• Journal of Information Technology Applications and Management
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• 제21권4호
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• pp.203-223
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• 2014

This study proposes a novel context-aware recommender system, which is designed to recommend the items according to the customer's responses to the previously recommended item. In specific, our proposed system predicts the user's emotional state from his or her responses (such as facial expressions and movements) to the previous recommended item, and then it recommends the items that are similar to the previous one when his or her emotional state is estimated as positive. If the customer's emotional state on the previously recommended item is regarded as negative, the system recommends the items that have characteristics opposite to the previous item. Our proposed system consists of two sub modules-(1) emotion prediction module, and (2) responsive recommendation module. Emotion prediction module contains the emotion prediction model that predicts a customer's arousal level-a physiological and psychological state of being awake or reactive to stimuli-using the customer's reaction data including facial expressions and body movements, which can be measured using Microsoft's Kinect Sensor. Responsive recommendation module generates a recommendation list by using the results from the first module-emotion prediction module. If a customer shows a high level of arousal on the previously recommended item, the module recommends the items that are most similar to the previous item. Otherwise, it recommends the items that are most dissimilar to the previous one. In order to validate the performance and usefulness of the proposed recommender system, we conducted empirical validation. In total, 30 undergraduate students participated in the experiment. We used 100 trailers of Korean movies that had been released from 2009 to 2012 as the items for recommendation. For the experiment, we manually constructed Korean movie trailer DB which contains the fields such as release date, genre, director, writer, and actors. In order to check if the recommendation using customers' responses outperforms the recommendation using their demographic information, we compared them. The performance of the recommendation was measured using two metrics-satisfaction and arousal levels. Experimental results showed that the recommendation using customers' responses (i.e. our proposed system) outperformed the recommendation using their demographic information with statistical significance.

• International Journal of Computer Science & Network Security
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• 제21권2호
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• pp.148-157
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• 2021

The effectiveness of recommendation systems depends on the performance of the algorithms with which these systems are designed. The quality of the algorithms themselves depends on the quality of the strategies with which they were designed. These strategies differ from author to author. Thus, designing a good recommendation system means implementing the good strategies. It's in this context that several research works have been proposed on various strategies applied to algorithms to meet the needs of recommendations. Researchers are trying indefinitely to address this objective of seeking the qualities of recommendation algorithms. In this paper, we propose a new algorithm for recommending learning items. Learner performance predictions and collaborative recommendation methods are used as strategies for this algorithm. The proposed performance prediction model is based on convolutional neural networks (CNN). The results of the performance predictions are used by the proposed recommendation algorithm. The results of the predictions obtained show the efficiency of Deep Learning compared to the k-nearest neighbor (k-NN) algorithm. The proposed recommendation algorithm improves the recommendations of the learners' learning items. This algorithm also has the particularity of dissuading learning items in the learner's profile that are deemed inadequate for his or her training.

• Journal of Information Processing Systems
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• 제17권4호
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• pp.707-720
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• 2021

To improve the accuracy of the recommendation system, multi-criteria recommendation systems have been widely researched. However, it is highly complicated to extract the preferred features of users and items from the data. To this end, subjective indicators, which indicate a user's priorities for personalized recommendations, should be derived. In this study, we propose a method for generating recommendation candidates by predicting multi-criteria ratings from reviews and using them to derive user priorities. Using a deep learning model based on convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM), multi-criteria prediction ratings were derived from reviews. These ratings were then aggregated to form a linear regression model to predict the overall rating. This model not only predicts the overall rating but also uses the training weights from the layers of the model as the user's priority. Based on this, a new score matrix for recommendation is derived by calculating the similarity between the user and the item according to the criteria, and an item suitable for the user is proposed. The experiment was conducted by collecting the actual "TripAdvisor" dataset. For performance evaluation, the proposed method was compared with a general recommendation system based on singular value decomposition. The results of the experiments demonstrate the high performance of the proposed method.

• International Journal of Computer Science & Network Security
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• 제21권3호
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• pp.177-184
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• 2021

All over the world, people are affected by many chronic diseases and medical practitioners are working hard to find out the symptoms and remedies for the diseases. Many researchers focus on the feature detection of the disease and trying to get a better health recommendation system. It is necessary to detect the features automatically to provide the most relevant solution for the disease. This research gives the framework of Health Recommendation System (HRS) for identification of relevant and non-redundant features in the dataset for prediction and recommendation of diseases. This system consists of three phases such as Pre-processing, Feature Selection and Performance evaluation. It supports for handling of missing and noisy data using the proposed Imputation of missing data and noise detection based Pre-processing algorithm (IMDNDP). The selection of features from the pre-processed dataset is performed by proposed ensemble-based feature selection using an expert's knowledge (EFS-EK). It is very difficult to detect and monitor the diseases manually and also needs the expertise in the field so that process becomes time consuming. Finally, the prediction and recommendation can be done using Support Vector Machine (SVM) and rule-based approaches.

