• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.42-42
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• 2011

To evaluate the Hwangsu spring as natural mordants effect on dyeing. The natural mordants effect of Hwangsu spring were analyzed by pH, temperature, trace elements, organic matter and color fastness. Hwangsu spring having pH 2.42 and $14.4^{\circ}C$ was harvested at the end of September, in Yeongcheon (Gyeongbuk Province, Korea) and left on a $0^{\circ}C$ and $25^{\circ}C$ before use. Hwangsu spring during storage at $25^{\circ}C$ turned brown by photochemical reaction. The Result of ICP analysis, it contained Fe(414.9 ppm), Al(88.9 ppm), Mn(4.9 ppm) and observed character by water analysis. Dyeing and post-mordant procedure; Cotton(KS K 0905) were dyed with clove powder for 30 min at $70^{\circ}C$. Hwangsu spring, Aluminium Sulfate $14-18H_20(Al_2(SO_4)_3{\cdot}14-18H_2O)$, Iron Sulfate Heptahydrate($FeSO_4{\cdot}7H_2O$) were used by post mordant at the same ratio. The dyed fabrics were treated with 20% each mordant solution at $25^{\circ}C$ for 10min. Comparison with a reproduced chemical mordant, the K/S values of cotton fabrics dyed with Hwangsu sping were increased.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.807-816
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• 2018

Threat hunting is defined as a process of proactively and iteratively searching through networks to detect and isolate advanced threats that evade existing security solutions. The main concept of threat hunting is to find out weak points and remedy them before actual cyber threat has occurred. And HMM(Hunting Maturity Matrix) is suggested to evolve hunting processes with five levels, therefore, CSOC(Cyber Security Operations Center) can refer HMM how to make them safer from complicated and organized cyber attacks. We are developing a system for cyber situation awareness system with pro-active threat hunting process called unMazeTM. With this unMaze, it can be upgraded CSOC's HMM level from initial level to basic level. CSOC with unMaze do threat hunting process not only detecting existing cyber equipment post-actively, but also proactively detecting cyber threat by fusing and analyzing cyber asset data and threat intelligence.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.6
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• pp.629-637
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• 2021

For the stabilization of laser output power and wavelength of the high power fiber laser, the cooling plate must be properly taken into account. In this study, three analyzing methods which are heat transfer theory, CFD and experiment are used to analyze cooling plate performance by measuring pump Laser Diode(LD) temperature. Under limited operating conditions of a cooling plate, the internal flow of cooling plate is transitional flow so that the internal flow is assumed to be laminar and turbulence flow and conducted theoretical calculation. Through CFD, temperature of pump LD and characteristics of the internal flow were analyzed. By the experiment, temperature of pump LD was measured in real conditions and the performance of the cooling plate was verified. The results of this study indicate that three analyzing methods are practically useful to design the cooling plate for the high power fiber laser or similar things.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1211-1214
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• 1992

AC servo motor drives, Fara DS series, proposed in this paper can be effectively used in robots, CNC machine tools, and FA system with AC servo motors as actuators. The inverter of the AC servo drive consists of IGBT (Insulated Gate Bipolar Transistor) which have high switching frequency. Noises and vibrations generated in variable speed control of AC servo motors can be greatly reduced due to their high switching frequencies. In the developed servo drive, maximum torque is always generated in the whole speed range by compensating phase shift, which results from the nonlinearies of the AC servo motor during abrupt acceleration and deceleration. Abundant protection functions are provided to prevent abnormal state of the servo motor, and furthermore diverse user options are considered provided for the effective application. The proposed AC servo motor drive is designed to minimize velocity variation with respect to external load, supply voltage, environmental temperature, and humidity, so can be widely used in the fields of factory automation including robots and CNC msachine tools.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.1
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• pp.35-42
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• 2021

Recent defense R&D projects have been required as weapons systems applied with advanced technology considering exports. As a result, the complexity of the applied technology increases, and the risk of system development increases. Under these circumstances, an effectives method of performing evolutionary development for economical and timely deployment is presented. To this end, we hope that this study, which proposed the maintenance of related laws and measures for realistic and active evolutionary development, will help the R&D of the weapons systems.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.2
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• pp.174-181
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• 2012

