• Title/Summary/Keyword: Recursive Method

Search Result 745, Processing Time 0.027 seconds

Combining Support Vector Machine Recursive Feature Elimination and Intensity-dependent Normalization for Gene Selection in RNAseq (RNAseq 빅데이터에서 유전자 선택을 위한 밀집도-의존 정규화 기반의 서포트-벡터 머신 병합법)

  • Kim, Chayoung
    • Journal of Internet Computing and Services
    • /
    • v.18 no.5
    • /
    • pp.47-53
    • /
    • 2017
  • In past few years, high-throughput sequencing, big-data generation, cloud computing, and computational biology are revolutionary. RNA sequencing is emerging as an attractive alternative to DNA microarrays. And the methods for constructing Gene Regulatory Network (GRN) from RNA-Seq are extremely lacking and urgently required. Because GRN has obtained substantial observation from genomics and bioinformatics, an elementary requirement of the GRN has been to maximize distinguishable genes. Despite of RNA sequencing techniques to generate a big amount of data, there are few computational methods to exploit the huge amount of the big data. Therefore, we have suggested a novel gene selection algorithm combining Support Vector Machines and Intensity-dependent normalization, which uses log differential expression ratio in RNAseq. It is an extended variation of support vector machine recursive feature elimination (SVM-RFE) algorithm. This algorithm accomplishes minimum relevancy with subsets of Big-Data, such as NCBI-GEO. The proposed algorithm was compared to the existing one which uses gene expression profiling DNA microarrays. It finds that the proposed algorithm have provided as convenient and quick method than previous because it uses all functions in R package and have more improvement with regard to the classification accuracy based on gene ontology and time consuming in terms of Big-Data. The comparison was performed based on the number of genes selected in RNAseq Big-Data.

Template Fusion for Fingerprint Recognition (지문 등록을 위한 템플릿 융합 알고리즘)

  • 류춘우;문지현;김학일
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.41 no.2
    • /
    • pp.51-64
    • /
    • 2004
  • This paper proposes an algerian of generating a tuner-template from multiple fingerprint impressions using a data fusion technique for fingerprint enrollment. The super-template is considered as a single fingerprint template which contains most likely true minutiae based on multiple fingerprint images. The proposed algorithm creates the super template by utilizing a recursive Bayesian estimation method (RBEM), which assumes a sequential fingerprint input model and estimates the credibility of the minutiae in previous input templates froma current input template. Consequently. the RBEM assigns a higher credibility to commonly detectable minutiae from several input templates and a lower credibility to rarely found minutiae from other input templates. Likewise, the RBEM is able to estimate a credibility of the minutia type (ridge ending or bifurcation). Preliminary experiments demonstrate that, as the number of fingerfrint images increases, the performance of recognition can be improved while maintaining the processing time and the size of memory storage for tile super-template almost constant.

An Empirical Study on the long-term Relationship between House Prices and Inflation in the U.S. (주택가격과 물가의 장기관련성에 관한 실증연구 : 미국을 중심으로)

  • Lee, Young Soo
    • International Area Studies Review
    • /
    • v.14 no.3
    • /
    • pp.246-263
    • /
    • 2010
  • This study examines how the long-run relations between housing price and inflation in the United Sates have changed since the year of 2000. Johansen co-integration test, estimation of long-run equilibrium equation, and Granger causality tests are conducted, based on the VECM. Data covers the period from the first quarter of 1975 to the second quarter of 2010. I adopt the recursive estimation method in which the final period of the estimation is expanded by one quarter, starting from the first quarter of 2000. The empirical results are as follows: (1) In spite of the sharp increase of housing price, the long-run relationship of house prices and inflation has been remained stable until 2007, showing that house prices are a stable inflation hedge in the long run. (2) The housing price plunge since 1997 does not seem to be related to the restore of the long-run relationship between housing prices and inflation. (3) Granger causality test results support the hypothesis that inflation granger-causes housing prices with 10% significance level, but reject the hypothesis that housing price granger-causes inflation.

