• The Mathematical Education
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• v.60 no.2
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• pp.209-228
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• 2021

The purpose of this study is developed the Item Feature Analysis (IFA) frameworks for curriculum-based assessments, focusing on Math competency and representation in secondary schools and implemented the IFA in National Assessment of Educational Achievement. To conduct the study, previous studies were analyzed, and feasibility studies were conducted twice. As a result of the study, we structured the IFA framework based on the 2015 revised mathematics curriculum in Korea and developed a method to analyze the characteristics of the math items. The results of structuring the framework for math included two categories: math competency in the content aspects, and representation type in the formal aspects. Specifically, 12 features of math competency and 8 features of representation type were identified, and an item feature analysis framework composed of these features was developed. The math competency was developed based on the subject competency of 2015 national curriculum. Math assessments in high schools, which have been changed to the competency-based assessments, had more frequency of the feature of math competency compared to middle schools. In this study, implemented the IFA in National Assessment of Educational Achievement and explored the way of ensuring the validity. These have been proved as critical applications for ensuring the validity of curriculum-based student assessment as well as building a tool for assessment.

• Communications for Statistical Applications and Methods
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• v.23 no.6
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• pp.531-541
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• 2016

Cerebral atrophy affects the brain and is a common feature of patients with mild cognitive impairment or Alzheimer's diseases. It is evaluated by the radiologist or reader based on patient's history, age and the space between the brain and the skull as indicated by magnetic resonance (MR) images. A total of 70 patients were scanned in the supine and prone positions before three radiologist assessed their atrophy level. This study examined the radiologist's assessment of the cerebral atrophy level using a graded response model of item response theory (IRT). A graded response model (GRM) is fitted to our data and then item-fit and person-fit statistics are evaluated to assess the fitted model. Our analysis found that the cerebral atrophy level is better discriminated by readers in the prone position because all item slopes were greater than 2 at this position, versus the supine position where all the slope parameters were less than 1. However, the thresholds are very similar for the first reader and are quite different for the second and third readers because the scanning position affects readers differently as the category threshold estimates vary considerably between the readers..

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.5
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• pp.1413-1432
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• 2023

Recommender systems aim to recommend items to users by taking into account their probable interests. This study focuses on creating a model that utilizes multiple sources of information about users and items by employing a multimodality approach. The study addresses the task of how to gather information from different sources (modalities) and transform them into a uniform format, resulting in a multi-modal feature description for users and items. This work also aims to transform and represent the features extracted from different modalities so that the information is in a compatible format for integration and contains important, useful information for the prediction model. To achieve this goal, we propose a novel multi-modal recommendation model, which involves extracting latent features of users and items from a utility matrix using matrix factorization techniques. Various transformation techniques are utilized to extract features from other sources of information such as user reviews, item descriptions, and item categories. We also proposed the use of Principal Component Analysis (PCA) and Feature Selection techniques to reduce the data dimension and extract important features as well as remove noisy features to increase the accuracy of the model. We conducted several different experimental models based on different subsets of modalities on the MovieLens and Amazon sub-category datasets. According to the experimental results, the proposed model significantly enhances the accuracy of recommendations when compared to SVD, which is acknowledged as one of the most effective models for recommender systems. Specifically, the proposed model reduces the RMSE by a range of 4.8% to 21.43% and increases the Precision by a range of 2.07% to 26.49% for the Amazon datasets. Similarly, for the MovieLens dataset, the proposed model reduces the RMSE by 45.61% and increases the Precision by 14.06%. Additionally, the experimental results on both datasets demonstrate that combining information from multiple modalities in the proposed model leads to superior outcomes compared to relying on a single type of information.

• Journal of Information Processing Systems
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• v.15 no.3
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• pp.500-519
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• 2019

The blooming of social media has simulated interest in sentiment analysis. Sentiment analysis aims to determine from a specific piece of content the overall attitude of its author in relation to a specific item, product, brand, or service. In sentiment analysis, the focus is on the subjective sentences. Hence, in order to discover and extract the subjective information from a given text, researchers have applied various methods in computational linguistics, natural language processing, and text analysis. The aim of this paper is to provide an in-depth up-to-date study of the sentiment analysis algorithms in order to familiarize with other works done in the subject. The paper focuses on the main tasks and applications of sentiment analysis. State-of-the-art algorithms, methodologies and techniques have been categorized and summarized to facilitate future research in this field.

