• 산업경영시스템학회지
• /
• 제40권4호
• /
• pp.154-163
• /
• 2017

Collaborative filtering, one of the most widely used techniques to build recommender systems, is based on the idea that users with similar preferences can help one another find useful items. Credit card user behavior analytics show that most customers hold three or less credit cards without duplicates. This behavior is one of the most influential factors to data sparsity. The 'cold-start' problem caused by data sparsity prevents recommender system from providing recommendation properly in the personalized credit card recommendation scenario. We propose a personalized credit card recommender system to address the cold-start problem, using multiple user profiles. The proposed system consists of a training process and an application process using five user profiles. In the training process, the five user profiles are transformed to five user networks based on the cosine similarity, and an integrated user network is derived by weighted sum of each user network. The application process selects k-nearest neighbors (users) from the integrated user network derived in the training process, and recommends three of the most frequently used credit card by the k-nearest neighbors. In order to demonstrate the performance of the proposed system, we conducted experiments with real credit card user data and calculated the F1 Values. The F1 value of the proposed system was compared with that of the existing recommendation techniques. The results show that the proposed system provides better recommendation than the existing techniques. This paper not only contributes to solving the cold start problem that may occur in the personalized credit card recommendation scenario, but also is expected for financial companies to improve customer satisfactions and increase corporate profits by providing recommendation properly.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제16권12호
• /
• pp.1244-1248
• /
• 2010

기존의 방송 추천 시스템은 사용자 프로파일 정보를 입력하고 이를 기반으로 콘텐츠 메타데이터와 일치되는 콘텐츠를 추천하는 형태로 연구가 진행되었다. 그러나 디지털 TV와 같이 사용자와의 상호동작이 많은 기기에서는 사용자들의 프로파일은 계속 변경이 일어나고 있고, 사용자의 의도와 프로파일을 정확히 파악하는 것이 추천의 정확도와 만족도를 높이는 것이다. 따라서 본 논문에서는 사용자의 리모컨 입력과 방송시청시간을 통해 실시간으로 사용자 프로파일 정보를 추출하고, 이 정보와 콘텐츠 메타데이터와 연관성을 파악하여 사용자에게 최적의 방송 콘텐츠를 추천한다. 또한 임베디드 시스템의 하드웨어 및 컴퓨팅 파워의 제약을 고려하여 네트워크 통신이나 상용 데이터베이스 시스템을 사용하지 않았고, 시청 시간에 따라 사용자가 원하는 콘텐츠의 장르가 다르다는 점을 고려하여 현재시간을 기준으로 콘텐츠를 추천하여 사용자 만족도를 증가시켰다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권1호
• /
• pp.446-465
• /
• 2015

In this modern era of technology and information, e-learning approach has become an integral part of teaching and learning using modern technologies. There are different variations or classification of e-learning approaches. One of notable approaches is Personal Learning Environment (PLE). In a PLE system, the contents are presented to the user in a personalized manner (according to the user's needs and wants). The problem arises when a new user enters the system, and due to the lack of information about the new user's needs and wants, the system fails to recommend him/her the personalized e-learning contents accurately. This phenomenon is known as cold-start problem. In order to address this issue, existing researches propose different approaches for recommendation such as preference profile, user ratings and tagging recommendations. In this research paper, the implementation of a novel interaction-based approach is presented. The interaction-based approach improves the recommendation accuracy for the new-user cold-start problem by integrating preferences profile and tagging recommendation and utilizing the interaction among users and system. This research work takes leverage of the interaction of a new user with the PLE system and generates recommendation for the new user, both implicitly and explicitly, thus solving new-user cold-start problem. The result shows the improvement of 31.57% in Precision, 18.29% in Recall and 8.8% in F1-measure.

• 한국멀티미디어학회논문지
• /
• 제21권2호
• /
• pp.242-249
• /
• 2018

In this paper, the customized sports convergence contents curation system is proposed for activation of life sports. The proposed system collects and analyzes profile of social sports group (club, society, etc.) for recommending optimized sports convergence contents to user. In addition, the feedback based on the recommendation result from the user is continuously reflected and the optimal recommendation is made possible. For the system evaluation, the proposed system is tested to 300 users (about 20 sports team) for about 3 months and the system is verified by analyzing the initial recommendation results and recommendation results reflected by user feedback.

