• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.354-355
• /
• 2006

We manufactured photoelectrode of dye-sensitized solar cells (DSC) by using three methods such as squeeze method, spray method, and combination method (squeeze method first, spray method second). We examined how the morphology of an electrode's surface, the pore between particles, and condensation have an effect on an open-circuit voltage, photocurrent, fill factor, and energy conversion efficiency. Open-circuit voltage of dye-sensitized solar cells manufactured by using three methods is about 0.66V when the photoelectrode of the three DSCs is about $5{\mu}m$ thick. Photocurrent and fill factor and conversion efficiency of DSC manufactured by using squeeze method is 18.5 and 34 and 7.8, respectively. Photocurrent and fill factor and conversion efficiency of DSC manufactured by using spray method is 3.62 and 62 and 2.8, respectively. Photocurrent and fill factor and conversion efficiency of DSC manufactured by using combination method is 10.7 and 46 and 5.9, respectively. In conclusion, we find that the combination method is better than the other two methods in such respects as energy conversion efficiency and fill factor.

• Journal of the Korean Data and Information Science Society
• /
• v.13 no.2
• /
• pp.185-193
• /
• 2002

The purpose of this paper is to suggest a method for detecting the linear regression change-points or variance change-points in regression model by the combination of Schwarz information criteria. The advantage of the suggested method is to detect change-points more detailed when one compares the suggest method with Chen (1998)'s method.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.3 s.49
• /
• pp.65-75
• /
• 2006

Nonlinear pushover analysis is used to evaluate the earthquake response of building structures. To accurately predict the inelastic response of a structure, the prescribed story load profile should be able to describe the earthquake force profile which actually occurs during the time-history response of the structure. In the present study, a new modal combination method was developed to predict the earthquake load profiles of building structures. In the proposed method, multiple story load profiles are predicted by combining the modal spectrum responses multiplied by the modal combination factors. Parametric studies were performed far moment-resisting frames and walls. Based on the results. the modal combination factors were determined according to the hierarchy of each mode affecting the dynamic responses of structures. The proposed modal combination method was applied to prototype buildings with and without vertical irregularity. The results showed that the proposed method predicts the actual story load profiles which occur during the time-history responses of the structures.

• Journal of Pharmaceutical Investigation
• /
• v.20 no.3
• /
• pp.115-119
• /
• 1990

The reaction rates, duration times and neutralizing capacities of the antacids which are frequently used in Korean market and three different commercial combination products were evaluated in vitro by Fuchs method and Johnson-duncan method, respectively. In vivo tests of combination products were determined in the fasted state of rat by Aspiration method. Comparing the result of in vitro test with that of in vivo test, the maximal pH was lowered by 2-3 value and the durational time increased by two folds in vivo test. Each antacid composition and combination products from three phamaceutical companies (A, B, and C) were studied, respectively. The duration times measured by Fuchs method were double compared to those by Johnson-Duncan method. A and C preparation maintained the pH range from 3 to 7 for 60 min by Fuchs method. In vovo test, maximum pH of A, B and C preparation was 6.50, 3.65, 2.65 and duration time of those was 200, 500, 0 min, respectively.

• Journal of Mechanical Science and Technology
• /
• v.20 no.10
• /
• pp.1567-1575
• /
• 2006

In an automatic combination weigher, the line feeders distribute the product to several weighing hoppers. The ability to supply appropriate amount of product to the weighing hoppers for each combination operation is crucial for the overall performance. Determining the right duration of operating a line feeder to supply a given amount of product becomes very challenging in case of products which are irregular in volume or specific gravity such as granular secondary processed foods. In this research, several schemes were investigated to determine the best way for a line feeder to approximate the next operating time in order to supply a set amount of irregular goods to the corresponding weighing hopper. Results obtained show that a weighted least squares method (WLS) employing 10 data points is the most effective in determining the operating times of line feeders.

