• Title/Summary/Keyword: image clustering

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Human Visual Perception-Based Quantization For Efficiency HEVC Encoder (HEVC 부호화기 고효율 압축을 위한 인지시각 특징기반 양자화 방법)

  • Kim, Young-Woong;Ahn, Yong-Jo;Sim, Donggyu
    • Journal of Broadcast Engineering
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    • v.22 no.1
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    • pp.28-41
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    • 2017
  • In this paper, the fast encoding algorithm in High Efficiency Video Coding (HEVC) encoder was studied. For the encoding efficiency, the current HEVC reference software is divided the input image into Coding Tree Unit (CTU). then, it should be re-divided into CU up to maximum depth in form of quad-tree for RDO (Rate-Distortion Optimization) in encoding precess. But, it is one of the reason why complexity is high in the encoding precess. In this paper, to reduce the high complexity in the encoding process, it proposed the method by determining the maximum depth of the CU using a hierarchical clustering at the pre-processing. The hierarchical clustering results represented an average combination of motion vectors (MV) on neighboring blocks. Experimental results showed that the proposed method could achieve an average of 16% time saving with minimal BD-rate loss at 1080p video resolution. When combined the previous fast algorithm, the proposed method could achieve an average 45.13% time saving with 1.84% BD-rate loss.

Field and remote acquisition of hyperspectral information for classification of riverside area materials (현장 및 원격 초분광 정보 계측을 통한 하천 수변공간 재료 구분)

  • Shin, Jaehyun;Seong, Hoje;Rhee, Dong Sop
    • Journal of Korea Water Resources Association
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    • v.54 no.12
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    • pp.1265-1274
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    • 2021
  • The analysis of hyperspectral characteristics of materials near the South Han River has been conducted using riverside area measurements by drone installed hyperspectral sensors. Each spectrum reflectance of the riverside materials were compared and analyzed which were consisted of grass, concrete, soil, etc. To verify the drone installed hyperspectral measurements, a ground spectrometer was deployed for field measurements and comparisons for the materials. The comparison results showed that the riverside materials had their unique hyperspectral band characteristics, and the field measurements were similar to the remote sensing data. For the classification of the riverside area, the K-means clustering method and SVM classification method were utilized. The supervised SVM method showed accurate classification of the riverside area than the unsupervised K-means method. Using classification and clustering methods, the inherent spectral characteristic for each material was found to classify the riverside materials of hyperspectral images from drones.

A Methodology of Customer Churn Prediction based on Two-Dimensional Loyalty Segmentation (이차원 고객충성도 세그먼트 기반의 고객이탈예측 방법론)

  • Kim, Hyung Su;Hong, Seung Woo
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.111-126
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    • 2020
  • Most industries have recently become aware of the importance of customer lifetime value as they are exposed to a competitive environment. As a result, preventing customers from churn is becoming a more important business issue than securing new customers. This is because maintaining churn customers is far more economical than securing new customers, and in fact, the acquisition cost of new customers is known to be five to six times higher than the maintenance cost of churn customers. Also, Companies that effectively prevent customer churn and improve customer retention rates are known to have a positive effect on not only increasing the company's profitability but also improving its brand image by improving customer satisfaction. Predicting customer churn, which had been conducted as a sub-research area for CRM, has recently become more important as a big data-based performance marketing theme due to the development of business machine learning technology. Until now, research on customer churn prediction has been carried out actively in such sectors as the mobile telecommunication industry, the financial industry, the distribution industry, and the game industry, which are highly competitive and urgent to manage churn. In addition, These churn prediction studies were focused on improving the performance of the churn prediction model itself, such as simply comparing the performance of various models, exploring features that are effective in forecasting departures, or developing new ensemble techniques, and were limited in terms of practical utilization because most studies considered the entire customer group as a group and developed a predictive model. As such, the main purpose of the existing related research was to improve the performance of the predictive model itself, and there was a relatively lack of research to improve the overall customer churn prediction process. In fact, customers in the business have different behavior characteristics due to heterogeneous transaction patterns, and the resulting churn rate is different, so it is unreasonable to assume the entire customer as a single customer group. Therefore, it is desirable to segment customers according to customer classification criteria, such as loyalty, and to operate an appropriate churn prediction model individually, in order to carry out effective customer churn predictions in heterogeneous industries. Of course, in some studies, there are studies in which customers are subdivided using clustering techniques and applied a churn prediction model for individual customer groups. Although this process of predicting churn can produce better predictions than a single predict model for the entire customer population, there is still room for improvement in that clustering is a mechanical, exploratory grouping technique that calculates distances based on inputs and does not reflect the strategic intent of an entity such as loyalties. This study proposes a segment-based customer departure prediction process (CCP/2DL: Customer Churn Prediction based on Two-Dimensional Loyalty segmentation) based on two-dimensional customer loyalty, assuming that successful customer churn management can be better done through improvements in the overall process than through the performance of the model itself. CCP/2DL is a series of churn prediction processes that segment two-way, quantitative and qualitative loyalty-based customer, conduct secondary grouping of customer segments according to churn patterns, and then independently apply heterogeneous churn prediction models for each churn pattern group. Performance comparisons were performed with the most commonly applied the General churn prediction process and the Clustering-based churn prediction process to assess the relative excellence of the proposed churn prediction process. The General churn prediction process used in this study refers to the process of predicting a single group of customers simply intended to be predicted as a machine learning model, using the most commonly used churn predicting method. And the Clustering-based churn prediction process is a method of first using clustering techniques to segment customers and implement a churn prediction model for each individual group. In cooperation with a global NGO, the proposed CCP/2DL performance showed better performance than other methodologies for predicting churn. This churn prediction process is not only effective in predicting churn, but can also be a strategic basis for obtaining a variety of customer observations and carrying out other related performance marketing activities.

