• Title/Summary/Keyword: Moment coefficient

Search Result 437, Processing Time 0.034 seconds

Modified p-y curves to characterize the lateral behavior of helical piles

  • Hyeong-Joo, Kim;James Vincent, Reyes;Peter Rey, Dinoy;Tae-Woong, Park;Hyeong-Soo, Kim;Jun-Young, Kim
    • Geomechanics and Engineering
    • /
    • v.31 no.5
    • /
    • pp.505-518
    • /
    • 2022
  • This study introduces soil resistance multipliers at locations encompassed by the zone of influence of the helix plate to consider the added lateral resistance provided to the helical pile. The zone of influence of a helix plate is a function of its diameter and serves as a boundary condition for the modified soil resistance springs. The concept is based on implementing p-multipliers as a reduction factor for piles in group action. The application of modified p-y springs in the analysis of helical piles allows for better characterization and understanding of the lateral behavior of helical piles, which will help further the development of design methods. To execute the proposed method, a finite difference program, HPCap (Helical Pile Capacity), was developed by the authors using Matlab. The program computes the deflection, shear force, bending moment, and soil resistance of the helical pile and allows the user to freely input the value of the zone of influence and Ω (a coefficient that affects the value of the p-multiplier). Results from ten full-scale lateral load tests on helical piles embedded at depths of 3.0 m with varying shaft diameters, shaft thicknesses, and helix configurations were analyzed to determine the zone of influence and the magnitude of the p-multipliers. The analysis determined that the value of the p-multipliers is influenced by the ratio between the pile embedment length and the shaft diameter (Dp), the effective helix diameter (Dh-Dp), and the zone of influence. Furthermore, the zone of influence is recommended to be 1.75 times the helix diameter (Dh). Using the numerical analysis method presented in this study, the predicted deflections of the various helical pile cases showed good agreement with the observed field test results.

The Effect of Children's Perceived Parental Attachment and Parents' Happiness on Children's Autonomy (아동이 지각한 부모애착, 부모의 행복감이 아동의 자율성에 미치는 영향)

  • Jeong, Yeong Mi
    • The Journal of the Convergence on Culture Technology
    • /
    • v.9 no.1
    • /
    • pp.95-100
    • /
    • 2023
  • The purpose of this study was to examine the relationship among children's perceived parental attachment, parental happiness, and children's autonomy, and to find out in detail the influence of parental attachment and parental happiness on children's autonomy. Frequency analysis and descriptive statistical analysis were performed on data from the 12th year of the Korean Children's Panel (2019), and Pearson's moment correlation coefficient was calculated for correlation analysis between variables. Multiple regression analysis was conducted to examine the influence of parental attachment and parental happiness on children's autonomy. The research results were as follows. First, parental attachment perceived by children, parental happiness, and children's autonomy were all positively correlated. Second, among the sub-variables of parental attachment, maternal trust, paternal trust, and maternal communication were found to have an influence, and only maternal happiness was found to have an effect on parental happiness. This means that parental attachment acts as a more important variable than parental happiness. Therefore, we need constant attention and effort to support children in a more intimate and stable relationship with their parents so that they can gain life satisfaction through active and proactive choices and decisions.

Analysis of the Rotational Behavior of Piles under Lateral Loading Installed in Multi Layered Soil (다층지반에 근입된 수평재하 말뚝의 회전거동 분석)

  • Kang, Beong-Joon;Kyung, Doo-Hyun;Hong, Jung-Moo;Lee, Jun-Hwan
    • Journal of the Korean Geotechnical Society
    • /
    • v.25 no.1
    • /
    • pp.55-64
    • /
    • 2009
  • One of the important use of piles is to furnish lateral support and nowadays it is getting highlighted due to the increase of skyscrapers, transmission towers, wind turbines, and other lateral action dependent structures. After Broms (1964), many researchers have suggested methods for estimating lateral capacity of pile. But each method assumes different earth pressure distribution and lateral earth pressure coefficient causing confusion on the part of pile designers. Lateral earth pressure, essential in lateral capacity estimation, is influenced by pile's rotational behavior under lateral load. Prasad and Chari (1999) assumed the rotation point of pile and suggested an equation of ultimate lateral load capacity. In this study, we investigate the depth of rotation point in both homogeneous soil and multi layered soil, and compare with the estimation value by previous research. Test results show that measured rotation point and estimated value by Prasad and Chari's equation show good agreement and multi layered condition affects the location of rotation point to be changed.