• 스마트미디어저널
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• 제12권5호
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• pp.9-16
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• 2023

In the recommendation system of the credit card company, it is necessary to understand the customer patterns to predict a customer's next merchant based on their histories. The data we want to model is much more complex and there are various patterns that customers choose. In such a situation, it is necessary to use an effective model that not only shows the relevance of the merchants, but also the relevance of the customers relative to these merchants. The proposed model aims to predict the next merchant for the customer. To improve prediction performance, we propose a novel model, called Customer-based Recommendation Model (CRM), to produce a more efficient representation of customers. For the next merchant recommendation system, we use a synthetic credit card usage dataset, BC'17. To demonstrate the applicability of the proposed model, we also apply it to the next item recommendation with another real-world transaction dataset, IJCAI'16.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.105-110
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• 2003

Collaborative filtering is one of the methodologies that are most widely used for recommendation system. It is based on a data matrix of each customer's preferences of products. There could be a lot of missing values in such preference. data matrix. This incomplete data is one of the reasons to deteriorate the accuracy of recommendation system. Multiple imputation method imputes m values for each missing value. It overcomes flaws of single imputation approaches through considering the uncertainty of missing values.. The objective of this paper is to suggest multiple imputation-based collaborative filtering approach for recommendation system to improve the accuracy in prediction performance. The experimental works show that the proposed approach provides better performance than the traditional Collaborative filtering approach, especially in case that there are a lot of missing values in dataset used for recommendation system.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2007년도 추계학술대회
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• pp.489-498
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• 2007

For better predictions and classifications in customer recommendation, this study proposes an integrative model that efficiently combines the currently-in-use statistical and artificial intelligence models. In particular, by integrating the models such as Association Rule, Frequency Matrix, and Rule Induction, this study suggests an integrative prediction model. The data set for the tests is collected from a convenience store G, which is the number one in its brand in S. Korea. This data set contains sales information on customer transactions from September 1, 2005 to December 7, 2005. About 1,000 transactions are selected for a specific item. Using this data set, it suggests an integrated model predicting whether a customer buys or not buys a specific product for target marketing strategy. The performance of integrated model is compared with that of other models. The results from the experiments show that the performance of integrated model is superior to that of all other models such as Association Rule, Frequency Matrix, and Rule Induction.

• 지능정보연구
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• 제27권3호
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• pp.29-56
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• 2021

전자상거래 시장이 빠르게 성장하면서 다양한 유형의 제품이 출시되고 있으며, 이로 인해 사용자들은 구매 의사결정과정에 많은 시간이 소요되는 정보 과부하 문제에 직면하고 있다. 따라서 사용자에게 맞춤형 제품 및 서비스를 제공해줄 수 있는 개인화 추천 서비스의 중요성이 대두되고 있다. 대표적으로 Netflix, Amazon, Google 등 세계적 기업은 개인화 추천 서비스를 도입하여 사용자의 구매 의사결정을 지원하고 있다. 이에 따라 사용자의 정보탐색 비용이 감소하는 효과가 나타났고, 기업의 매출 상승에도 긍정적인 영향을 끼치고 있다. 기존 개인화 추천 서비스 관련 연구에서 주로 사용된 협업필터링(Collaborative Filtering, CF) 기법은 정량화된 정보를 활용하여 사용자의 선호도를 예측하였다. 그러나 정량화된 정보만을 활용하면 사용자의 구매 의도는 고려하지 못하므로 추천 성능이 저하될 수 있다는 문제점이 제기되고 있다. 이와 같은 기존 연구의 문제점을 개선하기 위해 최근에는 사용자가 작성한 리뷰를 활용한 개인화 추천 서비스 연구가 활발히 진행되고 있다. 그러나 리뷰에는 광고성 내용, 거짓 후기, 의미를 전혀 파악할 수 없거나 제품과 관련 없는 내용 등 구매의사결정을 저해하는 요소들이 포함되어 있다. 이러한 요소들이 포함된 리뷰를 활용하여 추천 서비스를 제공하게 되면, 추천 성능이 저하되는 문제가 발생할 수 있다. 따라서 본 연구에서는 이러한 문제점을 개선하기 위해 Convolutional Neural Network(CNN) 기반 리뷰 유용성 점수 예측을 통한 새로운 추천 방법론을 제안하였다. 본 연구에서 제안하는 유용한 리뷰를 포함하는 방법론과 기존 모든 선호도 평점을 고려하는 추천 방법론을 비교한 결과, 본 연구에서 제안한 방법론이 더 우수한 예측 성능을 나타내고 있음을 확인할 수 있었다. 또한 본 연구의 결과는 리뷰 유용성에 대한 정보를 개인화 추천 서비스에 반영하면 전통적인 CF의 성능을 향상할 수 있음을 시사한다.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.439-450
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• 2010

In this paper, we propose a new idea to evaluate the prediction accuracy of user's preference generated by memory-based collaborative filtering algorithm before prediction process in the recommender system. Our analysis results show the possibility of a pre-evaluation before the prediction process of users' preference of item's transaction on the web. Classification functions proposed in this study generate a user's rating pattern under certain conditions. In this research, we test whether classification functions select users who have lower prediction or higher prediction performance under collaborative filtering recommendation approach. The statistical test results will be based on the differences of the prediction accuracy of each user group which are classified by classification functions using the generative probability of specific rating. The characteristics of rating patterns of classified users will also be presented.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제11권2호
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• pp.112-123
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• 2005

최근의 전자상거래 사이트들은 사용자 만족을 극대화 시키기 위해 사용자별로 개인화된 서비스를 제공하고 있다. 협력적 필터링은 개인화된 아이템 실시간 추천을 위하여 고안된 알고리즘이며 예측의 정확도와 성능을 증대시키기 위해서 다양한 보완 방법들이 제시되고 있다. 유용한 추천 시스템을 구축하기 위해서는 두 가지 문제를 동시에 고려해야 한다. 그러나, 협력적 필터링 기술에 관한 연구는 정확도 향상에 관한 연구가 주로 수행되었고 성능 문제는 간과하여 왔다. 본 연구에서는 추천 에이전트 시스템의 성능을 향상시킬 수 있는 대표 속성을 이용한 이웃 선택, 추천 텍스타일 집합, 유사 군집 요소를 협력적 필터링 기술에 추가하여 실험해 보았다. 패션 디자인 추천 에이전트 시스템(FDRAS)을 개발하여 시스템의 논리적 타당성과 유효성을 검증하기 위해 실험적인 적용을 시도하고자 한다.