Centroid Neural Network with Bhattacharyya Kernel (Bhattacharyya 커널을 적용한 Centroid Neural Network)

  • Lee, Song-Jae;Park, Dong-Chul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.9C
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    • pp.861-866
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    • 2007
  • A clustering algorithm for Gaussian Probability Distribution Function (GPDF) data called Centroid Neural Network with a Bhattacharyya Kernel (BK-CNN) is proposed in this paper. The proposed BK-CNN is based on the unsupervised competitive Centroid Neural Network (CNN) and employs a kernel method for data projection. The kernel method adopted in the proposed BK-CNN is used to project data from the low dimensional input feature space into higher dimensional feature space so as the nonlinear problems associated with input space can be solved linearly in the feature space. In order to cluster the GPDF data, the Bhattacharyya kernel is used to measure the distance between two probability distributions for data projection. With the incorporation of the kernel method, the proposed BK-CNN is capable of dealing with nonlinear separation boundaries and can successfully allocate more code vector in the region that GPDF data are densely distributed. When applied to GPDF data in an image classification probleml, the experiment results show that the proposed BK-CNN algorithm gives 1.7%-4.3% improvements in average classification accuracy over other conventional algorithm such as k-means, Self-Organizing Map (SOM) and CNN algorithms with a Bhattacharyya distance, classed as Bk-Means, B-SOM, B-CNN algorithms.

Cluster Cell Separation Algorithm for Automated Cell Tracking (자동 세포 추적을 위한 클러스터 세포 분리 알고리즘)

  • Cho, Mi Gyung;Shim, Jaesool
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.3
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    • pp.259-266
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    • 2013
  • An automated cell tracking system is used to automatically analyze and track the changes in cell behavior in time-lapse cell images acquired using a microscope with a cell culture. Clustering is the partial overlapping of neighboring cells in the process of cell change. Separating clusters into individual cells is very important for cell tracking. In this study, we proposed an algorithm for separating clusters by using ellipse fitting based on a direct least square method. We extracted the contours of clusters, divided them into line segments, and then produced their fitted ellipses using a direct least square method for each line segment. All of the fitted ellipses could be used to separate their corresponding clusters. In experiments, our algorithm separated clusters with average precisions of 91% for two overlapping cells, 84% for three overlapping cells, and about 73% for four overlapping cells.

Contrast Enhancement based on Gaussian Region Segmentation (가우시안 영역 분리 기반 명암 대비 향상)

  • Shim, Woosung
    • Journal of Broadcast Engineering
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    • v.22 no.5
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    • pp.608-617
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    • 2017
  • Methods of contrast enhancement have problem such as side effect of over-enhancement with non-gaussian histogram distribution, tradeoff enhancement efficiency against brightness preserving. In order to enhance contrast at various histogram distribution, segmentation to region with gaussian distribution and then enhance contrast each region. First, we segment an image into several regions using GMM(Gaussian Mixture Model)fitting by that k-mean clustering and EM(Expectation-Maximization) in $L^*a^*b^*$ color space. As a result region segmentation, we get the region map and probability map. Then we apply local contrast enhancement algorithm that mean shift to minimum overlapping of each region and preserve brightness histogram equalization. Experiment result show that proposed region based contrast enhancement method compare to the conventional method as AMBE(AbsoluteMean Brightness Error) and AE(Average Entropy), brightness is maintained and represented detail information.

Preference Differences in Interior Images of Restaurants according to Lifestyles (라이프스타일 유형에 따른 레스토랑 실내이미지 선호도 차이에 관한 연구)

  • Kim, Tae-Hee;Park, Young-Seok
    • Journal of the Korean Home Economics Association
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    • v.43 no.10 s.212
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    • pp.69-79
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    • 2005
  • The purpose of this study was to determine restaurant patrons' preference differences in interior design style of restaurants according to their lifestyles. Written questionnaires were handed out to 500 adults in Seoul and surroundings and the results were sampled by convenience sampling. The questionnaire was composed of respondents' general characteristics, lifestyles, and preference for 10 types of interior design style. A total of 415 questionnaires were usable for data analysis, resulting in a response rate of $83\%$. To analyze the collected data, frequency, factor, reliability, quick clustering K- means and One-Way ANOVA analysis were conducted using SPSS 10.0. The results showed that there were preference differences in 10 types of interior design style of restaurants according to lifestyle types which were categorized into 4 groups. The conservative and self-convinced group showed the lowest preference scores in the 10 types of interior design style which are Romantic, Ethnic, Classic, High-Tech, Elegant, Country, Modem, Minimal, Natural, and Casual style. The quality life pursuing group and extroverted individuality groups showed the high preference scores in most of the styles, especially in the Classic and Elegant styles. The realistic self-centered group showed the highest preference scores in Casual style among the 4 groups. These study findings indicate that restaurants should take into account their patrons' lifestyles as a mean of market segmentation, and respond to their taste and preference when they have established suitable servicescape.

