• Proceedings of the Korea Inteligent Information System Society Conference
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• 2007.05a
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• pp.321-328
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• 2007

데이터마이닝은 대용량의 데이터에 숨겨진 의미있고 유용한 패턴과 상관관계를 추출하여 의사결정에 활용하는 작업이다. 그 중에서도 고객 트랜잭션의 데이터베이스에서 아이템 사이에 존재하는 연관규칙을 찾는 것은 중요한 일이 되었다. Apriori 알고리즘 이후 연관규칙을 찾기 위해 대용량 데이터베이스로부터 압축된 의미있는 정보를 저장하기 위한 데이터 구조와 알고리즘들이 제안되어 왔다. 본 논문에서는 정점으로 아이템을 표현하고, 간선으로 두 아이템집합을 표현하는 빈발 패턴 네트워크(FPN)이라 불리는 새 자료 구조를 제안한다. 빈발 패턴 네트워크에서 아이템 사이의 연관 관계를 발견하기 위해 이 구조를 어떻게 효율적으로 사용 하느냐에 초점을 두고 있다. 구조의 효율적인 사용을 위하여 한 아이템이 클러스터 내의 아이템과는 유사도가 높고, 다른 클러스터의 아이템과는 유사도가 낮도록 네트워크의 정점을 클러스터링하는 방법을 사용한다. 실험은 신뢰도, 상관관계 그리고 간선 가중치 유사도를 이용하여 네트워크에서 아이템 클러스터링의 정확도를 보여준다. 본 논문의 실험 결과를 통해 신뢰도 유사도가 네트워크의 정점을 클러스터링할 때 클러스터의 정확성에 가장 많은 영향을 미친다는 것을 알 수 있었다.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1443-1446
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• 2003

본 논문에서는 MPEG-21 프레임워크에서 이용되는 기본 단위인 디지털 아이템(Digital Item)의 처리에 관한 과정을 설명하고, 처리과정에 적용 가능한 디지털 아이템의 모델링에 대하여 논하였다 MPEG-21 에서 정의된 디지털 아이템 선언(Digital Item Declaration;DID)은 디지털 아이템의 정적인 선언에 그치는 반면, 디지털 아이템 프로세싱(Digital Item Processing;DIP)을 기반으로 한 디지털 아이템에는 처리 및 이용에 관한 기능이 부여된다. 모델링된 디지털 아이템의 처리를 위한 구조를 정의하고, DIP 구조와 디지털 아이템의 유효성을 입증하기 위해 교육용 멀티미디어 컨텐츠를 담고 있는 디지털아이템을 생성하였다. 또한 DIP 기반에서 모델링된 디지털 아이템을 소비할 수 있는 디지털 아이템 플레이어의 구현과 테스트 결과에 대해서도 설명하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.211-213
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• 2003

본 논문에서는 MPEG-21 통합 멀티미디어 프레임워크에서 이용되는 기본 단위인 디지털 아이템(Digital Item)의 처리 방안에 대해 설명하고, 디지털 아이템 소비 시스템에 대해 논하였다. 현재 MPEG을 중심으로 표준화중인 디지털 아이템 프로세싱(Digital Item Processing; DIP)을 이용한 디지털 아이템 처리는 디지털 아이템에 소비 및 이용에 대한 기능을 부여한다. DUP 에 기반을 둔 디지털 아이템 처리 및 소비 구조의 적용을 위해 교육용 멀티미디어 컨텐츠를 표현하는 디지털 아이템을 구조화하고 디지털 아이템 소비기를 구현하여 구조화된 디지털 아이템 처리 및 소비 시스템의 유효성을 입증하였다.

• Journal of Korea Game Society
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• v.18 no.1
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• pp.95-104
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• 2018

This study analyzes the system of Loot Box in Overwatch, FPS genre game produced by an American company Blizzard. Currently, one of the most controversial issues in the recent industry is "Probability-Type Item" that game users purchase high-end game items as a form of lottery. As this study examines a foreign case of Loot Box that is similar to Probability-Type Item, it would show how it is constructed and does legal approaches. Throughout this, it not only analyzes pros and cons of the Loot Box system, but also provides thought-provoking messages for the issue of the Probability-Type Item.

• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.193-221
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• 2007

This study explored the efficient hierarchical data structure of mobile interfaces. The first experiment demonstrated the effects of grouping(clear/unclear), depth level(2/3/5), and the number of items(32/64/128) on the search time and the number of errors. The results indicated that participants spent less time and made fewer errors to perform the task when the clear mobile interfaces, low depth level, and fewer items were provided. In addition, the results indicated that there were no effects of the depth level and the number of items on the search time and number of errors in clear mobile interfaces conditions. As depth level and the number of items changed, on the other hand, participants spent longer time to complete the task and made more mistakes in unclear mobile interfaces conditions. The second experiment investigated the effects of grouping(clear/unclear), the number of items(32/64/128), and spacial cues(colors/ windows/ number of cues) on search time and the number of errors in hierarchical data structures which had five depth levels. The results indicated that participants spent less time to complete the task and made less errors in a mobile interface when grouping is clear and the number of items are fewer. The results were identical with the first experiments. In addition, the main effect of spacial cues indicated that providing spacial cues via pictures and numbers can be helpful to reduce errors in search behaviors.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.313-322
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• 2005