Statistical Estimation of Wind Speed in the Gwangyang-Myodo Region (광양 - 묘도 지역의 통계학적인 풍속 추정)

  • Bae, Yong Gwi;Han, Gwan Mun;Lee, Seong Lo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.2A
    • /
    • pp.197-205
    • /
    • 2008
  • In order to estimate mean wind speed in the Gwangyang-Myodo Region, the probability distribution model of extreme values has been used in the statistical analysis of joint distribution probability of daily maximum wind speed and corresponding direction in this paper. For this purpose frequency of daily maximum records at respective stations is inquired into and sample of largest yearly wind speed of sixteen compass direction and non-direction is extracted from daily data of maximum wind speed and appropriate direction of the meteorological observing stations nearby the bridge construction site. These extreme speed records are applied to Gumbel and Weibull distribution model and parameters are estimated through method of moment and method of least squares etc. And also, distribution and parameters are inquired into whether it is fitted through the probability plot correlation coefficient examination. From fitted parameters the largest yearly wind speed of sixteen compass direction and non-direction is extrapolated taking into account factors regarding sample size of data and distance from the bridge construction site according to the appropriate stations.

Two-dimensional Tracer Tests in Natural Rivers Using Radioisotope (방사성 동위원소를 이용한 자연하천의 2차원 추적자 실험)

  • Seo, Il Won;Baek, Kyong Oh;Jeon, Tae Myong
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.2B
    • /
    • pp.161-170
    • /
    • 2006
  • A tracer test technique using a radioisotope was proposed to investigate pollutant mixing characteristics in rivers. The main advantages of radioisotope as a tracer in field tests are that it can be detected easily, and that its detection range is quite large. Also, using the radioisotope, the amount sorbed by the bed material and the biota may be a minimum. Field tracer tests were conducted at seven different sites in natural rivers with various meandering pattern. Based on the acquired data, the behavior of the tracer cloud in the intermediate-field was examined two-dimensionally, and dispersion coefficients were calculated using several evaluation methods. Results revealed that the tracer cloud was transported skewed to the outer bank and dispersion coefficients in bends were larger than those in straight reaches.

Population diversity, admixture, and demographic trend of the Sumba Ongole cattle based on genomic data

  • Pita Sudrajad;Hartati Hartati;Bayu Dewantoro Putro Soewandi;Saiful Anwar;Angga Ardhati Rani Hapsari;Tri Satya Mastuti Widi;Sigit Bintara;Dyah Maharani
    • Animal Bioscience
    • /
    • v.37 no.4
    • /
    • pp.591-599
    • /
    • 2024
  • Objective: Sumba Ongole (SO) cattle are valuable breed due to their important role in the development of Indonesian cattle. Despite rapid advances in molecular technology, no genomic studies on SO cattle have been conducted to date. The aim of this study is to provide genomic profile related to the population diversity, admixture, and demographic trends of SO cattle. Methods: Genomic information was gathered from 79 SO cattle using the Illumina Bovine SNP50 v3 Beadchip, and for comparative purposes, additional genotypes from 209 cattle populations worldwide were included. The expected and observed heterozygosity, inbreeding coefficient, pairwise fixation indices between-population, and Nei's genetic distance were examined. Multidimensional scaling, admixture, and treemix analyses were used to investigate the population structure. Based on linkage disequilibrium and effective population size calculations, the demographic trend was observed. Results: The findings indicated that the genetic diversity of SO cattle was similar to that of other indicine breeds. SO cattle were genetically related to indicines but not to taurines or Bali cattle. The study further confirmed the close relationship between SO, Ongole, and Nellore cattle. Additionally, a small portion of the Ongole mixture were identified dominant in the SO population at the moment. The study also discovered that SO and Bali cattle (Bos javanicus) could have been ancestors in the development of Ongole Grade cattle, which corresponds to the documented history of Ongolization. Our finding indicate that SO cattle have maintained stability and possess unique traits separate from their ancestors. Conclusion: In conclusion, the genetic diversity of the SO cattle has been conserved as a result of the growing significance of the present demographic trend. Consistent endeavors are necessary to uphold the fitness of the breed.

