• Food Science and Preservation
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• v.12 no.3
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• pp.223-229
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• 2005

Response surface methodology(RSM) was used for monitoring the quality change of muskmelon beverage with storage temperature and time. Muskmelon beverage was prepared with the ratio of liquid fructose($11\%$), muskmelon vinegar($3\%$), concentrated muskmelon juice($1\%$) and refined water($84\%$). To examine physicochemical properties of muskmelon beverage, various factors such as color, brown color intensity and sugar content were determined using physicochemical methods. Physicochemical properties of muskmelon beverage were more affordable with the increased storage temperature. While, organoleptic properties decreased with the increased storage time and temperature. The result of this study indicated that the quality of muskmelon beverage was mostly influenced by the storage temperature. Muskmelon beverage showed the good score under $60^{\circ}C$ as a storage temperature.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.37-48
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• 2004

This study is focused on the constitutive model in order to represent brittleness and dilatancy for cohesionless soils. The constitutive model was based on an anisotropic hardening rule derived from generalized isotropic hardening nile, which includes an appropriate hardening equation for the overall strain behavior at small to large strains. The yield surface is a simple cylinder type in stress space and it makes the model practically useful. Hence dilatancy behavior in cohesionless soils could be modeled reasonably. A peak stress ratio was defined in order to model brittle stress-strain relationships. An optimized design methodology was proposed on the basis of real-coded genetic algorithm in order to determine parameters for the proposed model systematically. The material parameters were then determined by that algorithm. In order to verify the proposed model, triaxial tests were performed under $K_0$ conditions far weathered soils. In comparison with the triaxial test results under $K_0$ conditions, the proposed model could calculate appropriately the actual effective stress behavior on brittle stress-strain relationships and dilatancy.

• Journal of the Korean earth science society
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• v.31 no.1
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• pp.88-94
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• 2010

A simple laboratory device and methodology are developed for deep understanding of the western boundary current (WBC). The apparatus consists of a rotating (count-clockwise) rectangular tank with a sloping bottom in order to simulate the beta effect, the variation of the Coriolis parameter with latitude. We also used a clockwise rotating disk at the surface water to mimic the wind stress forcing in mid-latitude oceans. Four experiments were carried out using some combination of a bottom type and a rotation of the tank. Experiment with the beta effect clearly demonstrated the WBClike flow as well as the Sverdrup interior. However, the water in a tank gave rise to an inertial motion under the influence of a constant Coriolis force alone. We also discussed a stiffening of the rotating fluid on the basis of the Taylor-Proudman effect. We believe that the apparatus and methods developed in this study help to understand the WBC due to the beta effect.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.42-50
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• 1998

Titanium dioxide $(TiO_2)$ thin film samples were prepared by using spray pyrolysis methodology and were by using X-ray photoelectron spectroscopy and X-ray diffraction analysis. It was found that anatase prepared by the hydrolysis of titanium(Ⅳ) oxyacetylacetonate exhibited the largest specific surface area. The particle size increased with increasing temperature, while the thickness decreased. Titanium dioxide $(TiO_2)$ in the anatase form was prepared at $400^{\circ}C$ and the photoconductivity was determined using photocurrent measurements. Photoelectrochemical properties of the $TiO_2$-phthalocyanine system were measured in a three-electrode system. The photocurrent action spectrum in the visible region coincided with intrinsic absorption spectrum of phthalocyanine. The crystal structure of phthalocyanine is considered to be a very important property in the photogeneration phenomena.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.181-185
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• 2017

Senior-friendly strawberry jelly was developed using strawberry juice, sugar, xanthan gum, and locust bean gum. The experimental variables included strawberry juice (30.0-40.0%, w/w) and sugar (7.5-10.0%, w/w) concentrations and the xanthan gum/locust bean gum ratio (0.3-4.0), and interactions among these variables were predicted using a response surface methodology. The optimal concentrations of strawberry juice and sugar and the ratio of xanthan gum/locust bean gum, determined against jelly hardness, were found to be 40.0, 10.0, and 1.5%, respectively. The hardness, gumminess, and chewiness of strawberry jelly increased significantly during storage at 5 and $15^{\circ}C$ (p<0.05). The lightness of the gum decreased significantly at both temperatures (p<0.05), whereas the hue angle increased during storage at $15^{\circ}C$. The zero-order kinetics was used to predict the shelf-life of the prepared jelly ($R^2=0.89-0.96$), which was determined to be 38 and 26 days at 5 and $15^{\circ}C$, respectively.

