• Title/Summary/Keyword: Clustering Problem

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System identification of a super high-rise building via a stochastic subspace approach

  • Faravelli, Lucia;Ubertini, Filippo;Fuggini, Clemente
    • Smart Structures and Systems
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    • v.7 no.2
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    • pp.133-152
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    • 2011
  • System identification is a fundamental step towards the application of structural health monitoring and damage detection techniques. On this respect, the development of evolved identification strategies is a priority for obtaining reliable and repeatable baseline modal parameters of an undamaged structure to be adopted as references for future structural health assessments. The paper presents the identification of the modal parameters of the Guangzhou New Television Tower, China, using a data-driven stochastic subspace identification (SSI-data) approach complemented with an appropriate automatic mode selection strategy which proved to be successful in previous literature studies. This well-known approach is based on a clustering technique which is adopted to discriminate structural modes from spurious noise ones. The method is applied to the acceleration measurements made available within the task I of the ANCRiSST benchmark problem, which cover 24 hours of continuous monitoring of the structural response under ambient excitation. These records are then subdivided into a convenient number of data sets and the variability of modal parameter estimates with ambient temperature and mean wind velocity are pointed out. Both 10 minutes and 1 hour long records are considered for this purpose. A comparison with finite element model predictions is finally carried out, using the structural matrices provided within the benchmark, in order to check that all the structural modes contained in the considered frequency interval are effectively identified via SSI-data.

Designing a Distribution Network for Faster Delivery of Online Retailing : A Case Study in Bangkok, Thailand

  • Amchang, Chompoonut;Song, Sang-Hwa
    • The Journal of Industrial Distribution & Business
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    • v.9 no.5
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    • pp.25-35
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    • 2018
  • Purpose - The purpose of this paper is to partition a last-mile delivery network into zones and to determine locations of last mile delivery centers (LMDCs) in Bangkok, Thailand. Research design, data, and methodology - As online shopping has become popular, parcel companies need to improve their delivery services as fast as possible. A network partition has been applied to evaluate suitable service areas by using METIS algorithm to solve this scenario and a facility location problem is used to address LMDC in a partitioned area. Research design, data, and methodology - Clustering and mixed integer programming algorithms are applied to partition the network and to locate facilities in the network. Results - Network partition improves last mile delivery service. METIS algorithm divided the area into 25 partitions by minimizing the inter-network links. To serve short-haul deliveries, this paper located 96 LMDCs in compact partitioning to satisfy customer demands. Conclusions -The computational results from the case study showed that the proposed two-phase algorithm with network partitioning and facility location can efficiently design a last-mile delivery network. It improves parcel delivery services when sending parcels to customers and reduces the overall delivery time. It is expected that the proposed two-phase approach can help parcel delivery companies minimize investment while providing faster delivery services.

A New Forest Fire Detection Algorithm using Outlier Detection Method on Regression Analysis between Surface temperature and NDVI

  • Huh, Yong;Byun, Young-Gi;Son, Jeong-Hoon;Yu, Ki-Yun;Kim, Yong-Il
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.574-577
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    • 2006
  • In this paper, we developed a forest fire detection algorithm which uses a regression function between NDVI and land surface temperature. Previous detection algorithms use the land surface temperature as a main factor to discriminate fire pixels from non-fire pixels. These algorithms assume that the surface temperatures of non-fire pixels are intrinsically analogous and obey Gaussian normal distribution, regardless of land surface types and conditions. And the temperature thresholds for detecting fire pixels are derived from the statistical distribution of non-fire pixels’ temperature using heuristic methods. This assumption makes the temperature distribution of non-fire pixels very diverse and sometimes slightly overlapped with that of fire pixel. So, sometimes there occur omission errors in the cases of small fires. To ease such problem somewhat, we separated non-fire pixels into each land cover type by clustering algorithm and calculated the residuals between the temperature of a pixel under examination whether fire pixel or not and estimated temperature of the pixel using the linear regression between surface temperature and NDVI. As a result, this algorithm could modify the temperature threshold considering land types and conditions and showed improved detection accuracy.

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An Energy-Efficient Clustering Algorithm consider Minimum-hop in Hierarchical Sensor Network (계층구조 센서 네트워크에서 Minimun-hop 을 고려한 클러스터 구성 알고리즘)

  • Kim, Yong;Lee, Doo-Wan;Jang, Kyung-Sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.510-513
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    • 2010
  • In hierarchical wireless sensor network, Sensor nodes forming a cluster with a hierarchy. And there are being study for balanced energy consumption between cluster nodes. When forming network routing path, if there are configured incorrectly then it can be wasting energy. In this paper to solve these problem, We propose that it can consider sensor's communication range to create minimum hop layer when cluster heads configure routing path.

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Data Mining for High Dimensional Data in Drug Discovery and Development

  • Lee, Kwan R.;Park, Daniel C.;Lin, Xiwu;Eslava, Sergio
    • Genomics & Informatics
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    • v.1 no.2
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    • pp.65-74
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    • 2003
  • Data mining differs primarily from traditional data analysis on an important dimension, namely the scale of the data. That is the reason why not only statistical but also computer science principles are needed to extract information from large data sets. In this paper we briefly review data mining, its characteristics, typical data mining algorithms, and potential and ongoing applications of data mining at biopharmaceutical industries. The distinguishing characteristics of data mining lie in its understandability, scalability, its problem driven nature, and its analysis of retrospective or observational data in contrast to experimentally designed data. At a high level one can identify three types of problems for which data mining is useful: description, prediction and search. Brief review of data mining algorithms include decision trees and rules, nonlinear classification methods, memory-based methods, model-based clustering, and graphical dependency models. Application areas covered are discovery compound libraries, clinical trial and disease management data, genomics and proteomics, structural databases for candidate drug compounds, and other applications of pharmaceutical relevance.