Predicting restraining effects in CFS channels: A machine learning approach

  • Seyed Mohammad Mojtabaei;Rasoul Khandan;Iman Hajirasouliha
    • Steel and Composite Structures
    • /
    • v.51 no.4
    • /
    • pp.441-456
    • /
    • 2024
  • This paper aims to develop Machine Learning (ML) algorithms to predict the buckling resistance of cold-formed steel (CFS) channels with restrained flanges, widely used in typical CFS sheathed wall panels, and provide practical design tools for engineers. The effects of cross-sectional restraints were first evaluated on the elastic buckling behaviour of CFS channels subjected to pure axial compressive load or bending moment. Feedforward multi-layer Artificial Neural Networks (ANNs) were then trained on different datasets comprising CFS channels with various dimensions and properties, plate thicknesses, and restraining conditions on one or two flanges, while the elastic distortional buckling resistance of the elements were determined according to the Finite Strip Method (FSM). To develop less biased networks and ensure that every observation from the original dataset has the chance of appearing in the training and test set, a K-fold cross-validation technique was implemented. In addition, the hyperparameters of the ANNs were tuned using a grid search technique to provide ANNs with optimum performances. The results demonstrated that the trained ANNs were able to predict the elastic distortional buckling resistance of CFS flange-restrained elements with an average accuracy of 99% in terms of coefficient of determination. The developed models were then used to propose a simple ANN-based design formula for the prediction of the elastic distortional buckling stress of CFS flange-restrained elements. Finally, the proposed formula was further evaluated on a separate set of unseen data to ensure its accuracy for practical applications.

Evaluation of Setup Errors for Tomotherapy Using Differently Applied Vacuum Compression with the Bodyfix Immobilization System (토모테라피 치료 시 Bodyfix System에서 진공압박에 따른 환자 위치잡이오차(Setup errors)의 평가)

  • Jung, Jae-Hong;Cho, Kwang-Hwan;Lee, Jeong-Woo;Kim, Min-Joo;Lim, Kwang-Chae;Moon, Seong-Kwon;Kim, Yong-Ho;Suh, Tae-Suk
    • Progress in Medical Physics
    • /
    • v.22 no.2
    • /
    • pp.72-78
    • /
    • 2011
  • The aim of this study is to evaluate the patient's setup errors in TomoTherapy (Hi-Art II, TomoTherapy, USA) Bodyfix system (Medical Intelligence, Ele-kta, Schwabmuchen, Germany) pressure in the vacuum compression, depending on and were evaluated. Bodyfix immobilization system and vacuum pressure was compression applied to the patients who received Tomotherapy thoracic and abdominal area, 21 patients were selected and TomoTehpay treatment total 477 of MVCT images were obtained. The translational (medial-lateral: ML, anterior-posterior: AP, superior-inferior: SI directions) and rolling were recorded and analyzed statistically. Using Pearson's product-moment coefficient and One-way ANOVA, the degree of correlation depending on the different vacuum pressure levels were statistically analyzed for setup errors from five groups (p<0.05). The largest average and standard deviation of systematic errors were 6.00, 5.95 mm in the AP and SI directions, respectively. The largest average of random errors were 4.72 mm in the SI directions. The correlation coefficients were 0.485, 0.244, and 0.637 for the ML-Roll, AP-Vector, and SI-Vector, respectively. SI-Vector direction showed the best relationship. In the results of the different degree of vacuum pressure in five groups (Pressure range: 30~70 mbar), the setup errors between the ML, SI in both directions and Roll p=0.00 (p<0.05) were shown significant differences. The average errors of SI direction in the vacuum pressure of 40 mbar and 70 mbar group were 4.78 mm and -0.74 mm, respectively. In this study, the correlation between the vacuum pressure and the setup-errors were statistically analyzed. The fact that setup-errors in SI direction is dependent in vacuum pressure considerly setup-errors and movement of interal organs was identified. Finally, setup-errors, and it, based on the movement of internal organs in Bodyfix system we should apply more than 50 mbar vacuum pressure. Based on the results of this study, it is suggested that accuracy of the vacuum pressure and the quantitative analysis of movement of internal organs and the tumor should be studied.

