• Title/Summary/Keyword: Cross coefficients

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Factors Affecting Successful Aging in Rural Elderly People (농촌 노인의 성공적 노화 영향요인 분석)

  • Ahn, Okhee;Cha, Hye Gyeong;Chang, Soo Jung;Kim, Hee Sun;Jang, Eun Hee
    • Journal of Digital Convergence
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    • v.11 no.11
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    • pp.499-508
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    • 2013
  • This study was done to examine the affecting factors of successful aging to provide basic information for developing intervention program for the rural elderly. Methods: A cross-sectional descriptive design was used. Data was collected through questionnaire from 208 people with age over 65 residing in an rural community. They were recruited by convenience sampling. Collected data were analyzed by independent t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression through SPSS/WIN 21.0 program. Results: Explanatory factors affecting the rural elderly's successful aging were social support, depression, cognitive function, productive activity and Activities of daily living, respectively, and these five factors accounted for 42.1% of the variance in successful aging. Conclusion: The rural elderly's successful aging requires establishment of social support system such as health medical service supply and social activities by being connected with social communities, and for this, this study suggests that there be a necessity of developing customized nursing intervention program.

Numerical and experimental study of unsteady wind loads on panels of a radar aerial

  • Scarabino, Ana;Sainz, Mariano Garcia;Bacchi, Federico;Delnero, J. Sebastian;Canchero, Andres
    • Wind and Structures
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    • v.23 no.1
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    • pp.1-18
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    • 2016
  • This work experimentally and numerically analyzes the flow configurations and the dynamic wind loads on panels of rectangular L/h 5:1 cross section mounted on a structural frame of rectangular bars of L/h 0.5:1, corresponding to a radar structure. The fluid dynamic interaction between panels and frame wakes imposes dynamic loads on the panels, with particular frequencies and Strouhal numbers, different from those of isolated elements. The numerical scheme is validated by comparison with mean forces and velocity spectra of a panel wake obtained by wind tunnel tests. The flow configuration is analyzed through images of the numerical simulations. For a large number of panels, as in the radar array, their wakes couple in either phase or counter-phase configurations, changing the resultant forces on each panel. Instantaneous normal and tangential force coefficients are reported; their spectra show two distinct peaks, caused by the interaction of the wakes. Finally, a scaled model of a rectangular structure comprised of panels and frame elements is tested in the boundary layer wind tunnel in order to determine the influence of the velocity variation with height and the three-dimensionality of the bulk flow around the structure. Results show that the unsteady aerodynamic loads, being strongly influenced by the vortex shedding of the supporting elements and by the global 3-D geometry of the array, differ considerably on a panel in this array from loads acting on an isolated panel, not only in magnitude, but also in frequency.

Prediction of the turning and zig-zag maneuvering performance of a surface combatant with URANS

  • Duman, Suleyman;Bal, Sakir
    • Ocean Systems Engineering
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    • v.7 no.4
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    • pp.435-460
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    • 2017
  • The main objective of this study is to investigate the turning and zig-zag maneuvering performance of the well-known naval surface combatant DTMB (David Taylor Model Basin) 5415 hull with URANS (Unsteady Reynolds-averaged Navier-Stokes) method. Numerical simulations of static drift tests have been performed by a commercial RANS solver based on a finite volume method (FVM) in an unsteady manner. The fluid flow is considered as 3-D, incompressible and fully turbulent. Hydrodynamic analyses have been carried out for a fixed Froude number 0.28. During the analyses, the free surface effects have been taken into account using VOF (Volume of Fluid) method and the hull is considered as fixed. First, the code has been validated with the available experimental data in literature. After validation, static drift, static rudder and drift and rudder tests have been simulated. The forces and moments acting on the hull have been computed with URANS approach. Numerical results have been applied to determine the hydrodynamic maneuvering coefficients, such as, velocity terms and rudder terms. The acceleration, angular velocity and cross-coupled terms have been taken from the available experimental data. A computer program has been developed to apply a fast maneuvering simulation technique. Abkowitz's non-linear mathematical model has been used to calculate the forces and moment acting on the hull during the maneuvering motion. Euler method on the other hand has been applied to solve the simultaneous differential equations. Turning and zig-zag maneuvering simulations have been carried out and the maneuvering characteristics have been determined and the numerical simulation results have been compared with the available data in literature. In addition, viscous effects have been investigated using Eulerian approach for several static drift cases.

