• Animal Systematics, Evolution and Diversity
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• v.28 no.4
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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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• v.29 no.3
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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.

• Journal of Sensor Science and Technology
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• v.20 no.1
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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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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• v.11 no.5
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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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• v.19 no.2
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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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• v.5 no.5
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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.

• Journal of IKEEE
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• v.22 no.4
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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.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.54.1-54.1
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• 2003

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.219-224
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• 2013

In the case of occurring marine oil pollution, it is the most effective way that to prepare all the necessary response resources in advance and to respond to incidents, but there are limits in reality. Therefore, may be an important alternative ways to use a fishing vessel registered in the affected area by massive marine oil pollution efficiently. In the United States and other developed countries, it is can be found that temporary response program by local fishing vessels(VOO program) has been developed and operated. This study was examined for sweeping arm system suitable for domestic small fishing vessels. The selected small vessel was as the model of Coastal gill-net and compound fishing vessel with classes of 2.5~3.5tons, length 8~9m, breath 2.5~2.8m, horsepower 200~250 HP and FRP materials. The developed equipment was designed that can be easily mounted on the model ship and portable structure. For increasing the field practicality, the weight of each part was composed less than 10kg for easy assembly and disassembly.