• Animal Systematics, Evolution and Diversity
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• 제28권4호
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• pp.241-260
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• 2012

Adult chironomids were collected by various methods, such as light traps, sweeping on grasses, aspiration of light-attracted adults, and sweeping of swarming males with insect nets at various localities. All collected specimens were slide-mounted and identified. I report eight species new to science: Chironomus jangchungensis n. sp., Demicryptochironomus paracamptolabis n. sp., Demicryptochironomus wontongensis n. sp., Microtendipes paratamagouti n. sp., Polypedilum macrohemisphere n. sp., Eukiefferiella busanensis n. sp., Psectrocladius paratogaminimus n. sp., and Pseudosmittia seosania n. sp. I also report four species for the first time in Korea: Chironomus fujiprimus Sasa, Pentapedilum convexum Johannsen, Tanytarsus smolandicus Brundin, and Tanytarsus oyamai Sasa. All species are fully described with illustrations. This is the first report of the genera Eukiefferiella and Pseudosmittia in Korea.

• Animal Systematics, Evolution and Diversity
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• 제29권3호
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• pp.217-226
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• 2013

Chironomid adults were collected by light traps at night, sweeping on grasses, during daytime hours, sweeping of swarming males with an insect net, and aspiration of light-attracted adults using a sucking tube. The collected specimens were slide-mounted and examined. I identified two species new to science, namely Orthocladius manhaei n. sp. and Ablabesmyia jeongi n. sp., and three species for the first time in Korea: Paratrichocladius tamaator Sasa, 1981, Rheocricotopus chalybeatus (Edwards, 1929) and Hayesomyia tripunctata (Goetghebuer, 1922). This is the first report of the genera Rheocricotopus and Hayesomyia in Korea. The genus Hayesomyia in the tribe Pentaneurini of Tanypodinae has a Holarctic distribution with only one species recorded from each of the Palaearctic and Nearctic regions.

• 센서학회지
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• 제20권1호
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• pp.46-52
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• 2011

In this paper, the swept source-optical coherence tomography system using frequency domain mode locked(FDML) laser has realized. The FDML swept source laser showed 55.03 kHz sweeping speed, 125 nm sweeping range, and 9 mW output optical power, which are the superiority of FDML laser compared to previous swept source lasers. Also, through the cross-sectional image captured at 5 frames per second for a mirror, a 1 mm-thickness glass plate, and a thumb bottom, the performance of the system has demonstrated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.424-429
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• 2003

As a critical member of cable-stayed bridges, stay cables play an important role of supporting the entire structure. Traffic, wind or rain-wind induced vibrations of stay cables would be a major cause of degrading both safety and serviceability of the bridge. One of the effective alternatives to solve this problem is to employ the cable dampers. In order to design the cable damper optimally. it is necessary to exactly estimate the dynamic characteristics of the existing cables. Therefore, in this study, a cable exciting system (exciter) controlled digitally was developed. And to evaluate the performance of the cable exciter developed, a solution of the differential equation of cable motion considering the exciter was derived. Using the cable exciter. sine sweeping and resonance tests on a cable model were carried out to obtain the dynamic characteristics effectively.

• Membrane and Water Treatment
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• 제11권5호
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• pp.353-361
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• 2020

The present study deals with a numerical investigation of heat and mass transfer in a Sweeping Gas Membrane Distillation (SGMD) used for desalination. The governing equations expressing the conservation of mass, momentum, energy and species with coupled boundary conditions were solved numerically. The slip boundary condition applied on the feed saline solution-hydrophobic membrane interface is taken into consideration showing its effects on profiles and process parameters.The numerical model was validated with available experimental data and was found to be in good agreement particularly when the slip condition is considered. The results of the simulations highlighted the effect of slip boundary condition on the velocity and temperature distributions as well as the process effectiveness. They showed in particular that as the slip length increases, the permeate flux of fresh water and process thermal efficiency rise.

• Journal of the Optical Society of Korea
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• 제19권2호
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• pp.154-158
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• 2015

We experimentally demonstrated a novel wavelength-swept laser using a cascaded Raman gain around 1310 nm. A 1064/1310 wavelength division multiplexing (WDM) coupler and coupled fiber Bragg gratings mirrors at 1064, 1117, 1175, 1240 nm are effectively used to increase the power efficiency in a laser ring cavity with highly non-linear fiber (HNLF) of 2 km. Linear wavelength sweeping is demonstrated with the 100 Hz triangular driving signal to fiber Fabry-Perot tunable filter (FFP-TF) around the 1310 nm region. The measured sweeping range and output power were 27 nm and 2.1 mW, respectively, which are suitable for optical coherence tomography (OCT) imaging.

• Wind and Structures
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• 제5권5호
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• pp.441-462
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• 2002

This paper presents a practical numerical method to determine both the spatial and temporal distribution of driving rain on buildings. It is based on an existing numerical simulation technique and uses the building geometry and climatic data at the building site as input. The method is applied to determine the 3D spatial and temporal distribution of wind-driven rain on the facade a low-rise building of complex geometry. Distinct wetting patterns are found. The important causes giving rise to these particular patterns are identified : (1) sweeping of raindrops towards vertical building edges, (2) sweeping of raindrops towards top edges, (3) shelter effect by various roof overhang configurations. The comparison of the numerical results with full-scale measurements in both space and time for a number of on site recorded rain events shows the numerical method to yield accurate results.

• 전기전자학회논문지
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• 제22권4호
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• pp.1019-1024
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• 2018

In this paper, we suggest a combined cost function to find out the optimal operation of an envelope tracking system, and evaluated its performance with Quadrature Amplitude Modulation (QAM) waveform, with which envelope tracking coefficients for the peak drain efficiency and the bandwidth of power amplifiers are determined. Based on the classical envelope tracking theory, the operation of the supply modulator, which is a key part of the envelope tracking process, is modeled and analyzed mathematically. Then characteristics of the modulator by setting envelope shaping function as a cubic polynomial and sweeping the coefficients of this function was analyzed. By sweeping the coefficients, efficiency and bandwidth at each condition with 64-QAM signal was used to obtain optimal point of the supply modulator. Compared to the conventional shaping functions, the optimized function showed the bandwidth reduction by 12.7 percent point while the efficiency was maintained.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.54.1-54.1
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• 2003

• 해양환경안전학회지
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• 제19권2호
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• pp.219-224
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• 2013

해양유류오염사고가 발생한 경우에 필요한 모든 방제자원을 사전에 확보하고 사고에 대응하는 것이 가장 효과적이지만 현실적으로는 한계가 있는 실정이다. 그러므로 대규모 유류오염사고에 대비하여 유류오염으로 피해를 입게 되는 오염지역의 어선을 활용하는 방안이 중요한 대안이 될 수 있다. 미국 등 선진국에서도 지역 어선을 이용한 임시방제정 프로그램이 개발되어 운영되고 있는 사례를 찾아볼 수 있다. 본 연구는 국내 소형어선에 적합한 기름방제용 스위핑 암 시스템을 검토하였다. 모델로 선정된 소형 선박은 연안유자망어선 및 연안복합어선으로 2.5~3.5톤, 길이 8~9 m, 폭 2.5~2.8 m, 마력 200~250 HP, 선질 FRP인 어선이다. 개발된 장치는 모델 선박에 간편하게 장착할 수 있고 이동이 가능한 구조로 설계되었다. 조립 및 분해를 쉽게 하기위해 각 부품의 무게를 10 kg 이하로 구성함으로써 현장 실용성을 높였다.