• Environmental Engineering Research
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• v.11 no.1
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• pp.33-44
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• 2006

The objective of this study was to develop and assess a method for estimating the rain scavenging ratios (RSRs) of particle-bound PAHs and PCBs using measured scavenging ratio of particulate matters (PM) and routinely available data of physico-chemical properties of PM. Paired atmospheric and rainwater sampling was conducted for a total of 4 rain events. Assuming equilibrium partitioning in rainwater-gas-PM system, an equation was derived for estimating the RSR of particle-bound chemicals as a function of RSR of PM and three equilibrium partition constants (i.e. dimensionless Henry's law constant, gas-particle partition coefficient, and water-particle partition coefficient). For all PAHs, the model significantly under-predicted the RSR while the model prediction for PCBs agreed with observation mostly within a factor of 5. The RSR model for the chemicals is of limited use as its accuracy critically depends on how close the observed partitioning of the chemicals in the gas-PM-rainwater system is to that estimated under the equilibrium assumption.

• Proceedings of the KSPS conference
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• 2000.07a
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• pp.47-58
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• 2000

For the learners of English as a foreign language, oral repetition of model sentences is an e essential practice to improve their listening and speaking abilities of English. Skill training of both speech perception and production is involved in this practice. This paper reports on an observation of production e$\pi$ors in such practice made by Japanese college students in my class. The teaching material used is intended for acquainting the learners with basic English rhythm and intonation p patterns. The students were required to repeat each sentence in a series of conversations after a model reading. Although the vocabulary and expressions were rather limited, I monitored different kinds of errors in their repetition. Putting aside intonation, their difficulties are classified into five types; 1. Omission of words or morphemes, 2. Addition of unnecessary words or morphemes, 3. Replacement of words, 4. Japanization of English sounds, 5. Wrong rhythm caused by improper stress assignment. Accurate listening, especially to weakly stressed syllables and to assimilated sounds, as has often been pointed out, is the most difficult part in perception for them. Japanese sound system interferes in production of English sounds. More often than not their knowledge of grammar or the context does not work at all to guess the words they are hearing

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.53-58
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• 2014

The object of this study was to evaluate the single dose toxicity of Choweseuncheng-tang (CWS), a polyherbal formula have been traditionally used as prevention or treatment agent for various diseases as Tae-eumin prescription on Korean medicinal theory, Sasang-euihak, in male and female mice. Aqueous extracts of CWS (yield = 11.00%) was administered to female and male mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 14 principle organs were also examined. As results, we could not find any CWS treatment related mortality and clinical signs, changes in the body and organ weights, gross findings and changes in histopathology of principle organs, except for some dose-independent accidental findings. The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of CWS aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines, and can be safety used in clinics.

• The Journal of Korean Medical History
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• v.19 no.2
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• pp.49-66
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• 2006

1) Objective External treatments have various curative effects. So it had been used to cure various patients. But, it has a limited sphere of application in the present South Korea. And treatments of wander doctors had been disregarded by general doctors and the public. But Zhao-Xue-Min(趙學敏) had thought that there are useful treatments in it. So, the "Chuan-Ya(串雅)" had been written by Zhao-Xue-min in 1759. The book had included treatments of wander doctors. Especially, it had included various external treatments. Therefore we would like to bring out it's external treatments theory 2) Conclusions We have researched external treatments of "Chuan-Ya", and then we have arrived at following conclusions. "Chuan-Ya" has 48 sentences that have related to external treatments in internal medicine. And it had recorded fire conducting method(引火法) to explain process of external teratment principle.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.25-34
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• 2017

PURPOSES: The purpose of this paper is to evaluate interface performance while using various tack coat materials for asphalt overlay. METHODS : The evaluation was conducted with tracking test, permeability, and interface bond strength. Tracking test was conducted using an image processing technique, to investigate the susceptibility of the tack coat materials. BBS and pull-off test were conducted to evaluate bond strength. The permeability test was conducted to evaluate the effect of tack coat materials. RESULTS : Results reveal that the trackless tack coat material demonstrates less tracking compared to other materials. Moreover, both BBS and pull-off tests can effectively evaluate the bond strength at the interface. RSC-4 was measured less bond strength. Moreover, tack coat prevents water penetration through the surface and aids the extension of the surface life of asphalt pavement. CONCLUSIONS : Trackless tack coat demonstrated a high and consistent bond strength performance. The tack coat types demonstrate marginally different performance as function of curing times. Field applicability was tested based on visual observation. Therefore, these should be considered when trackless tack coat is slightly enhanced the pavement performance based on limited this study results. Finally, it is necessary to allow reasonable time for the tack coat to completely cure.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.6
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• pp.1019-1026
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• 2010

