• The Journal of Society for e-Business Studies
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• v.15 no.4
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• pp.165-179
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• 2010

Recently, the processing of data streams such as stock quotes, buy-sell orders, and billing records becomes more important in e-Business environments. Especially, the use of skyline queries over data streams is rapidly increasing to support multiple criteria decision making. Given a set of multi-dimensional tuples, a skyline query retrieves a set of tuples which are not dominated by other tuples. Although there has been much work on processing skyline queries over static datasets, there has been relatively less work on processing multiple skyline queries over data streams. In this paper, we propose an efficient method for processing multiple continuous skyline queries over data streams. The proposed method efficiently identifies which tuple is a skyline tuple of which query, resulting in a lower cost of processing multiple skyline queries. Through performance evaluation, we show the performance advantage of the proposed method.

• Journal of KIISE:Databases
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• v.29 no.6
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• pp.477-491
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• 2002

The broadcast environment has asymmetric communication aspect that is typically much greater communication bandwidth available from server to clients than in the opposite direction. In addition, mobile computing systems generate mostly read-only transactions from mobile clients for retrieving different types of information such as stock data, traffic information and news updates. Since previous concurrency control protocols, however, do not consider such a particular characteristics, the performance degradation occurs when previous schemes are applied to the broadcast environment. In this paper, we propose optimistic concurrency control based on timestamp interval for broadcast environment. The following requirements are satisfied by adapting weak consistency that is the appropriate correctness criterion of read-only transactions: (1) the mutual consistency of data maintained by the server and read by clients (2) the currency of data read by clients. We also adopt the timestamp Interval protocol to check the weak consistency efficiently. As a result, we improved a performance by reducing unnecessary aborts and restarts of read-only transactions caused when global serializability was adopted.

• The Transactions of the Korea Information Processing Society
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• v.5 no.6
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• pp.1418-1430
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• 1998

Temporal databases support an efficient historical management by means of valid time and transaction time. Valid time stands for the time when a data happens in the real world. And transaction time stands for the time when a data is stored in the database, Temporal Query Processing System(TQPS) should be extended so as tc process the temporal operations for the historical informations in the user query as well as the conventional relational operations. In this paper, the extended temporal query processing systems which is based on the previous temporal query processing system for TQuel(Temporal Query Language) consists of the temporal syntax analyzer, temporal semantic analyzer, temporal code generator, and temporal interpreter is to be described, The algorithm for additional functions such as transaction time management, temporal aggregates, temporal views, temporal joins and the heuristic optimization functions and their example how to be processed is shown.

• The Journal of Society for e-Business Studies
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• v.15 no.3
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• pp.85-98
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• 2010

The prevailing infrastructure of ubiquitous computing paradigm on the one hand making significant development for integrating technology in the daily life but on the other hand raising concerns for privacy and confidentiality. This research presents a new privacy-preserving spatio-temporal query processing technique, in which location based services (LBS) can be serviced without revealing specific locations of private users. Existing location cloaking techniques are based on a grid-based structures such as a Quad-tree and a multi-layered grid. Grid-based approaches can suffer a deterioration of the quality in query results since they are based on pre-defined size of grids which cannot be adapted for variations of data distributions. Instead of using a grid, we propose a location-cloaking algorithm which uses the R-tree, a widely adopted spatio-temporal index structure. The proposed algorithm uses the MBRs of leaf nodes as the cloaked locations of users, since each leaf node guarantees having not less than a certain number of objects. Experimental results show the superiority of the proposed method.

• The Journal of Society for e-Business Studies
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• v.12 no.3
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• pp.211-234
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• 2007

In e-business, XML is a major format of data and it is essential to efficiently process queries against XML data. XML query caching has received much attention for query performance improvement. In employing XML query caching, some efficient technique of cache replacement is required. The previous techniques considered as a replacement unit either the whole query result or the path in the query result. The former is simple to employ but it is not efficient whereas the latter is more efficient and yet the size difference among the potential victims is large, and thus, efficiency of caching would be limited. In this paper, we propose a new technique where the element in the query result is are placement unit to overcome the limitations of the previous techniques. The proposed technique could enhance the cache efficiency to a great extent because it would not pick a victim whose size is too large to store a new cached item, the variance in the size of victims would be small, and the unused space of the cache storage would be small. A technique of XML semantic cache replacement is presented which is based on the replacement function that takes into account cache hit ratio, last access time, fetch time, size of XML semantic region, size of element in XML semantic region, etc. We implemented a prototype XML semantic cache system that employs the proposed technique, and conducted a detailed set of experiments over a LAN environment. The experimental results showed that our proposed technique outperformed the previous ones.

