• 제목/요약/키워드: support parameters

검색결과 1,367건 처리시간 0.029초

Semisupervised support vector quantile regression

  • Seok, Kyungha
    • Journal of the Korean Data and Information Science Society
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    • 제26권2호
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    • pp.517-524
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    • 2015
  • Unlabeled examples are easier and less expensive to be obtained than labeled examples. In this paper semisupervised approach is used to utilize such examples in an effort to enhance the predictive performance of nonlinear quantile regression problems. We propose a semisupervised quantile regression method named semisupervised support vector quantile regression, which is based on support vector machine. A generalized approximate cross validation method is used to choose the hyper-parameters that affect the performance of estimator. The experimental results confirm the successful performance of the proposed S2SVQR.

모노파일 형식 해상풍력발전기 지지구조물의 손상추정기법 (Damage Estimation Method for Monopile Support Structure of Offshore Wind Turbine)

  • 김상렬;이종원;김봉기;이준신
    • 한국소음진동공학회논문집
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    • 제22권7호
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    • pp.667-675
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    • 2012
  • A damage estimation method for support structure of offshore wind turbine using modal parameters is presented for effective structural health monitoring. Natural frequencies and mode shapes for a support structure with monopile of an offshore wind turbine were calculated considering soil condition and added mass. A neural network was learned based on training patterns generated by the changes of natural frequency and mode shape due to various damages. Natural frequencies and mode shapes for 10 prospective damage cases were input to the trained neural network for damage estimation. The identified damage locations and severities agreed reasonably well with the accurate damages. Multi-damage cases could also be successfully estimated. Enhancement of estimation result using another parameters as input to neural network will be carried out by further study. Proposed method could be applied to other type of support structure of offshore wind turbine for structural health monitoring.

Real-time seismic structural response prediction system based on support vector machine

  • Lin, Kuang Yi;Lin, Tzu Kang;Lin, Yo
    • Earthquakes and Structures
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    • 제18권2호
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    • pp.163-170
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    • 2020
  • Floor acceleration plays a major role in the seismic design of nonstructural components and equipment supported by structures. Large floor acceleration may cause structural damage to or even collapse of buildings. For precision instruments in high-tech factories, even small floor accelerations can cause considerable damage in this study. Six P-wave parameters, namely the peak measurement of acceleration, peak measurement of velocity, peak measurement of displacement, effective predominant period, integral of squared velocity, and cumulative absolute velocity, were estimated from the first 3 s of a vertical ground acceleration time history. Subsequently, a new predictive algorithm was developed, which utilizes the aforementioned parameters with the floor height and fundamental period of the structure as the new inputs of a support vector regression model. Representative earthquakes, which were recorded by the Structure Strong Earthquake Monitoring System of the Central Weather Bureau in Taiwan from 1992 to 2016, were used to construct the support vector regression model for predicting the peak floor acceleration (PFA) of each floor. The results indicated that the accuracy of the predicted PFA, which was defined as a PFA within a one-level difference from the measured PFA on Taiwan's seismic intensity scale, was 96.96%. The proposed system can be integrated into the existing earthquake early warning system to provide complete protection to life and the economy.

Vibrations of rotationally restrained Timoshenko beam at hinged supports during an earthquake

  • Kim, Yong-Woo;Ryu, Jeong Yeon
    • Nuclear Engineering and Technology
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    • 제52권5호
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    • pp.1066-1078
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    • 2020
  • The present paper describes an analytic solution procedure for flexural vibration of a rotationally restrained hinged-hinged Timoshenko beam at the supports during an earthquake. Focusing on maximal magnitudes of internal loads such as bending moment and shearing force under wide variations of two parameters, kL/EI and kGAL2/EI, various beams under synchronous and asynchronous support motions are simulated. The simulations under asynchronous support motions show the following facts. The variations of the maximal magnitudes of internal loads of stocky beams due to the variation of kL/EI from zero to infinity show much wider variations than those of slender beams as kGAL2/EI decreases. The maximal magnitudes of internal loads of a beam tend to be governed by their static components as kL/EI increases and kGAL2/EI decreases. When the internal loads are governed by their static components, maximal magnitudes of internal loads of the stocky tend to increase monotonically as the value of kL/EI increases. However, the simulations under synchronous support motions show the static components of the internal loads vanish and the internal loads are governed by dynamic components irrespective of the two parameters.