• Journal of Intelligence and Information Systems
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• v.18 no.4
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• pp.1-17
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• 2012

Personalized smart devices such as smartphones and smart pads are widely used. Unlike traditional feature phones, theses smart devices allow users to choose a variety of functions, which support not only daily experiences but also business operations. Actually, there exist a huge number of applications accessible by smart device users in online and mobile application markets. Users can choose apps that fit their own tastes and needs, which is impossible for conventional phone users. With the increase in app demand, the tastes and needs of app users are becoming more diverse. To meet these requirements, numerous apps with diverse functions are being released on the market, which leads to fierce competition. Unlike offline markets, online markets have a limitation in that purchasing decisions should be made without experiencing the items. Therefore, online customers rely more on item-related information that can be seen on the item page in which online markets commonly provide details about each item. Customers can feel confident about the quality of an item through the online information and decide whether to purchase it. The same is true of online app markets. To win the sales competition against other apps that perform similar functions, app developers need to focus on writing app descriptions to attract the attention of customers. If we can measure the effect of app descriptions on sales without regard to the app's price and quality, app descriptions that facilitate the sale of apps can be identified. This study intends to provide such a quantitative result for app developers who want to promote the sales of their apps. For this purpose, we collected app details including the descriptions written in Korean from one of the largest app markets in Korea, and then extracted keywords from the descriptions. Next, the impact of the keywords on sales performance was measured through our econometric model. Through this analysis, we were able to analyze the impact of each keyword itself, apart from that of the design or quality. The keywords, comprised of the attribute and evaluation of each app, are extracted by a morpheme analyzer. Our model with the keywords as its input variables was established to analyze their impact on sales performance. A regression analysis was conducted for each category in which apps are included. This analysis was required because we found the keywords, which are emphasized in app descriptions, different category-by-category. The analysis conducted not only for free apps but also for paid apps showed which keywords have more impact on sales performance for each type of app. In the analysis of paid apps in the education category, keywords such as 'search+easy' and 'words+abundant' showed higher effectiveness. In the same category, free apps whose keywords emphasize the quality of apps showed higher sales performance. One interesting fact is that keywords describing not only the app but also the need for the app have asignificant impact. Language learning apps, regardless of whether they are sold free or paid, showed higher sales performance by including the keywords 'foreign language study+important'. This result shows that motivation for the purchase affected sales. While item reviews are widely researched in online markets, item descriptions are not very actively studied. In the case of the mobile app markets, newly introduced apps may not have many item reviews because of the low quantity sold. In such cases, item descriptions can be regarded more important when customers make a decision about purchasing items. This study is the first trial to quantitatively analyze the relationship between an item description and its impact on sales performance. The results show that our research framework successfully provides a list of the most effective sales key terms with the estimates of their effectiveness. Although this study is performed for a specified type of item (i.e., mobile apps), our model can be applied to almost all of the items traded in online markets.

• The Research Journal of the Costume Culture
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• v.17 no.6
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• pp.1009-1020
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• 2009

