• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.181-188
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• 2015

The non-contact permanent magnet gear has advantages of high efficiency and improved reliability. It has other advantages of no mechanical friction loss, very little noise and vibration, and no need for lubricant. With these advantages, the non-contact permanent magnet gear that solves the physical contact problem of the mechanical gear has drawn attention. Due to this unique non-contact characteristic, the non-contact permanent magnet gear which is capable of non-contact torque transmission has replaced mechanical gear. The mechanical gears which is in many fields of the modern industry, is used mostly for power transmitting mechanical devices. However, it also has the problem of a low torque density, which requires improvement. In this paper, a novel pole piece shape is proposed in order to improve the problem of low torque density of the non-contact permanent magnet gear. The experiment data required for predicting the relationships among them are obtained using finiteelement Operating method based on two-dimensional (2-D) numerical analysis. Therefore, this paper derived an optimal model for thenon-contact permanent magnet gear with the novel pole piece using the Box-Behnken design, and the validity of the optimal design of the proposed pole piece shape through variance analysis and regression analysis demonstrated. In this paper, we performed the thransfer torque analysis in order to improve the torque density and power density, we have performed on optimal design of proposed pole piece shape using box-behnken.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.105-113
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• 2010

This study is for the preservation plan of the tradition space which is performed by the damage status analysis through performing the value assessment. Especially, it is an experimental study for finding the process and methods by analyzing the major element for the value assessment of the selected object's damage status through the expert group who are systematized in their interest to conserve the traditional structure in traditional space. For that purpose, this study should be performed by the fundamental understanding of the physical property of the Supyo-bridge and the condition of the selected site's environment. Meanwhile, this study has been done that 'map of the damage status distribution' for making records of damage status of the Supyo-bridge on the property utilized field measurement adapted by photogrammetry and assessment guidelines, which are for investigation on damage status of objects that are standardized 'Raccomandazioni Normal' which could be said construction culture assets management guidelines of Italian government. As the result of investigation, damage status of each part in the Supyo-bridge was mostly composed of damage by sediment and corrosion and in case of 9 damage types including corrosion, in consideration of physical and chemical properties and distribution status of those elements, it is made an judgement that is not working as a threatened factor regarding security of the Supyo-bridge. On the contrary, for the improvement landscape, in case of 'Thermoclastism' phenomenon observed in 'upper floor', 'Myungae stone' and 'bridge pier' is that when taking it into consideration that is widely distributed concentrated on the bridge pier, surface reinforcement job along with elimination of damage part will be judged to be requested for earliest treatment.

• Economic and Environmental Geology
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• v.44 no.3
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• pp.239-246
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• 2011

Groundwater in small islands is used as main water resource but the overuse of groundwater may cause seawater intrusion and temperature decrease in geothermal wells. This study aimed to characterize the hydrogeology of Maeum-ri area in Seokmo Island of Ganghwagun using long-term monitoring at groundwater wells and geothermal wells. In the monitoring period seasonal water level change, consistent drop or increase of water levels are not detected. The groundwater temperature about 10m below ground surface shows year cycle variation having two to five months difference with ambient temperature cycle. The storativity was calculated by tidal method. The storativity estimated by adapting tidal efficiency factor showed some larger values than that by using tidal time lag. The result suggested that the tidal method assuming several assumptions on aquifer condition may produce broad ranges but the calculated ranges at this application are reasonable. The similar shape of groundwater level change and tidal effects was observed at several wells clustered east-south-east direction which may implicate the distribution of vertical fracture system strongly related with groundwater flow channels. The applied methodology and study results will bc valuable to evaluate optimal pumping rate for the preservation of groundwater resources, and to manage geothermal development.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.378-385
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• 2017

This study investigated the design of a snap fit, which is widely used for fastening plastic parts. We analyzed the assembly mechanism of a lock snapfit, measured the assembly force and separation force based on the design of experiments, and derived a regression equation through an analysis of variance. The response surface methodology was also used. Polybutylene terephthalate was used to fabricate specimens, and the assembly force and separation force were measured using a micro-tensile tester. The length, width, thickness, and interference were considered as factors. A second-order regression model was used to derive the regression equation. The assembly force decreased with increasing length and width, but it increased with increasing thickness and interference. The finite element method was used to analyze the assembly mechanics. The width decreased the assembly force by increasing the ductility. The influences of the factors for low assembly force and high release force were shown to be opposite to each other. It was necessary to design a structure that minimized the assembly force while maintaining an appropriate level of separation force.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.92-103
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• 2015

Box-Wilson experimental design method, known as central composite design, is the design of any information-gathering exercises where variation is present. This method was devised to gather as much data as possible in spite of the low design cost. This method was employed to model the effect of mixing factors on several performances of 60 MPa high strength self compacting concrete and to numerically calculate the optimal mix proportion. The nonlinear relations between factors and responses of HSSCC were approximated in the form of second order polynomial equation. In order to characterize five performances like compressive strength, passing ability, segregation resistance, manufacturing cost and density depending on five factors like water-binder ratio, cement content, fine aggregate percentage, fly ash content and superplasticizer content, the experiments were made at the total 52 experimental points composed of 32 factorial points, 10 axial points and 10 center points. The study results showed that Box-Wilson experimental design was really effective in designing the experiments and analyzing the relation between factor and response.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.13-19
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• 2013

