• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.214-221
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• 2022

The purpose of this study is to produce works with motifs from organic forms of nature and to try to drive various forms. As a research method, literature was investigated through rsearch in domestic academic jounals, and four hair sculptures that can be used easily in practice were produced by combining the organic forms and design concepts of nature. As a result of the study, first, the work was produced by applying the law of harmony and balance with the motif of the crescent moon. Second, the flow of wave waves was expressed by applying the law of repetition with the motif of waves. Third, the haze rising from the waterfall was expressed by applying the law of dissonance. Fourth, l tried to give the image of the sun announcing a new beginning by emphasizing the rising sun. As a result, it can be seen that the organic form of nature gives an embarrassing inspiration to create design. The limitation of this study is that the accuracy of producing works only with mannequins and producing the same image in the actual model should be limited, and as a follow-up study, research that can be used in the actual model should be continuously conducted.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.3
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• pp.231-245
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• 2023

In the cosmetics industry, it is important to develop new materials for functional cosmetics such as whitening, wrinkles, anti-oxidation, and anti-aging, as well as technology to increase absorption when applied to the skin. Therefore, in this study, we tried to optimize the nanoemulsion formulation by utilizing response surface methodology (RSM), an experimental design method. A nanoemulsion was prepared by a high-pressure emulsification method using Glabridin as an active ingredient, and finally, the optimized skin absorption rate of the nanoemulsion was evaluated. Nanoemulsions were prepared by varying the surfactant content, cholesterol content, oil content, polyol content, high-pressure homogenization pressure, and cycling number of high-pressure homogenization as RSM factors. Among them, surfactant content, oil content, high-pressure homogenization pressure, and cycling number of high-pressure homogenization, which are factors that have the greatest influence on particle size, were used as independent variables, and particle size and skin absorption rate of nanoemulsion were used as response variables. A total of 29 experiments were conducted at random, including 5 repetitions of the center point, and the particle size and skin absorption of the prepared nanoemulsion were measured. Based on the results, the formulation with the minimum particle size and maximum skin absorption was optimized, and the surfactant content of 5.0 wt%, oil content of 2.0 wt%, high-pressure homogenization pressure of 1,000 bar, and the cycling number of high-pressure homogenization of 4 pass were derived as the optimal conditions. As the physical properties of the nanoemulsion prepared under optimal conditions, the particle size was 111.6 ± 0.2 nm, the PDI was 0.247 ± 0.014, and the zeta potential was -56.7 ± 1.2 mV. The skin absorption rate of the nanoemulsion was compared with emulsion as a control. As a result of the nanoemulsion and general emulsion skin absorption test, the cumulative absorption of the nanoemulsion was 79.53 ± 0.23%, and the cumulative absorption of the emulsion as a control was 66.54 ± 1.45% after 24 h, which was 13% higher than the emulsion.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.1
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• pp.75-82
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• 2007

This paper addresses a method for shape optimization of a continuous elastic body considering stability, i.e., buckling behavior. The sensitivity formula for critical load is analytically derived and expressed in terms of shape variation, based on the continuum formulation of the stability problem. Unlike the conventional finite difference method (FDM), this method is efficient in that only a couple of analyses are required regardless of the number of design parameters. Commercial software such as ANSYS can be employed since the method requires only the result of the analysis in computation of the sensitivity. Though the buckling problem is more efficiently solved by structural elements such as a beam and shell, elastic solids have been chosen for the buckling analysis because solid elements can generally be used for any kind of structure whether it is thick or thin. Sensitivity is then computed by using the mathematical package MATLAB with the initial stress and buckling analysis of ANSYS. Several problems we chosen in order to illustrate the efficiency of the presented method. They are applied to the shape optimization problems to minimize weight under allowed critical loads and to maximize critical loads under same volume.

• Journal of the Korean GEO-environmental Society
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• v.10 no.4
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• pp.15-24
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• 2009

Korea is known to have seasonal frost during winter and the effect of low temperatures and water may cause a weakening of pavements. For that reason, frost protection layers have been constructed in pavements to avoid damage caused by frost action. The practies established in USA and Japan have been adopted as anti-frost design methods in Korea. However, the characteristics of Korean soils are different. Additionally, there is no formulation of a reasonable equation for frost penetration depth and the criterion to identify potentially frost-susceptible soils in present pavement design manuals in Korea. Therefore, adequate pavement design procedures in seasonal frost areas, as well as construction and maintenance practices are required. In this paper, frost penetration depths along national roads in Korea were measured and analyzed over several years. The frost penetration depth was analyzed with respect to the provinces of Korea and sunny/ shaded areas. Additionally, measurement results were compared to the formula of the US Army Corps of Engineers and Ifukube in Japan.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.175-184
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• 2015

The purpose of this study was to determine the optimal mixing ratio of Agaricus blazei Murill powder and butter in the preparation of cookies. The experimental design utilized herein was based on central composite design for response surface methodology, which included 10 experimental points, including 2 replicates for Agaricus blazei Murill and butter. The physical, mechanical, and sensory properties of the test were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the final mixed product. The spread ratio increased significantly with an increase in Agaricus blazei Murill powder and butter (p<0.05). The response surface methodology was applied to evaluate the effect of Agaricus blazei Murill powder and butter on cookie moisture and color (L, a) (p<0.001). Sensory evaluation showed significant values for color (p<0.05), flavor (p<0.05), texture (p<0.05) and overall quality (p<0.01) in the predicted model. The optimum formulation by numerical and graphical methods was calculated as follows: Agaricus blazei Murill powder 3.63 g, butter 55.37 g.