Accessing LSTM-based multi-step traffic prediction methods (LSTM 기반 멀티스텝 트래픽 예측 기법 평가)

  • Yeom, Sungwoong;Kim, Hyungtae;Kolekar, Shivani Sanjay;Kim, Kyungbaek
    • KNOM Review
    • /
    • v.24 no.2
    • /
    • pp.13-23
    • /
    • 2021
  • Recently, as networks become more complex due to the activation of IoT devices, research on long-term traffic prediction beyond short-term traffic prediction is being activated to predict and prepare for network congestion in advance. The recursive strategy, which reuses short-term traffic prediction results as an input, has been extended to multi-step traffic prediction, but as the steps progress, errors accumulate and cause deterioration in prediction performance. In this paper, an LSTM-based multi-step traffic prediction method using a multi-output strategy is introduced and its performance is evaluated. As a result of experiments based on actual DNS request traffic, it was confirmed that the proposed LSTM-based multiple output strategy technique can reduce MAPE of traffic prediction performance for non-stationary traffic by 6% than the recursive strategy technique.

Non-recursive Path Model Analysis on the Relationship between Perceived Safety Management Activities and Safety of Construction Sites (건설현장의 지각된 안전관리 활동과 안전성과의 관계에 대한 비재귀 경로모형분석)

  • Yong Hoon Kim
    • Journal of the Society of Disaster Information
    • /
    • v.18 no.4
    • /
    • pp.786-794
    • /
    • 2022
  • In construction sites, effective preventive safety management is required beyond post-processing safety management. Purpose: The purpose of this study is to present a model and analyze the relationship between safety management activities, safety culture key elements, safety, unsafe behavior management, and safety for autonomous and preventive safety management. Method: The relationship was analyzed by applying the survey data to the structural equation, and the path to safety outcomes from exogenous variables was explored and major issues were presented by interpreting the part suggested by the hypothesis verified by the analysis results. Result: As a result of analyzing the preliminary model and the path model, the appropriate model fit was confirmed, and the significant effect of exogenous variables on endogenous variables was confirmed. Conclusion: It is judged that it can contribute to continuously improving safety performance before safety accidents occur through safety management activities, safety and unsafe behavior management, and management of key elements of safety culture.

Speech Enhancement Based on Modified IMCRA Using Spectral Minima Tracking with Weighted Subband Selection (서브밴드 가중치를 적용한 스펙트럼 최소값 추적을 이용하는 수정된 IMCRA 기반의 음성 향상 기법)

  • Park, Yun-Sik;Park, Gyu-Seok;Lee, Sang-Min
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.49 no.3
    • /
    • pp.89-97
    • /
    • 2012
  • In this paper, we propose a novel approach to noise power estimation for speech enhancement in noisy environments. The method based on IMCRA (improved minima controlled recursive averaging) which is widely used in speech enhancement utilizes a rough VAD (voice activity detection) algorithm which excludes speech components during speech periods in order to improves the performance of the noise power estimation by reducing the speech distortion caused by the conventional algorithm based on the minimum power spectrum derived from the noisy speech. However, since the VAD algorithm is not sufficient to distinguish speech from noise at non-stationary noise and low SNRs (signal-to-noise ratios), the speech distortion resulted from the minimum tracking during speech periods still remained. In the proposed method, minimum power estimate obtained by IMCRA is modified by SMT (spectral minima tracking) to reduce the speech distortion derived from the bias of the estimated minimum power. In addition, in order to effectively estimate minimum power by considering the distribution characteristic of the speech and noise spectrum, the presented method combines the minimum estimates provided by IMCRA and SMT depending on the weighting factor based on the subband. Performance of the proposed algorithm is evaluated by subjective and objective quality tests under various environments and better results compared with the conventional method are obtained.

Performance Analysis of the Robust Least Squares Target Localization Scheme using RDOA Measurements

  • Choi, Ka-Hyung;Ra, Won-Sang;Park, Jin-Bae;Yoon, Tae-Sung
    • Journal of Electrical Engineering and Technology
    • /
    • v.7 no.4
    • /
    • pp.606-614
    • /
    • 2012
  • A practical recursive linear robust estimation scheme is proposed for target localization in the sensor network which provides range difference of arrival (RDOA) measurements. In order to radically solve the known practical difficulties such as sensitivity for initial guess and heavy computational burden caused by intrinsic nonlinearity of the RDOA based target localization problem, an uncertain linear measurement model is newly derived. In the suggested problem setting, the target localization performance of the conventional linear estimation schemes might be severely degraded under the low SNR condition and be affected by the target position in the sensor network. This motivates us to devise a new sensor network localization algorithm within the framework of the recently developed robust least squares estimation theory. Provided that the statistical information regarding RDOA measurements are available, the estimate of the proposition method shows the convergence in probability to the true target position. Through the computer simulations, the omnidirectional target localization performance and consistency of the proposed algorithm are compared to those of the existing ones. It is shown that the proposed method is more reliable than the total least squares method and the linear correction least squares method.