Development of the Korean Form of Zung's Self-Rating Anxiety Scale (한국형 자가평가 불안척도의 개발)

  • Lee, Jung-Hoon
    • Journal of Yeungnam Medical Science
    • /
    • v.13 no.2
    • /
    • pp.279-294
    • /
    • 1996
  • This study was carried out to develop a Korean language version of Zung's self-rating anxiety scale(SAS) from august, 1994 to September, 1996. The subjects consisted of 205 normal control subjects from the general population group, and 97 subjects with anxiety disorders. These 97 subjects were chosen from a group by the structured clinical interview for DSM-IV of in patients and out patients. Both normal control subjects and anxiety disorder subjects were drawn utilizing a cluster of sampling methods. In order to analyze the data on anxiety scores, Pearson's product moment correlation coefficient method was carried out, as well as reliability, factor analysis and discriminant function analysis, utilizing the SPSS/PC+ program. The results obtained were as follows: The mean average of the total anxiety scores were 32.36 + 6.35 for the normal control subjects and 50.53 + 7.67 for anxiety disorder subjects. Test-retest reliability(coefficient r=0.98, p < 0.001), and internal consistency(coefficient r=0.96, p < 0.001) were satisfactory. Factor analysis using oblique technique rotation yielded four factors. The normal control subjects scored higher concerning the symptoms such as sweating, restlessness, apprehension, insomnia and dyspnea, and lower for faintness, mental disintegration, paresthesia, dizziness and tremor. On the other hand, for the anxiety disorders, apprehension, restlessness, sweating, dyspnea and insomnia scored higher, and lower for faintness, paresthesia, nightmare, dizziness and tremor.

  • PDF

The Relationship between Climate and Food Incidents in Korea (식품안전 사건 사고와 기후요소와의 관련성)

  • Lee, Jong-Hwa;Kim, Young-Soo;Baek, Hee-Jung;Chung, Myung-Sub
    • Journal of Climate Change Research
    • /
    • v.2 no.4
    • /
    • pp.297-307
    • /
    • 2011
  • This study investigates relation of food safety incidents with climate. Therefore food safety incidents and climate data during 1999 to 2009 have been analyzed. In situ observations of monthly mean temperature, maximum temperature, minimum temperature, precipitation, and relative humidity in 60 observation stations of Korean Meteorological Administration (KMA) have been used in this study. Food safety incidents data have been constructed by searching media reports following Park's method (2009) during the same period. According to the Park's method, 729 events were collected. To analyze its relations, food safety incidents data have been classified into chemical, biological, and physical hazards. Pearson product-moment correlation coefficients have been applied to analyze the relations. The correlation of food safety incidents has negative one with precipitation (-0.48), and positive one with minimum temperature(0.45). Precipitation has been correlated with biological and physical hazards more than chemical hazard. Temperatures (mean temperature, maximum temperature, and minimum temperature) have been correlated closely with chemical hazard than others. Food safety incidents data has been interblended with human behavior factor through decision-making processes in food manufacturing, processing, and consumption phases of "farm-totable" food processing. Act in the preventing damage will be obvious if the hazard were apparent. Therefore abnormal condition could be more dangerous than that of apparent extreme events because apparent events or extreme events become one of alarm over hazards. Therefore, human behavior should be considered as one of the important factors for analysis of food safety incidents. The result of this study can be used as a better case study for food safety researches related to climate change.