• Title/Summary/Keyword: POI search algorithm

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Implementation of A Set-based POI Search Algorithm Supporting Classifying Duplicate Characters (중복글자 구분을 지원하는 집합 기반 POI 검색 알고리즘 구현)

  • Ko, Eunbyul;Lee, Jongwoo
    • Journal of Digital Contents Society
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    • v.14 no.4
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    • pp.463-469
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    • 2013
  • The set-based POI search algorithm showed better performance than the existing hard matching search when inaccurate queries are entered. In the set-based POI search algorithm, however, there is a problem that can't classify duplicate characters within a record. This is due to it's 'set-based' search property. To solve this problem, we improve the existing set-based POI search algorithm. In this paper, we propose and implement an improved set-based POI search algorithm that is able to deal duplicate characters properly. From the experimental results, we can find that our technique for duplicate characters improves the performance of the existing set based POI search algorithm.

Sentence Similarity Measurement Method Using a Set-based POI Data Search (집합 기반 POI 검색을 이용한 문장 유사도 측정 기법)

  • Ko, EunByul;Lee, JongWoo
    • KIISE Transactions on Computing Practices
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    • v.20 no.12
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    • pp.711-716
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    • 2014
  • With the gradual increase of interest in plagiarism and intelligent file content search, the demand for similarity measuring between two sentences is increasing. There is a lot of researches for sentence similarity measurement methods in various directions such as n-gram, edit-distance and LSA. However, these methods have their own advantages and disadvantages. In this paper, we propose a new sentence similarity measurement method approaching from another direction. The proposed method uses the set-based POI data search that improves search performance compared to the existing hard matching method when data includes the inverse, omission, insertion and revision of characters. Using this method, we are able to measure the similarity between two sentences more accurately and more quickly. We modified the data loading and text search algorithm of the set-based POI data search. We also added a word operation algorithm and a similarity measure between two sentences expressed as a percentage. From the experimental results, we observe that our sentence similarity measurement method shows better performance than n-gram and the set-based POI data search.

Accuracy Improvement Methods for String Similarity Measurement in POI(Point Of Interest) Data Retrieval (POI(Point Of Interest) 데이터 검색에서 문자열 유사도 측정 정확도 향상 기법)

  • Ko, EunByul;Lee, JongWoo
    • KIISE Transactions on Computing Practices
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    • v.20 no.9
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    • pp.498-506
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    • 2014
  • With the development of smart transportation, people are likely to find their paths by using navigation and map application. However, the existing retrieval system cannot output the correct retrieval result due to the inaccurate query. In order to remedy this problem, set-based POI search algorithm was proposed. Subsequently, additionally a method for measuring POI name similarity and POI search algorithm supporting classifying duplicate characters were proposed. These algorithms tried to compensate the insufficient part of the compensate set-based POI search algorithm. In this paper, accuracy improvement methods for measuring string similarity in POI data retrieval system are proposed. By formulization, similarity measurement scheme is systematized and generalized with the development of transportation. As a result, it improves the accuracy of the retrieval result. From the experimental results, we can observe that our accuracy improvement methods show better performance than the previous algorithms.

Design and Implementation of Navigation Operating System APIs for Set-based POI Search Algorithm (집합 기반 POI 검색을 지원하는 내비게이션 운영체제 기능 설계 및 구현)

  • Ahn, Hyeyeong;Lee, Jongwoo
    • KIISE Transactions on Computing Practices
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    • v.21 no.3
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    • pp.269-274
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    • 2015
  • As smart device companies such as Google or Apple develop competitive mobile-based automotive operating systems and navigation systems, the range of choice for users in such markets is expanding. Navigation systems equipped with mobile operating systems have increased convenience for users. However, since an API for the POI databases used in navigation systems doesn't exist, the number of applications using POI data is insufficient. In this paper, we designed and implemented system calls for navigation operating systems with a focus on POI search, in order to resolve such limitations. The system calls support set-based POI search functions, and therefore provides solutions to search performance degradation problems caused by false inputs. As a result of performance evaluation, not only did the search performance improve, but there was also no problem in applying APIs in applications.

DGR-Tree : An Efficient Index Structure for POI Search in Ubiquitous Location Based Services (DGR-Tree : u-LBS에서 POI의 검색을 위한 효율적인 인덱스 구조)

  • Lee, Deuk-Woo;Kang, Hong-Koo;Lee, Ki-Young;Han, Ki-Joon
    • Journal of Korea Spatial Information System Society
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    • v.11 no.3
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    • pp.55-62
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    • 2009
  • Location based Services in the ubiquitous computing environment, namely u-LBS, use very large and skewed spatial objects that are closely related to locational information. It is especially essential to achieve fast search, which is looking for POI(Point of Interest) related to the location of users. This paper examines how to search large and skewed POI efficiently in the u-LBS environment. We propose the Dynamic-level Grid based R-Tree(DGR-Tree), which is an index for point data that can reduce the cost of stationary POI search. DGR-Tree uses both R-Tree as a primary index and Dynamic-level Grid as a secondary index. DGR-Tree is optimized to be suitable for point data and solves the overlapping problem among leaf nodes. Dynamic-level Grid of DGR-Tree is created dynamically according to the density of POI. Each cell in Dynamic-level Grid has a leaf node pointer for direct access with the leaf node of the primary index. Therefore, the index access performance is improved greatly by accessing the leaf node directly through Dynamic-level Grid. We also propose a K-Nearest Neighbor(KNN) algorithm for DGR-Tree, which utilizes Dynamic-level Grid for fast access to candidate cells. The KNN algorithm for DGR-Tree provides the mechanism, which can access directly to cells enclosing given query point and adjacent cells without tree traversal. The KNN algorithm minimizes sorting cost about candidate lists with minimum distance and provides NEB(Non Extensible Boundary), which need not consider the extension of candidate nodes for KNN search.