Evolutionary Nonlinear Regression Based Compensation Technique for Short-range Prediction of Wind Speed using Automatic Weather Station (AWS 지점별 기상데이타를 이용한 진화적 회귀분석 기반의 단기 풍속 예보 보정 기법)

  • Hyeon, Byeongyong;Lee, Yonghee;Seo, Kisung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.1
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    • pp.107-112
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    • 2015
  • This paper introduces an evolutionary nonlinear regression based compensation technique for the short-range prediction of wind speed using AWS(Automatic Weather Station) data. Development of an efficient MOS(Model Output Statistics) is necessary to correct systematic errors of the model, but a linear regression based MOS is hard to manage an irregular nature of weather prediction. In order to solve the problem, a nonlinear and symbolic regression method using GP(Genetic Programming) is suggested for a development of MOS wind forecast guidance. Also FCM(Fuzzy C-Means) clustering is adopted to mitigate bias of wind speed data. The purpose of this study is to evaluate the accuracy of the estimation by a GP based nonlinear MOS for 3 days prediction of wind speed in South Korean regions. This method is then compared to the UM model and has shown superior results. Data for 2007-2009, 2011 is used for training, and 2012 is used for testing.

On the Recognition of the Occluded Objects Using Matching Probability (정합확률을 이용한 겹쳐진 물체의 인식에 대하여)

  • Nam, Ki-Gon;lee, Soo-Dong;Lee, Ryang-Sung
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.1
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    • pp.20-28
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    • 1989
  • The recognition of partially occluded objects is of prime importance for industrial machine vision applications and to solve real provlems in factory automation. This paper describes a method tc solve the problem of occlusion in a two dimensional scene. The technique consists of three steps: searching of border, extracting of line segments and clustering of hypotheses by matching probability. Computer simulation results have been tested for 20 scenes contained the 80 models, and have obtained 95% of properly correct recognition rate on the average.

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Efficient Energy and Position Aware Routing Protocol for Wireless Sensor Networks

  • Shivalingagowda, Chaya;Jayasree, P.V.Y;Sah, Dinesh.K.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.5
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    • pp.1929-1950
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    • 2020
  • Reliable and secure data transmission in the application environment assisted by the wireless sensor network is one of the major challenges. Problem like blind forwarding and data inaccessibility affect the efficiency of overall infrastructure performance. This paper proposes routing protocol for forwarding and error recovery during packet loss. The same is achieved by energy and hops distance-based formulation of the routing mechanism. The reachability of the intermediate node to the source node is the major factor that helps in improving the lifetime of the network. On the other hand, intelligent hop selection increases the reliability over continuous data transmission. The number of hop count is factor of hop weight and available energy of the node. The comparison over the previous state of the art using QualNet-7.4 network simulator shows the effectiveness of proposed work in terms of overall energy conservation of network and reliable data delivery. The simulation results also show the elimination of blind forwarding and data inaccessibility.

Obesity and Metabolic Syndrome in Adults with Prader-Willi Syndrome

  • Kim, Su Jin
    • Journal of mucopolysaccharidosis and rare diseases
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    • v.1 no.2
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    • pp.44-48
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    • 2015
  • Body fat distribution in patients with Prader-Willi syndrome (PWS) is characterized by reduce lean body mass (LBM), increased total body fat mass (FM), and lower percentage of visceral adipose tissue (VAT). Individuals with PWS seem to have a lower risk for insulin resistance with high levels of adiponectin, an anti-atherogenic adipocytokine that is decreased in visceral fat hypertrophy subjects compared to simple obese subjects, both in children and in adults. The mechanism of the reduction in visceral adiposity in PWS is still unclear. It might be related to qualitative intrinsic characteristics of adipocyte or novel genetic influences on the control of fat distribution. However, obesity remains a critical problem, and obesity status plays a crucial role in individual metabolic risk clustering and development of metabolic syndrome (Mets) in PWS children and adults. Long-term growth hormone (GH) treatment after cessation of skeletal growth improved body composition, with an increase in lean body mass and a reduction in total body fat and subcutaneous and visceral fat in PWS adults. Thus, the role of GH is important after childhood because it might attenuate obesity and Mets in PWS adult by adipocyte modification.

Acoustic Model Improvement and Performance Evaluation of the Variable Vocabulary Speech Recognition System (가변 어휘 음성 인식기의 음향모델 개선 및 성능분석)

  • 이승훈;김회린
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.8
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    • pp.3-8
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    • 1999
  • Previous variable vocabulary speech recognition systems with context-independent acoustic modeling, could not represent the effect of neighboring phonemes. To solve this problem, we use allophone-based context-dependent acoustic model. This paper describes the method to improve acoustic model of the system effectively. Acoustic model is improved by using allophone clustering technique that uses entropy as a similarity measure and the optimal allophone model is generated by changing the number of allophones. We evaluate performance of the improved system by using Phonetically Optimized Words(POW) DB and PC commands(PC) DB. As a result, the allophone model composed of six hundreds allophones improved the recognition rate by 13% from the original context independent model m POW test DB.

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