• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.4
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• pp.67-75
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• 2000

A simulation model for reservoir sizing was developed to be applied in a region with insufficient hydrological data. Reservoir storage balance equation was formulated on a monthly basis. Gajiyama equation was generalized to estimate monthly reservoir inflow more accurately. Monthly evaporation equation on a reservoir water surface was introduced , which was functioned with monthly mean temperature. Generalized Gajiyama equation was applied to estmate reservoir inflow of the Sayeon dam. Nash-Sutcliffe's model efficiency was 0.793. Using developed model for reservoir sizing, water supply capacity was analyzed with 118.000㎥/day on the Sayeon dam. This showed a reasonable result as compared with 110000㎥/day in other technical report. For general application of developed model, a virtual reservoir was considered and its dta of surface area and volume by elevation was prepared using DEM. Using the model, size of reservoir was determined and water supply capacity was anlayzed on a virtual reservoir.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.1
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• pp.44-50
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• 2005

In the present study, the characteristics of upward bubble flow were experimentally investigated in a liquid bath. An electro-conductivity probe was used to measure local volume fraction and bubble frequency. Since the gas was concentrated at the near the nozzle, the flow parameters were high near the nozzle. In general their axial and radial values tended to decrease with increasing distance. For visualization of flow characteristics, a Particle Image Velocimetry (PIV) and a thermo-vision camera were used in the present study. The experimental results showed that heat transfer from bubble surface to water was largely completed within z = 10 mm from the nozzle, and then the temperature of bubble surface reached that of water rapidly. Due to the centrifugal force, the flow was more developed near the wall than at bubble-water plume. Vortex flow in the bottom region was relatively weaker than that in the upper region.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.687-694
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• 2002

This paper presents the results of 3-D analysis on steady state flow in the region where the leakage in a cable tunnel is occurred due to high excess ground water pressure. In numerical modeling, a relief well is selected as a method of reduction in water pressure at the surrounding region of the cable tunnel. The distribution of ground water level after dewatering by relief wells is analyzed, Results show that the amount of dewatering level in the layer of hard rock is about 4.2∼8.6m, and that in the layer of fracture zone is about 5.8∼8.2m. The predicted settlement at the cable tunnel due to the increase of effective stress by dewatering is 0.3mm.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1039-1041
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• 2003

Ocean color products derived from remote sensing satellite data are useful for monitoring the sea water quality such as the concentrations of chlorophyll, sediments and dissolved organic matter. Currently, ocean color products derived from MODIS data can be requested from NASA over the internet. However, due to the bandwidth limitation of most users in this region, and the time delay in data delivery, the products cannot be use for near-real time monitoring of sea water chlorophyll. CRISP operates a MODIS data receiving station for environmental monitoring purposes. MODIS data have been routinely received and processed to level 1B. We have adapted the higher level processing algorithms from the Institutional Algorithms provided by NASA to run in a standalone environment. The implemented algorithms include the MODIS ocean color algorithms. Seasonal chlorophyll concentration composite can be compiled for the region. By comparing the near-real time chlorophyll product with the seasonal composite, anomaly in chlorophyll concentration can be detected.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.611-611
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• 2015

One of the hazard of nature is a drought. Its impact varies from region to region and it is difficult for people to understand and define due to differences in hydrometeorological and social economic aspects across much of the country. In the most general sense, drought originates from a deficiency of precipitation over an extended period of time, usually month, season or more, resulting in a water shortage for some activity, group, or environmental sector. Palmer Drought Severity Index (PDSI) is well known and has been used to study aridity changes in modern and past climates. The PDSI index is estimated over US using USHCN historical data.(e.g. precipitation, temperature, latitude and soil moisture). In this study, low frequency drought variability associated with climate variability such as El-Nino and ENSO is mainly investigated. With respect to the multi-scale analysis, wavelet transform analysis is applied to the PDSI index in order to extract the low frequency band corresponding to 2-8 years. Finally, low frequency patterns associated with drought by comparing global wavelet power, with significance test are explored.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1283-1283
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• 2001

NIR spectroscopy has been used extensively to investigate the structure of water, alcohol and other self-associate molecules because the frequencies of NIR bands due to OH and NH groups strength of hydrogen bonds. We have studied the structure of water -methanol mixtures by use of NIR spectroscopy. Strong features in the 7200-6300 $cm^{-1}$ / region consist of a number of overlapped bands due to the combination of OH antisymmetric and symmetric stretching modes of water and the first overtone of the OH stretching modes of free and hydrogen bonded methanol, while weak fratures in the 6000-5800 cm-1 region are ascribed to the first overtones of $CH_3$ stretching modes of methanol. We will focus the discussion on the $CH_3$ stretching bands. They seem to show a significant shift is not clear from the spectra shown in figure 1(a). Figure 1(b) depicts the second derivative in the 6000-5700 $cm^{-1}$ / region. Now, it is clear from the second derivative that there are two major bands near 5950 and 5900 $cm^{-1}$ / and that they do show a shift be about 30 $cm^{-1}$ / Why do the $CH_3$ bands show the shift with increasing concentration of methanol\ulcorner Probably, the CH, group interacts directly with OH groups of water. The results in figure 1(b) demonstrate the usefulness of the second derivative in resolution enhancement as well as the potential of NIR spectroscopy in the studies of molecular interactions.(Figure omitted).

