• 한국정보과학회논문지:소프트웨어및응용
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• 제32권7호
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• pp.581-591
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• 2005

협력적 여과 시스템은 희박성과 단지 두 고객만의 선호도에 따른 상관 관계로 추천을 제공한다는 문제점과 군집내의 가장 유사한 두 사용자만의 상관 관계에 의하여 추천을 한다는 단점이 있다. 또한, 상품의 내용을 기반으로 하지 않고 선호도만을 기반으로 하므로 추천의 정확도가 사용자에 의해 평가한 자료에만 의존한다는 문제점도 있다. 이와 같이 평가된 자료를 추천에 이용할 경우, 모든 사용자가 모든 상품에 대해 성의 있게 평가할 수는 없으므로 추천의 정확도가 낮아지는 결과를 가져온다. 따라서 본 논문에서는 엔트로피을 사용하여 사용자가 상품에 대하여 평가한 자료를 기반으로 검증되지 않은 사용자를 제외시키고, 다음으로 사용자 프로파일을 생성한 후 사용자를 군집시키며, 마지막으로 그룹의 대표 선호도를 추출하는 방법을 제안한다. 기존의 사용자 군집을 이용한 방법은 군집내의 사용자만을 대상으로 유사한 사용자를 찾으므로 희박성은 해결할 수 있으나 그 외의 단점을 해결하지 못하였다. 제안한 방법에서는 상품에 대해 평가한 선호도 뿐만 아니라 상품에 대한 정보를 반영하기 위하여 연관 단어 마이닝의 방법에 의해 협력적 사용자의 프로파일을 생성하고, 이를 기반으로 벡터 공간 모델과 K-means 알고리즘에 의해 사용자를 군집시킨다. 군집된 사용자를 대상으로 상품의 선호도와 사용자의 엔트로피를 병합함으로써 최종적으로 그룹의 대표 선호도를 추출한다. 대표 선호도를 이용한 추천 시스템은 한 사용자의 부정확한 선호도를 기반으로 추천을 하는 경우에 나타나는 추천의 부정확도 문제를 해결하며, 군집내의 가장 유사한 두 사용자만의 상관 관계에 의하여 추천을 하는 단점을 보완하고, 또한 그룹 내에 가장 유사한 사용자를 찾는 데 소요되는 시간을 절약할 수 있다는 장점을 갖는다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권12호
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• pp.3798-3814
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• 2022

Social recommendation algorithm can alleviate data sparsity and cold start problems in recommendation system by integrated social information. Among them, matrix-based decomposition algorithms are the most widely used and studied. Such algorithms use dot product operations to calculate the similarity between users and items, which ignores user's potential preferences, reduces algorithms' recommendation accuracy. This deficiency can be avoided by a metric learning-based social recommendation algorithm, which learns the distance between user embedding vectors and item embedding vectors instead of vector dot-product operations. However, previous works provide no theoretical explanation for its plausibility. Moreover, most works focus on the indirect impact of social friends on user's preferences, ignoring the direct impact on user's rating preferences, which is the influence of user rating preferences. To solve these problems, this study proposes a user bias drift social recommendation algorithm based on metric learning (BDML). The main work of this paper is as follows: (1) the process of introducing metric learning in the social recommendation scenario is introduced in the form of equations, and explained the reason why metric learning can replace the click operation; (2) a new user bias is constructed to simultaneously model the impact of social relationships on user's ratings preferences and user's preferences; Experimental results on two datasets show that the BDML algorithm proposed in this study has better recommendation accuracy compared with other comparison algorithms, and will be able to guarantee the recommendation effect in a more sparse dataset.

• 한국경영과학회지
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• 제33권4호
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• pp.31-51
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• 2008

Predicting the preferences of users and providing the personalized services/products based on users' preferences is one of the important issues. However, the research considering users' preferences on context-aware computing is a relatively insufficient research field. Hence, this paper aims to propose a framework for providing the personalized services based on context history in context-aware computing. Based on this framework, we have implemented a prototype system to show the feasibility of the framework. Previous researches have reasoned the preferences of the user considering only the user's input, but this research provides the personalized services using the relationship between users' profile and services.

• 반도체디스플레이기술학회지
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• 제17권1호
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• pp.71-75
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• 2018

Image enhancement is a necessary end essential step after taking a picture with a digital camera. Many different photo software packages attempt to automate this process with various auto enhancement techniques. This paper provides and implements a system that can learn a user's preferences and apply the preferences into the process of image enhancement. Five major components are applied to the implemented system, which are computing a distance metric, finding a training set, finding an optimal parameter set, training and finally enhancing the input image. To estimate the validity of the method, we carried out user studies, and the fact that the implemented system was preferred over the method without learning user preferences.