• 한국멀티미디어학회논문지
• /
• 제25권8호
• /
• pp.1242-1250
• /
• 2022

When recommending cold items that do not have user-item interactions to users, even we adopt state-of-the-arts algorithms, the predicted information of cold items tends to have lower accuracy compared to warm items which have enough user-item interactions. The lack of information makes for recommender systems to recommend monotonic items which have a few top popular contents matched to user preferences. As a result, under-diversified items have a negative impact on not only recommendation diversity but also on recommendation accuracy when recommending cold items. To address the problem, we adopt a diversification algorithm which tries to make distributions of accumulated contents embedding of the two items groups, recommended items and the items in the target user's already interacted items, similar. Evaluation on a real world data set CiteULike shows that the proposed method improves not only the diversity but also the accuracy of cold item recommendation.

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

• 방송공학회논문지
• /
• 제18권1호
• /
• pp.98-105
• /
• 2013

최근의 미디어 생성/소비 패턴은 UCC 같은 소비자가 직접 미디어를 생성하고 소비하는 프로세스가 등장하여 일반화되고 있다. 그동안 다양한 콘텐츠 중에서 사용자가 원하는 콘텐츠만을 제공하기 위해 사용자 프로파일을 이용한 콘텐츠 추천 엔진에 대한 연구가 많이 진행되어왔다. 본 연구는 사용자 프로파일 이외에 다종의 멀티미디어 콘텐츠의 소비를 바탕으로 사용자들을 소셜 네트워킹화하고 이를 통해 유사 콘텐츠 선호패턴을 가진 구성원들의 사용자 프로파일을 바탕으로 개인화된 맞춤형 콘텐츠를 추천할 수 있는 추천 에이전트를 개발하였다. 개발한 추천 에이전트는 방송/통신망 상에 존재하는 다양한 콘텐츠 중에 사용자의 선호패턴과 일치하는 콘텐츠들을 추천하고 소셜 네트워크상의 사용자들간의 연관성을 통해 선호도를 갱신하는 시스템이다.

• 통합자연과학논문집
• /
• 제14권4호
• /
• pp.183-188
• /
• 2021

Collaborative filtering is one of the commonly used methods in the web recommendation system. Numerous researches on the collaborative filtering proposed the numbers of measures for enhancing the accuracy. This study suggests the movie recommendation system applied with Word2Vec and ensemble convolutional neural networks. First, user sentences and movie sentences are made from the user, movie, and rating information. Then, the user sentences and movie sentences are input into Word2Vec to figure out the user vector and movie vector. The user vector is input on the user convolutional model while the movie vector is input on the movie convolutional model. These user and movie convolutional models are connected to the fully-connected neural network model. Ultimately, the output layer of the fully-connected neural network model outputs the forecasts for user, movie, and rating. The test result showed that the system proposed in this study showed higher accuracy than the conventional cooperative filtering system and Word2Vec and deep neural network-based system suggested in the similar researches. The Word2Vec and deep neural network-based recommendation system is expected to help in enhancing the satisfaction while considering about the characteristics of users.

• 한국멀티미디어학회논문지
• /
• 제13권10호
• /
• pp.1453-1462
• /
• 2010

본 연구는 IPTV 환경에서 사용자의 취향에 맞는 VOD 프로그램을 추천할 수 있는 시스템을 새로이 제안하였다. 추천 알고리즘으로는 협업 필터링 기법을 사용하였다. 사용자의 프로그램 선호 취향을 나타내는 사용자 프로파일(user profile)은 사용자와 유사한 취향의 이웃 사용자들의 프로그램 선호도와 중분류 선호도 그리고 사용자 유사도를 감안하여 1주 단위로 갱신하였다. 제안 시스템의 성능평가를 위해 시청률 조사기관인 닐슨 리서치의 24주분 지상파 및 케이블 방송 시청 데이터를 IPTV 형식에 맞게 재구성하여 사용하였으며, 다양한 실험을 통해 그 실용성을 입증하였다. 실험결과 사용자 유사도 가중치를 사용하며, 그룹 크기가 5명 그리고 추천 프로그램 수가 5개 일 때 최적의 성능을 나타내었다.

• Management Science and Financial Engineering
• /
• 제16권2호
• /
• pp.29-38
• /
• 2010

As the Internet is more embedded in people's lives, Internet users draw on new Internet applications to express themselves through "user-created content (UCC)." In addition, there is a noticeable shift from text-centered contents mainly posted on bulletin boards to multimedia contents such as images and videos on UCC web sites. The changes require different way of recommendations comparing to traditional products or contents recommendation on the Internet. This paper aims to design UCC recommendation methods with user behavior data and contents metadata such as tags and titles, and compare performances of the suggested methods. Real web logs data of a major Korean video UCC site was used to empirical experiments. The results of the experiments show that collaborative filtering technique based on similarity of UCC customers' preferences performs better than other content-based recommendation methods based on tag information and content metadata.