• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1293-1304
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• 2022

The personalization recommendation system means analyzing each individual's interests or preferences and recommending information or products accordingly. These personalized recommendations can reduce the time consumers spend searching for information by accessing the products they need more quickly, and companies can increase corporate profits by recommending appropriate products that meet their needs. In this study, products are recommended to consumers using collaborative filtering, matrix factorization, and deep learning, which are representative personalization recommendation techniques. To this end, the data set after purchasing shopping mall products, which is raw data, is pre-processed in the form of transmitting the data set to the input of the recommended system, and the pre-processed data set is analyzed from various angles. In addition, each model performs verification and performance comparison on the recommended results, and explores the model with optimal performance, suggesting which model should be used when building the recommendation system at the mall.

• Information Systems Review
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• v.18 no.3
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• pp.155-183
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• 2016

Research on personalized recommender service that uses big data has gained considerable attention given the increasing volume of contents being created. This development indicates the need for service providers to collect personal information and content rating data to personalize content recommendations. Previous studies on this topic proposed algorithms to offer improved recommendations using minimal rating data or service designs and increase the number of ratings. However, limited studies have been conducted on the factors that motivate the ratings input of users, as well as the factors that influence their continuous usage of recommender service. The present study explored the factors that motivate users to enter ratings by conducting in-depth interviews with users who use recommender services. The meanings of these ratings were also explored. Results show that the meaning and usage range of ratings differed based on the stage of a user's with utilization of the service. When users input an initial rating, they treat such a rating as a database to save the impression of a past experience. Such a rating is then used as a tool to reflect the current feeling and thoughts of a user. In the end, users were not only interested in their own rating system, but they also actively sought out the meaning of the rating systems of others and utilized them. Users also expressed mistrust in the recommendations of the service because they were aware of the limitation of the algorithms. This study identified a number of practical implications regarding recommender services.

• Journal of KIISE:Databases
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• v.36 no.5
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• pp.366-373
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• 2009

In this paper, we propose a similarity search algorithm for image databases. One of the central problems regarding content-based image retrieval (CBIR) is the semantic gap between the low-level features computed automatically from images and the human interpretation of image content. Many search algorithms used in CBIR have used the Minkowski metric (or $L_p$-norm) to measure similarity between image pairs. However those functions cannot adequately capture the aspects of the characteristics of the human visual system as well as the nonlinear relationships in contextual information. Our new search algorithm tackles this problem by employing new similarity measures and ranking strategies that reflect the nonlinearity of human perception and contextual information. Our search algorithm yields superior experimental results on a real handwritten digit image database and demonstrates its effectiveness.

• The Journal of Information Systems
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• v.25 no.4
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• pp.105-119
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• 2016

Purpose The conventional solution methods for production scheduling problems typically focus on the active schedules, which result in short makespans. However, the active schedules are more difficult to generate than the semi active schedules. In other words, semi active schedule based search strategy may help to reduce the computational costs associated with production scheduling. In this context, this paper aims to compare the performances of active schedule based and semi active schedule based search methods for production scheduling problems. Design/methodology/approach Two decoding approaches, active schedule decoding and semi active schedule decoding, are introduced in this paper, and they are used to implement genetic algorithms for classical job shop scheduling problem. The permutation representation is adopted by the genetic algorithms, and the decoding approaches are used to obtain a feasible schedule from a sequence of given operations. Findings The semi active schedule based genetic algorithm requires slightly more iterations in order to find the optimal schedule, while its execution time is quite shorter than active schedule based genetic algorithm. Moreover, the operations of semi active schedule decoding is easy to understand and implement. Consequently, this paper concludes that semi active schedule based search methods also can be useful if effective search strategies are given.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.663-666
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• 2003