A study on the adaptive method of control model for tandem cold rolling mill (연속냉간압연기 제어모델의 적응수정방법에 관한 연구)

  • Lee, Won-Ho;Lee, Sang-Ryong
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.21 no.7
    • /
    • pp.1030-1041
    • /
    • 1997
  • The control model in the tandem cold rolling mill consists of many mathematical theories and is used to calculate the reference values such as the roll gap and the rolling speed for good operation of rolling mill. But, the control model used presently has a problem causing inaccurate prediction of the rolling force. By the parameter identification, it was found that the main factor causing inaccurate prediction of the rolling force was incorrect modeling of the friction coefficient and the flow stress. To get rid of the erroneous factor new adaptive schemes are suggested in this work. Those are a long-time adaptation by the iterative least-square method and a short-time adaptation by the recursive weighted least-square method respectively. The new equations for the friction coefficient and the flow stress are derived by applying the suggested adaptive algorithms. Through the on-line test in an actual mill, it is proved that the rolling force predicted by the new equations is more accurate than the one by the existing equations ever used.

An integrated particle swarm optimizer for optimization of truss structures with discrete variables

  • Mortazavi, Ali;Togan, Vedat;Nuhoglu, Ayhan
    • Structural Engineering and Mechanics
    • /
    • v.61 no.3
    • /
    • pp.359-370
    • /
    • 2017
  • This study presents a particle swarm optimization algorithm integrated with weighted particle concept and improved fly-back technique. The rationale behind this integration is to utilize the affirmative properties of these new terms to improve the search capability of the standard particle swarm optimizer. Improved fly-back technique introduced in this study can be a proper alternative for widely used penalty functions to handle existing constraints. This technique emphasizes the role of the weighted particle on escaping from trapping into local optimum(s) by utilizing a recursive procedure. On the other hand, it guaranties the feasibility of the final solution by rejecting infeasible solutions throughout the optimization process. Additionally, in contrast with penalty method, the improved fly-back technique does not contain any adjustable terms, thus it does not inflict any extra ad hoc parameters to the main optimizer algorithm. The improved fly-back approach, as independent unit, can easily be integrated with other optimizers to handle the constraints. Consequently, to evaluate the performance of the proposed method on solving the truss weight minimization problems with discrete variables, several benchmark examples taken from the technical literature are examined using the presented method. The results obtained are comparatively reported through proper graphs and tables. Based on the results acquired in this study, it can be stated that the proposed method (integrated particle swarm optimizer, iPSO) is competitive with other metaheuristic algorithms in solving this class of truss optimization problems.

Precision Position Control of PMSM using Neural Observer and Parameter Compensator

  • Ko, Jong-Sun;Seo, Young-Ger;Kim, Hyun-Sik
    • Journal of Power Electronics
    • /
    • v.8 no.4
    • /
    • pp.354-362
    • /
    • 2008
  • This paper presents neural load torque compensation method which is composed of a deadbeat load torque observer and gains compensation by a parameter estimator. As a result, the response of the PMSM (permanent magnet synchronous motor) obtains better precision position control. To reduce the noise effect, the post-filter is implemented by a MA (moving average) process. The parameter compensator with an RLSM (recursive least square method) parameter estimator is adopted to increase the performance of the load torque observer and main controller. The parameter estimator is combined with a high performance neural load torque observer to resolve problems. The neural network is trained in online phases and it is composed by a feed forward recall and error back-propagation training. During normal operation, the input-output response is sampled and the weighting value is trained multi-times by the error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. As a result, the proposed control system has a robust and precise system against load torque and parameter variation. Stability and usefulness are verified by computer simulation and experiment.