This study was carried out to find the optimal conditions for red cabbage seed sprouts in terms of their physicochemical and sensory qualities by electron-beam irradiation, cultivation and storage using the response surface methodology (RSM). Moisture content ($R^2$=0.9638) was affected by irradiation dose and cultivation time. Total phenolics content ($R^2$=0.9117) was mainly affected by irradiation dose, but carotenoid content ($R^2$=0.8338) was affected in the order of irradiation dose, cultivation time and storage time. Sensory properties were also affected by irradiation dose, and thus scores decreased as irradiation dose increased. The optimum conditions estimated by superimposing total phenolics content and overall acceptance were 2.2-3.8 kGy of the irradiation dose, 3.0-4.0 days of cultivation and 2.0-3.0 days of storage.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.286-290
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• 2010

Angiotensin-converting enzyme (ACE) inhibitory activity and production optimization of ovotransferrin hydrolysates were studied. Ovotransferrin was hydrolyzed by several enzymes (protamex, alcalase, trypsin, pepsin, neutrase, and flavorzyme) and acid (0.03 N HCl). Ovotransferrin hydrolysate reduced ACE activity by 60.2%, 55.8%, and 42.6% when treated with trypsin, acid, and pepsin, respectively. Trypsin was selected for production of peptide having maximum AC inhibitory effect, which was greatest with 7 h hydrolysis. Central composite design determined that optimum composition of ACE inhibitory substances using substrate concentration of 20-35%, temperature of $35-55^{\circ}C$, and pH of 6.0-8.0. The optimum composition was 1% trypsin, substrate concentration of 26.32%, $51.29^{\circ}C$, and pH 6.32. Under this conditions, a maximum ACE inhibitory effect of 69.1% was evident, similar to the predicted value.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.596-602
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• 2001

This study was conducted to find out optimum conditions of kanjang fermented with barley bran. Fermentation conditions for optimization of taste of kanjang made with barley bran was investigated with response surface methodology. Optimal conditions of salty taste was as follows, the content of meju: 15%, the content of salt: 7%, initial temperature: $24^{\circ}C$, middle temperature: $29^{\circ}C$ and end temperature: $14^{\circ}C$. Optimal conditions of palatable taste was as follows, the content of meju: 24%, the content of salt: 13%, initial temperature: $26^{\circ}C$, middle temperature: $25^{\circ}C$ and end temperature: $20^{\circ}C$. Optimal conditions of bitter taste was as follows, the content of meju: 28%, the content of salt: 18%, initial temperature: $35^{\circ}C$, middle temperature: $10^{\circ}C$ and end temperature: $38^{\circ}C$. Optimal conditions of overall acceptability was as follows, the content of meju: 15%, the content of salt: 19%, initial temperature: $30^{\circ}C$, middle temperature: $38^{\circ}C$ and end temperature: $23^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.495-500
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• 1999

The carrageenans are linear, sulfated Polysaccharides extracted from various species of the Rhodophyta (marine red algae). The carrageenan backbone is based on a repeating disaccharide sequence of $\beta$-D-galactopyranose residues linked glycosidically through position 1 and 3, and $\alpha$-D-galactopyranose residues linked glycosidically through position 1 and 4. Carrageenans are typical food polysaccharides in that food applications overwhelmingly dominate their end uses. Other applications, hewer, including cosmetics, pharmaceuticals, industrial suspensions and paints are also of importance But because of its high degree of gelling and viscosity with low solubility, carrageenan is limited to use beyond $0.03\%$ as food additives. Response Surface Methodology was applied for optimizing the processing parameters of ultrasound treatment in order to produce low-molecular-weight carrageenan. The use of ultrasound significantly reduced viscosity of $\lambda$-carrageenan solutions. Optimal parameters for ultrasound reduction of carrageenan molecular weight were: temperature, $10^{\circ}C$; ultrasound intensity, 121.64 $W/cm^2$ ; tarrageenan concentration, $2\%$; treatment time, 40 min. As the gel permeation chromatogram of dextran standards (M.W.= 500,000 ; 260,000 ; 167,000 ; 71,400 ; 42,000) and ultrsound treated carrageenan, the molecular weight of ultrasound treated carrageenan were approximately 200,000 (peak 1) and 60,000 (peak 2), respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1034-1042
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• 2004

This study was carried out to investigate preparation of reconstructed red peppers, effects of pungency and redness of red peppers on the Kimchi quality using central composite design and response surfaces methodology. Capsaicinoids and ASTA (American Spice Trading Association) value put in X$_1$, X$_2$ of independent variable. The result of response surface regression analysis of reconstructed red peppers, correlation coefficient ($R^2$) of overall pungency intensity, persistence and degree of redness was 0.935, 0.935 and 0.821, respectively. After it was made Kimchi samples with reconstructed red peppers, it was examined pH, titratable acidity and lactic acid bacteria of its during fermentation. In the initial fermentation period of Kimchi, it showed pH of 5.46∼5.78, titratable acidity of 0.27∼0.31%, salt content of 2.26∼2.48% and lactic acid bacteria of 4.05${\times}$10$^{5}$ ∼6.23${\times}$10$^{5}$ , respectively. And it showed traditional fermentation pattern in the pH, titratable acidity and microbes of the middle (appropriate fermentation) and last (excessive) fermentation period. While capsaicinoids content in the Kimchi decreased a little according to extend fermentation period, ASTA value showed low correlation reconstructed red pepper and fermentation period. Also, it was analyzed correlation coefficient ($R^2$) of independent variables (capsaicinoids, X$_1$; ASTA value, X$_2$) between sensory attribute in the Kimchi during fermentation. The result of regression analysis, $R^2$ in the overall pungency intensity, persistence and degree of redness showed 0.515, 0.675, 0.784, respectively.