• Journal of Information Processing Systems
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• 제8권2호
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• pp.191-212
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• 2012

Since a social network by definition is so diverse, the problem of estimating the preferences of its users is becoming increasingly essential for personalized applications, which range from service recommender systems to the targeted advertising of services. However, unlike traditional estimation problems where the underlying target distribution is stationary; estimating a user's interests typically involves non-stationary distributions. The consequent time varying nature of the distribution to be tracked imposes stringent constraints on the "unlearning" capabilities of the estimator used. Therefore, resorting to strong estimators that converge with a probability of 1 is inefficient since they rely on the assumption that the distribution of the user's preferences is stationary. In this vein, we propose to use a family of stochastic-learning based Weak estimators for learning and tracking a user's time varying interests. Experimental results demonstrate that our proposed paradigm outperforms some of the traditional legacy approaches that represent the state-of-the-art technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권5호
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• pp.1260-1272
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• 2024

This paper tackles the prevalent challenges faced by existing tourism route recommendation methods, including data sparsity, cold start, and low accuracy. To address these issues, a novel intelligent tourism route recommendation method based on collaborative filtering is introduced. The proposed method incorporates a series of key steps. Firstly, it calculates the interest level of users by analyzing the item attribute rating values. By leveraging this information, the method can effectively capture the preferences and interests of users. Additionally, a user attribute rating matrix is constructed by extracting implicit user behavior preferences, providing a comprehensive understanding of user preferences. Recognizing that user interests can evolve over time, a weight function is introduced to account for the possibility of interest shifting during product use. This weight function enhances the accuracy of recommendations by adapting to the changing preferences of users, improving the overall quality of the suggested tourism routes. The results demonstrate the significant advantages of the approach. Specifically, the proposed method successfully alleviates the problem of data sparsity, enhances neighbor selection, and generates tourism route recommendations that exhibit higher accuracy compared to existing methods.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.83-90
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• 2012

With the rapid growth of internet infrastructure, World Wide Web is evolving recently into various services such as cloud computing, social network services. It simply go beyond the sharing of information. It started to provide new services such as E-business, remote control or management, providing virtual services, and recently it is evolving into new services such as cloud computing and social network services. These kinds of communications through World Wide Web have been interested in and have developed user-centric customized services rather than providing provider-centric informations. In these environments, it is very important to check and analyze the user requests to a website. Especially, estimating user preferences is most important. For these reasons, analyzing web logs is being done, however, it has limitations that the most of data to analyze are based on page unit statistics. Therefore, it is not enough to evaluate user preferences only by statistics of specific page. Because recent main contents of web page design are being made of media files such as image files, and of dynamic pages utilizing the techniques of CSS, Div, iFrame etc. In this paper, large log analyzer was designed and executed to analyze web server log to estimate web contents preferences of users. With mapreduce which is based on Hadoop, large logs were analyzed and web contents preferences of media files such as image files, sounds and videos were estimated.

• 대한인간공학회지
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• 제26권4호
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• pp.49-56
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• 2007

Handles on objects are very important to increase the safety and efficiency of manual handling of people who use them. In this study, four different prototype cartons combined with auxiliary handles were designed to determine the optimal handle position of cartons through the evaluation of user preferences. Twenty male students are participated in the experiment. Likert-5 point summated rating method was applied to evaluate the user preferences for provided handles of the carton among upper, middle, and lower position under the four different sizes and materials handling conditions(carrying positions). The results show that the subjects preferred upper part of the handle on the small cartons regardless of the carrying positions while upper and middle parts of the handle on the big cartons for handling above the waist height were preferred. An optimal handle position depending on the different sizes of carton and the different carrying positions were recommended based on the results of evaluation. It is thus recommended that the cartons provide handles on its relevant position depending on the size and materials handling condition to reduce the musculoskeletal stress and in turn to increase the user satisfaction.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권3호
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• pp.1065-1085
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• 2020

With rapid growth of content demands, device-to-device (D2D) content sharing is exploited to effectively improve the service quality of users. Considering the limited storage space and various content demands of users, caching schemes are significant. However, most of them ignore the influence of the asynchronous content reuse and the selfishness of users. In this work, the user preferences are defined by exploiting the user-oriented content popularity and the current caching situation, and further, we propose the social-aware rate, which comprehensively reflects the achievable contents download rate affected by the social ties, the caching indicators, and the user preferences. Guided by this, we model the collaborative caching problem by making a trade-off between the redundancy of caching contents and the cache hit ratio, with the goal of maximizing the sum of social-aware rate over the constraint of limited storage space. Due to its intractability, it is computationally reduced to the maximization of a monotone submodular function, subject to a matroid constraint. Subsequently, two social-aware collaborative caching algorithms are designed by leveraging the standard and continuous greedy algorithms respectively, which are proved to achieve different approximation ratios in unequal polynomial-time. We present the simulation results to illustrate the performance of our schemes.

• 한국산업정보학회논문지
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• 제24권4호
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• pp.29-36
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• 2019

본 논문은 주차장에서 운전자의 다양한 선호도를 고려하여 실시간으로 주차 가능한 주차면을 안내하는 방안을 제안한다. 본 시스템은 주차장 진입 시부터 사용자가 유휴 주차면에 주차할 때까지, 각 주요 지점에서 차량을 검지함으로써 각 경로상 교통상황을 활용하고, 각 주차 구역 내의 주차 가능 주차면 및 목적지 근접도 등의 사용자 선호도에 가장 적합한 유휴 주차면을 실시간으로 탐색하여 각 안내 지점에서 최적의 경로를 안내한다. 이를 위하여 본 논문은 최적경로 안내를 위한 다양한 사용자 선호도 기반의 비용 함수를 제안하고 본 시스템의 가능성을 평가하기 위해 이벤트 기반 시뮬레이터를 설계하고 구현한 결과를 제시한다.