• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.3-7
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• 2009

Data centric storages for sensor networks have been proposed to efficiently process multi-dimensional range queries as well as exact matches. Usually, a sensor network does not process only one type of the query but supports various types of queries such as range queries, exact matches and skyline queries. Therefore, a sensor network based on a data centric storage for range queries and exact matches should process skyline queries efficiently. However, existing algorithms for skyline queries have not considered the features of data centric storages. Some of the data centric storages store similar data in sensor nodes that are placed on geographically similar locations. Consequently, all data are ordered in a sensor network. In this paper, we propose a new skyline query processing algorithm that exploits the above features of data centric storages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.370-381
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• 2012

Multi-criteria result extraction is crucial in many scientific applications that support real-time stream processing, such as habitat research and disaster monitoring. Skyline evaluation is computational intensive especially over continuous time-interval data streams where each object has its own customized expiration time. In this work, we propose TI-Sky - a continuous skyline evaluation framework. To ensure correctness, the result space needs to be continuously maintained as new objects arrive and older objects expire. TI-Sky strikes a perfect balance between the costs of continuously maintaining the result space and the costs of computing the final skyline result from this space whenever a pull-based user query is received. Our key principle is to incrementally maintain a partially precomputed skyline result space - however doing so efficiently by working at a higher level of abstraction. TI-Sky's algorithms for insertion, deletion, purging and result retrieval exploit both layers of granularity. Our experimental study demonstrates the superiority of TI-Sky over existing techniques to handle a wide variety of data sets.

• Journal of Korean Association for Spatial Structures
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• v.10 no.3
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• pp.65-74
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• 2010

In this study, the vibration control effect according to the installation location of the sky-bridge and the difference of natural periods of the connected buildings has been investigated. To this end, 40-story and 50-story building structures connected by a sky-bridge were used as example structures and the equivalent modeling method was used. Boundary nonlinear time history analyses were performed using El Centro and Taft earthquakes to investigate the dynamic behavior of the example structures and vibration control effect of the sky-bridge. Based on numerical results, it has been shown that displacement responses can be effectively controlled as the installation floor of the sky-bridge increases and acceleration responses can be effectively reduced when the sky-bridge is installed on the mid-stories of the example building.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.970-978
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• 2011

The high-rise buildings have been indiscriminately located in the good natural landscape in Busan. They destroy the mountain skyline that is the key role of urban landscape and lower the index of greenness. Busan need the efficient management methods of the mountain skyline to improve the quality of urban life, the amenity of urban landscape, and the index of greenness. This study is to propose the method of building height restriction both through the GIS bases multiple sight surface analysis and through the analysis of the floor area ratio to make up for the weakness of single sight surface analysis has been used as a means of building height restriction. It studies the residential district with Hwangreung Mountain in the background at Deeyeon-don, Nam-gu, Busan. It achieves both objectivity and time efficiency by multiple sight surface analysis. Reflecting the result of this simulation at strategic viewpoints, it enables landscape planning to be comprehensive. Lastly it suggests building height regulation for protecting the mountain skyline which responds to the local conditions.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.1
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• pp.1-8
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• 2017

Given a multi-dimensional dataset of tuples, a skyline query returns a subset of tuples which are not 'dominated' by any other tuples. Skyline query is very useful in Big data analysis since it filters out uninteresting items. Much interest was devoted to the MapReduce-based parallel processing of skyline queries in large-scale distributed environment. There are three requirements to improve parallelism in MapReduced-based algorithms: (1) workload should be well balanced (2) avoid redundant computations (3) Optimize network communication cost. In this paper, we introduce MR-SEAP (MapReduce sample Skyline object Equality Angular Partitioning), an efficient angular space partitioning based skyline query processing using sampling-based pruning, which satisfies requirements above. We conduct an extensive experiment to evaluate MR-SEAP.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.1
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• pp.17-24
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• 2020

The traveling salesman problem is an algorithmic problem tasked with finding the shortest route that a salesman visits, visiting each city and returning to the started city. Due to the exponential time complexity of TSP, it's hard to implement on cases like amusement park or delivery. Also, TSP is hard to meet user's demand that is associated with multi-dimensional attributes like travel time, interests, waiting time because it uses only one attribute - distance between nodes. This paper proposed Top-n Skyline-Multi Dimension TSP to resolve formerly adverted problems. The proposed algorithm finds the shortest route faster than the existing method by decreasing the number of operations, selecting multi-dimensional nodes according to the dominance of skyline. In the simulation, we compared computation time of dynamic programming algorithm to the proposed a TS-MDT algorithm, and it showed that TS-MDT was faster than dynamic programming algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4614-4622
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• 2010

Urban Skyline is strongly influenced by high-rise buildings. It is changed and becoming over time and is formed by the human choice. This study does an analysis of the foreign urban skyline managements in three aspects: criteria and control, operation and deliberation, and citizen participation and inducement. It draws common characteristics of foreign cases; preparing rational and premeditated building height control in the aspect of district, transformation from height restrictions of individual building to height standards in the aspect of urban landscape, devising efficient design review and citizen participation methods, and administrative processing for an integrated building height management. It also suggests policy implications for preparing both comprehensive and systematic building height standards in the aspect of district to create a desirable city image and urban skyline.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.13-14
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• 2014

최근 스마트폰, 태블릿 PC 등 다양한 모바일 기기들의 처리 능력이 향상됨에 따라 모바일 P2P 환경에서의 질의 처리 성능이 향상되고 있다. 본 논문에서는 모바일 P2P 네트워크에서 에너지 효율적인 유사성 스카이라인 질의 처리 기법을 제안한다. 제안하는 기법은 질의 배포 범위를 확장 및 제한함으로써 결과로 제공될 수 있는 잠재적 객체를 얻음과 동시에 전체 네트워크로의 불필요한 배포를 방지한다. 또한 각 피어들은 질의를 받았을 때 자신이 보유하고 있는 객체를 이용하여 로컬 유사성 스카이라인을 처리하고, 질의를 요청한 피어(질의 피어)에게 처리된 결과를 병합하여 전송한다.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.47-48
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• 2017

최근 각종 실험 장비의 발전에 따라 유사 서브 그래프 매칭에 대한 연구가 활발하게 진행되고 있다. 하지만 유사 서브 그래프 매칭은 다수의 최종 결과들이 반환되었을 경우, 사용자는 어떤 결과가 자신에게 가장 유의미한 결과인지를 판별하기 힘든 문제점이 존재한다. 본 논문에서는 대용량 그래프 환경에서 스카이라인을 이용한 서브 그래프 유사도 측정 기법을 제안한다. 제안하는 기법은 스카이라인 기법과 피드백에 기반한 랭킹을 수행하여 유사 서브 그래프 매칭에서 사용자에게 유의미한 결과를 반환한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.282-285
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• 2009

대부분의 스카이라인 질의에 대한 연구는 완전한 데이터에 관하여 이루어지고 있다. 하지만, 우리가 웹이나 기타 다른 도구로 데이터베이스에 자료를 입력할 때는 null을 허용하는 부분이 존재한다. 현재 이런 불완전한 데이터를 처리하기 위한 많은 연구가 이루어지고 있다. 본 논문에서는 이러한 문제를 해결하기 위하여 기존에 제안되었던 불완전한 데이터를 처리하는 기법과 차원의 저주를 해결하기 위한 기법을 고려하여 이를 바탕으로 완전한 데이터와 동등하거나 혹은 더 좋을지도 모르는 데이터를 우선순위가 높은 순서대로 k(g)개 검색해주는 스카이라인 그룹 질의를 도입하고 이를 처리하는 방법을 제안한다.