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Implementation of a Spam Message Filtering System using Sentence Similarity Measurements (문장유사도 측정 기법을 통한 스팸 필터링 시스템 구현)

  • Ou, SooBin;Lee, Jongwoo
    • KIISE Transactions on Computing Practices
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    • v.23 no.1
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    • pp.57-64
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    • 2017
  • Short message service (SMS) is one of the most important communication methods for people who use mobile phones. However, illegal advertising spam messages exploit people because they can be used without the need for friend registration. Recently, spam message filtering systems that use machine learning have been developed, but they have some disadvantages such as requiring many calculations. In this paper, we implemented a spam message filtering system using the set-based POI search algorithm and sentence similarity without servers. This algorithm can judge whether the input query is a spam message or not using only letter composition without any server computing. Therefore, we can filter the spam message although the input text message has been intentionally modified. We added a specific preprocessing option which aims to enable spam filtering. Based on the experimental results, we observe that our spam message filtering system shows better performance than the original set-based POI search algorithm. We evaluate the proposed system through extensive simulation. According to the simulation results, the proposed system can filter the text message and show high accuracy performance against the text message which cannot be filtered by the 3 major telecom companies.

k-NN Query Processing Algorithm based on the Matrix of Shortest Distances between Border-point of Voronoi Diagram (보로노이 다이어그램의 경계지점 최소거리 행렬 기반 k-최근접점 탐색 알고리즘)

  • Um, Jung-Ho;Chang, Jae-Woo
    • Journal of Korea Spatial Information System Society
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    • v.11 no.1
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    • pp.105-114
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    • 2009
  • Recently, location-based services which provides k nearest POIs, e.g., gas stations, restaurants and banks, are essential such applications as telematics, ITS(Intelligent Transport Systems) and kiosk. For this, the Voronoi Diagram k-NN(Nearest Neighbor) search algorithm has been proposed. It retrieves k-NNs by using a file storing pre-computed network distances of POIs in Voronoi diagram. However, this algorithm causes the cost problem when expanding a Voronoi diagram. Therefore, in this paper, we propose an algorithm which generates a matrix of the shortest distance between border points of a Voronoi diagram. The shortest distance is measured each border point to all of the rest border points of a Voronoi Diagram. To retrieve desired k nearest POIs, we also propose a k-NN search algorithm using the matrix of the shortest distance. The proposed algorithms can m inim ize the cost of expanding the Voronoi diagram by accessing the pre-computed matrix of the shortest distances between border points. In addition, we show that the proposed algorithm has better performance in terms of retrieval time, compared with existing works.

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Implementation of A Mobile Application for Spam SMS Filtering Using Set-Based POI Search Algorithm (집합 기반 POI 검색 알고리즘을 활용한 스팸 메시지 판별 모바일 앱 구현)

  • Ahn, Hye-yeong;Cho, Wan-zee;Lee, Jong-woo
    • Journal of Digital Contents Society
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    • v.16 no.5
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    • pp.815-822
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    • 2015
  • By the growing of SMS phishing victims, applications for processing spam messages are being released in succession. However most spam messages that cleverly modified the content like separating the consonants and vowels are fail to be filtered. In this paper, we implemented an application 'AntiSpam' which is able to identify spam strings in the text message to solve this problem. 'AntiSpam' searches spam strings in the text message by using set-based POI search algorithm, and then calculate the possibility of whether it is spam or not in accordance with the search results. In addition, it catches skillfully disguised spam messages in order to avoid missing the spam filtering. Users, who received a message, can check the result in spam message possibility decision result and the contents of the message and they can choose how to handling the message.

A K-Nearest Neighbor Search Algorithm for DGR-Tree (DGR-Tree를 위한 KNN 검색 알고리즘)

  • Lee, Deuk-Woo;Kang, Hong-Koo;Han, Ki-Joon
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.11a
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    • pp.799-800
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    • 2009
  • 유비쿼터스 컴퓨팅 환경에서의 LBS에서는 점차 대용량화 및 밀집화 경향을 보이는 POI에 대한 빠른 KNN 검색이 중요하다. 따라서 본 논문에서는 기존의 DGR-Tree를 위해서 POI에 대한 빠른 KNN 검색을 위한 KNN 검색 알고리즘을 제시하고, 또한 성능 평가를 통해 그 우수성을 입증한다.

An Adaptive Priority-based Sequenced Route Query Processing Method in Road Networks (도로 네트워크 환경에서 적응적 우선순위 기반의 순차적 경로 처리 기법)

  • Ryu, Hyeongcheol;Jung, Sungwon
    • KIISE Transactions on Computing Practices
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    • v.20 no.12
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    • pp.652-657
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    • 2014
  • Given a starting point, destination point and various Points Of Interest (POIs), which contain a full or partial order, for a user to visit we wish to create, a sequenced route from the starting point to the destination point that includes one member of each POI type in a particular order. This paper proposes a method for finding the approximate shortest route between the start point, destination point and one member of each POI type. There are currently two algorithms that perform this task but they both have weaknesses. One of the algorithms only considers the distance between the visited POI (or starting point) and POI to visit next. The other algorithm chooses candidate points near the straight-line distance between the start point and destination but does not consider the order of visits on the corresponding network path. This paper outlines an algorithm that chooses the candidate points that are nearer to the network path between the start point and destination using network search. The algorithm looks for routes using the candidate points and finds the approximate shortest route by assigning an adaptive priority to the route that visits more POIs in a short amount of time.