• Journal of Information Processing Systems
• /
• v.20 no.3
• /
• pp.285-295
• /
• 2024

Driven by the vague assessment big data, a product service system (PSS) evaluation method is developed based on a hybrid model of multi-weight combination and improved TOPSIS by relative entropy. The index values of PSS alternatives are solved by the integration of the stakeholders' vague assessment comments presented in the form of trapezoidal fuzzy numbers. Multi-weight combination method is proposed for index weight solving of PSS evaluation decision-making. An improved TOPSIS by relative entropy (RE) is presented to overcome the shortcomings of traditional TOPSIS and related modified TOPSIS and then PSS alternatives are evaluated. A PSS evaluation case in a printer company is given to test and verify the proposed model. The RE closeness of seven PSS alternatives are 0.3940, 0.5147, 0.7913, 0.3719, 0.2403, 0.4959, and 0.6332 and the one with the highest RE closeness is selected as the best alternative. The results of comparison examples show that the presented model can compensate for the shortcomings of existing traditional methods.

• The Research Journal of the Costume Culture
• /
• v.20 no.1
• /
• pp.62-71
• /
• 2012

The purpose of this research is to analyze the characteristics of the color combination in Eco fashion design. 532 pictures related to eco was collected through Eco brand web sites from 2008 through 2011. The characteristics for analysis include color combination and tone. The method of research is content and statistical analysis. The result of the research is summed up below. First, achromatic color was most frequently presented in Eco fashion. Also monotone color or single color combination were displayed often. Secondly, many dresses were of single color combination and T-shirt items displayed contrast color combination created by luminosity difference. Third, the outcome of comparing seasons was that both seasons presented single color and contrast color combination. The difference between countries proved slight as single color coloration dominated. This considered the process which was non-chemical manufacture for eco-friendly. For the combination of colors, the same coloration with single colors or contrast coloration due to the differences of brightness were presented quite often, generally, the modern image fashion without fancy factors have shown a lot. These results that minimalism trend was included in eco-friendly image.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.11
• /
• pp.5903-5908
• /
• 2012

Objective: The purpose of this study is to investigate the combined effects of exemestane and aspirin on MCF-7 human breast cancer cells. Methods: Antiproliferative effects of exemestane and aspirin, alone and in combination, on growth of MCF-7 human breast cancer cells were assessed using the MTT assay. Synergistic interaction between the two drugs was evaluated in vitro using the combination index (CI) method. The cell cycle distribution was analyzed by flow cytometry and Western blotting was used to investigate the expression of cyclooxygenase-1, cyclooxygenase-2 and Bcl-2. Results: MTT assays indicated that combination treatment obviously decreased the viability of MCF-7 human breast cancer cells compared to individual drug treatment (CI<1). In addition, the combination of exemestane and aspirin exhibited a synergistic inhibition of cell proliferation, significantly arrested the cell cycle in the $G_0/G_1$ phase and produced a stronger inhibitory effect on COX-1 and Bcl-2 expression than control or individual drug treatment. Conclusion: These results indicate that the combination of exemestane and aspirin might become a useful method to the treatment of hormone-dependent breast cancer. The combination of the two inhibitors significantly increased the response as compared to single agent treatment, suggesting that combination treatment could become a highly effective approach for breast cancer.

• Journal of the Korea Convergence Society
• /
• v.11 no.11
• /
• pp.257-267
• /
• 2020

In this study, we predicted the employment ratio by the export industry using various machine learning methods and verified whether the prediction performance is improved by applying the constrained forecast combination method to these predicted values. In particular, the constrained forecast combination method is known to improve the prediction accuracy and stability by imposing the sum of predicted values' weights up to one. In addition, this study considered various variables affecting the employment ratio of each industry, and so we adopted recursive feature elimination method that allows efficient use of machine learning methods. As a result, the constrained forecast combination showed more accurate prediction performance than the predicted values of the machine learning methods, and in particular, the stability of the prediction performance of the constrained forecast combination was higher than that of other machine learning methods.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.49 no.7
• /
• pp.313-322
• /
• 2000

This paper presents optimal placement of minimal set of Phasor Measurement Units (PMU's) and observability analysis of the network with PMU's. In order to find a observable system, a symbolic method which directly assigns an appropriate symbol for measurement or pseudo-measurement to every entry of node-branch incidence matrix is proposed. It is much simpler and easier to analyze the observability of the network with PMU's than the conventional ones. For the optimal PMU placement problem, two approaches which are based on a modified Simulated-Annealing (SA) method and a Direct Combination method are proposed. Some case studies with IEEE sample system are made to show the performance of the proposed methods are almost alike and more effective than the conventional simulated-annealing method. It is also shown that the Direct Combination method is more effective than the modified simulated-annealing one in the sense of computation burden. The results of this study showed also that the accuracy of power system estimation and system observability can be improved the proposed PMU placements.