The object of this study was to evaluate the single dose toxicity of Iijintanggami-bang (IJTGMB), a polyherbal formula have been traditionally used as prevention or treatment agent for various digestive disorders including reflux esophagitis, in male and female mice. Aqueous extracts of IJTGMB (Yield = 8.45%) was administered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 12 principal organs were examined. As results, we could not find any mortality, clinical signs, and changesin the body and organ weight except for soft feces restricted to IJTGMB 2,000 mg/kg treated two male mice (2/5; 40%) at 1 day after administration. In addition, no IJTGMB-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for some sporadic accidental findings. The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of IJTGMB aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines.

• Laser Solutions
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• v.11 no.4
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• pp.21-28
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• 2008

Remote Laser welding technology for manufacturing automotive body is studied. Laser welding and industrial robot systems are used for the robot based laser welding system. The laser system is used 1.6kW Fiber laser(YLR-1600) of IPG. The robot system is used HX130-02 of Hyundai Heavy Industry(payload : 130kg). The robot based laser welding system is equipped with laser scanner system for remote laser welding. The welding joints of steel plate and steel plate coated with zinc are butt and lapped joints. The quality test of the laser welding are through the observation the shape of bead on plate and cross-section of welding part. During past three years the laser system, 4kW Nd:YAG laser (HL4006D) of Trumpf was used and the robot system, IRB6400R of ABB (payload:120kg) was used. The new laser source, robot and laser scanner system are used to increase the processing speed and to improve the process efficiency. This paper introduces the robot based remote laser welding system to resolve the limited welding speed and accuracy of the conventional laser welding system.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.52.2-52.2
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• 2011

We searched and studied galaxy overdensities at 0.6 < z < 4.5 in the areas of two GOODS fields. These overdensities are identified by running top-hat filters on the two dimensional spatial distribution of two galaxy samples - a K-band limited, photometric redshift sample at 0.6 < z < 4.5, and BVz-color selected sample targeting overdensities at z ~ 3.7 and z ~ 4.0. Here photometric redshifts are derived from multi-wavelength data ranging from U-band through 8 micron band of the Spitzer. We find 52 overdensities with significances of 3.5-7 ${\sigma}$. The derived masses found to be a > $10^{13}\;M_{\odot}$ with the comoving number density of a few ${\times}10^{-6}\;Mpc^{-3}$ at z ~ 3. In order to understand the high number density of massive overdensities at high redshift, we carried out an analysis of galaxy overdensities using the mock galaxy catalog based on Millennium simulation selected in the same way as the analysis of the observational data. In the simulation, we find 650 galaxy overdensities with a 3.5 ${\sigma}$ detection threshold over $2^{{\circ}2}$ sky field. The number density of the very massive overdensities (M > $10^{14}\;M_{\odot}$) in simulation shows a similar trend with the observation. We further discuss implications of our results.

• Journal of The Korean Astronomical Society
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• v.41 no.3
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• pp.77-81
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• 2008

As a continuation of a previous work by Park et al. (2006), we have developed a two-element radio interferometer that can measure both the phase and amplitude of a visibility function. Two small radio telescopes with diameters of 2.3 m are used as before, but this time an external reference oscillator is shared by the two telescopes so that the local oscillator frequencies are identical. We do not use a hardware correlator; instead we record signals from the two telescopes onto a PC and then perform software correlation. Complex visibilities are obtained toward the sun at ${\lambda}\;=\;21\;cm$, for 24 baselines with the use of the earth rotation and positional changes of one element, where the maximum baseline length projected onto UV plane is ${\sim}\;90{\lambda}$. As expected, the visibility amplitude decreases with the baseline length, while the phase is almost constant. The image obtained by the Fourier transformation of the visibility function nicely delineates the sun, which is barely resolved due to the limited baseline length. The experiment demonstrates that this system can be used as a "toy" interferometer at least for the education of (under)graduate students.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8C
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• pp.779-787
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• 2003

In this paper, we propose an improved early detection of all-zero DCT coefficients for fast video encoding. From the experimental observation, it is shown that the performance of the conventional method is limited because of the imprecision sufficient condition. When the calculation of the SAD in motion estimation is simply modified, more precise sufficient condition is derived from the theoretical analysis. Based on this idea, DCT and the quantization stages are effectively skipped in the proposed algorithm with no image degradation. The simulation results show that the proposed algorithm achieves computational saving over 10% compared to the conventional method.