This study aims to express the androgynous image via shirts as a fashion item. Shirts are widely worn as a fashion item regardless of sex and age, with growing importance as a casual outer, with the increase in leisure activities driven by the recent implementation of the 5-Day Work Week system in Korea. As for the theoretical background, the study was reviewed previous studies of books, thesis, a series of publication, and the Internet sites on this topic. Through a careful analysis of these previous studies, it designed and made shirts that inspired by androgynous image. Conclusions of this study are as follows: First, the study found that meanings of symbolism in clothing continue to change, not fixed at all, depending on historic and cultural environments, and so does symbolism for femininity and masculinity of clothing. Second, shirts are widely worn as a fashion item regardless of sex and age, with growing importance as a casual outer, with the increase in leisure activities driven by the recent implementation of the 5-Day Work Week system in Korea. Third, two patters were used for the work in this study in order to emphasize its form, along with mono color white and stripe patterns. For materials, cotton and blend as a most basic material for a shirt were used with unique variations in the form. Fourth, decorative details or trimming such as ribbon tying methods, shirring, attaching in layers, and irregular pleading widely used for women's wear were applied, and silhouettes with strong drape feelings were used to add feminine feature to men' shirts, in an effort to propose a fashion design of the androgynous look. Fifth, clothes proposed in this study are different from feminine clothing item blouse, because they are androgynous shirts mixing masculinity and femininity. Stiff pads were used in collars and cuffs characteristics of men's traditional shirts to maintain masculinity of a shirt, and design was developed by adding feminine decorative elements, which is different from women's blouse.

• Cross-Cultural Studies
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• v.37
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• pp.383-400
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• 2014

Synonym means that the conceptual meaning of the word is the same or similar while other meanings or function of language difference may exist. That is two or more identified names correspond with one sense and have the words with minor difference. Words with synonym relation are a set of same meaning but conceptual area or emotional color, language function can be identified. Therefore, the core research of synonym is the difference analysis and in general difference analysis is progress in the three aspects of Meaning, Pragmatic, and Semantic. However, the difference analysis is the most important. In this paper, the set of meaning item of synonym word 'Attack' is 'zheng', 'fa', 'tao', 'qin', 'xi'. We compare the meaning of five verbs and analyze the difference and characteristics.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.1-7
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• 2008

Due to the development of ubiquitous computing, a wide variety of information is being produced and distributed rapidly in digital form. In this excess of information, it is not easy for users to search and find their desired information in short time. In this paper, we propose the personalized item recommendation using the image based filtering. This research uses the image based filtering which is extracting the feature from the image data that a user is interested in, in order to improve the superficial problem of content analysis. We evaluate the performance of the proposed method and it is compared with the performance of previous studies of the content based filtering and the collaborative filtering in the MovieLens dataset. And the results have shown that the proposed method significantly outperforms the previous methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.10
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• pp.1814-1829
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• 2011

In this paper, we present a model-based video bit rate estimation scheme for reducing the bit rate while maintaining a given target quality in many video streaming services limited by network bandwidth, such as IPTV services. Each item of video content can be stored on a video streaming server and delivered with the estimated bit rate using the proposed scheme, which consists of the following two steps: 1) In the first step, the complexity of each intra-frame in a given item of video content is computed as a frame feature to extract a group of candidate frames with a lot of bits. 2) In the second step, the bit rate of the video content is determined by applying statistical analysis and hypothesis testing to that group. The experimental results show that our scheme can reduce the bit rate by up to 78% with negligible degradation of subjective quality, especially with the low-complexity videos commonly used in IPTV services.

• Korean Journal of Human Ecology
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• v.23 no.3
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• pp.515-527
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• 2014

This study is intended to develop the creative and high value-added products as well as the development of diversity for jump suit for the future by analyzing the trend and feature shown in jump suit in the modern fashion. In the research methodology, the analysis was carried out over a total of 351 work pieces on jump suit among those presented in the collection of Paris, Milan, New York and London from 2006S/S to 2013F/W as well as literature review. The aesthetic features on suit jump design introduced in the modern fashion could be characterized as the following. First, both upper and lower garments are composed with a simple array of items and the stress was put on modernity feature through minimal expression technique. The feature of solid simplicity was also given with achromatic color or neutral monochrome. Second, the feminity image was emphasized with adoption of such highlighting items as detailed add-ons, tops, camisoles and blouses that stress the organically curved streamline including silhouette, material itself, crease and drape that enable the direct and indirect exposition of human body and the expression of smooth curve in human body. Third, jump suit revealed the multipurpose feature as item available for the diverse wear such as working habiliment, sports wear, uniform, office wear and evening wear, depending on the terms and conditions. Fourth, the deconstructive characteristic appeared through integration with various items, destruction of formative structure, non-structural shape, and ambiguity in wearing method.