• 한국토양비료학회지
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• 제49권5호
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• pp.461-468
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• 2016

One of the important phytohormones produced by plant growth promoting bacteria is the auxin; indole-3-acetic acid (IAA), with L-tryptophan as the precursor. In this study, we focused on the investigation of optimal conditions for the production of IAA by Bacillus megaterium BM5. We investigated culturing conditions, such as incubation temperature, pH of the culture medium and incubation period, with varying media components such as inoculation volume, tryptophan concentration and carbon and nitrogen source. Besides, optimization study intended for high IAA production was carried out with fermentation parameters such as rpm and aeration. The initial yield of $42{\mu}g\;IAA\;ml^{-1}$ after 24 hr increased to $85{\mu}g\;ml^{-1}$ when 5% (v/v) of L-tryptophan was used in the culture broth. The maximum yield of $320{\mu}g\;IAA\;ml^{-1}$ was observed in trypticase soy broth (TSB) supplemented with starch and soybean meal as C and N sources with a C/N ratio of 3:1 (v/v) at $30^{\circ}C$, pH 8.0 for 48 hrs with 1.0 vvm and 250 rpm in 5 L working volume using 10 L scale fermenter. The bacterial auxin extracted from the culture broth was confirmed by thin layer chromatography and high-performance liquid chromatography and effect on plant growth was confirmed by root elongation test.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.172-178
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• 2013

PURPOSE. The purpose of this study was to assess the difference in efficacy between calcium metaphosphate (CMP)-coated implant fixtures and conventional resorbable blasted media (RBM) processed implant fixtures. MATERIALS AND METHODS. This study targeted 50 implants from 44 patients who visited Dankook University Dental Hospital. Implantations were done separately for RBM treated and CMP-coated implants, although their design was the same. Calcium metaphosphate has a quicker biodegradation process through hydrolysis compared to other phosphate calcium groups. For the first year of the implantation, the resorption volume of marginal bone analyzed via radiography and perio-test value were measured, under the check plan. Their analyses were composed of a non-inferiority trials test. A 95% level of reliability was used. RESULTS. In the comparative analysis of the resorption volume of marginal bone and the perio-test value, no statistically significant difference was found between the CMP-coated implants and RBM implants. CONCLUSION. One year after the implant placement, CMP-coated implants were found not to be inferior to the conventional RBM implants.

• 대한조선학회논문집
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• 제48권6호
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• pp.581-591
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• 2011

This paper describes the air compressibility effect in the CFD simulation of water impact load prediction. In order to consider the air compressibility effect, two sets of governing equations are employed, namely the incompressible Navier-stokes equations and compressible Navier-Stokes equations that describe general compressible gas flow. In order to describe violent motion of free surface, volume-of-fluid method is utilized. The role of air compressibility is presented by the comparative study of water impact load obtained from two different air models, i.e. the compressible and incompressible air. For both cases, water is considered as incompressible media. Compressible air model shows oscillatory behavior of pressure on the solid surface that may attribute to the air-cushion effect. Incompressible air model showed no such oscillatory behavior in the pressure history. This study also showed that the CFD simulation can capture the formation of air pockets enclosed by water and solid surface, which may be the location where the air compressibility effect is dominant.

• Journal of Information Processing Systems
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• 제10권1호
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• pp.23-35
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• 2014

Recently, novel application areas in digital geometry processing, such as simulation, dynamics, and medical surgery simulations, have necessitated the representation of not only the surface data but also the interior volume data of a given 3D object. In this paper, we present an efficient framework for the shape approximations of spherical solid objects based on trivariate B-splines. To do this, we first constructed a smooth correspondence between a given object and a unit solid cube by computing their harmonic mapping. We set the unit solid cube as a rectilinear parametric domain for trivariate B-splines and utilized the mapping to approximate the given object with B-splines in a coarse-to-fine manner. Specifically, our framework provides user-controllability of shape approximations, based on the control of the boundary condition of the harmonic parameterization and the level of B-spline fitting. Experimental results showed that our method is efficient enough to compute trivariate B-splines for several models, each of whose topology is identical to a solid sphere.

• 분석과학
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• 제35권5호
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• pp.218-227
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• 2022

A simple and fast throughput flow injection (FI) system with a merging-zone technique was designed to determine ferrous and ferric in an aqueous solution. The method is based on the direct reaction of ferrous with a Bathophenanthroline reagent (Bphen) in acidic media. The forming red complex absorbs light at 533 nm. All conditions of the flow injection system were investigated. The analytical curve of ferrous was linear in the range of 0.07 to 4 mg/L with an r² value of 0.9968. The detection and quantification limits were 0.02 and 0.04 mg/L, respectively. The molar absorptivity and Sandell's sensitivity were 4.0577 × 10⁶ L/mol cm and 25 × 10^-5 ㎍/cm², respectively. The homemade valve was low-cost with high repeatability (n = 7) at an RSD of 1.26 % and zero dead volume. The values of the dispersion coefficient were 2.318, 2.022, and 1.636 for the concentrations of 0.2, 1, and 3 mg/L, respectively. The analysis throughput of the designed flow injection unit was 57 sample per hour.