• Korean journal of food and cookery science
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• v.26 no.6
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• pp.707-716
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• 2010

Germinated brown rice is a useful material that contains natural nutrients and biologically active substances. This study was conducted to develop a optimal composite recipe for functional germinated brown rice cookie with added spinach (spinacia oleracea L) powder and with high preference in all age groups. The experimental design utilized herein was based on the Central composite design methodology of response surface, which included 16 experimental points, including 2 replicates for spinach, sugar, and butter. The physical, mechanical, and sensory properties of the test were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the mixed final product. The results of spread ratio decreased significantly with increases in spinach powder, sugar, and butter(p<0.01). L value shows that lightness decreased significantly with an increase in sugar(p<0.05), but the a and b values were not significant. Sensory evaluation found significant values for color(p<0.05), flavor(p<0.05), texture(p<0.05) and overall quality(p<0.05) in the predicted model. The optimum formulation by the numerical and graphical methods was calculated as follows: spinach powder 3 g, sugar 35.5 g butter 54.4 g.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1452-1460
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• 2000

A series of papers in recent literature on logical topology design for wavelength routed optical networks have proposed mathematical models and solution methods unifying logical topology design wavelength assignment and traffic routing. The most recent one is by Krishnaswamy and Sivarajan which is more unifying and complete than the previous models. Especially the mathematical formulation is an integer linear program and hence regarded in readiness for an efficient solution method compared to the previous nonlinear programming models. The solution method in [7] is however elementary one relying on the rounding of linear program relaxation. When the rounding happens to be successful it tends to produce near-optimal solutions. In general there is no such guarantee so that the obtained solution may not satisfy the essential constraints such as logical -path hop-count and even wavelength number constraints. Also the computational efforts for linear program relaxation seems to be too excessive. In this paper we propose an improved and unifying solution method based on the same to be too excessive. In this paper we propose an improved and unifying solution method based on the same model. First its computation is considerably smaller. Second it guarantees the solution satisfies all the constraints. Finally applied the same instances the quality of solution is fairly competitive to the previous near optimal solution.

• Journal of Ship and Ocean Technology
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• v.11 no.2
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• pp.10-25
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• 2007

With the sharp increase of the oil price, the issue of the energy saving requires even higher propulsive efficiency of the propellers. Traditionally the propellers have been designed with the criteria such as that of Lerbs optimum based on the lifting line theory and the empirical formulae of Lerbs and van Manen giving relations of the wake pitch with the wake non-uniformity. With the aid of the high speed computer, it is now possible to apply the time-consuming iterative approaches for the solution of the lifting surface problems. In this paper we formulate the variational problem to optimize the efficiency of the propeller operating in the given ship wake using the lifting surface method. The variational formulation relating the spanwise circulation distribution with the propulsive efficiency to be maximized is however non-linear in circulation distribution functions, thus the iterative method is applied to the quasi-linearized equations. The blade shape design also requires the iterative procedures, because the shape of the blade which is represented by the lifting surface is unknown a priori. The numerical code was validated with the DTNSRDC propeller 4119 which is well-known to be optimum in uniform inflow condition. In addition existing (well-designed) commercial propellers were selected and compared with the results of the open water tests and the self-propulsion tests.

• Structural Engineering and Mechanics
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• v.41 no.2
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• pp.183-204
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• 2012

Several issues regarding the structural idealization of steel buildings with perimeter moment resisting steel frames (MRSFs) and interior gravity frames (GFs) are studied. Results indicate that the contribution of GFs to the lateral structural resistance may be significant. The contribution increases when the stiffness of the connection of the GFs is considered and is larger for inelastic than for elastic behavior. The interstory shears generally increase when the connections stiffness is taken into account. Resultant stresses at some base columns of MRSFs also increase in some cases but to a lesser degree. For columns of the GFs, however, the increment is significant. Results also indicate that modeling the building as planes frames may result in larger interstory shears and displacements and resultant stresses than those obtained from the more realistic 3-D formulation. These differences may be much larger when semi-rigid (SR) connections are considered. The conservativism is more for resultant stresses. The differences observed in the behaviour of each structural representation are mainly due to a) the elements that contribute to strength and stiffness and b) the dynamics characteristics of each structural representation. It is concluded that, if the structural system under consideration is used, the three-dimensional model should be used in seismic analysis, the GFs should be considered as part of the lateral resistance system, and the stiffness of the connections should be included in the design of the GFs. Otherwise, the capacity of gravity frames may be overestimated while that of MRSFs may be underestimated.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.484-491
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• 2014

Objectives: An image processing program for asbestos fibers analyzing the gradient components and partial linearity was developed in order to accurately segment fibers. The objectives were to increase the accuracy of counting through the formulation of the size and shape of fibers and to guarantee robust fiber detection in noisy backgrounds. Methods: We utilized samples mixed with sand and sepiolite, which has a similar structure to asbestos. Sample concentrations of 0.01%, 0.05%, 0.1%, 0.5%, 1%, 2%, and 3%(w/w) were prepared. The sand used was homogenized after being sieved to less than $180{\mu}m$. Airborne samples were collected on MCE filters by utilizing a personal pump with 2 L/min flow rate for 30 minutes. We used the NIOSH 7400 method for pre-treating and counting the fibers on the filters. The results of the NIOSH 7400 method were compared with those of the image processing program. Results: The performance of the developed algorithm, when compared with the target images acquired by PCM, showed that the detection rate was on average 88.67%. The main causes of non-detection were missing fibers with a low degree of contrast and overlapping of faint and thin fibers. Also, some duplicate countings occurred for fibers with breaks in the middle due to overlapping particles. Conclusions: An image detection algorithm that could increase the accuracy of fiber counting was developed by considering the direction of the edge to extract images of fibers. It showed comparable results to PCM analysis and could be used to count fibers through real-time tracking by modeling a branch point to graph. This algorithm can be utilized to measure the concentrations of asbestos in real-time if a suitable optical design is developed.