Psychosocial support interventions for women with gestational diabetes mellitus: a systematic review

  • Jung, Seulgi;Kim, Yoojin;Park, Jeongok;Choi, Miyoung;Kim, Sue
    • 여성건강간호학회지
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    • 제27권2호
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    • pp.75-92
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    • 2021
  • Purpose: This study aimed to analyze the content and effectiveness of psychosocial support interventions for women with gestational diabetes mellitus (GDM). Methods: The following databases were searched with no limitation of the time period: Ovid-MEDLINE, Cochrane Library, Ovid-Embase, CINAHL, PsycINFO, NDSL, KoreaMed, RISS, and KISS. Two investigators independently reviewed and selected articles according to the predefined inclusion/exclusion criteria. ROB 2.0 and the RoBANS 2.0 checklist were used to evaluate study quality. Results: Based on the 14 selected studies, psychosocial support interventions were provided for the purpose of (1) informational support (including GDM and diabetes mellitus information; how to manage diet, exercise, stress, blood glucose, and weight; postpartum management; and prevention of type 2 diabetes mellitus); (2) self-management motivation (setting goals for diet and exercise management, glucose monitoring, and enhancing positive health behaviors); (3) relaxation (practicing breathing and/or meditation); and (4) emotional support (sharing opinions and support). Psychosocial supportive interventions to women with GDM lead to behavioral change, mostly in the form of self-care behavior; they also reduce depression, anxiety and stress, and have an impact on improving self-efficacy. These interventions contribute to lowering physiological parameters such as fasting plasma glucose, glycated hemoglobin, and 2-hour postprandial glucose levels. Conclusion: Psychosocial supportive interventions can indeed positively affect self-care behaviors, lifestyle changes, and physiological parameters in women with GDM. Nurses can play a pivotal role in integrative management and can streamline the care for women with GDM during pregnancy and following birth, especially through psychosocial support interventions.

뇌졸중 환자의 회전 보행 시 회전 방향이 보행 특성에 미치는 영향 (Effects of Rotation Direction during Curved Walking on Gait Parameters in Stroke Patients)

  • 정경만;주민철;정유진
    • 한국의료질향상학회지
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    • 제23권2호
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    • pp.11-20
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    • 2017
  • Purpose: The purpose of this study was to determine the effects of rotation direction during curved walking on gait parameters in stroke patients. Methods: A group of thirty subjects with stroke (Berg Balance Scale score${\geq}41$ were fifteen, Berg Balance Scale score${\leq}40$ were fifteen) were enrolled in this study. Testing indications included two directions for rotation in each subject. These indications were for rotation toward the affected and unaffected side in stroke patients. The gait speed, affected side single support duration, affected side double support duration were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 40 points of Berg Balance Scale score. Results: There was significant increase affected side single support duration was turned the affected side in stroke patients that presented a Berg Balance Scale score${\geq}41$ (p<.05). There were significant increase gait speed, affected side single support duration, and significant decrease affected side double support duration while subjects were turned the affected side in stroke patients that presented a Berg Balance Scale score${\leq}40$ (p<.05). Conclusion: This result may be effective to rotate in the paralyzed direction to improve the ability of the paralyzed lower limb to gain weight during gait training for stroke patients with a Berg Balance Scale score<40. Therefore, walking training program for hemiplegic patient needs to be suggested in the direction of turning for suitable balance ability.

Two dimensional reduction technique of Support Vector Machines for Bankruptcy Prediction

  • Ahn, Hyun-Chul;Kim, Kyoung-Jae;Lee, Ki-Chun
    • 한국경영정보학회:학술대회논문집
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    • 한국경영정보학회 2007년도 International Conference
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    • pp.608-613
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    • 2007
  • Prediction of corporate bankruptcies has long been an important topic and has been studied extensively in the finance and management literature because it is an essential basis for the risk management of financial institutions. Recently, support vector machines (SVMs) are becoming popular as a tool for bankruptcy prediction because they use a risk function consisting of the empirical error and a regularized term which is derived from the structural risk minimization principle. In addition, they don't require huge training samples and have little possibility of overfitting. However. in order to Use SVM, a user should determine several factors such as the parameters ofa kernel function, appropriate feature subset, and proper instance subset by heuristics, which hinders accurate prediction results when using SVM In this study, we propose a novel hybrid SVM classifier with simultaneous optimization of feature subsets, instance subsets, and kernel parameters. This study introduces genetic algorithms (GAs) to optimize the feature selection, instance selection, and kernel parameters simultaneously. Our study applies the proposed model to the real-world case for bankruptcy prediction. Experimental results show that the prediction accuracy of conventional SVM may be improved significantly by using our model.

