• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.381-385
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• 2005

Characterization of particle behavior is becoming more important in performance evaluation of water treatment system as well as in operation of the system because conventional parameter, turbidity has lack of explaining ability on small sized microorganisms such like Cryptosporidium etc. Accordingly, particle counter has been introduced in evaluation and operation of the treatment system. However researches on the relationship between turbidity, particle count and/or different sand/anthracite sizes have not been concurrent. Therefore in this study, the relationship was investigated to improve performance evaluation of sand filter so as to help choosing sand/anthracite effective size as a design parameter of water treatment facility. According to the results, too small or too large effective size media filter reached to turbidity limit(0.1 NTU)earlier. However, because shallow sand layer may cause early breakthrough, the depth of sand layer should be provided enough in order to compromise water quality and productivity.

• New & Renewable Energy
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• v.1 no.2 s.2
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• pp.41-52
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• 2005

The effects of internal manifold designs on the reactants feed-stream in Polymer Electrolyte Fuel Cells [PEFCs] is studied to figure out flow and thermal distribution patterns over an entire fuel cell stack. Reactants flows are modeled either laminar of turbulent depending on regions and the open channels in the bipolar plates are simulated by porous media where permeability should be pre-deter-mined for computational analysis. In this work, numerical models for reactants feed-stream In the PEFC manifolds are classified Into two major flow patterns: Z-shape and U-shape. Several types of manifold geometries are analyzed to find the optimal manifold configurations. The effect of heat generation in PEFC on the flow distribution is also Investigated applying a simplified heat transfer model in the stack level (i.e. multi-cell electrochemical power-generation unit). This modeling technique Is well suited for many large scale problems and this scheme can be used not only to account for the manifold flow pattern but also to obtain Information on the optimal design and operation of PEFC systems.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1645-1654
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• 2007

The total methylotrophic population associated with rice plants from different cultivars was enumerated at three different stages: vegetative, flowering, and harvesting. The bacterial population in the leaf, rhizosphere soil, endophytic in the stem and roots, and epiphytic in the florets and grains were determined from four rice cultivars, Il-mi, Nam-pyeoung, O-dae, and Dong-jin, sampled from three different field sites. The methylotrophic bacteria isolated on AMS media containing 0.5% methanol as the sole carbon source uniformly showed three distinct morphologies, which were recorded as separate groups and their distribution among the various samples was determined using the ecophysiological index. The growth stage at the time of sampling had a more significant effect on the methylotrophic population and their distribution than the field site or cultivar. A similar effect was also observed for the PPFMs, where their population in different plant parts increased from V10 to R4 and then decreased towards stage R9. A canonical discriminant analysis of the PPFM population from different parts of rice showed clear variations among the cultivars, sampled sites, and growth stages, although the variations were more prominent among the growth stages.

• The Korean Journal of Mycology
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• v.8 no.3
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• pp.143-148
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• 1980

The authors performed clinical and mycological studies on Tinea cruris of 842 outpatients who had visited the dermatology clinic of Seoul National University Hospital from 1975 to 1979. 1) The incidence of Tinea cruris was 4.4% in maximum and 3.0% in minimum of the total superficial mycotic diseases cases, so there are no remarkable changes of the yearly prevalence rate. 2) Tinea cruris was more frequent among males, and the male cases were 15.2 times higher than those of female cases. 3) By the monthly distribution, Tinea cruris shows most high in summer season (June, July and August). 4) The age distribution group for Tinea cruris varied from the first to the eighth decade, but most of them were in their third decade. 5) Concurrent infection of Tinea cruris with other types of dermatophytoses(Tinea) was noted in 19.0% of the cases. Patients with Tinea cruris and Tinea pedis were most highly observed in 51.3%, and on next. Tinea cruris and Tinea corporis 25.6% in all of the concurrent infection cases. 6) The strains were identified by culture on ordinary Sabouraud's glucose agar media and abtained three species and 99 strains. a) Trichophyton rubrum was most common causative organism of Tinea cruris. Trichophyton rubrum was isolated 64 strains (64.6%). b) Trichophyton mentagrophytes was isolated 27 stains (27.3%) and Epidermophyton floccosum was 8 strains (8.1%).