Energy storage system connected to the grid has two functions such as the surplus power of a grid is stored in batteries or the energy stored in batteries will supply to the grid when the grid needs. The battery energy storage system consist of power condition system (PCS) for power supply and battery conditioning system (BCS). Lithium-ion batteries are mainly used. In this paper, the battery energy storage system connected to the grid described. The configuration of the 2MVA class power control system using water cooling and battery system are presented. And control method for the system and the output filter design method are proposed. Experimental verification of the proposed system is provided with 2MVA PCS and 500kWh BCS.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2003.11a
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• pp.69-72
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• 2003

This paper presents a signal processing IC for digital HDTV, which is designed to operate in bunt-in HDW or in HD-set-top Box. The chip supports de-multiplexing an ISO/IEC 13818-1 MPEG-2 TS stream. It decodes MPEG-2 MP@HL video bitstream, and provides high-quality scaled video for display on HDTV monitor. The chip consists of ARM7TDMI for TS-Demux, PCI interface, Audio interface, MPEG2 MP@HL video decoder Display processor, Graphic processor, Memory controller, Audio int3face, Smart Card interface and UART. It is fabricated using Sam sung's 0.18-um and the package of 492-pin BGA is used.

• Korean Journal of Optics and Photonics
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• v.32 no.3
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• pp.120-125
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• 2021

We have developed a linearly polarized high-power Yb-doped fiber laser in the master oscillator power amplifier (MOPA) scheme for efficient spectral beam combining. We modulated the phase of the seed laser by pseudo-random binary sequence (PRBS), with the bit length optimized to suppress stimulated Brillouin scattering (SBS), and subsequently amplified seed power in a 3-stage amplifier system. We have constructed by coiling the polarization-maintaining (PM) Yb-doped fiber, with core and cladding diameters of 20 ㎛ and 400 ㎛ respectively, to a diameter of 9-12 cm for suppression of the mode instability (MI). Finally, we obtained an output power of 1.004 kW with a slope efficiency of 83.7% in the main amplification stage. The beam quality factor M² and the polarization extinction ratio (PER) were measured to be 1.12 and 21.5 dB respectively. Furthermore, the peak-intensity difference between the Rayleigh signal and SBS signal was observed to be 2.36 dB in the backward spectra, indicating that SBS is successfully suppressed. In addition, it can be expected that the MI does not occur because not only there is no decrease in slope efficiency, but also the beam quality for each amplified output is maintained.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.529-532
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• 2006

과학기술 연구자들의 협업을 지원하기 위해서 정보 자원 공유에 기반한 정보 유통 체제가 필요하나 현재 정보 유통 체제에서는 서로 이질적인 형태로 정보가 표현되어 있기 때문에 정보 공유의 기술적 한계를 갖고 있다. 그리고 대량의 정보 속에서 사용자가 원하는 정보를 선별하여 제공하기 위해서는 새로운 정보 유통 플랫폼이 필요하다. 본 논문에서는 지식 기반 정보 유통 플랫폼 상에서 이용되는 국가과학기술 R&D 기반정보를 지식화하기 위해 국가과학기술 R&D 기반정보 온톨로지를 구축하여 이용함으로써 각 기관별로 관리하고 있는 인력, 성과물 등의 과학기술 R&D 기반 정보의 표준화된 지식관리 체계로 이용할 수 있다. 우리는 국가과학기술 R&D 기반정보 온톨로지를 구축하기 위하여 한국과학기술정보연구원(KSITI) 내부 성과물 정보의 실제 데이터들을 이용하여 온톨로지의 Individuals를 생성하였다. 정보 유통 플랫폼에서 온톨로지 형태로 구축된 지식을 이용하면 과학기술 R&D 기반정보에 대한 효율적인 관리가 가능하고, 정형화된 형태의 지식으로 개념화했기 때문에 지식 데이터의 공유와 재사용이 가능하다. 또한 단순 질의 검색이 아닌 의미 기반 추론을 이용한 지식 검색이 가능해지는 장점을 가진다. 우리가 구축한 국가 과학기술 R&D 기반정보 온톨로지를 이용하여 정보유통플랫폼(OntoFrame-K)에서 연구자 네트워크, 연구자 추적, 연구맵의 추론 서비스를 제공한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1013-1021
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• 2014

For efficient investments of government budgets, It is important to analyze the similarities of R&D projects. So, existing studies have proposed a techniques for analyzing similarities using keywords or segments. However, the techniques have low accuracy. We propose a technique for similarities of projects using patent information. To achieve our goal, we suggest three metrics that are based some mathematic theories; set theory and probability theory. In order to validate our technique, we perform case studies that have 156 R&D projects and 160,218 patent informations.