• Journal of the Korea Society of Computer and Information
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• v.15 no.5
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• pp.23-31
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• 2010

With the advances in the information technology and mobile communications, we now face increasing demands for various services based on both of position tracking of moving objects and their efficient index scheme. Accordingly, the $TPR^*$-tree, which were proposed for efficiently tracking moving objects and predicting their positions in the future time, has drawn much intention. As the $TPR^*$-tree came from the R-tree that is suitable for indexing static objects, it does not support cheap update costs. Therefore, it seems to be very costly to index moving objects if there are frequent occurrences of node updates caused by continuously changing velocities and positions. If some moving objects with high velocities have node updates, in particular, then the $TPR^*$-tree may suffer from many unnecessary updates in the wide range of tree regions. To avoid such a problem, we propose a method that can keep fast-moving objects in the child nodes of the root node, thereby saving node update costs in the $TPR^*$-tree. To show our performance advantages and retaining $TPR^*$-tree features, we performed some performance experiments using a simulation technique.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.3227-3235
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• 2011

In this paper, a relational embedded DBMS was designed and a prototype 'Miracle' RDBMS (MDB) was developed. MDB is written in C and works on Unix, Linux and Windows platforms locally. It accesses database through SQL interfaces and API functions and uses $B^+$ tree index. It guarantees ACID in transactions and supports low concurrency control and processes SQL statements on a single table. To evaluate the performance of MDB on an ARM board EZ-S3C6410 and to compare the performance of MDB with that of SQLite, an experiment was carried out to estimate processing times for insertion, selection, update and deletion operations. The result shows that the average times for selections and insertions in MDB were 38.46% and 22.86% faster than those in SQLite, respectively, but the average times for updates and deletions in SQLite were 28.33% and 26.00% faster than MDB, respectively, This experiment shows that fetching data from database and sending data to database in MDB is faster than in SQLite, but $B^+$ tree index is implemented more effectively in SQlite than in MDB.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.6 s.312
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• pp.52-59
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• 2006

Recently, the internet has seen tremendous growth with plenty of enriched information due to an increasing number of specialized personal interests and popularizations of private cyber space called, blog. Many of today's blog provide internet users, RSS, which is also hewn as the syndication technology. It enables blog users to receive update automatically by registering their RSS channel address with RSS aggregator. In other words, it keeps internet users wasting their time checking back the web site for update. This paper propose the ways to manage RSS Channel Searching Crawler and collected RSS Channels for internet users to search for a specific RSS channel of their want without any obstacles. At the same time. This paper proposes RSS channel ranking based on user popularity. So, we focus on an idea of adding index to information and web update for users to receive appropriate information according to user property.

• Journal of Korea Spatial Information System Society
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• v.6 no.2 s.12
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• pp.51-62
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• 2004

Recently, the location-based service for moving customers is becoming one of the most important service in mobile communication area. For moving object applications, there are lots of update operations and such update loads are concentrated on some particular area unevenly. The primary processing of LBS application is spatio-temporal range queries. To improve the throughput of spatio-temporal range queries, the time of disk I/O in query processing should be reduced. In this paper, we adopt non-uniform two-level grid index structures of GALIS architecture,which are designed to minimize update operations. We propose query scheduling technique using spatial relationship and time relationship and a combined spatio-temporal query processing method using time zone concepts to improve the throughput of query processing. Some experimental results are shown for range queries with different query range to show the performance tradeoffs of the proposed methods.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.1
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• pp.35-40
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• 2005

Recently, the location based service for moving customers is becoming one of the most important service in mobile communication area and for moving object applications, there are lots of update operations and such update loads are concentrated on some particular area unevenly. The primary processing of LBS application is spatio-temporal range queries and to improve the throughput of spatio-temporal range queries, the time of disk I/O in query processing should be reduced. In this paper, we adopt non-uniform two-level grid index structure, which are designed to minimize update operations. We propose query scheduling technique using spatial relationship and time relationship and a combined spatio-temporal query processing method using time zone concepts to improve the throughput of query processing. Some experimental results are shown for range queries with different query range to show the performance tradeoffs of the proposed methods.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.835-844
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• 2004

