• 제목/요약/키워드: parameters study

Search Result 27,023, Processing Time 0.058 seconds

Relationship between airborne pollen concentrations and meteorological parameters in Ulsan, Korea

  • Jung, In-Yong;Choi, Kee-Ryong
    • Journal of Ecology and Environment
    • /
    • v.36 no.1
    • /
    • pp.65-71
    • /
    • 2013
  • The concentration of airborne pollen is related to meteorological parameters. The main purpose of this study was to determine the correlation between airborne pollen and meteorological parameters in Ulsan based on sampling from 2010 to 2011. The primary factors of interest were differences in the pollen scattering start date, end date, and peak date, and the fluctuations in pollen concentration. The meteorological parameters that affected the start and peak dates of the pollen season were as follows. For Pinus and Alnus, the dates were correlated with sunshine and an increase in temperature, whereas for Quercus, the dates were correlated with increasing temperature. During the pollen season, Alnus peaked when the temperature was highest and Pinus peaked when the relative humidity was lowest. The concentration of airborne pollen was correlated with meteorological parameters during the sampling period as follows: Pinus, Alnus, and Humulus pollen concentrations were positively correlated with increasing temperature and negatively correlated with rainfall and relative humidity; Humulus pollen concentration was positively correlated with sunshine; and Quercus and Humulus pollen concentrations were positively correlated with wind speed.

Development of Nonlinear Fatigue Model Based on Particle Filter Method (파티클 필터기법을 통한 비선형 피로모델 개발 연구)

  • Mun, Sungho
    • International Journal of Highway Engineering
    • /
    • v.18 no.4
    • /
    • pp.63-68
    • /
    • 2016
  • PURPOSES : The nonlinear model of fatigue cracking is typically used for determining the maintenance period. However, this requires that the model parameters be known. In this study, the particle filter (PF) method was used to determine various statistical parameters such as the mean and standard deviation values for the nonlinear model of fatigue cracking. METHODS : The PF method was used to determine various statistical parameters for the nonlinear model of fatigue cracking, such as the mean and standard deviation. RESULTS : On comparing the values obtained using the PF method and the least square (LS) method, it was found that PF method was suitable for determining the statistical parameters to be used in the nonlinear model of fatigue cracking. CONCLUSIONS : The values obtained using the PF method were as accurate as those obtained using the LS method. Furthermore, reliability design can be applied because the statistical parameters of mean and standard deviation can be obtained through the PF method.

Parameter Estimation of Shallow Arch Using Quantum-Inspired Evolution Algorithm (양자진화 알고리즘을 이용한 얕은 아치의 파라미터 추정)

  • Shon, Sudeok;Ha, Junhong
    • Journal of Korean Association for Spatial Structures
    • /
    • v.20 no.1
    • /
    • pp.95-102
    • /
    • 2020
  • The structural design of arch roofs or bridges requires the analysis of their unstable behaviors depending on certain parameters defined in the arch shape. Their maintenance should estimate the parameters from observed data. However, since the critical parameters exist in the equilibrium paths of the arch, and a small change in such the parameters causes a significant change in their behaviors. Thus, estimation to find the critical ones should be carried out using a global search algorithm. In this paper we study the parameter estimation for a shallow arch by a quantum-inspired evolution algorithm. A cost functional to estimate the system parameters included in the arch consists of the difference between the observed signal and the estimated signal of the arch system. The design variables are shape, external load and damping constant in the arch system. We provide theoretical and numerical examples for estimation of the parameters from both contaminated data and pure data.

An Acoustic Analysis of Diadochokinesis in Patients with Parkinson's Disease (파킨슨병 환자 대상 조음교대운동의 음향적 분석)

  • Kang, Young Ae;Park, Hyun Young;Koo, Bon Seok
    • Phonetics and Speech Sciences
    • /
    • v.5 no.4
    • /
    • pp.3-15
    • /
    • 2013
  • The acoustic analysis of diadochokinesis(DDK) has been used to evaluate dysarthria. However, there has not been an automatic method to evaluate dysarthria. The aim of this study was to introduce a new automated program to measure DDK tasks and to apply this to clinical patients with idiopathic Parkinson's disease(IPD). Fourty-seven patients with IPD and a healthy control group of twenty participants were selected with every DDK task recorded three times. Twenty-five acoustic parameters in the program were developed. The relevant parameters were times of DDK, pitch related parameters, intensity parameters which were analyzed by 2-way ANOVA. Significant differences between the groups were found in the times of DDK, pitch related parameters, and intensity parameters. The findings indicated that the pitch of control group was more stable than that of the IPD. Even though the patients with IPD had a higher intensity value, this phenomenon was caused by the weakness of the IPD group who could not control their speech with a breath.

A study on the design of adaptive generalized predictive control (적응 일반형 예측제어 설계에 관한 연구)

  • 김창회;이상정
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1992.10a
    • /
    • pp.176-181
    • /
    • 1992
  • In this paper, an adaptive generalized predictive control(GPC) algorithm which minimizes a N-stage cost function is proposed. The resulting controller is based on GPC algorithm and can be used in unknown plant parameters as the parameters of one step ahead predictor are estimated by recursive least squares method. The estimated parameters are extended to G,P, and F amtrix which contain the parameters of N step ahead predictors. And the minimization of cost function assuming no constraints on future controls results in the projected control increment vector. Hence this adaptive GPC algorithm can be used for either unknown system or varing system parameters, and it is also shown through simulations that the algorithm is robust to the variation of system parameters. This adaptive GPC scheme is shown to have the same stability properties as the deterministic GPC, and requires small amount of calculation compared to other adaptive algorithms which minimize N-stage cost function. Especially, in case that the maximum output horizon is 1, the proposed algorithm can be applicable to direct adaptive GPC.