• 한국컴퓨터그래픽스학회논문지
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• 제15권1호
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• pp.1-6
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• 2009

이 논문은 비격자메쉬에서의 비물리적 감쇄현상을 감소시키는 새로운 CIP 대류방법을 제안한다. 제시되는 방법은 물리량과 물리량의 미분정보를 함께 사용하여 기존의 선형방법보다 더 정확한 물리현상을 반영할 수 있다. 비격자메쉬에서 해결하기 힘든 CIP의 비대류항을 풀기 위해 기존의 격자 메쉬에서 사용되었던 유한차분법 방법과는 다른 유한체적법을 사용하였다. 그리고 대류항의 보다 나은 정확도를 위해 여러가지 보간법에 대해 정확도 실험을 수행하였으며, 선형방법과의 비교 실험을 통해 보다 적은 비물리적 감쇄현상을 보임을 확인할 수 있었다.

• 한국실내디자인학회논문집
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• 제18권2호
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• pp.41-49
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• 2009

Contemporary design environment is formed with image-centered trend based on pluralism. In this point of view, enterprises' building lobbies are public places containing the equivocal meaning, actively utilizing light as a design element to express the image of enterprises' identifications. Light is an immaterial entity having unlimited possibilities and potentials on space. It also acts as media to activate spaces and create new images in connection with formative elements of space. This study is to figure out how lightings are expressed and affected the formative characteristics of office lobby spaces and activate the specific characteristics of spaces. As a result, we drew conclusions as follows. First, as state-of-the-art technology and media are introduced, light is expressed on spaces as floating, direction, rhythm, silhouette, metaphor and allusion, sense of depth and volume. Second, expressive aspects of light in lobby space are embodiment of light, substantiation of immateriality, standing of materiality from the perspective of spatial aesthetics, and distortion/transformation of shape, pluralism phenomena of space from the perspective of spatial structure. In this way, light on building lobbies which are greatly required design differentiation strategy, specializes space and also integrates all the designs as not only a functional element but also a mental, psychological, formative element. Consequently, light on lobby spaces induces communication between spaces and users, makes formative value of existence in itself, and presents the characteristics of differentiated enterprises' identities.

• Environmental Analysis Health and Toxicology
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• 제16권3호
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• pp.133-137
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• 2001

Acetanilide is a High Production Volume Chemical, which is produced about 2,300 tons/year in Korea as of 1998 survey. Most is used as an intermediate for synthesis of pharmaceuticals and dyes and the chemical is one of seven chemicals of which human and environmental risks are being assessed by National Institute of Environmental Research under the frame of OECD SIDS program. The chemical is water soluble (4 g/1 at 20$\^{C}$) and readily biodegradable (68.7％). Partition coefficiency (Log Pow) is 1.16 at 23$\^{C}$ so that the chemical has a low potential for bioaccumulation. The acute toxicities of algae, daphnia and fish are not high. The 72 hr-EｂC50 of algae is 13.5 mg/1,48 hr-EC50 of daphnia is over 100 mg/1 and 96 hr-LC50 of Oryzias latipes is over 100mg/1. Regarding the exposure, levels in air, water, soil or sediment have not been monitored or estimated so that risk evaluation of acetanilide was not possible. In this study, distribution of the chemical among environmental media was estimated using EQC model based on the chemical-physical properties. In Level I and IIof which the chemical are hypothesized in equilibrium and no transfer through the media, more than 98％ of acetanilide are estimated to be distributed in water. However, in Level Ⅲ of which non-equilibrium and intermedia transfer could be occurred, the chemical is estimated to distributed to soil as 51.8％ and water as 47.8％ as of total amount.

• 상하수도학회지
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• 제22권4호
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• pp.413-420
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• 2008

In order to utilize cinder melting slag as a filter media to control the quality of early rainwater, its environmental stability was verified by heavy metal elution experiment and improved by pre-treatment. Possibilities of improving its function as an absorbent was considered. Absorption characteristics of melting slag before and after the pre-treatment were analyzed by heavy metal equilibrium and stationary-phase column experiments, which in turn were analyzed by comparison experiment with activated carbon. As a result of heavy metal elution experiment, every metal item existed in a much lower amount than the criteria or was not detected, implying that there is no problem recycling it. Absorption equilibrium experiment showed that the time for pre-treatment melting slag to reach the equilibrium was reduced, while the absorbed amount was greatly increased. Stationary-phase column experiment assures us that the elimination rate was not changed much by influx rate, pH and the change in packing volume rate, indicating that this melting slag can be used not only as a filter media to control the quality of early rainwater but also in many areas of water-processing.

• 한국초지조사료학회지
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• 제20권1호
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• pp.25-30
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• 2000

이탈리안 라이그라스 (Lolium multiflorum Lam.) 종자로부터 직접 갤러스를 유도하고, 형성된 캘러스로부터 식물체를 재분화하는데 조건을 확립하였다. 캘러스 유도시 사용한 SH (Schenk and Hildebrandt), MS (Murashige and Skoog) 및 N6(Chu). 배지중에서 MS 배지가 캘러스 유도에 유리한 것으로 나타났으며, 캘러스 유도시에는 2,4-D $5\;mg/{\ell}$를 첨가한 조건, 캘러스 증식시에는 2,4-D $3\;mg/{\ell}$을 첨가한 조건이 가장 효율이 좋았다. 식물제 재분화 조건은 MS 배지에 BA $1.0\;mg/{\ell}$와 NAA $0.1\;mg/{\ell}$를 첨가한 재분화배지에서 계대배양하며 재분화를 완성한 처리구 9의 조건에서 재분화율 (15%)이 가장 높았다.