• The Journal of Society for e-Business Studies
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• v.25 no.1
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• pp.35-43
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• 2020

Smart grid aims to achieve efficient energy-related operations. Smart grid will become a central component of Smart city that aims to improve citizens' quality of life. This paper validates that smart grid at matured state is the state where smart grid is naturally integrated into smart grid. Also, this paper describes smart grid as an essential element of smart city. This paper discusses necessary social infrastructure and investigates necessary technological features.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.108-110
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• 2023

본 연구는 web3.0(웹3.0) 서버 환경에서 이더리움 시스템을 구현하려는 것에 목적이 있다. 이더리움 거래 시스템을 만들기 위해 서버 시스템은 web3.0(웹3.0)과 node.js를 사용하였으며, 알케미를 사용하여 기존의 서버 기능을 구현하였다. 또한, 이더리움 실제 거래를 구현하기 위해 메타마스크를 사용하였으며, 이더리움 거래한 데이터를 보기 위해 이더스캔을 사용하였다. 이더리움 거래는 가스를 이용하여 거래의 승인을 하며, 매수자와 매도자는 ERC-20으로 만들어진 토큰을 거래하여 서로의 거래가 성사된다. 그리고 매수자와 매도자의 데이터를 삽입하여 그 정보를 토대로 거래할 수 있게 하였고,. 본 연구에서는 부동산 거래정보를 반응형 웹에 넣어서 그 정보에 의하여 서로 거래가 이루어 질 수 있도록 하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.161-163
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• 2011

소셜커머스의 이용의 증가와 더불어 단점이 부각되고 있다. 하지만 소셜커머스의 특성상 소셜커머스 사이트를 통해 소개되어지는 업체들은 대부분이 소비자들이 많이 접하지 못했던 영세 업체가 많고, 사용자들은 미리 구입한 쿠폰을 통해서 받은 상품의 질과 서비스가 좋지 않아도 이벤트 성으로 이루어진 판매이기에 환불이나 교환 등이 어렵다는 점에서 소비자의 주의가 필요하다. 본 논문에서는 PMI-IR 수식을 이용하여 소셜커머스에서 거래가 이루어지는 상품명과 연관 있는 상위 세개의 평을 추출하여 제공함으로써 상품의 질과 서비스에 대한 평가를 알아보고 사용자의 신뢰성 있는 거래를 도모한다.

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.268-273
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• 2003

□ e-비즈니스의 활성화로 비대면 거래의 특성과 유료화의 증가에 따른 거래 당사자간의 분쟁을 예방하는 차원에서 디지털콘텐츠의 품질을 향상시키는 방안을 강구 ㆍ우리나라 디지털콘텐츠(S/W) 품질 완성도 향상을 위한 제3차 시험 필요 ㆍ선진국의 기술보호 장벽에 대한 제도적 대안 필요 ㆍ해외 시험소 이용에 따른 비용유출 방지 과다한 초기 투자비용의 부담으로 민간업체에서 운영 불가능 ㆍ사전 검증된 고급품질의 디지털콘텐츠(S/W)공급으로 사용자 구매 촉진 ㆍ고급품질의 디지털콘텐츠(S/W) 공급으로 사용자 만족도 향상르로 우리나라 산업 발전에 기여 ㆍ고급품질의 지지털콘텐츠(S/W) 공급으로 수입대체로 인한 국제 수지 개선 효과

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.331-345
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• 2012

The main purpose of this study is to investigate the effects of operational practices of contract foodservice management company on relationship quality and recontract intention. To verify research model, 126 data were collected from client companies of E contract foodservice management company and analyzed using structural equation modeling and multiple regression. The results of this study can be summarized as follows. First, direct factors such as operational costs, menu management, and service management had significant influences on food service quality. On the other hand, indirect factors such as operational supportability, brand image, and capacity of sales management were not important to food service quality. Second, indirect operational practices had significant effects on trust. That is, when operational supportability was increased, brand image was enhanced, and capacity of sales management was strengthened, client company's trust on contract foodservice company was increased. Among them, brand image showed the highest effect. Also, direct practices such as operational costs, menu management, and sanitary/facilities management significantly influenced on trust. Third, food service quality significantly affected trust. Finally, only trust had significant effect on recontract intention but food service quality did not. This means that food service quality alone is not enough to earn recontract intention. Relationship marketing efforts to form trust should be made between contract foodservice company and client company.