• Journal of Broadcast Engineering
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• v.13 no.1
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• pp.86-91
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• 2008

In the field of network data analysis, the research of how much the estimation data reflects the population data is inevitable. This paper compares and analyzes the well known MIT Lincoln Lab network data, which is composed of collectable standard information from the network with the KDD CUP 99 dataset which was composed from the MIT/LL data. For comparison and analysis, the protocol information of both the data was used. Correspondence analysis was used for analysis, SVD was used for 2 dimensional visualization and weigthed euclidean distance was used for network data quantification.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.288-301
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• 2023

This study aims to identify benthic macroinvertebrate fauna inhabiting at the mountain valley stream (Mt. Cheonggye) in Korea and the relationship between physical environmental factors and biological indices. Benthic macroinvertebrates were collected at five locations on August 24 and October 14, 2020, and were identified as 4 phyla, 7 classes, 16 orders, 42 families, and 72 species. Dominance ranged from 0.38 to 0.59, diversity 2.81 to 3.75, richness 3.25 to 4.63, evenness 0.65 to 0.84, and %EPT (Ephemeroptera-PlecopteraTrichoptera) richness value 42% to 73%, respectively. All sites were evaluated as a very good status by mostly biological indices based on tolerance of indicator organisms in Korea. As a result of principal component analysis, biological indices are classified into species-level indices and higher cartegory-level indices according to the taxonomic level of the indicator organism considered in each index. As a result of canonical correspondence analysis, it was confirmed that current velocity was a major factor that increased species richness and classified biological indices according to taxonomic category level. Water depth was a major factor related to the community indices, and the deeper the water depth, the lower the diversity and the evenness.

• Communications of Mathematical Education
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• v.27 no.3
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• pp.267-281
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• 2013

In this paper, we explore the possibility that ladder diagram games can be used for the introduction of the function and composite function. A ladder diagram with at most one rung is a bijection. Thus a ladder diagram with r rungs is the composition of r one-to-one correspondence. In this paper, we use ladder diagrams to give simple proofs of some fundamental facts about one-to-one correspondence. Also, we suggest Story-telling for introduction of function in middle school and high school. The ladder diagram approach to one-to-one correspondence not only grabs our students' attention, but also facilitates their understanding of the concept of functions.

• Information Systems Review
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• v.9 no.1
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• pp.85-103
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• 2007

The purpose of this study is to evaluate the performance of collaborative filtering recommender algorithms for better prediction accuracy of the customer's preference. The accuracy of customer's preference prediction is compared through the MAE of neighborhood based collaborative filtering algorithm and correspondence mean algorithm. It is analyzed by using MovieLens 1 Million dataset in order to experiment with the prediction accuracy of the algorithms. For similarity, weight used in both algorithms, commonly, Pearson's correlation coefficient and vector similarity which are used generally were utilized, and as a result of analysis, we show that the accuracy of the customer's preference prediction of correspondence mean algorithm is superior. Pearson's correlation coefficient and vector similarity used in two algorithms are calculated using the preference rating of two customers' co-rated movies, and it shows that similarity weight is overestimated, where the number of co-rated movies is small. Therefore, it is intended to increase the accuracy of customer's preference prediction through expanding the number of the existing co-rated movies.

• The Mathematical Education
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• v.58 no.2
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• pp.239-262
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• 2019

This study deals with the anxieties that originated from specific student questions. Through the analysis of the textbooks, we confirmed that the question was a sufficiently plausible question. Third interviews were also held with three high school students. Through the interviews, we analyzed students' expressions about the new correspondence relationship that the two correspondence relations are linked. In the determination of the composite function and the determination of the inverse function existence, We have observed a case of how the worries about domain are being reconstructed from students into meaningful mathematical knowledge. Through this, we confirmed that the question will be confusing to students in the field. In this study, we observed the transfer of domain in relation to student domain in composite function. In particular, a present study revealed that the students involved in the interview were influenced by this domain transfer phenomenon in determining whether the task given in the interview was a function. This was the same in determining the existence of a inverse function. The examples presented in this study are limited to specific cases in limited circumstances. Therefore, it can not be applied directly to teaching and learning situations. However, it is expected that this study will provide other researchers with insight into function learning related research.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1409-1416
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• 2020

The study of heat transfer coefficient of supercritical water plays an important role in improving the heat transfer efficiency of the reactor. Taking the supercritical natural circulation experimental bench as the research object, the effects of power, flow, pipe diameter and mainstream temperature on the heat transfer coefficient of supercritical water were studied. At the same time, the experimental data of Chen Yuzhou's supercritical water heat transfer coefficient was collected. Through the factorial design method, the influence of different factors and their interactions on the heat transfer coefficient of supercritical water is analyzed. Through the corresponding analysis method, the influencing factors of different levels of heat transfer coefficient are analyzed. It can be found: Except for the effects of flow rate, power, power-temperature and temperature, the influence of other factors on the natural circulation heat transfer coefficient of supercritical water is negligible. When the heat transfer coefficient is low, it is mainly affected by the pipe diameter. As the heat transfer coefficient is further increased, it is mainly affected by temperature and power. When the heat transfer coefficient is at a large level, the influence of the flow rate is the largest at this time.

