• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제36권2호
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• pp.136-142
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• 2023

In the past, the efficiency of solar cells had been increased in order to increase the efficiency of solar modules. However, in recent years, in order to increase output in the solar industry and market, the competitiveness of solar cells based on large-area solar cells and multi-bus bar has been increasing. Multi-busbar solar module is a technology to reduce power loss by increasing the number and width of the front busbar of the solar cell and reducing the current value delivered by the busbar by half through half-cutting. In the case of the existing M2 (156.75×156.75 mm²) solar cell, even with a half-cut, power loss could be sufficiently reduced, but as the area of the solar cell is enlarged to more than M6 (166×166 mm²), the need for more divisions emerged. This affected not only solar cells but also inverters required for module array configuration. Therefore, in this study, the electrical characteristics of a large-area solar cell and after division were extracted using Griddler simulation. The output characteristics of the module were predicted by applying the solar cell parameters after division to PSPice, and a guideline for the large-area solar module design was presented according to the number of divisions of the large-area solar cell.

• The Journal of the Acoustical Society of Korea
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• 제32권4호
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• pp.329-334
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• 2013

Order spectrum analysis is widely used to grasp the features of noises due to powertrain system including engine and intake/exhaust system. It is known from many previous researches that order components related to the first and second firing frequencies of engine considerably affect the noise of car interior. The purpose of this paper is to find out the difference in sound quality: Pleasantness of car interior noise according to the change of its order spectrum. For this, car interior noises of 6-cylinder and 4-cylinder engines are recorded and their order spectrum levels are modified by applying adaptive digital filters. After subjective listening test employing paired comparison method is conducted, it is investigated that the level change of half-order components is a noticeable factor to improve Pleasantness of the car interior noises whereas level decrease of firing order does not always give the positive effect on its sound quality.

• Journal of Distribution Science
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• 제17권2호
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• pp.71-76
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• 2019

Purpose - People have long thought that disorderly space would influence their lives negatively. However, disorderly space may have positive impact such as increasing sales for new products for store managers. Borrowing the prior findings that disorderly space enhances creativity, we developed two hypotheses regarding space order, product newness, and new product adoption. We hypothesize that space order negatively influences new product adoption and that the proposed negative effect of space order on new product adoption is moderated by product newness. Research design, data, and methodology - We conducted a pre-test in China using 70 undergraduate students to test whether two newly developed cosmetic products were appropriate for the experimental stimuli. We confirmed that a fragrance patch concept, which is unavailable in the market, is a RNP (Really New Product), and an edible fragrance, which is available in the market, is an INP (Incrementally New Product). Next, we conducted a main experiment with a 2 (Space order: orderly vs. disorderly) × 2 (Product newness: RNP vs. INP) between-subjects design in China using 100 undergraduate students. Half of the participants answered questions on the disorderly desk and the other half answered questions on the orderly desk. Results - We obtained evidence from the main experiment that consumers' new product adoption is the function of space order and product newness. First, participants were more likely to adopt the RNP when they were in the disorderly space than in the orderly space. However, the effect of space order on new product adoption disappeared when the product was INP; the adoption rates for the INP did not differ between the participants who answered questions on the disorderly desk and the participants who did so on the orderly desk. Conclusions - Our findings are counter intuitive. Contrary to the conventional wisdom that neat and tidy space benefits store managers, the research demonstrated that disorderly space increases sales, providing fresh insights into store managers to manage their stores and shops to sell new products. In order to help store visitors understand the value of really new products, store managers will have to sacrifice space order to some extent.

• Communications of the Korean Mathematical Society
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• 제19권3호
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• pp.495-506
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• 2004

Some oscillation criteria are given for second order nonlinear differential equations by means of integral averaging technique.

• Journal of Information Technology Services
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• 제13권1호
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• pp.23-42
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• 2014

This study investigates the impact of Internet Banking Systems on the business performance of bank. Although Internet Banking Systems were introduced about 15 years ago in Korea, there were few studies which evidenced the relationship between Internet Banking Systems and the performance of banks. For this empirical investigation, this study collected the panel data of 13 domestic banks over 8.5 years and divided the dataset into two parts-the first half period (2003~2007) and the second half period (2008~2011) in order to examine the dynamic changes in the impact of Internet Banking Systems. The fixed-effects panel regression results were different in the two parts of dataset. Internet Banking Systems showed only cost-efficiency impact in the first half period. However, in the second half period, Internet Banking Systems showed positive impact on the bank profitability. Moreover, the dummy variable regarding local bank showed no additional impact on this result, implying that the impact of Internet Banking Systems was still significant for the local banks. The results will deliver managerial interpretation on the value of Internet Banking Systems and additional implication on the strategic planning of Internet Banking Systems for many domestic banks.

