• Title/Summary/Keyword: Nearest Neighbor(NN)

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k-Nearest Neighbor Classifier using Local Values of k (지역적 k값을 사용한 k-Nearest Neighbor Classifier)

  • 이상훈;오경환
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10a
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    • pp.193-195
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    • 2003
  • 본 논문에서는 k-Nearest Neighbor(k-NN) 알고리즘을 최적화하기 위해 지역적으로 다른 k(고려할 neighbor의 개수)를 사용하는 새로운 방법을 제안한다. 인스턴스 공간(instance space)에서 노이즈(noise)의 분포가 지역적(local)으로 다를 경우, 각 지점에서 고려해야 할 최적의 이웃 인스턴스(neighbor)의 수는 해당 지점에서의 국부적인 노이즈 분포에 따라 다르다. 그러나 기존의 방법은 전체 인스턴스 공간에 대해 동일한 k를 사용하기 때문에 이러한 인스턴스 공간의 지역적인 특성을 고려하지 못한다. 따라서 본 논문에서는 지역적으로 분포가 다른 노이즈 문제를 해결하기 위해 인스턴스 공간을 여러 개의 부분으로 나누고, 각 부분에 최적화된 k의 값을 사용하여 kNN을 수행하는 새로운 방법인 Local-k Nearest Neighbor 알고리즘(LkNN Algorithm)을 제안한다. LkNN을 통해 생성된 k의 집합은 인스턴스 공간의 각 부분을 대표하는 값으로, 해당 지역의 인스턴스가 고려해야 할 이웃(neighbor)의 수를 결정지어준다. 제안한 알고리즘에 적합한 데이터의 도메인(domain)과 그것의 향상된 성능은 UCI ML Data Repository 데이터를 사용한 실험을 통해 검증하였다.

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Fuzzy Kernel K-Nearest Neighbor Algorithm for Image Segmentation (영상 분할을 위한 퍼지 커널 K-nearest neighbor 알고리즘)

  • Choi Byung-In;Rhee Chung-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.7
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    • pp.828-833
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    • 2005
  • Kernel methods have shown to improve the performance of conventional linear classification algorithms for complex distributed data sets, as mapping the data in input space into a higher dimensional feature space(7). In this paper, we propose a fuzzy kernel K-nearest neighbor(fuzzy kernel K-NN) algorithm, which applies the distance measure in feature space based on kernel functions to the fuzzy K-nearest neighbor(fuzzy K-NN) algorithm. In doing so, the proposed algorithm can enhance the Performance of the conventional algorithm, by choosing an appropriate kernel function. Results on several data sets and segmentation results for real images are given to show the validity of our proposed algorithm.

Calculating Attribute Weights in K-Nearest Neighbor Algorithms using Information Theory (정보이론을 이용한 K-최근접 이웃 알고리즘에서의 속성 가중치 계산)

  • Lee Chang-Hwan
    • Journal of KIISE:Software and Applications
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    • v.32 no.9
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    • pp.920-926
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    • 2005
  • Nearest neighbor algorithms classify an unseen input instance by selecting similar cases and use the discovered membership to make predictions about the unknown features of the input instance. The usefulness of the nearest neighbor algorithms have been demonstrated sufficiently in many real-world domains. In nearest neighbor algorithms, it is an important issue to assign proper weights to the attributes. Therefore, in this paper, we propose a new method which can automatically assigns to each attribute a weight of its importance with respect to the target attribute. The method has been implemented as a computer program and its effectiveness has been tested on a number of machine learning databases publicly available.

A Search Interval Limitation Technique for Improved Search Performance of CNN (연속 최근접 이웃(CNN) 탐색의 성능향상을 위한 탐색구간 제한기법)

  • Han, Seok;Oh, Duk-Shin;Kim, Jong-Wan
    • Journal of Internet Computing and Services
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    • v.9 no.3
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    • pp.1-8
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    • 2008
  • With growing interest in location-based service (LBS), there is increasing necessity for nearest neighbor (NN) search through query while the user is moving. NN search in such a dynamic environment has been performed through the repeated applicaton of the NN method to the search segment, but this increases search cost because of unnecessary redundant calculation. We propose slabbed continuous nearest neighbor (Slabbed_CNN) search, which is a new method that searches CNN in the search segment while moving, Slabbed_CNN reduces calculation costs and provides faster services than existing CNN by reducing the search area and calculation cost of the existing CNN method through reducing the search segment using slabs.

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An Interval Type-2 Fuzzy K-Nearest Neighbor (Interval 제2종 퍼지 K-Nearest Neighbor)

  • 황철;이정훈
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2002.12a
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    • pp.271-274
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    • 2002
  • 본 논문은 (1)에 기술된 퍼지 K-nearest neighbor(NN) 알고리즘의 확장인 interval 제2종 퍼지 K-NN을 제안한다. 제안된 방법에서는, 각 패턴벡터의 멤버쉽 값들에 불확실성(Uncertainty)을 할당하는 것에 의해 interval 제2종 퍼지 멤버쉽으로의 확장을 시도한다. 이러한 확장은, K의 결정에 존재하는 불확실성은 다루고, 조정할 수 있게 한다.