• English Language & Literature Teaching
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• v.11 no.4
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• pp.287-304
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• 2005

Since Air and Correspondence High School (ACHS) in Korea was established in 1974, it has been serving many people who couldn't take the opportunities for learning in the regular high school due to several reasons. Regardless of the rapid change in technologies and educational needs during the past 31 years, however, ACHS hasn't changed much. Concerns have been recently made about the validity of the unchanged school system and many issues have been discussed relating to the innovation of the school system. Focusing on the teaching and learning contents, one of the important issues with respect to the school system, this paper examines the 7th English Curriculum for ACHS. The paper also investigates the textbooks used in ACHS to see how closely they align with the students' English proficiency and ACHS' instructional method by employing McDonough and Shaw's(1993) framework for textbook analysis. The results revealed that the current curriculum does not sufficiently reflect ACHS's characteristics, which leads to the adoption and development of inappropriate textbooks in terms of overall coherence, proficiency level, etc. The results suggest that the development of the curriculum and textbooks for ACHS should be based upon the students' needs and their level of proficiency rather than depending on the national curriculum and government-authorized textbooks intended for the relatively homogeneous school-age learners.

• Journal of the Korean Data and Information Science Society
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• v.20 no.2
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• pp.369-375
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• 2009

The next local election for Jeollabuk-do will be held in 2010. In preparation for this, we conducted a study to observe whether or not if minute regionalism occurred during the fourth "Nationally coordinated local election" which was held on May 31st in 2006. This study is based on Jeollabuk-do provincial governor election data. For this, we introduced a RS index which is used to measure how evenly each candidate for governor of the province received votes, and chi-statistics that measure each candidate's local intimacy. Further more, we checked out whether minute regionalism occurred or not by putting to practical use correspondence analysis. As a result, we could confirm that minute regionalism occurred to a few candidates. After reviewing many measurements, we found that a RS index's validity is not high.

• Fashion & Textile Research Journal
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• v.14 no.3
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• pp.430-437
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• 2012

This study analyzed the sensibility of eco-friendly fabrics for college students and investigated their attitude on environmental problems, trust reliability onto eco-apparel products, and their purchase state. We tested 6 eco-friendly fabrics (recycled polyester, organic cotton, green tea, charcoal, bamboo, and nettle) through a survey using the Likert scale of 12 polar sensibility words. Most fabrics showed feelings that were smooth, natural, female, and country these were followed by fashion, cheap, functional, sustainable, warm, and vintage. In addition, nettle fabric showed 'rough' feeling, and recycled polyester fabric showed an 'artificial' feeling. Correspondence analysis showed the distance and direction between fabric types and sensibility words with a 2D diagram where the X axis was named with 'Soft <-> Hard' and Y axis was with 'Environmental <-> Manmade' to represent the relationship between fabric types and the sensibility words. According to the results of the multiple regression analysis, the cognition level of the consumer for environmental problems was found to be the most influential variable on the loyalty purchase of eco-friendly products; however, the trust reliability level of consumer onto eco-friendly apparel products was found to be the most influential variable on the conditional purchase of eco-friendly apparel products.

• The Journal of Asian Finance, Economics and Business
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• v.10 no.2
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• pp.123-133
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• 2023

The COVID-19 pandemic has impacted the restaurant business adversely. The restaurant business is essential for Thailand's economy as it generates high income and a high employment rate. This study aimed to determine the relationships between restaurant businesses. Furthermore, it examined the problems encountered during COVID-19 and measures already implemented and planned. The research is intended to resolve these issues. We collected data from 136 people who worked in restaurants in Bangkok, Thailand, via telephone interviews. The data was analyzed by descriptive statistics and correspondence analysis using SPSS. The findings of this analysis indicate that all restaurants, irrespective of their size, face problems, though their planned and remedial actions are different. One finding was that medium restaurants face more financial problems and increased costs than others. They are countering this challenge through measures such as applying for loans and transitioning into a "non-restaurant" business. Nevertheless, typical medium restaurants have not engaged in extensive planning for the future. Based on a fact-finding survey, we considered appropriate short- and long-term measures suitable for micro, small and medium restaurants. In addition, our study's findings will help policymakers and practitioners identify strategies for responding to the COVID-19 outbreak and other future crises.