• Journal of Korean Library and Information Science Society
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• v.16
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• pp.129-157
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• 1989

Through this study, some considerations to be taken into account in order to construct the user model for the user friendly system which can provide each individuals user armed with varied intellectual level with the relevant information, can be summarized as follows : (1) The user' ability to use the system and users' subject knowledge, the distribution of the users' level knowledge should be considered for the decision of the typed of interaction between the users and the system. (2) the knowledge of the user models should include the following kinds of knowledge inharmony with one another, 1. Standard user knowledge which represents a general characteristic of user group, 2. individual user knowledge which represents an individual's unique characteristic, 3. Long-term user knowledge which represents the education level and subject background of users, 4. short-term user knowledge which represents the purpose of information science and information need by users (3) As knowledge generation technique, both the implicit method and explicit method should be a n.0, pplied, observation of the system during the interaction, and explicit method generates the knowledge by the user's answering the questions already made by the system. (4) The frame technique as the knowledge representation for the user-modelling in which user-knowledge is represented in a limited situation and in a qualitative aspects, can be recommended. The frame is adequated for the explanation of structured situation, and for the processing the present situation by inferring the previous experiences.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.404-407
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• 2011

The fluidic thrust vector control using co-flowing coanda effect of secondary jet at the nozzle exit is a new concept for efficient thrust vectoring of supersonic jet exhausts. Flow visualization of the flow fields in previous studies have shown some pros and cons of the technique, however, most of the observations were somewhat limited as qualitative data. The present study was designed to evaluate the quantitative performance-characteristics of the thrust-vectoring technique utilizing coanda effects of the secondary jet. Details of design of the test device and calibration/data reduction procedure are provided.

• Environmental Engineering Research
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• v.25 no.2
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• pp.163-170
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• 2020

Knowledge of organic micropollutant transfers in barrier seal materials from waste storage facilities is limited to volatile organic compounds and phenolic compounds at ambient temperature. This study focused on the sorption of chlorophenols (CPs) from various geotextiles from clay geosynthetics under the influence of temperature. Also to study the impact of the polarity or the amount of CPs adsorbed on geotextiles with the partition coefficient. The effect of various parameters such as contact time, effect of temperature, initial CPs concentration and adsorbent dosage has been carried out in this study. The result obtained is non-linear and the data was calculated for affinity with Freundlich isotherm model. An important observation is that the amount of CPs sorbed on geotextiles increases with a growing number of chlorine atoms, ie increases with the partition coefficient (log K_ow). During this study, a decrease in adsorbent properties was observed with the rise in temperature from 23℃ to 55℃. The partitioning coefficients for CPs examined range are from 2.4 (R² = 0.86) to 8.4 mL/g (R² = 0.90). Among the CPs studied, the highest adsorbed quantity was observed for pentachlorophenol with 0.052 g/g at 23℃, this quantity will decrease with the increase in temperature.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.5
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• pp.668-676
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• 2018

This study has developed a technique to divide the aerosol optical depth of the entire aerosol (${\tau}_{total}$) into the dust optical depth (${\tau}_D$) and the pollution particle optical depth (${\tau}_P$) using the AERONET sun/sky radiometer data provided in Version 3. This method was applied to the analysis of AERONET data observed from 2006 to 2016 in Beijing, China, Seoul and Gosan, Korea and Osaka, Japan and the aerosol optical depth trends of different types of atmospheric aerosols in Northeast Asia were analyzed. The annual variation of ${\tau}_{total}$ showed a tendency to decrease except for Seoul where observation data were limited. However, ${\tau}_D$ tended to decrease when ${\tau}_{total}$ were separated as ${\tau}_D$ and ${\tau}_P$, but ${\tau}_P$ tended to increase except for Osaka. This is because the concentration of airborne aerosols, represented by Asian dust in Northeast Asia, is decreased in both mass concentration and optical concentration. However, even though the mass concentration of pollution particles generated by human activity tends to decrease, Which means that the optical concentration represented as aerosol optical depth is increasing in Northeast Asia.

