• Title/Summary/Keyword: k-means algorithms

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3D Non-local Means(NLM) Algorithm Based on Stochastic Distance for Low-dose X-ray Fluoroscopy Denoising (저선량 X-ray 영상의 잡음 제거를 위한 확률 거리 기반 3차원 비지역적 평균 알고리즘)

  • Lee, Min Seok;Kang, Moon Gi
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.4
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    • pp.61-67
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    • 2017
  • Low-dose X-ray fluoroscopic image sequences to avoid radiation exposure risk are contaminated by quantum noise. To restore these noisy sequences, we propose a 3D nonlocal means (NLM) filter based on stochastic distancesed can be applied to the denoising of X-ray fluoroscopic image sequences. The stochastic distance is obtained within motion-compensated noise filtering support to remove the Poisson noise. In this paper, motion-adaptive weight which reflected the frame similarity is proposed to restore the noisy sequences without motion artifact. Experimental results including comparisons with conventional algorithms for real X-ray fluoroscopic image sequences show the proposed algorithm has a good performance in both visual and quantitative criteria.

Effective Image Segmentation using a Locally Weighted Fuzzy C-Means Clustering (지역 가중치 적용 퍼지 클러스터링을 이용한 효과적인 이미지 분할)

  • Alamgir, Nyma;Kim, Jong-Myon
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.12
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    • pp.83-93
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    • 2012
  • This paper proposes an image segmentation framework that modifies the objective function of Fuzzy C-Means (FCM) to improve the performance and computational efficiency of the conventional FCM-based image segmentation. The proposed image segmentation framework includes a locally weighted fuzzy c-means (LWFCM) algorithm that takes into account the influence of neighboring pixels on the center pixel by assigning weights to the neighbors. Distance between a center pixel and a neighboring pixels are calculated within a window and these are basis for determining weights to indicate the importance of the memberships as well as to improve the clustering performance. We analyzed the segmentation performance of the proposed method by utilizing four eminent cluster validity functions such as partition coefficient ($V_{pc}$), partition entropy ($V_{pe}$), Xie-Bdni function ($V_{xb}$) and Fukuyama-Sugeno function ($V_{fs}$). Experimental results show that the proposed LWFCM outperforms other FCM algorithms (FCM, modified FCM, and spatial FCM, FCM with locally weighted information, fast generation FCM) in the cluster validity functions as well as both compactness and separation.

Routing Algorithm with Adaptive Weight Function based on Possible Available Wavelength in Optical WDM Networks

  • Pavarangkoon, Praphan;Thipchaksurat, Sakchai;Varakulsiripunth, Ruttikorn
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1338-1341
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    • 2004
  • In this paper, we have proposed a new approach of routing and wavelength assignment algorithms, called Possible Available Wavelength (PAW) algorithm. The weight of a link is used as the main factor for routing decision in PAW algorithm. The weight of a link is defined as a function of hop count and available wavelengths. This function includes a determination factor of the number of wavelengths that are being used currently and are supposed to be available after a certain time. The session requests from users will be routed on the links that has the greatest number of link weight by using Dijkstra's shortest path algorithm. This means that the selected lightpath will has the least hop count and the greatest number of possible available wavelengths. The impact of proposed link weight computing function on the blocking probability and link utilization is investigated by means of computer simulation and comparing with the traditional mechanism. The results show that the proposed PAW algorithm can achieve the better performance in terms of the blocking probability and link utilization.

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A New Architecture of Genetically Optimized Self-Organizing Fuzzy Polynomial Neural Networks by Means of Information Granulation

  • Park, Ho-Sung;Oh, Sung-Kwun;Ahn, Tae-Chon
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1505-1509
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    • 2005
  • This paper introduces a new architecture of genetically optimized self-organizing fuzzy polynomial neural networks by means of information granulation. The conventional SOFPNNs developed so far are based on mechanisms of self-organization and evolutionary optimization. The augmented genetically optimized SOFPNN using Information Granulation (namely IG_gSOFPNN) results in a structurally and parametrically optimized model and comes with a higher level of flexibility in comparison to the one we encounter in the conventional FPNN. With the aid of the information granulation, we determine the initial location (apexes) of membership functions and initial values of polynomial function being used in the premised and consequence part of the fuzzy rules respectively. The GA-based design procedure being applied at each layer of genetically optimized self-organizing fuzzy polynomial neural networks leads to the selection of preferred nodes with specific local characteristics (such as the number of input variables, the order of the polynomial, a collection of the specific subset of input variables, and the number of membership function) available within the network. To evaluate the performance of the IG_gSOFPNN, the model is experimented with using gas furnace process data. A comparative analysis shows that the proposed IG_gSOFPNN is model with higher accuracy as well as more superb predictive capability than intelligent models presented previously.

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A Method for Hybrid Message Transmission based on User-Customized Analysis (사용자 맞춤형 분석 기반의 Hybrid 메시지 전송 기법)

  • Kim, Yong-Hyun;Bong, Jae-Sic;Huh, Eui-Nam
    • Journal of KIISE
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    • v.42 no.7
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    • pp.939-945
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    • 2015
  • From 2009, the market of smart devices has been rapidly increasing. These devices provide various services to users. The cloud messaging service, especially, is applied to many various services, and sends messages asynchronously. In the cloud messaging service, there are two methods for message transmission, message transmission based on an IP address and a publish/subscribe technique. Each technique uses basic messages in order to send messages to mobile devices. In this paper, the hybrid message transmission, based on user-customized analysis to reduce basic messages, is proposed. The hybrid message transmission uses Exponential Moving Average (EMA) and K-means algorithms for user-customized analysis, and determines the message transmission techniques in each timeslot.

