• 한국염색가공학회지
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• 제27권4호
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• pp.270-274
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• 2015

Molecules always show broad absorption band envelopes, and this results from the vibrational properties of bonds. The width of an absorption band can have an important influence on the color of a dye. A narrow band imparts a bright, spectrally pure color to the dye, whereas a broad band can give the same hue, but with a much duller appearance. Typically, half-band widths of cyanine dyes are about 25nm compared to value of over 50nm for typical merocyanine dyes. Thus, cyanine dyes are exceptionally bright. The factors influencing the width of an absorption band can be understood with reference to the Morse curves. The width of the absorption band depends on how closely the bond order of the molecules in the first excited state resembles that in the ground state. We have quantitatively evaluated the "molecular structure-absorption band shape" relationship of dye molecules by means of Pariser-Parr-Pople Molecular Orbital Method(PPP-MO).

• 한국군사과학기술학회지
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• 제24권1호
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• pp.84-98
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• 2021

The hydrodynamic characteristics of amphibious assault vehicles are investigated using commercial CFD code, STAR-CCM+. Resistance performances of a displacement-type vehicle and a semi-planing type vehicle are analyzed in calm water. The self-propelled model is also computed for the semi-planing type vehicle. All computations are performed using an overset mesh system and a RANS based flow-solver coupled with a two-degree of freedom equations of motion. A moving reference frame is applied to simulate revolutions of impeller blades for a waterjet propulsion system. Grid dependency tests are performed to evaluate discretization errors for the mesh systems. The numerical analysis results are compared with the experimental results obtained from model tests. It is shown that RANS is capable of investigating the resistance and self-propulsion characteristics of high-speed amphibious assault vehicles. It is also found that a fully covered side skirt, which is covering tracks, reduces resistance and stern trim, besides increasing propulsive efficiency.

• 수산해양기술연구
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• 제45권3호
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• pp.177-187
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• 2009

This paper describes a automatic video surveillance system(AVSS) with long range and 360$^{\circ}$ coverage that is automatically rotated in an elevation over azimuth mode in response to the TTM(tracked target message) signal of vessels tracked by ARPA(automatic radar plotting aids) radar. This AVSS that is a video security and tracking system supported by ARPA radar, CCTV(closed-circuit television) camera system and other sensors to automatically identify and track, detect the potential dangerous situations such as collision accidents at sea and berthing/deberthing accidents in harbor, can be used in monitoring the illegal fishing vessels in inshore and offshore fishing ground, and in more improving the security and safety of domestic fishing vessels in EEZ(exclusive economic zone) area. The movement of the target vessel chosen by the ARPA radar operator in the AVSS can be automatically tracked by a CCTV camera system interfaced to the ECDIS(electronic chart display and information system) with the special functions such as graphic presentation of CCTV image, camera position, camera azimuth and angle of view on the ENC, automatic and manual controls of pan and tilt angles for CCTV system, and the capability that can replay and record continuously all information of a selected target. The test results showed that the AVSS developed experimentally in this study can be used as an extra navigation aid for the operator on the bridge under the confusing traffic situations, to improve the detection efficiency of small targets in sea clutter, to enhance greatly an operator s ability to identify visually vessels tracked by ARPA radar and to provide a recorded history for reference or evidentiary purposes in EEZ area.

• 산업경영시스템학회지
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• 제41권4호
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• pp.111-122
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• 2018

The private sector is currently reviewing the feasibility of the project or deciding economic policies by analyzing the economic ripple effects. However, the arms acquisition project focuses on the need for the national defense weapons system by analyzing the costs and the effectiveness of the analysis and reviewing the necessity and feasibility of the project. In order to analyze the economic ripple effects, KB (the Bank of Korea) prepares and publishes an analysis table of industrial associations in a given unit. IAAR (the industrial association analysis report) is difficult to apply directly to the defense weapons system. Therefore, research on the economic ripple effects applicable to the defense arms procurement project was needed. In this study, we propose the generic methodology for estimating economical and technical ripple effects resulted in acquiring new weapon systems. Based on the analysis of inter-industrial relations, economical ripple effects are estimated with production inducing effects, value-induced effects, employment-induced effects and export-induced effects. Also, the technological ripple effects are estimated with technological intensity represented by investment cost in research and development. To show the validity of proposed methodology, a case study of acquiring new weapon systems such as GR (guided rocket), destroyer, and helicopter is accomplished. From the case study, it is concluded that these economical & technological ripple effects can be used as a reference to decision making in the course of acquiring major future defense weapons systems.

• 한국항공우주학회지
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• 제39권10호
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• pp.946-951
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• 2011

본 논문에서는 제주 국제 공항에서 실시된 항공우주연구원의 비행 실험 데이터를 기반으로 항공기 착륙 상황을 시뮬레이션하고, Protection Level 관점에서 제주 국제 공항 GBAS 시스템의 가용성 및 성능 향상을 위한 요구조건을 분석하였다. 요구조건을 분석하기위해, CAT I, CAT II/III의 결심고도에서 항공기 착륙 상황 (기준국 정밀좌표, 항공기 착륙 속도, 기준국 및 항공기 안테나 성능지표 등)을 Protection Level 계산에 적용하였다. 이 때 귀무가설 / 대립가설 (H0 / H1) Protection Level을 한계치 (Alert Limit)와 비교 분석하여, 현재 CAT I, CAT II/III의 가용도 및 개선 방향을 도출하였다.