Genome Wide Expression Analysis of the Effect of Woowhangchongshim-won on Rat Brain Injury

  • Kim, Bu-Yeo;Lim, Se-Hyun;Kim, Hyun-Young;Kim, Young-Kyun;Lim, Chi-Yeon;Cho, Su-In
    • The Journal of Internal Korean Medicine
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    • v.30 no.3
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    • pp.594-603
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    • 2009
  • Objectives : ICH breaks down blood vessels within the brain parenchyma, which finally leads to neuronal loss, drugs to treat ICH have not yet been established. In this experiment, we measured the effect of Woowhangchongshim-won (WWCSW) on intracerebral hemorrhage (ICH) in rat using microarray technology. Methods : We measured the effect of WWCSW on ICH in rat using microarray technology. ICH was induced by injection of collagenase type IV, and total RNA was isolated. Image files of microarray were measured using a ScanArray scanner, and the criteria of the threshold for up- and down-regulation was 2 fold. Hierarchical clustering was implemented using CLUSTER and TREEVIEW program, and for Ontology analysis. GOSTAT program was applied in which p-value was calculated by Chi square or Fisher's exact test based on the total array element. Results : WWCSW-treatment restored the gene expression altered by ICH-induction in brain to the levels of 76.0% and 70.1% for up- and down-regulated genes, respectively. Conclusion : Co-regulated genes by ICH model of rat could be used as molecular targets for therapeutic effects of drug including WWCSW. That is, the presence of co-regulated genes may represent the importance of these genes in ICH in the brain and the change of expression level of these co-regulated genes would also indicate the functional change of brain tissue.

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Advanced Freeway Traffic Safety Warning Information System based on Surrogate Safety Measures (SSM): Information Processing Methods (Surrogate Safety Measures(SSM)기반 고속도로 교통안전 경고정보 처리 및 가공기법)

  • O, Cheol;O, Ju-Taek;Song, Tae-Jin;Park, Jae-Hong;Kim, Tae-Jin
    • Journal of Korean Society of Transportation
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    • v.27 no.3
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    • pp.59-70
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    • 2009
  • This study presents a novel traffic information system which is capable of detecting unsafe traffic events leading to accident occurrence and providing warning information to drivers for safer driving. Unsafe traffic events are captured by a vehicle image processing-based detection system in real time. Surrogate safety measures (SSM) representing quantitative accident potentials were derived, and further utilized to develop a data processing algorithm and analysis techniques in the proposed system. This study also defined 'emergency warning area' and 'general warning area' for more effective provision of warning information. In addition, methodologies for determining thresholds to trigger warning information were presented. Technical issues and further studies to fully exploit the benefits of the proposed system were discussed. It is expected that the proposed system would be effective for better management of traffic flow to prevent traffic accidents on freeways.

Extraction of paddy field in Jaeryeong, North Korea by object-oriented classification with RapidEye NDVI imagery (RapidEye 위성영상의 시계열 NDVI 및 객체기반 분류를 이용한 북한 재령군의 논벼 재배지역 추출 기법 연구)

  • Lee, Sang-Hyun;Oh, Yun-Gyeong;Park, Na-Young;Lee, Sung Hack;Choi, Jin-Yong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.3
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    • pp.55-64
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    • 2014
  • While utilizing high resolution satellite image for land use classification has been popularized, object-oriented classification has been adapted as an affordable classification method rather than conventional statistical classification. The aim of this study is to extract the paddy field area using object-oriented classification with time series NDVI from high-resolution satellite images, and the RapidEye satellite images of Jaeryung-gun in North Korea were used. For the implementation of object-oriented classification, creating objects by setting of scale and color factors was conducted, then 3 different land use categories including paddy field, forest and water bodies were extracted from the objects applying the variation of time-series NDVI. The unclassified objects which were not involved into the previous extraction classified into 6 categories using unsupervised classification by clustering analysis. Finally, the unsuitable paddy field area were assorted from the topographic factors such as elevation and slope. As the results, about 33.6 % of the total area (32313.1 ha) were classified to the paddy field (10847.9 ha) and 851.0 ha was classified to the unsuitable paddy field based on the topographic factors. The user accuracy of paddy field classification was calculated to 83.3 %, and among those, about 60.0 % of total paddy fields were classified from the time-series NDVI before the unsupervised classification. Other land covers were classified as to upland(5255.2 ha), forest (10961.0 ha), residential area and bare land (3309.6 ha), and lake and river (1784.4 ha) from this object-oriented classification.