Feature Selection for Multiple K-Nearest Neighbor classifiers using GAVaPS (GAVaPS를 이용한 다수 K-Nearest Neighbor classifier들의 Feature 선택)

  • Lee, Hee-Sung;Lee, Jae-Hun;Kim, Eun-Tai
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.6
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    • pp.871-875
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    • 2008
  • This paper deals with the feature selection for multiple k-nearest neighbor (k-NN) classifiers using Genetic Algorithm with Varying reputation Size (GAVaPS). Because we use multiple k-NN classifiers, the feature selection problem for them is vary hard and has large search region. To solve this problem, we employ the GAVaPS which outperforms comparison with simple genetic algorithm (SGA). Further, we propose the efficient combining method for multiple k-NN classifiers using GAVaPS. Experiments are performed to demonstrate the efficiency of the proposed method.

Flexible Nearest Neighbor Search for Grouping kNN (그룹핑 k-NN을 위한 유연한 최근접 객체 검색)

  • Song, Doohee;Park, Kwangjin
    • Proceedings of the Korea Information Processing Society Conference
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    • 2015.10a
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    • pp.469-470
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    • 2015
  • 우리는 그룹핑 k-최근접 (Grouping k Nearest Neighbor; GkNN)질의를 지원하기 위하여 유연한 최근접객체(Flexible Nearest Neighbor; FNN)검색 방법을 제안한다. GkNN이란 기존에 제안된 kNN과 다르게 질의자가 요청한 k개의 객체를 모두 확인한 후에 이동 경로의 총합이 가장 작은 k개의 객체를 검색하는 방법이다. 기존 연구에서 제안된 최근접 객체들 (Nearest Neighborhood; NNH) 또한 이 문제를 해결하기 위하여 제안되었다. 그러나 NNH의 문제점은 객체 k와 p가 고정되어 있기 때문에 이동 환경에서 q에서 C까지의 거리가 증가하는 것이다. FNN의 환경은 NNH의 환경과 유사하다. 우리는 NNH의 q에서 집합 C 중 거리 중 가장 짧은 $c_i$ 선택한 후 q에서 $c_i$에 포함된 객체들 모두 검색하는 이동 경로의 총합과 FNN의 이동경로의 총 합을 비교하여 NNH의 문제점을 해결하였다.

Ordered Reverse k Nearest Neighbor Search via On-demand Broadcast

  • Li, Li;Li, Guohui;Zhou, Quan;Li, Yanhong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.11
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    • pp.3896-3915
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    • 2014
  • The Reverse k Nearest Neighbor (RkNN) query is valuable for finding objects influenced by a specific object and is widely used in both scientific and commercial systems. However, the influence level of each object is unknown, information that is critical for some applications (e.g. target marketing). In this paper, we propose a new query type, Ordered Reverse k Nearest Neighbor (ORkNN), and make efforts to adapt it in an on-demand scenario. An Order-k Voronoi diagram based approach is used to answer ORkNN queries. In particular, for different values of k, we pre-construct only one Voronoi diagram. Algorithms on both the server and the clients are presented. We also present experimental results that suggest our proposed algorithms may have practical applications.

Study on Continuous Nearest Neighbor Query on Trajectory of Moving Objects (이동객체의 궤적에 대한 연속 최근접 질의에 관한 연구)

  • Jeong, Ji-Mun
    • 한국디지털정책학회:학술대회논문집
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    • 2005.06a
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    • pp.517-530
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    • 2005
  • Researches for NN(nearest neighbor) query which is often used in LBS system, have been worked. However, Conventional NN query processing techniques are usually meaningless in moving object management system for LBS since their results may be invalidated as soon as the query and data objects move. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet continuous trajectory nearest neighbor query processing. The proposed technique consists of Approximate CTNN technique which has quick response time, and Exact CTNN technique which makes it possible to search accurately nearest neighbor objects. Experimental results using GSTD datasets showed that the Exact CTNN technique has high accuracy, but has a little low performance for response time. They also showed that the Approximate CTNN technique has low accuracy comparing with the Exact CTNN, but has high response time.

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Study on Continuous Nearest Neighbor Query on Trajectory of Moving Objects (이동객체의 궤적에 대한 연속 최근접 질의에 관한 연구)

  • Chung, Ji-Moon
    • Journal of Digital Convergence
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    • v.3 no.1
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    • pp.149-163
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    • 2005
  • Researches for NN(nearest neighbor) query which is often used in LBS system, have been worked. However. Conventional NN query processing techniques are usually meaningless in moving object management system for LBS since their results may be invalidated as soon as the query and data objects move. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet continuous trajectory nearest neighbor query processing. The proposed technique consists of Approximate CTNN technique which has quick response time, and Exact CTNN technique which makes it possible to search accurately nearest neighbor objects. Experimental results using GSTD datasets shows that the Exact CTNN technique has high accuracy, but has a little low performance for response time. They also shows that the Approximate CTNN technique has low accuracy comparing with the Exact CTNN, but has high response time.

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