• Proceedings of the KSRS Conference
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• v.2
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• pp.977-980
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• 2006

Ships and industries damage the delicate coastal ecosystem in many parts of the world by releasing oil or pollutants into rivers, coastal and offshore waters. After a tanker accident the biggest problem is to get a clear idea of the extent of the oil slick and predict the way it will move. For natural and man-made oil spills it is necessary to operate a regular and operational monitoring. In the Mediterranean, North and Baltic seas aircrafts or ships normally carry it out. This is expensive and is constrained by the limited availability of these resources, borders between countries, daylight hours, good weather conditions, etc. Satellite imagery can help greatly identifying probable spills over large areas and then guiding aerial surveys for precise observation of specific locations. The Synthetic Aperture Radar (SAR) instrument, which can collect data almost independently of weather and light conditions, is an excellent tool to monitor and detect oil on water surfaces. SAR is currently on board the ENVISAT, ERS-2 and RADARSAT satellites. The application of this technology to the investigation of oil pollution in the Caspian, Black, Mediterranean, North and Baltic seas is shown.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.141-155
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• 1999

Korea Ocean Research & Development Institute(KORDI) conducted an offshore geotechnical investigation for the Eardo Ocean Research Station with the help of the Fugro International Limited at a site location approximately 152 km away from Mara Island, Korea. The primary purpose of the geotechnical investigation was to obtain information on soil and foundation conditions, and to develop foundation design data for a fixed offshore observation platform. This paper discussed the details of the geotechnical investigation and the foundation design recommendations for the Ocean Research Station. Clear recommendations were proposed for the foundation type of driven pile considering the existing soil conditions.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.52.2-52.2
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• 2017

Recent success of gravitational wave (GW) detection by LIGO opened a new window to expand our understanding of the Universe. In addition to LIGO, several other developments are going on or under planning. However, each of these detectors has a specific sensitive frequency range. There is a missing frequency band, 0.1-10 Hz, where detectors loose sensitivity significantly due to Newtonian noise on the Earth. We introduce a plan to develop a Superconducting Low-frequency Gravitational- wave Telescope (SLGT), which can observe massive black holes in 0.1-10 Hz. The SLGT system consists of magnetically levitated six test masses, superconducting quantum interference devices (SQUIDs), rigid support frame, cooling system, vibration isolation, and signal acquisition. By taking the advantage of nearly quantum-limited low-noise SQUIDs and capacitor bridge transducers, SLGT's detection sensitivity can be improved to allow astrophysical observation of black holes in cosmological distances. We present preliminary design study and expected sensitivity, and its technical feasibility.

• Journal of the Korean Society of Costume
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• v.59 no.1
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• pp.47-59
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• 2009

This paper aimed at the development of face covers which is face protection articles for blocking UV rays and yellow sands, with a view to assist the further activation of outdoor life. The four-stage design process of field study, design, design evaluation, final selection of designs was set up for the effective product development. Field study included on-line and off-line market survey on the products for sale in market and observation on those wearing face covers. Depth interviews were done to know consumer understandings and satisfaction levels for current face covers. The results of market survey showed that most of the face covers currently in the market were mask types, which were produced for the blocking of dust and yellow sands rather than UV ray protection. The major clients of the mask were the women in their 30's-50's and the designs for these clients were very limited. Since the number of younger women and men enjoy the outdoor sports has increased, the face covers for these people should be developed. For this purpose, the direction of new face cover design had 2 points: diversification of design in terms of color, material, shape and giving seasonal differences. 12 designs were designed on the first design stage, but after both wearing test by 16 testees and UV ray blocking test to evaluate these designs, 6 face cover designs were finally selected.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.2
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• pp.21-38
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• 2011

Objective : This study was to evaluate the single dose toxicity of Bojungikki-tang(Buzhongyiqi-tang, BJIKT) in male and female mice. Method : Aqueous extracts of BJIKT were 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 principle organs were examined. Results : we could not find any mortality, clinical signs, and changes in the body and organ weight. In addition, no BJIKT-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for some sporadic accidental findings. Conclusion : The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of BJIKT 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.1
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• pp.122-131
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• 2011

The object of this study was to evaluate the single dose toxicity of Yukmijihwangtanggamibang (YMJHTGMB), a polyherbal formula have been traditionally used as prevention or treatment agent for various lung diseases including chronic obstructive pulmonary disease (COPD), in male and female mice. Aqueous extracts of YMJHTGMB (Yield = 16.33%) wasadministered 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 principle 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 YMJHTGMB 2,000 mg/kg treated two male mice (2/5; 40%) at 1 day after administration. In addition, no YMJHTGMB-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 YMJHTGMB aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines.