been shown to involve a single-base modification of either G-C base pair at codon 12 leading to aspartate or cystein substitutions for glycine. The oncogenicity of an N-ras oncogene containing the N-ras C gene region may be related to an amino acid substitution of valine for glycine at codon 13.

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