• Earthquakes and Structures
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• 제8권5호
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• pp.1215-1240
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• 2015

In this paper, the Theory of Plastic Mechanism Control (TPMC) is applied to the seismic design of dual systems composed by moment-resisting frames and Chevron braced frames. The application of TPMC is aimed at the design of dual systems able to guarantee, under seismic horizontal forces, the development of a collapse mechanism of global type. This design goal is of primary importance in seismic design of structures, because partial failure modes and soft-storey mechanisms have to be absolutely prevented due to the worsening of the energy dissipation capacity of structures and the resulting increase of the probability of failure during severe ground motions. With reference to the examined structural typology, diagonal and beam sections are assumed to be known quantities, because they are, respectively, designed to withstand the whole seismic actions and to withstand vertical loads and the net downward force resulting from the unbalanced axial forces acting in the diagonals. Conversely column sections are designed to assure the yielding of all the beam ends of moment-frames and the yielding and the buckling of tensile and compressed diagonals of the V-Braced part, respectively. In this work, a detailed designed example dealing with the application of TPMC to moment frame-chevron brace dual systems is provided with reference to an eight storey scheme and the design procedure is validated by means of non-linear static analyses aimed to check the actual pattern of yielding. The results of push-over analyses are compared with those obtained for the dual system designed according to Eurocode 8 provisions.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.372-375
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• 2004

The UV radiometer payload was launched successfully from the west coastal area of Korea Peninsula aboard KSR-III on 28, Nov 2002. KSR-III was the Korean third generation sounding rocket and was developed as intermediate step to larger space launch vehicle with liquid propulsion engine system. UV radiometer onboard KSR-III consists of UV and visible band optical phototubes to measure the direct solar attenuation during rocket ascending phase. For UV detection, 4 channel of sensors were installed in electronics payload section and each channel has 255, 290, 310nm center wavelengths, respectively. 450nm channel was used as reference for correction of the rocket attitude during the flight. Transmission characteristics of all channels were calibrated precisely prior to the flight test at the Optical Lab. in KARI (Korea Aerospace Research Institute). During a total of 231s flight time, the onboard data telemetered to the ground station in real time. The ozone column density was calculated by this telemetry raw data. From the calculated column density, the vertical ozone profile over Korea Peninsula was obtained with sensor calibration data. Our results had reasonable agreements compared with various observations such as ground Umkhr measurement at Yonsei site, ozonesonde at Pohang site, and satellite measurements of HALOE and POAM. The sensitivity analysis of retrieval algorithm for parameters was performed and it was provided that significant error sources of the retrieval algorithm.

• 한국산림과학회지
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• 제94권4호통권161호
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• pp.243-251
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• 2005

이 연구는 김해시 상동면 매리 산사태지의 발생특성을 밝히기 위한 일련의 연구로 본보에서는 강수량 및 지형, 지질적인 요인을 조사, 분석 결과 다음과 같은 결론을 얻었다. 이 지역의 산사태 발생의 주된 원인은 지형, 지질적인 요인이다. 지형적으로 지표수가 침투되기 쉽게 너덜이 넓게 분포하고 있으며, 산록부 하장사면의 요(凹)부는 붕적토층과 풍화토층이 깊게 형성되어 있다. 또한, 붕적토층 내에는 직경 10~100 cm 정도의 원마도가 매우 불량한 자갈 및 전석으로 구성되어 있어 강우시 침식이 용이하다. 또한, 지하수위 상승에 의해서도 산사태가 발생하었다. 즉, 산정상부의 지하수위가 지표면과 가깝고 산 하부에서 깊게 분포하는 등 지형 및 지질적 특성으로 인하여 지하수위가 상승하여 산사태 발생에 크게 영향을 미친 것으로 판단된다. 아울러 강우로 인한 상부 너덜지대에서 많은 지표수가 침투되고 있음에도 불구하고 붕적층에 대한 지하수 배제시설이 미비되어 산사태를 발생시키고 있는 것으로 판단된다.

• 전력전자학회논문지
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• 제8권1호
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• pp.89-97
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• 2003

PWM 인버터에 의해 구동리근 유도전동기에 발생되는 고주파 커먼 모드 전압은 전도성 EMI, 전통기 접지전류, 베어링 전류 및 다른 원치 않는 결과의 주원인이 된다. 인버터 제어의 무효벡터 스위칭 상태는 나머지 유효벡터 스위칭 상태에 비교하여 큰 커먼 모드 전압을 일으킨다. 그러므로 이 논문은 커먼 모드 전압을 완화하는 스위칭기법을 다룬다. 즉 정현파 PWM 기법을 기본으로 한 커먼 모드 전압 제거방법을 제안하였다. PWM 신호는 각자의 정현과 기준신호와 120$^{\circ}$위상차가 나는 3개의 캐리어 파형과 비교하여 발생된다. 시뮬레이션과 실험적 결과는 제안된 PWM 기법에서 커먼 모드 전압이 종래의 PWM 기법보다 약 66% 더 저감됨을 보였다.

• ETRI Journal
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• 제34권5호
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• pp.674-683
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• 2012

We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular-ring-shaped tuning stub that can be deployed in ultra-wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band-notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L- and J-shaped parasitic elements. The antenna characteristics can be modified to tune the band-notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L- and J-shaped parasitic elements also provide the band-rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies.