• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.112-120
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• 1997

The clamp mode (CM) forward zero voltage switching multi resonant converter (ZVS-MPC) with self-driven synchronous rectifier is studied. The loss at the synchronous rectification stage of the converter is analyzed using MOSFET piecewise linear model and is compared with the loss at the conventional schottky diode rectification stage of th econverter. From the results of the analysis, it is known that the use fo MOSFETs as a synchronous rectifier reduces the loss at the rectification stage overthe whole load range comparing the use of schottky diodes as a conventional rectifier in the converter. In order to verify the validit of the analysis, we have built a 33W(3.3V/10A) CM forward ZVS-MRC with self-driven synchronous rectifier, in which switching frequency is 1MHz, and tested. FRom the experimental results, it is known that the synchronous rectification achieved about 1W improvement in the loss at the rectification stage and about 3% in the efficiency at the converter as compared with the conventional schottky diode rectification.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.584-588
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• 2007

A comparative Life Cycle Assessment(LCA) among three types of Electric Motor Unit(EMU) Interior Panel(IP) was conducted. A functional unit for comparative LCA is a weight of IP for 1 EMU. It assumed that Manufacturing stage and its upstream processes, Use stage and End of Life(EoL) stage are included in the boundary of product system. For Use stage, the weight of IP causes electricity consumption. It is assumed that aluminum IP is recycled and the other IPs are incinerated at the EoL stage. As comparison results, aluminum IP has much larger environmental impact(5.162pt) than others(FRP IP; 4.069pt, Phenol IP; 4.053pt) even though recycling consideration is included. The manufacturing stage of aluminum has relative big envrionmental impact(1.824pt) and this point make the most important difference from other IPs(FRP IP; 0.1617pt, Phenol IP; 0.4534pt)). Despite of large weight difference between FRP IP(888.56Kg) and phenol IP(315Kg), the final environmental impact result has only little difference(0.016pt, 0.39%). With this result, the EMU designer can choose IP with a consideration of the environmental performance of IP.

• Korean Journal of Human Ecology
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• v.14 no.1
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• pp.81-94
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• 2005

With an analysis of recent, nationwide data, this study figured out the level of consumers' pro-environmental behavior and investigated tile behavioral determinants in the hight of purchase, use, and disposal of pro-environmental goods. The major results are as below: Married consumers or consumers in their 40s were more likely to purchase pro-environmental goods. Consumers with high income-for example, over 3 million won per month-were less likely to purchase such goods. Married women or 40s/50s consumers tended not to buy used goods. Males than females, non-married than married, employed than unemployed had a higher pro-environmental behavior in the use stage. Furthermore, in the disposal stage, male than female, married than non-married, young than old, and consumers with low income than high income showed more active pro-environmental behavior. The purchasing behavior of pro-environmental goods was supported by both perspectives of rational behavior and social behavior. On tile other hand, the purchasing behavior of used goods was supported only by rational behavior perspective. It is also revealed that personal value perspective, along with the above two, influences the pro-environmental behavior in the stage of use and disposal. Overall, a high level of pro-environmental behavior was detected in such consumers as rational, public rule-abiding in favor of environmental policy, and also in consumers with strong family values or those with less materialistic value.

• Journal of the Korean Society of Systems Engineering
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• v.20 no.spc1
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• pp.30-44
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• 2024

The DMAIC methodology, which is most familiar to battery production system developers, is partially inadequate in its conformity to utilize battery production system tasks, so it is necessary to improve the function and structure of the methodology, but many battery production system developers use the DMAIC method based on experience, causing side effects such as confusion, delay in tasks, and insufficient performance during tasks. Accordingly, we intend to conduct an empirical study to improve the "efficiency improvement and conformity evaluation method" so that the DMAIC methodology can be used more reasonably and easily. Using the three-stage research model, we derive components that affect conformity through literature and questionnaire surveys in the first stage, use relational characteristics between components in the second stage to confirm the effect on conformity, and use the relational characteristics in the third stage to confirm the possibility of improving efficiency by applying them to the DMAIC methodology in actual cases. Finally, the "Conformity Assessment Index (CAI) equation" based on relational characteristics is established to enable effective conformity evaluation and continuous improvement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.3
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• pp.267-275
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• 2023

The cement industry has been contributing to solve the wastes problem by using various combustible wastes as alternative fuel to replace natural coal. To use more alternative fuels such as waste plastics, in the cement manufacturing process, it is necessary to stably burn alternative fuels and reduce air emissions such as NOx. This study is a case study on the multi-stage combustion calciner process, which is a technology that decreases the amount of NOx while increasing the use of alternative fuels. This study is a case study on the multi-stage combustion process, a technology that reduces the amount of harmful air emissions such as NOx while increasing the use of alternative fuels. Along results of comparing before and after applying the technology to actual cement manufacturing facilities, the amount of coal consumption decreased by 38 %, waste plastics consumption increased by 122 %, and NOx emissions decreased by 17 %. Results show that increasing the use of alternative fuels and reducing NOx emissions by multi-stage combustion is effective.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.111-120
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• 2010

Initial stage of emotion has a great influence on building up product image and impression. Because of its influencing effects, measuring initial stage of emotion has potential to be a key factor for designers and marketers to achieve a distinct product concept. While many researchers have studied this topic with the emotion measurement method in product use stage, there are very few cases specialized in the initial stage of emotion. Even though present emotion measurement methods have difficulties to derive accurate user's initial stage of emotion, most case of initial emotion study applies these defective methods. The purpose of this study is to develop initial stage of emotion measurement method and apply this method to real product context. In the design of the initial stage of emotion measurement method, noticeable characteristics of initial stage of emotion were explored and initial emotion measurement framework was presented. Based on this framework, Initial Emotion Measurement System(IEMS) was suggested. This method collects user's eye movement, behavior and verbal data accurately and objectively.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.1
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• pp.29-39
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• 2013

The purpose of this study is to analyze middle school teachers' concern about and implementation degree of performance assessment in China. The research questions are as follows: First, what kind of concern is held by middle school teachers who implement performance assessment? Second, is there any significant difference in stages of concern the teachers on performance assessment according to their gender, education level and teaching career? Third, which level of use is shown by middle school teachers who implement performance assessment? Fourth, what is the correlation between middle school teachers' Stages of Concern and Levels of Use on performance assessment? This study was conducted based on a Concerns-Based Adoption Model (Hall, 1973; CBAM) that viewed teachers as the most primary factor of the execution of innovation, in this case, performance assessment. Performance assessment is assessment based on observation and judgement (Stiggins, 1994), and require test takers to complete a process or produce a product in a context that closely resembles real-life situations. The subjects of this study were randomly sampled from 120 middle school teachers throughout Bei-Jing, China. The questionnaires were distributed to them by mail, and they were asked to return their questionnaire by mail. The collect data were analyzed by SPSS/WIN 18.0 program in terms of frequency, correlation, or MANOVA. Frequency analysis was used to analyze concern of middle school teachers on performance assessment. To gain an frequency of the individuals in each stage, we regarded the stage in which a teacher had his/her highest score as his/her relevant stage. Correlation analysis was adopted to identify the correlation between teachers' stage of concern and level of use. To analyze the difference of the concern of China middle school teachers on performance assessment according to their individual background variables such as gender, education level, and teaching career, MANOVA was performed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.63-63
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• 2022

Wheat flour can be categorized into bread, all-purpose, cake flour according to its protein content. Since optimal wheat flour protein content is different for each end use, it is necessary to diversify the nitrogen fertilizer methods depending on the end use and cultivar. Optimal wheat flour protein content of soft wheat (for cake flour) is lowest (<=10%) among all end use, it is necessary to develop nitrogen fertilizer methods for high yield and low protein content. In order to analyze the yield and quality changes of soft wheat as nitrogen fertilizer amount and splitting timing, soft wheat cultivar 'goso' was sown on paddy soil in jeunju, Republic of Korea ('21.10). the amount of nitrogen fertilizer was divided into 4 levels by adjusting 2kg/10a increments from 5.1 to ll.lkg/lOa, and in the N 7.1 and 9.1 kg/1 Oa(standard) treatment, N amount divided into sowing date:regrowing stage=3:7,4:6(standard), 5:5. In regrowing stage, Tiller number and N fertilizer amount at sowing date showed a correlation; y=-121.14x²+792.66x-525.41 (R²=0.77^*, y: Tiller number/m², x: N amount at sowing date(kg/10a)). Tiller number in regrowing stage was the highest when the nitrogen fertilizer amount at sowing date was 3.23kg/10a. spike number per m² was the highest when N fertilizer was divided into sowing date:regrowing stage=3:7(N amount: 9.1kg/10a). If N fertilizer amount was fixed, grain yield was also the highest when N fertilizer was divided into sowing date :regrowing stage=3:7. Also, N amount at sowing date and grain yield showed no correlation, but N amount at regrowing stage and grain yield showed significant correlation. As N amount increased, protein content also showed a tendency to increase.

• Journal of the Korean Chemical Society
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• v.60 no.5
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• pp.353-361
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• 2016

The goal of this study was to examine the current status of science teachers’ stage of concern (SOC) and level of use (LoU) on descriptive assessment and determine the relationship between SoC and LoU. To achieve this, concerns-based adoption model (CBAM) was used, and a survey was conducted on 138 science teachers. The data from this study were analyzed by frequency analysis, percentile analysis based on CBAM, χ² test, and Spearman correlation analysis. SoC and LoU of the science teachers observed in this study are as follows. First, the science teachers’ overall SoC for the descriptive assessment was low and showed a typical pattern of the initial stage when the program was introduced. Second, LoU analysis on descriptive assessment showed that the “mechanical Use” (N=49, 35.5%) or “routine” (N=48, 34.8%) accounted for the majority. Third, the Spearman correlation between SoC and LoU on descriptive assessment was .299(p<.01). This suggests that teachers’ SoC needs to be increased in order to promote higher LoU on descriptive assessment, which requires new alternative measures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.3873-3887
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• 2018

In this paper, we propose a novel method to recover images corrupted by impulse noise. The proposed method uses two stages: noise detection and filtering. In the first stage, we use pixel values, rank-ordered logarithmic difference values, and median values to train a neural-network-based impulse noise detector. After training, we apply the network to detect noisy pixels in images. In the next stage, we use group-based weighted couple sparse representation to filter the noisy pixels. During this second stage, conventional methods generally use only clean pixels to recover corrupted pixels, which can yield unsuccessful dictionary learning if the noise density is high and the number of useful clean pixels is inadequate. Therefore, we use reconstructed pixels to balance the deficiency. Experimental results show that the proposed noise detector has better performance than the conventional noise detectors. Also, with the information of noisy pixel location, the proposed impulse-noise removal method performs better than the conventional methods, through the recovered images resulting in better quality.