• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.442-460
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• 2021

Nowadays, recommendation systems (RSs) are applied to all aspects of online life. In order to overcome the problem that individuals who do not meet the constraints need to be regenerated when the many-objective evolutionary algorithm (MaOEA) solves the hybrid recommendation model, this paper proposes a many-objective particle swarm optimization algorithm based on multiple criteria (MaPSO-MC). A generation-based fitness evaluation strategy with diversity enhancement (GBFE-DE) and ISDE⁺ are coupled to comprehensively evaluate individual performance. At the same time, according to the characteristics of the model, the regional optimization has an impact on the individual update, and a many-objective evolutionary strategy based on bacterial foraging (MaBF) is used to improve the algorithm search speed. Experimental results prove that this algorithm has excellent convergence and diversity, and can produce accurate, diverse, novel and high coverage recommendations when solving recommendation models.

• Journal of Internet Technology
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• 제19권6호
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• pp.1691-1698
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• 2018

In this paper, we are to address the problem of item recommendations to users in shopping malls selling several different kinds of items, e.g., daily necessities such as cosmetics, detergent, and food ingredients. Most of current recommendation algorithms are developed for sites selling only one kind of items, e.g., music or movies. To devise efficient recommendation algorithms suitable for repetitively purchasing items, we give a method to implicitly assign ratings for these items by making use of repetitive purchase counts, and then use these ratings for the purpose of recommendation prediction with the help of user-based collaborative filtering and item-based collaborative filtering algorithms. We also propose associate item-based recommendation algorithm. Items are called associate items if they are frequently bought by users at the same time. If a user is to buy some item, it is reasonable to recommend some of its associate items. We implement user-based (item-based) collaborative filtering algorithm and associate item-based algorithm, and compare these three algorithms in view of the recommendation hit ratio, prediction performance, and recommendation coverage, along with computation time.

• 한국컴퓨터정보학회논문지
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• 제26권10호
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• pp.185-198
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• 2021

인터넷 기술의 발달로 기존의 추천 알고리즘은 사용자나 항목의 심층적인 특성을 학습할 수 없기 때문에 본 논문은 이 문제를 해결하기 위해 AMITI(주의 메커니즘 및 개선된 TF-IDF)에 기반한 추천 알고리즘을 제안했다. CNN(Convolutional Neural Network)에 2중 주의 메커니즘을 도입함으로써 CNN의 특징 추출 능력이 향상되고, 항목 특징에 다른 선호도 가중치가 할당되며, 사용자 선호도와 더 일치하는 권고사항이 달성되었다. 대상 사용자에게 항목을 추천할 때 점수 데이터와 항목 유형 데이터를 TF-IDF와 결합하여 권장 결과의 그룹화를 완료하였다. 본 논문에서 진행한 MovieLens-1M 데이터 세트에 대한 실험 결과는, AMITI 알고리즘이 권장 사항의 정확도를 향상시키고 프레젠테이션 방법의 순서와 선택성을 향상시킨다는 것을 보여준다.

• 정보처리학회논문지D
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• 제10D권7호
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• pp.1225-1230
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• 2003

많은 사이버 쇼핑몰들은 다양한 추천 방법을 도입하여 상품을 추천하고 있다. 상세한 알고리즘은 공개되어 있지 않지만 대부분 비교적 단순한 알고리즘을 쓰고 있다. 본 연구는 상품 자체의 특성, 소비자 집단의 특성, 그리고 소비자 개인의 특성을 고려한 다단계 알고리즘을 이용하여 상품추천 능력을 향상시키고자 시도하였다. 소비자와 관련된 더 많은 요인을 고려함에 따라 상품추천의 내용이 변화하는 사례를 도표로 비교 예시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권11호
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• pp.5344-5356
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• 2018

Nowadays with the help of Location-Based Social Networks (LBSNs), users of Point-of-Interest (POI) recommendation service in LBSNs are able to publish their geo-tagged information and physical locations in the form of sign-ups and share their experiences with friends on POI, which can help users to explore new areas and discover new points-of-interest, and promote advertisers to push mobile ads to target users. POI recommendation service in LBSNs is attracting more and more attention from all over the world. Due to the sparsity of users' activity history data set and the aggregation characteristics of sign-in area, conventional recommendation algorithms usually suffer from low accuracy. To address this problem, this paper proposes a new recommendation algorithm based on a novel Preference-Content-Region Model (PCRM). In this new algorithm, three kinds of information, that is, user's preferences, content of the Point-of-Interest and region of the user's activity are considered, helping users obtain ideal recommendation service everywhere. We demonstrate that our algorithm is more effective than existing algorithms through extensive experiments based on an open Eventbrite data set.