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.97-110
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• 2000

To investigate characteristics of water masses and current structures around Noto Peninsula located in south-east coastal region of the East Sea, observation results of CREAMS (Circulations Research of the East Asian Marginal Seas) cruise and data report of oceanographic observation (Japan Meteorological Agency) in June, 1995 and 1996 were used. Water mass showing characteristics of Tsushima Warm Current (TWC) exists over the continental shelf. The depth is shallower than 200m and its width and thickness are 190km and 200m, respectively. Minimum level of dissolved oxygen occurred at the layers of maximum salinity. In the current structure, a noteworthy phenomenon is that the positions of the high-salinity water (more than 34.6 psu) match well with the distributions of the southwestward flow. In June of 1995 and June of 1996, a southwestward flow were separated into two parts along line C and line G. Current directions derived from the temperature and salinity match well with the distributions of the geostrophic currents in the vertical sections. The isothermal lines and the isohaline, which exist horizontally along the coastal area of the Japan, change abruptly at the frontal area of the Noto Peninsula, then turn toward the center of the East Sea. The dynamic depth anomalies centering around the region far northwest of the Noto Peninsula were relatively high, compared to those of other regions. The isopycnic surface (sigma-t, 25.8) existed near the surface in the central part of the East Sea, but, at the depth of 100m, the isopycnic surface was found in the coastal waters.

• Journal of Radiation Protection and Research
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• v.41 no.3
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• pp.286-290
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• 2016

Background: Activation of air and water in the electron linear accelerator for medical use has not been considered severely. By the new Japanese regulation for protection of radiation hazard, it became indispensable to evaluate of activation of air and water in the accelerator room. The measurement of induced activity in air and water components in the electron energy region of 10 to 20 MeV is very difficult, because this energy region is close to the threshold energy region of photonuclear reactions. Then, we measured the photonuclear reaction yields of $^{13}N$, $^{15}O$, and $^{11}C$ by using the electron linear accelerator. Obtained data were compared with the data calculated by the Monte Carlo method. Materials and Methods: An activation experiment was performed at the Research Center for Electron Photon Science, Tohoku University. Highly purified $SiO_2$, $Si_3N_4$, and carbon disks were irradiated for 10 minutes by bremsstrahlung converted by a tungsten plate. Induced activity from C, N, and O was obtained. Monte Carlo calculation was performed using MCNP5 and AERY (DCHAIN-SP) to simulate the experimental condition. Cross section data were adopted the KAERI dataset. Results and Discussion: In our experiment in hospital, calculated values were not agreed with experimental values. It might be three possible reasons as the cause of this deference, such as irradiation energy, calculation procedure and cross section data. Obtained data of this work, calculated and experimental values were good agreement with each other within one order. In this work, we used KAERI dataset of photonuclear reaction instead of JENDL. Therefore, it was found that the photonuclear cross section data of light elements are most important for yield calculation in these reactions. Conclusion: Further improvement for calculation using a new dataset JENDL/PD-2015 and considering electron energy spreading will be needed.

• Journal of the Korean association of regional geographers
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• v.7 no.4
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• pp.18-32
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• 2001

Korean society has frequently seen the conflicts between environmentally oriented ideology and development ideology which generally take shape as regional problems. An interesting example is the case of Paldang water resource protection area in Yangpyung-kun, Kyunggi Province. At the area, the rural residents are trying to take regional development by utilizing as much as natural resource in the region, and the central government is trying to make clean water sustained for the public interest of the whole people living within the supplying area of the water resource. Accordingly, the conflict is inevitable. It is the role of environmental movement group that makes us pay attention to this region. Under the present situation regarding environmental protection as a core keyword, the environmental protection groups tend to stand on the side of the central government. That is, those groups let the government consolidate its dominance discourse, which help the resistance discourse of the residents weakened. This basic structure of relationship sometimes touches off the situations of antagonistic confrontation. It is the group for organic fanning movement on the region that is playing a significant mediating role between the two. It has eased severe confrontation, and has persuaded the residents, expecially the farmers, to accept so-called win-win strategies which are related with various kind of organic fanning. The agriculture can be regarded as a win-win action because it is a way of fanning adapted to the protected natural environment. It is taking firm hold in this region as an alternative which can satisfy the ideology of 'sustainable development' or 'sustainability'. It could give us a kind of paradoxical confusion that the strategies of regional development of pro-environment are being carried out in the region where the residents are fighting against the government's strict control of natural environment. The example of this region, however, could show a significant direction for solving the continuous problem of conflict between environmental protection and regional development.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.356-368
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• 2008

The effects of cosurfactant on silica nanoparticles were investigated in systems containing surfactant, oil and aqueous ammonia solution where nanoparticles were prepared using a single phase water-in-oil (W/O) microemulsion. For the same oil phase, a single phase region was dependent on the interaction between surfactant and oil. For the cyclohexane system, NP-5 surfactant showed a wider single phase region than NP-4. The addition of n-propanol as a cosurfactant resulted in an increase or a decrease of a single phase W/O microemulsion region depending on the continuous oil phase. For both cyclohexane and isooctane systems, the addition of n-propanol resulted in a decrease in the single phase region. On the other hand, for n-heptane system, the addition of n-propanol expanded a single phase W/O microemulsion region. Silica nanoparticles prepared within a single phase region showed that relatively large number of particles of irregular shape were obtained with the addition of n-propanol to NP surfactant system. The addition of n-propanol to LA-5 surfactant and n-heptane system produced a decrease in average particle size and an increase in the number of particles formed due to a decrease in the intermicellar exchange rate among microemulsion droplets.