Relationships between Fatigue, Sleep Disturbance, Stress, Self-efficacy and Depression in Hemodialysis Patients (혈액투석환자의 피로와 수면장애, 스트레스, 자기효능감 및 우울 관계)

  • Seo, Nam Sook;Kang, Seung Ja;Kim, Jae Hee;Kim, Sea Ja
    • Journal of Korean Clinical Nursing Research
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    • v.19 no.2
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    • pp.285-297
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    • 2013
  • Purpose: This study was conducted to investigate the differences in sleep disturbance, stress, self-efficacy and depression by fatigue level and to identify the factors influencing fatigue in hemodialysis patients. Methods: This study used a cross-sectional design and the subjects were 195 patients undergoing hemodialysis in a local unit. Data were collected using a structured questionnaire and medical records from June to August 2012. The data were analyzed using descriptive statistics, independent t-test, one way ANOVA, $Scheff{\grave{e}}$ test, and Pearson's correlation coefficients. Also a multiple regression analysis was used to assess the independent association between fatigue status and indices of sleep disturbance, stress, self-efficacy and depression. Results: A total of 99 (50.8%) subjects experienced a high level of fatigue and 96 (49.2%) experienced a low level of fatigue. There were significant differences in the levels of sleep disturbance, stress, self-efficacy and depression between the two groups. Fatigue was significantly correlated to sleep disturbance, stress, self-efficacy and depression. The most important factor related to fatigue was stress, followed by sleep disturbance. These factors explained about 37% of fatigue of the respondents. Conclusion: The results of this study showed that sleep disturbance and stress were significant predictors of fatigue in hemodialysis patients. Possible interventions for minimizing fatigue in patients undergoing long-term hemodialysis should be aimed to manage the known contributing factors.

Convergence Analysis of the Factors Influencing Job-Seeking Stress in Nursing Students (간호대학생의 취업 스트레스에 미치는 융합적 영향요인)

  • Yang, Seung Ae
    • Journal of Convergence for Information Technology
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    • v.7 no.4
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    • pp.171-183
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    • 2017
  • The purpose of the study was to identify the factors influencing the nursing students' job-seeking stress. A cross-sectional descriptive survey, using a structured questionnaire, was used to collect data from Sep. to Oct. 2016. A sample of convenience was 246 nursing students and a questionnaire was used to measure their major satisfaction, CDMSE, self-esteem, ego-resiliency, and job-seeking stress. A significant negative correlation was found among job-seeking stress, major satisfaction, CDMSE, self-esteem, and ego-resiliency. Grade of which the participant was in, self-esteem, academic achievement, experience of clinical practice, and family economic status were significant predictive variables of which accounted for 46.1% of the variance in job-seeking stress. The results from this study can be used to develop programs for job-seeking stress management.

Reliability of rehabilitative ultrasound imaging for measuring the gluteus maximus muscle at rest and during contraction

  • Jeong, Ju-Ri;Lee, Su-Jin;Lee, Wan-Hee
    • Physical Therapy Rehabilitation Science
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    • v.6 no.1
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    • pp.7-13
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    • 2017
  • Objective: The aim of this study was to investigate the inter-rater and intra-rater reliability of rehabilitative ultrasound imaging (RUSI) for measurement of muscle thickness with changes in angles of the gluteus maximus (GM) at rest and during contraction. Design: Cross-sectional study. Methods: Twenty-two healthy men volunteered for this study. GM muscle images were obtained in the resting position and during prone hip extension with knee flexion at hip abduction angles of $0^{\circ}$ and $30^{\circ}$, respectively. Two examiners randomly measured the thickness of the GM twice in three different positions. The first position was a comfortable prone position. The second position was prone hip extension with knee flexion (PHEKF) to $90^{\circ}$. The third position was achieved by hanging a 1-kg weight on the ankle of the lifted leg during PHEKF with the angle of the lifted leg the same as the second position. Intra-class correlation coefficients (ICCs), standard error measurements, and minimal detectable changes were used to estimate reliability. Results: The intra-rater reliability ICCs (95% confidence interval) of the GM were >0.870, indicating good reliability. Inter-rater reliability ICCs ranged from 0.668 to 0.913. The reliability of measurements of muscle thickness at each position was similar to the reliability of the angle change. Differences in muscle thickness and ratios for each position with $0^{\circ}$ and $30^{\circ}$ of hip abduction were not statistically significant. Conclusions: In the present study, the intra-rater reliability of muscle thickness measurements of the GM was good, and the inter-rater reliability was moderate to good. Reliable RUSI measurements of wide and large muscles, such as the GM muscle at rest and during contraction, are feasible. Further investigation is required to establish the reproducibility of the protocols presented in this study.

A study on the clinical usefulness, validity, and test-retest reliability of the Spirokit, a device that combines the pulmonary function test and respiratory muscle strength test