• Journal of Information Technology Applications and Management
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• 제25권4호
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• pp.145-156
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• 2018

This study proposes a content-based recommendation algorithm (NRA) for pet food. The proposed algorithm tries to recommend appropriate or inappropriate feed by using collective intelligence based on user experience and prior knowledge of experts. Based on the physical and health status of the dogs, this study suggests what kind of nutrients are necessary for the dogs and the most recommended pet food containing these nutrients. Performance evaluation was performed in terms of recall, precision, F1 and AUC. As a result of the performance evaluation, the AUC and F1 value of the proposed NRA was 15% and 42% higher than that of the baseline model, respectively. In addition, the performance of NRA is shown higher for recommendation of normal dogs than disease dogs.

• 한국콘텐츠학회논문지
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• 제17권11호
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• pp.183-191
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• 2017

본 연구는 과학 학술정보 서비스 플랫폼 이용자의 정보 검색 편의성을 확보하고 적합한 정보의 획득에 소요되는 시간을 절약하기 위하여, 운영 중인 서비스 메뉴와 각 서비스 별 콘텐츠 정보를 제공하는 알고리즘 중 콘텐츠 추천 알고리즘을 최적화하고 그 결과를 비교평가 하는 것이다. 추천 정확도를 높이기 위해 이용자의 '전공' 항목을 기존 알고리즘에 추가하였으며, 기존 알고리즘과 최적화된 알고리즘을 통한 추천 결과의 성능평가를 수행하였다. 성능평가 결과 최적화된 알고리즘을 통해 이용자에게 제공되는 콘텐츠의 적합도가 21.2% 증가함을 파악하였다. 이용자에게 적합한 콘텐츠를 시스템에서 자동 도출하여 각 서비스 메뉴 별로 제공함으로써 정보 획득 시간을 단축하고, 연구정보로서 가치 있는 연구결과물의 생명주기를 연장할 수 있는 방안이라는 데 본 연구의 의의가 있다.

• Journal of Information Technology Applications and Management
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• 제24권1호
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• pp.169-185
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• 2017

This study proposes a novel recommendation algorithm that reflects the results from trust/distrust network analysis as a solution to enhance prediction accuracy of recommender systems. The recommendation algorithm of our study is based on memory-based collaborative filtering (CF), which is the most popular recommendation algorithm. But, unlike conventional CF, our proposed algorithm considers not only the correlation of the rating patterns between users, but also the results from trust/distrust relationship network analysis (e.g. who are the most trusted/distrusted users?, whom are the target user trust or distrust?) when calculating the similarity between users. To validate the performance of the proposed algorithm, we applied it to a real-world dataset that contained the trust/distrust relationships among users as well as their numeric ratings on movies. As a result, we found that the proposed algorithm outperformed the conventional CF with statistical significance. Also, we found that distrust relationship was more important than trust relationship in measuring similarities between users. This implies that we need to be more careful about negative relationship rather than positive one when tracking and managing social relationships among users.

• 한국IT서비스학회지
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• 제6권2호
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• pp.113-123
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• 2007

In ubiquitous computing environment such as ubiquitous marketplace (u-market), there is a need of providing context-based personalization service while considering the nomadic user preference and corresponding requirements. To do so, the recommendation systems should deal with the tremendous amount of context data. Hence, the purpose of this paper is to propose a novel recommendation method which provides the products-group list of the customers in u-market based on the shopping intention and preferences. We have developed FREPIRS(FREquent Purchased Item-sets Recommendation Service), which makes recommendation listof product-group, not individual product. Collaborative filtering and apriori algorithm are adopted in FREPIRS to build product-group.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2003년도 춘계학술대회
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• pp.400-409
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• 2003

Collaborative filtering (CF) recommendation is a knowledge sharing technology for distribution of opinions and facilitating contacts in network society between people with similar interests. The main concerns of the CF algorithm are about prediction accuracy, speed of response time, problem of data sparsity, and scalability. In general, the efforts of improving prediction algorithms and lessening response time are decoupled. We propose a three-step CF recommendation model which is composed of profiling, inferring, and predicting steps while considering prediction accuracy and computing speed simultaneously. This model combines a CF algorithm with two machine learning processes, SOM (Self-Organizing Map) and CBR (Case Based Reasoning) by changing an unsupervised clustering problem into a supervised user preference reasoning problem, which is a novel approach for the CF recommendation field. This paper demonstrates the utility of the CF recommendation based on SOM cluster-indexing CBR with validation against control algorithms through an open dataset of user preference.