• Journal of Broadcast Engineering
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• v.14 no.1
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• pp.81-84
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• 2009

This paper explores the possibility of describing objects from the change in the shape according to the change in viewpoint. Specifically, we sample the shapes from various viewpoints of a 3-D model, and apply dimension reduction by locally linear embedding. A low dimensional distribution of points are constructed, and characteristics of the object are described from this distribution. Also, we propose two 3-D retrieval methods by applying the iterative closest point algorithm, and by applying Fourier transform and measuring similarity by modified Housdorff distance, and present experimental results. The proposed method shows that the change of shape according to the change in viewpoint can describe the characteristics of an object.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.7
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• pp.699-704
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• 2003

The characteristics of microwave reflectometry as a non-invasive device to examine the density distribution of inhomogeneous media using the technology of FM radar is presented. The microwave reflectometry system requires an optimized system hardware and the understanding of system response from the density distribution in order to provide the system solution to describe the object under test quantitatively. Among the applications, the use of microwave reflectomeoy in the area of applied plasma physics has been newly proposed and the number of usage is found to be increasing gradually. The microwave reflectometry systems that depend on the nature of the object under test are described. The experimental method to characterize the system is explained and the experimental results on the wavenumber dependence and the sensitivity on density perturbation are presented as well as the comparison to the results from the one dimensional numerical simulations.

• Journal of the Korean Society of Visualization
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• v.14 no.2
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• pp.40-45
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• 2016

Magnetic resonance velocimeter (MRV) is a powerful tool to non-invasively measure the velocity of a fluid flow in various fields ranging from medicine to engineering. However, since the demands for accurate measurement in the solid/liquid interface for cardiovascular diseases and porous media increase, the improvement of spatial resolution is required. In this study, a solenoid RF coil is developed for high spatial resolution measurement. The signal-to-noise ratio in solenoid RF coil is increased seventeen times better than that in commercial coil. Moreover, the velocity distribution of Hagen-Poiseuille flow is measured with in-plane resolution of $36{\mu}m$ by $36{\mu}m$ and the accuracy of the measured velocity is compared with theoretical distribution of the laminar flow. Flow rate calculated by MRV is estimated with the flow rate injected by syringe pump.

• Journal of Distribution Science
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• v.18 no.11
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• pp.23-30
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• 2020

Purpose: Increased awareness of the environment is essential, since the general health of people and the global economy is largely dependent on the health of the environment. The purpose of this study is to increase customer awareness and also to ensure that businesses enlighten their customers on how to act in an environmentally friendly manner, which can be done, for instance, through associations. Research design, data and methodology: Scant research is available regarding what elements of marketing strategy should be applied in an environmental plan to increase customer awareness. For this reason, this study suggests a specific marketing policy that conveys several strategies for practitioners who focus on successful environmental plans for their organizations. Results: The prior literature suggests that public education, mass media, campaign publications, and electronic networking, which are becoming more common today, can be used as platforms for conveying environmental messages that will increase environmental awareness among customers. Conclusions: Organizations can use health and safety training to ensure that customers are aware of the environment. Training programs by companies that point more to the environment can make customers aware of the environment and help them adopt activities that show respect to the environment.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.58-66
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• 2005

Pseudo-Near Field Recording (Pseudo-NFR) system is proposed to prevent contamination and oxidation of media surface occurred in conventional NFR systems. To solve these critical problems of the NFR systems, we investigate the optimal thickness of cover layer for Pseudo NFR. This paper presents the theoretical analysis for cover layer thickness based on the measured length of dust particle and numerical simulation for the temperature distribution using Finite Difference Time Domain (FDTD) method and heat conduction equation. To verify the simulation results, we conduct and compare simulation results in case of far field MO recording and near field MO recording. A measured dust particle length in general environment was mostly less than $20{\mu}m$, and the optimal thickness of cover layer is $30{\mu}m$ in this case. Based on the designed optimal cover layer thickness, temperature distribution is simulated to have $800{\~}850^{\circ}C$.

• Journal of Information Management
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• v.21 no.2
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• pp.1-8
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• 1990

Telecommunication revolution, which was triggered by the convergence of computer and telecommunication technologies, is changing the fundamental fabrics of industrial society. Especially, mass media of our society are forced to face the changes in both their production and distribution processes because of these emerging new technologies. News database industry is an area of new business opened by those technologies which made physical processes of newspaper production and distribution electronic. In this article, the status and trend of Korean newspaper database industry is described in comparison with those of the U.S. and Japan, and the difficulties to overcome are briefly discussed.