Recently, the location-based service for moving customers is becoming one of the most important service in mobile communication area. For moving object applications, there are lots of update operations and such update loads are concentrated on some particular area unevenly. Range queries, whose range can be window or circular, are the most essential query types in LBS. We need to distinguish completely contained cells from partially contained cells in those range queries. Also, it is necessary to consider temporal dimension to filter out qualifying objects correctly. In this paper, we adopt two-level index structures with fixed grid file structures in the second level, which are designed to minimize update operations. We propose a spatial ceil filtering method using VP filtering and a combined spatio-temporal filtering method using time gone concepts. Some experimental results are shown for various window queries and circular queries with different filtering combinations to show the performance tradeoffs of the proposed methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.460-464
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• 2003

The objects which continuously change their locations in the real world are called moving objects. The works on the existing spatial indices have been proposed the retrieval methods. However, keeping track of the terminal location of moving objects is more important than the efficiency of the query processing in the moving object database. Therefore, many pure spatial indices are not applicable to the moving objects database which should maintain the object's current location as precise as possible. This parer proposes a method for reducing the construction time of indexing moving objects. We analyze the characteristics of the method to re-index all the objects after each time period and the method to update immediately the locations on reporting their locations. We also newly propose a selective immediate update method using the properties of moving objects in order to minimize the number of database updates.

• 한국생물공학회:학술대회논문집
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• 2004.07a
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• pp.47-84
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• 2004

Principal Component Analysis나 Partial Least Squares와 같은 다변량 통계 기법은 변수간의 correlation structure로부터 공정의 variance를 설명할 수 있는 latent variable를 얻고 이를 이용하여 공정을 효과적으로 modeling할 수 있는 방법으로 최근 들어 많은 관심을 얻고 있다. 하지만 PLS는 공정이 stationary state에 있다고 가정하기 때문에, 생물학적 공정의 non-stationary and time-varying behavior를 설명하기에 부적절하다. 본 논문에서는 PLS 알고리즘의 혐기성 폐수처리 공정에의 적용에 있어, 이와 같은 문제를 해결하기 위해서 adaptive PLS 알고리즘을 사용함으로써 변화하는 공정의 특성에 대응하여 모델을 update하는 방법을 이용하였다. 하지만 실시간 데이터로부터 adaptive PLS 방법을 적용하는 데에는 많은 어려움이 존재하며, 특히 outlier나 abnormal disturbance에 모델이 부적절하게 adaptation하는 문제가 발생할 수 있다. 따라서 이의 해결을 위해 adaptive PLS를 적용하는데 있어 robustness를 향상시키기 위해 monitoring index를 이용하여 abnormal data에 weight를 주고 안정적인 모델의 update가 가능하게 하는 방법을 제안하였으며, 이를 적용하여 성공적으로 혐기성 폐수처리 공정의 Output을 예측하고 효과적으로 공정을 모니터링할 수 있었다. 만들어진 PLS 모델은 산업폐수를 처리하기 위한 industrial plan에서 측정된 실제 데이터에 적용하여 그 효용성을 입증하였으며, 그 결과는 mechanistic model을 적용하기 힘든 실공정에 비교적 쉽게 implementation할 수 있는 장점이 있다.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.113-116
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• 2004

Assisted by high technologies of information and communication in storing and collecting moving object information, many applications have been developing technical methods to exploit databases of moving objects effectively and variously. Among them, today, Current and Anticipated Future Position Indexing methods manage current positions of moving objects in order to anticipate future positions of them or more complex future queries. They, however, strongly demand update performance as fast enough to guarantee certainty of queries as possible. In this paper, we propose a new indexing mettled derived from the TPR-tree that should has update performance considerably improved, we named it BUR-tree. In our method, index structure can be inserted, deleted, and updated with a number (or bulk) of objects simultaneously rather than one object at a time as in conventional methods. This method is intended to be applied to a traffic network in which vast number of objects, such as cars, pedestrians, moves continuously.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.2
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• pp.196-201
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• 2013

In this paper, we proposed high speed LDPC encoder architecture for DVB-S2 standard. In conventional algorithm, the processes of parity calculations are serial fashion. Therefore conventional algorithm need clocks of number of parity. The proposed LDPC encoding architecture is based on a parallel 360 bits-wise operations. The key issues for realizing high speed are using the two kinds of index addresses and make use of memories efficiently. We implemented a half rate LDPC encoder on an FPGA, and confirmed its maximum throughput is up to 10 Gbps on 100MHz clock.