• Journal of the Korean Institute of Intelligent Systems
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• 제23권3호
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• pp.262-267
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• 2013

The recognition of human emotional state is one of the most important components for efficient human-human and human- computer interaction. In this paper, four emotions such as fear, disgust, joy, and neutral was a main problem of classifying emotion recognition and an approach of visual-stimuli for eliciting emotion based on physiological signals of skin conductance (SC), skin temperature (SKT), and blood volume pulse (BVP) was used to design the experiment. In order to reach the goal of solving this problem, half-against-half (HAH) multi-class support vector machine (SVM) with Gaussian radial basis function (RBF) kernel was proposed showing the effective techniques to improve the accuracy rate of emotion classification. The experimental results proved that the proposed was an efficient method for solving the emotion recognition problems with the accuracy rate of 90% of neutral, 86.67% of joy, 85% of disgust, and 80% of fear.

• Journal of Electrical Engineering and Technology
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• 제7권5호
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• pp.659-663
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• 2012

The application of large power transformer into a power distribution system was inevitable due to the increase of power demand and distributed generation. However, the decrease of the power transformer's impedance caused the short-circuit current of the power distribution system to be increase thus, the higher short-circuit current exceeded the cut-off ratings of the protective devices such as circuit breaker. To solve these problems, several countermeasures have been proposed to protect the power system effectively from higher fault current and the superconducting fault current limiter (SFCL) has been expected to be the promising countermeasure. In spite of excellent current limiting performances of the SFCL, on the other hand, the efforts to apply the SFCL into power system has been delayed due to both the limited spaces for the SFCL's installation and its long recovery time after the fault removal. In order to solve these problems, a hybrid SFCL, which can perform either first half cycle limiting of first half cycle non-limiting operation, has been developed by corporation of LSIS (LS Industrial System) and KEPCO (Korea Electric Power Corporation). In this paper, we tried to requirements hybrid SFCL by PSCAD/EMTDC. Simulation results of our analysis of the hybrid SFCL is that its accompanied the characteristics both the limit the fault current and quick recovery caused by the less impact from superconductor.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.143-149
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• 2016

The two-stage converter is widely used in traditional DC/AC inverter. It has several disadvantages such as complex topology, large volume and high loss. In order to overcome these shortcomings, a novel half load-cycle worked dual SEPIC single-stage inverter, which is based on the analysis of the relationship between input and output voltages of SEPIC converters operating in the discontinuous conduction mode (DCM), is presented in this paper. The traditional single-stage inverter has remarkable advantages in small and medium power applications, but it can’t realize boost DC/AC output directly. Besides one pre-boost DC/DC converter is needed between the DC source and the traditional single-stage inverter. A novel DC/AC inverter without pre-boost DC/DC converter, which is comprised of two SEPIC converters, is studied. The output of dual SEPIC converters is connected with anti-parallel and half load-cycle control is used to realize boost and buck DC/AC output directly and work properly, whatever the DC input voltage is higher or lower than the AC output voltage. The working principle, parameter selection and the control strategy of the inverters are analyzed in this paper. Simulation and experiment results verify the feasibility of the new inverter.

• Journal of Preventive Medicine and Public Health
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• 제21권2호
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• pp.380-389
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• 1988

This study was conducted in order to find out the attitude of housewives toward the home attendants system, the type of institute managing home attendants, the education for home attendants, the basic requisites for home attendants, and home nursing education, and identify the factors influencing on the housewives's attitude. The data were collected through questionnaires obtained from 401 housewives from March 1 to March 31, 1988. The results summarized were as follows; 1) 90.2 percent of total housewives favored the home attendants system, and housewives who had have their family member with health problem especially showed favorable response. 2) The favored types of institution managing home attendants appeared to be private social work agency(33.0%), half-private and half-public agency(32.2%), government agency(19.9%) and profit agency (2.2%). In particular, housewives who had experienced nursing favored half-private and half-public ageney (37.6%). 3) As the basic requisites for home attendants, housewives wanted service attitude(37.2%), nursing education(34.4%) and nursing experience(28.4%). But, housewives with nursing experience favored nursing education rather than service attitude. 4) 91.1% of total housewives favored the home nursing education. In particular, housewives of high education level and nursing experience showed more favorable response to the home nursing education.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제22권2호
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• pp.173-181
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• 2011

In this paper, we propose a half mode substrate integrated waveguide(HMSIW) balanced bandpass filter to yield improved isolation between output ports. In order to achieve good isolation, resistive coupling slot is employed in HMSIW filter. The measurement results show that the insertion losses($S_{21}$, $S_{31}$) are $5.4{\pm}0.2$ dB and input return loss($S_{11}$) is more than 10 dB from 5.8 GHz to 6.4 GHz. Moreover isolation between output ports is larger than 18 dB and phase difference of output ports is $180{\pm}10^{\circ}$.