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Investigations on the Optimal Support Vector Machine Classifiers for Predicting Design Feasibility in Analog Circuit Optimization

  • Lee, Jiho;Kim, Jaeha
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제15권5호
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    • pp.437-444
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    • 2015
  • In simulation-based circuit optimization, many simulation runs may be wasted while evaluating infeasible designs, i.e. the designs that do not meet the constraints. To avoid such a waste, this paper investigates the use of support vector machine (SVM) classifiers in predicting the design's feasibility prior to simulation and the optimal selection of the SVM parameters, namely, the Gaussian kernel shape parameter ${\gamma}$ and the misclassification penalty parameter C. These parameters affect the complexity as well as the accuracy of the model that SVM represents. For instance, the higher ${\gamma}$ is good for detailed modeling and the higher C is good for rejecting noise in the training set. However, our empirical study shows that a low ${\gamma}$ value is preferable due to the high spatial correlation among the circuit design candidates while C has negligible impacts due to the smooth and clean constraint boundaries of most circuit designs. The experimental results with an LC-tank oscillator example show that an optimal selection of these parameters can improve the prediction accuracy from 80 to 98% and model complexity by $10{\times}$.

서포트벡터머신을 이용한 충격전 낙상방향 판별 (Determination of Fall Direction Before Impact Using Support Vector Machine)

  • 이정근
    • 센서학회지
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    • 제24권1호
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    • pp.47-53
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    • 2015
  • Fall-related injuries in elderly people are a major health care problem. This paper introduces determination of fall direction before impact using support vector machine (SVM). Once a falling phase is detected, dynamic characteristic parameters measured by the accelerometer and gyroscope and then processed by a Kalman filter are used in the SVM to determine the fall directions, i.e., forward (F), backward (B), rightward (R), and leftward (L). This paper compares the determination sensitivities according to the selected parameters for the SVM (velocities, tilt angles, vs. accelerations) and sensor attachment locations (waist vs. chest) with regards to the binary classification (i.e., F vs. B and R vs. L) and the multi-class classification (i.e., F, B, R, vs. L). Based on the velocity of waist which was superior to other parameters, the SVM in the binary case achieved 100% sensitivities for both F vs. B and R vs. L, while the SVM in the multi-class case achieved the sensitivities of F 93.8%, B 91.3%, R 62.3%, and L 63.6%.

정상인의 후방 보행 시 시각 자극이 보행 변수에 미치는 영향 (The Effect of Visual Stimulation on Gait Parameters During Backward Walking in Healthy Individuals)

  • 성한별;서지원;조정현;우영근
    • PNF and Movement
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    • 제22권1호
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    • pp.91-99
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    • 2024
  • Purpose: Backward walking has shown positive effects on gait recovery in rehabilitation patients. It is increasingly used as an aerobic training method in rehabilitation populations, inducing more sensory and motor stimulation than forward walking. Therefore, the purpose of this study is to investigate the effects of visual stimulation during backward walking. Methods: Twenty-seven healthy adults with a visual acuity of 0.8 or higher participated in the study. To compare the effects of visual stimulation during various walking conditions among healthy individuals, the participants randomly selected cards numbered one to six and walked a distance of 10 meters. Walking ability was measured using Optogait. Results: Statistically significant differences were observed in speed, stride, and percentages of single support and contact phase during backward walking. Within eyes-closed conditions during backward walking, significant differences were found in percentages of single support, terminal stance, and contact phase. Moreover, the percentage of terminal swing significantly differed during backward walking with head turn conditions. Conclusion: Gait parameters such as speed, stride, and percentages of single support and contact phase were higher during backward walking than forward walking. These results indicate that backward walking involves multiple sensory systems and varying conditions.