Two-phase Machine-Part Group Formation Algorithm Based on Self-Organizing Maps (자기조직화 신경망에 근거한 2단계 기계-부품 그룹형성 알고리듬)

  • Lee, Jong-Sub;Jeon, Yong-Deok;Kang, Maing-Kyu
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.4
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    • pp.360-367
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    • 2002
  • The machine-part group formation is to group the sets of parts having similar processing requirements into part families, and the sets of machines needed to process a particular part family into machine cells. The purpose of this study is to develop a two-phase machine-part group formation algorithm based on Self-Organizing Maps (SOM). In phase I, it forms machine cells from the machine-part incidence matrix by means of SOM whose output layer is one-dimension and the number of output nodes is the twice as many as the number of input nodes in order to spread out the input vectors. In phase II, it generates part families which are assigned to machine cells by means of machine ratio related with processing part and it gives machine-part group formation. The proposed algorithm performs remarkably well in comparison with many well-known algorithms for the machine-part group formation problems.

Self-Identification of Boundary's Nodes in Wireless Sensor Networks

  • Moustafa, Kouider Elouahed;Hafid, Haffaf
    • Journal of Information Processing Systems
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    • v.13 no.1
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    • pp.128-140
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    • 2017
  • The wireless sensor networks (WSNs) became a very essential tool in borders and military zones surveillance, for this reason specific applications have been developed. Surveillance is usually accomplished through the deployment of nodes in a random way providing heterogeneous topologies. However, the process of the identification of all nodes located on the network's outer edge is very long and energy-consuming. Before any other activities on such sensitive networks, we have to identify the border nodes by means of specific algorithms. In this paper, a solution is proposed to solve the problem of energy and time consumption in detecting border nodes by means of node selection. This mechanism is designed with several starter nodes in order to reduce time, number of exchanged packets and then, energy consumption. This method consists of three phases: the first one is to detect triggers which serve to start the mechanism of boundary nodes (BNs) detection, the second is to detect the whole border, and the third is to exclude each BN from the routing tables of all its neighbors so that it cannot be used for the routing.

A Study of Similarity Measure Algorithms for Recomendation System about the PET Food (반려동물 사료 추천시스템을 위한 유사성 측정 알고리즘에 대한 연구)

  • Kim, Sam-Taek
    • Journal of the Korea Convergence Society
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    • v.10 no.11
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    • pp.159-164
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    • 2019
  • Recent developments in ICT technology have increased interest in the care and health of pets such as dogs and cats. In this paper, cluster analysis was performed based on the component data of pet food to be used in various fields of the pet industry. For cluster analysis, the similarity was analyzed by analyzing the correlation between components of 300 dogs and cats in the market. In this paper, clustering techniques such as Hierarchical, K-Means, Partitioning around medoids (PAM), Density-based, Mean-Shift are clustered and analyzed. We also propose a personalized recommendation system for pets. The results of this paper can be used for personalized services such as feed recommendation system for pets.

A Study on Cluster Hierarchy Depth in Hierarchical Clustering (계층적 클러스터링에서 분류 계층 깊이에 관한 연구)

  • Jin, Hai-Nan;Lee, Shin-won;An, Dong-Un;Chung, Sung-Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2004.05a
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    • pp.673-676
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    • 2004
  • Fast and high-quality document clustering algorithms play an important role in providing data exploration by organizing large amounts of information into a small number of meaningful clusters. In particular, hierarchical clustering provide a view of the data at different levels, making the large document collections are adapted to people's instinctive and interested requires. Many papers have shown that the hierarchical clustering method takes good-performance, but is limited because of its quadratic time complexity. In contrast, K-means has a time complexity that is linear in the number of documents, but is thought to produce inferior clusters. Think of the factor of simpleness, high-quality and high-efficiency, we combine the two approaches providing a new system named CONDOR system [10] with hierarchical structure based on document clustering using K-means algorithm to "get the best of both worlds". The performance of CONDOR system is compared with the VIVISIMO hierarchical clustering system [9], and performance is analyzed on feature words selection of specific topics and the optimum hierarchy depth.

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Fiscal Policy Effectiveness Assessment Based on Cluster Analysis of Regions

  • Martynenko, Valentyna;Kovalenko, Yuliia;Chunytska, Iryna;Paliukh, Oleksandr;Skoryk, Maryna;Plets, Ivan
    • International Journal of Computer Science & Network Security
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    • v.22 no.7
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    • pp.75-84
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    • 2022
  • The efficiency of the regional fiscal policy implementation is based on the achievement of target criteria in the formation and distribution of own financial resources of local budgets, reducing their deficit and reducing dependence on transfers. It is also relevant to compare the development of financial autonomy of regions in the course of decentralisation of fiscal relations. The study consists in the cluster analysis of the effectiveness of fiscal policy implementation in the context of 24 regions and the capital city of Kyiv (except for temporarily occupied territories) under conditions of fiscal decentralisation. Clustering of the regions of Ukraine by 18 indicators of fiscal policy implementation efficiency was carried out using Ward's minimum variance method and k-means clustering algorithm. As a result, the regions of Ukraine are grouped into 5 homogeneous clusters. For each cluster measures were developed to increase own revenues and minimize dependence on official transfers to increase the level of financial autonomy of the regions. It has been proved that clustering algorithms are an effective tool in assessing the effectiveness of fiscal policy implementation at the regional level and stimulating further expansion of financial decentralisation of regions.