자바는 썬 마이크로시스템즈사의 제임스 고슬링(James Gosling)에 의해 고안된 언어로 운영체제 및 하드웨어 플랫폼에 독립적인 차세대 언어로 최근에 가장 널리 사용하는 범용 프로그래밍 언어 중 하나이다. 자바 프로그램은 컴파일러에 의해 각 플랫폼에 독립적인 중간 코드 형태의 바이트코드로 변환된 클래스 파일로 생성되면 JVM(Java Virtual Machine)에 의해 실행된다. 마이크로소프트사의 .NET 플랫폼과 C# 언어는 프로그래머들의 요구를 충족시키고 썬사의 JVM 환경과 자바 언어에 대응하기 위해서 개발된 플랫폼과 언어이다. C#과 같은 .NET 언어는 컴파일러에 의해 MSIL(MicroSoft Intermediate Language) 코드로 번역되며 번역된 MSIL 코드는 .NET 플랫폼 환경에서 런타임 엔진인 CLR(Common Language Runtime)에 의해 실행이 된다. 자바로 작성된 프로그램은 JVM 플랫폼에서는 실행이 되지만 .NET 플랫폼에서 실행이 되지 않고, 반대로 C#과 같은 .NET 언어로 작성된 프로그램은 .NET 플랫폼에서는 실행이 되지만 JVM 플랫폼에서 실행이 되지 않는다. 이런 이유로 본 논문에서는 자바소스를 컴파일하여 생성된 클래스 파일에서 Oolong 코드를 생성하고 생성된 Oolong 코드를 .NET의 MSIL 코드로 변환하여 자바로 구현된 프로그램이 .NET 환경에서 실행되도록 하는 Bytecode-to-MSIL 번역기 시스템을 구현하였다. 따라서, 자바 프로그래머는 JVM이나 .NET 플랫폼 환경에 관계없이 프로그램을 작성하여 실행시킬 수 있다. 번역기 시스템의 구현을 정형화하기 위해 Oolong 코드의 명령어들을 문법으로 작성하였으며, PGS를 통해 생성된 어휘 정보를 가지고 스캐너를 구성하였으며, 파싱테이블을 가지고 파서를 설계하였다. 파서의 출력으로 AST가 생성되면 번역기는 AST를 탐색하면서 의미적으로 동등한 MSIL 코드를 생성하도록 시스템을 컴파일러 기법을 이용하여 모듈별로 구성하였다.

• Journal of The Korean Association of Information Education
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• v.25 no.6
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• pp.1005-1013
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• 2021

With the prolonged COVID-19, the existing academic gap is widening. The purpose of this study is to provide homeroom teachers with a visual confirmation of the academic achievement gap in grades and classrooms through academic achievement analysis, and to use this to help them design lessons and explore ways to improve the academic achievement gap. The data of students' Korean and math diagnostic evaluation scores at the beginning of the school year were visualized as clusters using the K-means algorithm, and as a result, it was confirmed that a meaningful clusters were formed. In addition, through the results of the teacher interview, it was confirmed that this system was meaningful in improving the academic achievement gap, such as checking the learning level and academic achievement of students, and designing classes such as individual supplementary instruction and level-specific learning. This means that this academic achievement data analysis system helps to improve the academic gap. This study provides practical help to homeroom teachers in exploring ways to improve the academic gap in grades and classes, and is expected to ultimately contribute to improving the academic gap.

• Archives of design research
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• v.13 no.3
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• pp.145-152
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• 2000

Since interactive systems that the user interaction is important factor can be very complex, its design process may have various testing and feedback based on continuous prototyping. The prototypes in this process function as medium to explore design problem and communicate opinions with another expert of project team. So prototyping strategy may be needed to enhance the design quality by focusing on the goals of project. This study clarifies critical issues around the prototypes and characteristics of interactive system to understand broad meaning of prototypes. And prototype model proposes as a framework for establishment of prototyping stategy.

• Journal of Engineering Education Research
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• v.13 no.1
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• pp.17-22
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• 2010

This paper examines major activities of Thomas Edison as an example to liberal education for engineers using researches in the history of technology. Edison, as a system builder, developed almost everything necessary to use electric light in the aspects of technology and management. On the contrary, Edison took a conservative stance to new alternating current technology in the case of current war. Edison developed phonograph and motion pictures but didn't understand the meaning of mass culture grown up based on his inventions. This study not only provides an illustrative content to the liberal education for engineers, but also helps to grope for the dynamic character of technological innovation and the desirable features of engineers.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.330-334
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• 2005

Our country has both relics of long history and cultural inheritance as the resources of cultural sightseeing all over the country. Recently we found the lots of cultural assets in history by the survey of the sightseeing resources. Those are known to the people to give their values and semantics and the government makes on a lot of constant efforts. In this study, a system to investigate the path and to visit the location are developed by combining various gio-spatial data with the multimedia contents. This system provides people with guidance to and locating the cultural assets in the cyber space. The developed guide system is more convenient to provide people with the information and they are able to access the designated cultural assets of the nation easily. In addition, the contents are made by that people are able to use easily in the public area as well as on the internet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1554-1561
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• 1998

When the superposition of realtime traffic and non-realtime traffic is applied to the ATM network, the successive cell loss(block loss) is more influential on the quality of service (QoS) of two traffic streams than the single loss in case of bursty traffic. Block loss can be identified as an important performance measure because of delay-oriented policy for realtime traffic. In this paper, we consider the system with the two-level overload control reducing of the recurrence of shut-down periods and develop a recursive algorithm to obtain both block loss and cell loss probabilities of both traffic. We can see that it gives the more precise and diverse investigations on performance analysis of queuing strategy.