  • PDF

A study on Analysis Technique of Design Parameters for Brushless DC motor (Brushless DC motor의 설계 Parameter 분석 기법에 관한 연구)

  • Maeng, Kyung-Ho;Park, Chang-Soon
    • Proceedings of the KIEE Conference
    • /
    • 2004.04a
    • /
    • pp.6-8
    • /
    • 2004
  • Recently, it is increasing to use more Brushless DC Motor with high energy density permanent magnet and semiconductor control unit for complementing the mechanical defect of Brushed DC Motors. For designing of BLDC Motors are required complex parameters like as rated characteristic, Geometries, B-H curve of magnet and steel materials, winding factor, etc. Moreover, design and manufacturing are difficult because of additional control circuits. Generally, Design parameters are gotten by analysis of Motor which is used. And the design parameters are used to design a new motor. But getting the design parameters through the eyes and experience is limited and it takes a long time. In this paper a method is proposed to efficiently analyze motor design parameters through the No load and Load Test, Back EMF Test, Simulation Analysis and Patent Analysis Method for existing BLDC Motor for a cooling Fan in Vehicle.

  • PDF

Gait analysis of the healthy elderly over 65years of age (65세 이상 건강한 노인의 보행분석)

  • Hong Wan-Sung;Kim Gi-Won
    • The Journal of Korean Physical Therapy
    • /
    • v.14 no.4
    • /
    • pp.45-54
    • /
    • 2002
  • The purpose of this study was to describe the gait pattern and parameters of the healthy elderly over 65years of age by the GATERite system. The subjects were sorted into two groups, depending on their sex: male and female. And female subjects were sorted into three groups, depending on their age. From time parameters and space parameters of gait cycle, between groups, the following results were made. The time parameters such as cadence, velocity, step time, single support and double support were the less the male than the female. And the higher age, the lower value except 80 age group, while no statistically significant. The space parameters(step length and stride length) were the longer the male than the female, and the higher age, the lower value while no statistically signigicant. The functional ambulation profile was high correlation with time and space parameters statistically significant.

  • PDF

Sensitivity Analysis of Processing Parameters for the Laser Surface Hardening Treatment by Using the Finite Element Method (유한요소법을 이용한 레이저 표면경화처리 공정변수의 민감도 해석)

  • 이세환;양영수
    • Journal of Welding and Joining
    • /
    • v.19 no.2
    • /
    • pp.228-234
    • /
    • 2001
  • A methodology is developed and used to evaluate the response sensitivity of the thermal systems to variations in their design parameters. Technique for computing the sensitivity of temperature distributions to changes in processing parameters needed to decide the more effective laser input parameters for laser surface hardening treatment is considered. In this study, a state equation governing the heat flow in laser surface treatment is analyzed using a three-dimensional finite element method and sensitivity data of the processing parameter obtained using a direct differentiation method is applied to the sensitivity analysis. The interesting processing parameters are taken as the laser scan velocity and laser beam radius ( $r_{ b}$), and the sensitivities of the temperature T versus v and $r_{b}$ are analyzed. These sensitivity results are obtained with another parameters fixed. To verify the numerical analysis results, hardened layer dimensions (width and depth) of the numerical analysis are compared with the experimental ones.nes.

  • PDF

A Study on Development of Algorithm for Predicting the Optimized Process Parameters on Bead Geometry (임의의 비드형상을 의한 최적의 공정변수 예측 알고리즘 개발에 관한 연구)

  • 김일수;차용훈;이연신;박창언;손준식
    • Journal of Welding and Joining
    • /
    • v.17 no.4
    • /
    • pp.39-45
    • /
    • 1999
  • The procedure of robotic Gas metal Arc (GMA) welding in order to achieve the optimized bead geometry needs the selection of suitable process parameters such as arc current, welding voltage, welding speed. It is required the relationships between process parameters and bead geometry. The objective of this paper is to develop the algorithm that enables the determination of process parameters from the optimized bead geometry for robotic GMA welding. It depends on the inversion of empirical equations derived from multiple regression analysis of the relationships between the process parameters and the bead dimensions using the least square method. The method not only directly determines those parameters which will give the desired set of bead geometry, but also avoids the need to iterate with a succession of guesses employed Finite Element Method(FEM). These results suggest that process parameter from experimental equation for robotic GMA welding may be employed to monitor and control the bead geometry in real time.

  • PDF

Sensitivity Analysis of Shape Design Parameters of a Toque Converter Using Potential Flow (포텐셜 유동 해석을 이용한 토크 컨버터의 형상설계 파라미터들의 민감도 해석)

  • 김준양;이장무;박찬일;임원식
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1994.10a
    • /
    • pp.924-929
    • /
    • 1994
  • In using a performance model of a torque converter determined by its gemetric condition, it is possible that the analysis of two arbitrary converters produces the the same results because of the same value of equivalent parameters despite their different shapes. Therefore, it is necessary to understand the effect of shape factor on dynamic perfomance, and equivalent parameters reoresenting a performace model of a converter should into its defined by the behavior of flow field. In this study, torus flow of a torque converter is changed into its equivalent system defined by the behavior of flow, and govering equations for the system are presented and used for analysis. Equivalent parameters are obtained from the results of flow analysis and are compared with parameters of one dimensional performance model. The influence that shape change of a converter has on the behavior of flow and the equivalent parameters is studied qualitatively.

  • PDF