• Applied Chemistry for Engineering
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• v.28 no.4
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• pp.437-441
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• 2017

This study was carried out to investigate the volumetric expansion ratio and hardness of expanded graphite after coating with various resins which were used as an additive of fireproof sealant. The coating thickness of the resin, which represents the coating rate, was dependent of the drying speed of the resin and the viscosity of the resin. Therefore the coating thickness was shown as follows: polyvinyl acetate > acrylic resin > urethane resin > water soluble latex. Furthermore, the volumetric expansion ratio was as follows: urethane resin > water soluble latex > acrylic resin > polyinyl acetate and the hardness was as follows: polyvinyl acetate resin > acrylic resin > water soluble latex > urethane resin. This showed that the volume of expansion was reduced by expansion, which was not covered by coating, but significantly increased by increasing hardness and allowed it to be used as a refractory addition. According to the response surface methodology, the optimized addition amount and stirring speed of acrylic resin were 37.6 wt% and 441.4 rpm, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.222-233
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• 2000

A methodology for determining age by otolith of small yellow croaker, Pseudosoiaena polyactis Bleeker, was developed. A thin section method was chosen to be suitable for age determination because the otolith had a three-dimensional shape and thus it was not possible to read the otolith rings on the surface. The clear rings were identified on the vertical-axis cross-sectioned otoliths. The total length-total weight relationship and the growth parameters were estimated with error structure to endow with accuracy. In the relationship between total length and total weight, a multiplicative error structure was assumed because variability in growth increased as a function of the length, and the estimated equation was $W=0.0049L^{3.2153}$. The variability in growth was constant as a function of the age, revealing an additive error structure. The von Bertalanffy growth parameters were obtained from a nonlinear regression as $L_{\infty}= 37.11cm, K=0.20/yr and t_0=-1.88.$

• The Korean Journal of Food And Nutrition
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• v.30 no.2
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• pp.319-325
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• 2017

In this study, we optimized the coffee extraction conditions for instant coffee production in two stage percolators, which is the most common coffee extractor for instant coffee production. A central composite design was used to build mathematical model equations for response surface methodology (RSM). In these equations, the yield and overall acceptability of the coffee extracts were expressed as second-order functions of three factors, the feed water temperature, draw-off factor (DOF), and extraction time (cycle time). Based on the result of RSM, the optimum conditions were obtained with the use of desirability function approach (DFA) which find the best compromise area among multiple options. The optimum extraction conditions to maximize the yield and overall acceptability over 40% of yield were found with $163^{\circ}C$ of feed water temperature, 4.3 of DOF and 27 minutes of extraction time (cycle time). These results provide a basic data for the coffee extraction conditions for the competitive instant coffee in the industry.

• Tunnel and Underground Space
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• v.18 no.6
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• pp.465-479
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• 2008

For the quantitative identification of rock behavior in shallow tunnels, we recommend using the rock behavior index (RBI) by the analytic hierarchy process (AHP) and the Rock Engineering Systems (RES). AHP and RES can aid engineers in effectively determining complex and un-structured rock behavior utilizing a structured pair-wise comparison matrix and an interaction matrix, respectively. Rock behavior types are categorized as rock fall, cave-in, and plastic deformation. Seven parameters influencing rock behavior for shallow depth rock tunnel are determined: uniaxial compressive strength, rock quality designation (RQD), joint surface condition, stress, pound water, earthquake, and tunnel span. They are classified into rock mass intrinsic, rock mass extrinsic, and design parameters. An advantage of this procedure is its ability to obtain each parameter's weight. We applied the proposed method to the basic design of Seoul Metro Line O and quantified the rock behavior into RBI on rock fall, cave-in, and plastic deformation. The study results demonstrate that AHP and RES can give engineers quantitative information on rock behavior.

• The Journal of the Korean bone and joint tumor society
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• v.12 no.1
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• pp.9-14
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• 2006

Purpose: The proximal tibial sarcoma patients, especially in their growing ages have problems of reconstruction. This study is to devise a methodology which can circumvent this limitations. Materials and Methods: Four cases of proximal tibial osteosarcoma underwent hemiarthroplasty. The mean age was 13 years (11~15) with a mean follow-up of 64 months (47~89). The procedure consists of ultrahigh molecular weight polyethylene (UHMWPE) liner as an substitute for the joint surface and this piece was fixed to the remaining tibial bone stock with Ender nail and bone cement. Results: Final functional score was 23.5 (78.3% of control) by MSTS criteria. All the cases showed stable joint without pain. Hemiarthroplasty related complications were absent. By saving the femoral physis, expected leg length discrepancy could be minimized by this procedure. Conclusions: Hemiarthroplasty of proximal tibia can be an option in pediatric sarcoma patients.