In order to access digital items in a server via ubiquitous devices, the digital items should be adapted according to the system environment, device characteristics and user preferences. In ubiquitous environment, those device-dependent adaptation requirements are not statically determined and not predictable. Therefore an application specific adaptation mechanism can not be applied to a general digital item adaptation engine. In this paper, we propose an application independent digital item adaptation architecture which has a set of minimal transcoders, transcoding path generator for a required adaptation requirement, and adaptation scheduler. And a CFG based method of finding a sequence of multiple unit transcoders called a transcoding path Is described in detail followed by experimental results.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.67-74
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• 2015

In recent years, frequent itemset mining for considering the importance of each item has been intensively studied as one of important issues in the data mining field. According to strategies utilizing the item importance, itemset mining approaches for discovering itemsets based on the item importance are classified as follows: weighted frequent itemset mining, frequent itemset mining using transactional weights, and utility itemset mining. In this paper, we perform empirical analysis with respect to frequent itemset mining algorithms based on transactional weights. The mining algorithms compute transactional weights by utilizing the weight for each item in large databases. In addition, these algorithms discover weighted frequent itemsets on the basis of the item frequency and weight of each transaction. Consequently, we can see the importance of a certain transaction through the database analysis because the weight for the transaction has higher value if it contains many items with high values. We not only analyze the advantages and disadvantages but also compare the performance of the most famous algorithms in the frequent itemset mining field based on the transactional weights. As a representative of the frequent itemset mining using transactional weights, WIS introduces the concept and strategies of transactional weights. In addition, there are various other state-of-the-art algorithms, WIT-FWIs, WIT-FWIs-MODIFY, and WIT-FWIs-DIFF, for extracting itemsets with the weight information. To efficiently conduct processes for mining weighted frequent itemsets, three algorithms use the special Lattice-like data structure, called WIT-tree. The algorithms do not need to an additional database scanning operation after the construction of WIT-tree is finished since each node of WIT-tree has item information such as item and transaction IDs. In particular, the traditional algorithms conduct a number of database scanning operations to mine weighted itemsets, whereas the algorithms based on WIT-tree solve the overhead problem that can occur in the mining processes by reading databases only one time. Additionally, the algorithms use the technique for generating each new itemset of length N+1 on the basis of two different itemsets of length N. To discover new weighted itemsets, WIT-FWIs performs the itemset combination processes by using the information of transactions that contain all the itemsets. WIT-FWIs-MODIFY has a unique feature decreasing operations for calculating the frequency of the new itemset. WIT-FWIs-DIFF utilizes a technique using the difference of two itemsets. To compare and analyze the performance of the algorithms in various environments, we use real datasets of two types (i.e., dense and sparse) in terms of the runtime and maximum memory usage. Moreover, a scalability test is conducted to evaluate the stability for each algorithm when the size of a database is changed. As a result, WIT-FWIs and WIT-FWIs-MODIFY show the best performance in the dense dataset, and in sparse dataset, WIT-FWI-DIFF has mining efficiency better than the other algorithms. Compared to the algorithms using WIT-tree, WIS based on the Apriori technique has the worst efficiency because it requires a large number of computations more than the others on average.

• Journal of Korea Multimedia Society
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• v.12 no.3
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• pp.427-435
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• 2009

Users are able to search and read interesting items and hence click hyperlink linked to the item which is detailed content unit such as menu, login, news, video, etc. Small screen like mobile device is very difficult to viewing all web contents at once. Browsing and searching for interesting items by scrolling to left and right or up and down is discomfort to users in small screen. Searching and displaying directly the item preferred by users can reduces difficulty of interface manipulation of mobile device. To archive it, web contents based on desktop will be segmented on a per-item basis which component unit of web contents. Most segment algorithms are based on segment method through analysis of HTML code or mobile size. However, it is difficult to extract item blocks. Because present web content is getting more complicated and diversified in structure and content like web portal services. A web content segment algorithm suggested in this paper is based on extracting item blocks is component units of web contents.

• Journal of Korea Game Society
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• v.7 no.2
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• pp.41-52
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• 2007

Presently, the online game industry of Korea are growing up fastly. The growth of online game give rise to the new problem of regulation on Real Money Trade(RMT). This article analyzed the market failure of RMT, and showed whether or not the government regulate RMT. The results showed that the RMT has efficiency in monopoly and external economie, and inefficiency in external diseconomies and uncertainty. But, the inefficiency in external diseconomie and uncertainty is based on the regulation of RMT by the game company. So, it is necessary for government to deregulate the RMT for curing the inefficiency of RMT.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1451-1454
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• 2003

본 논문에서는 MPEG-21 에서 정의한 디지털아이템의 파일 포맷의 구조 및 방법을 멀티미디어 파일 포맷으로 제안하였다. 제안한 방법은 디지털아이템을 이진화하는 방법 및 기능, XML로 구성된 디지털아이템 선언(Digital Item Declaration)에서 미디어 리소스를 참조하는 방법 등이다. 제안한 멀티미디어 파일 포맷은 디지털방송, 무선통신, 인터넷 환경에서의 다양한 형태의 컨텐츠들을 효과적이고 체계적으로 조합할 수 있는 기능 및 효과적인 전송 기능을 제공하며, 향후 xml 기반 메타데이터와 미디어리소스를 포함하는 멀티미디어 컨텐츠의 파일 포맷에 대한 참고 모델로서 사용될 수 있다.