  • Kim, Byeong-Soo;Lee, Myung-Mo
    • Physical Therapy Rehabilitation Science
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    • v.9 no.2
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    • pp.120-130
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    • 2020
  • Objective: This study was conducted to identify the clinical usefulness, validity, and reliability of the Spirokit, a device that combines the pulmonary function test (PFT) and respiratory muscle strength (RMS) test. Design: Cross-sectional study. Methods: Forty young adults (male: 23, female: 17) participated in a PFT and a RMS test. The concurrent validity for pulmonary function was assessed by comparing data obtained from MicroQuark and the Spirokit and the agreements between the MicroRPM and the Spirokit for RMS were compared. The test-retest reliability of the Spirokit was determined by comparing data obtained from the first and second sessions. The test and retest were performed at the same time after one day for the PFT and RMS test. Validity was estimated using intraclass correlation coefficients (ICCs), and by calculating 95% limits of agreement (LoA). To estimate interrater reliability, ICCs were calculated. Results: The Spirokit showed a high agreement intra class coefficient (ICC [2, 1]): 0.978-0.999, 95% limits of agreements (95% LOA): -0.798 to 0.847 with MicroQuark. It also showed a high level of concordance ICC (2, 1): 0.992 to 0.993, 95% LOA: -9.313 to 11.169 with MicroRPM. The test-retest reliability of the Spirokit was analyzed using ICC (2, 1), and showed a high level of reliability (ICC [2,1]=0.960 to 0.998). Standard error of measurement % (SEM%) was 0.12% to 3.39%, and minimum detectable change% (MDC%) was 0.02% to 3.79%, indicating high level of reliability. Conclusions: The Spirokit is a device with high validity and reliability that can be used to simultaneously measure PFT and RMS tests.

Reliability and validity of pelvic mobility measurement using a cushion sensor in healthy adults

  • Jung, Seung-Hwa;Kim, Su-Kyeong;Lee, Ji-Hyun;Choi, Soo-Ih;Park, Dae-Sung
    • Physical Therapy Rehabilitation Science
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    • v.9 no.2
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    • pp.74-81
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    • 2020
  • Objective: To prevent low back pain, an objective evaluation tool to evaluate pelvic mobility and exercise to improve the flexibility of the lumbar region is needed. The purpose of this study was to compare the results of pelvic mobility measurements using the Wii Balance Board (WBB) and Sensbalance Therapy Cushion (STC), evaluate the usefulness of the STC as a tool for measuring pelvic mobility. Design: Cross-sectional study. Methods: Fifty healthy subjects participated in this study. The subjects performed pelvic mobility range, proprioception, reaction time and reach of the arm using the STC. The pelvic movement parameter was measured two times to determine the intra-rater reliability. To measure the correlation between lumbar muscle tension and pelvic mobility, Myovision was used to measure tension of L4, L5 level erector spinae muscle. Correlations between measured variables were checked to determine the validity of the pelvic mobility assessment tool. Results: STC showed high test-retest reliability in pelvic tilt measurement and reaching task [intraclass correlation coefficients (3,1)=0.804-0.915]. The relationship between WBB and STC showed a significant positive correlation with the pelvic tilt and reaching task (p<0.05). Posterior tilt and erector spinae activation (Lt. L5) showed a significant negative correlation (p<0.05). Left, right tilt and erector spinae activation (L5) showed a significant negative correlation (p<0.05). Conclusions: This study confirmed the advantages of the STC and found efficiency as an objective measuring device of pelvic mobility.

The Experimental Analysis of the Effect of Wind Load on the Stability of a Container Crane (풍하중이 컨테이너 크레인 안정성에 미치는 영향의 실험적 해석)

  • Lee Seong-Wook;Shim Jae-Joon;Han Dong-Seup;Han Geun-Jo;Kim Tae-Hyung;Hwang Kyu-Seok
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.229-234
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    • 2005
  • This study was carried out to analyze the effect of wind load on the stability of a 50ton container crane using wind tunnel test and provide a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Effect type atmospheric boundary-layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.

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Evaluation of Millet (Panicum miliaceum subsp. miliaceum) Germplasm For Seed Fatty Acids Using Near-Infrared Reflectance Spectroscopy

  • Lee, Young-Yi;Kim, Jung-Bong;Lee, Ho-Sun;Jeon, Young-A;Lee, Sok-Young;Kim, Chung-Kon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.57 no.1
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    • pp.29-34
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    • 2012
  • The objective of this study was to rapidly evaluate fatty acids in a collection of millet (Panicum miliaceum subsp. miliaceum) of different origins so that this information could be disseminated to breeders to advance germplasm use and breeding. To develop the calibration equations for rapid and nondestructive evaluation of fatty acid content, near-infrared reflectance spectroscopy (NIRs) spectra (1104-2494 nm) of samples ground into flour ($n$=100) were obtained using a dispersive spectrometer. A modified partial least-squares model was developed to predict each component. For foxtail millet germplasm, our models returned coefficients of determination ($R^2$) of 0.89, 0.89, 0.89, and 0.92 for palmitic acid, oleic acid, linoleic acid, and total fatty acids, respectively. The prediction of the external validation set (n=10) showed significant correlation between references values and NIRs values ($r^2$=0.64, 0.90, 0.79, and 0.89 for palmitic acid, oleic acid, linoleic acid, and total fatty acids, respectively). Standard deviation/standard errors of cross-validation (SD/SECV) values were close to 3 (2.62, 2.40, 1.85, and 2.23 for palmitic acid, oleic acid, linoleic acid, and total fatty acids, respectively). These results indicate that these NIRs equations are functional for the mass screening and rapid quantification of the oleic and total fatty acids characterizing millet germplasm. Among the samples, IT153514 showed an especially high content of fatty acids ($48.14mg\;g^{-1}$), whereas IT123909 had a very low content ($34.44mg\;g^{-1}$).