• Wind and Structures
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• v.13 no.2
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• pp.127-144
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• 2010

Pressure measurements on static and autorotating flat plates have been recently reported by Lin et al. (2006), Holmes, et al. (2006), and Richards, et al. (2008), amongst others. In general, the variation of the normal force with respect to the angle of attack appears to stall in the mid attack angle range with a large scale separation in the wake. To date however, no surface pressures have been measured on auto-rotating plates that are typical of a certain class of debris. This paper presents the results of an experiment to measure the aerodynamic forces on a flat plate held stationary at different angles to the flow and allowing the plate to auto-rotate. The forces were determined through the measurement of differential pressures on either side of the plate with internally mounted pressure transducers and data logging systems. Results are presented for surface pressure distributions and overall integrated forces and moments on the plates in coefficient form. Computed static force coefficients show the stall effect at the mid range angle of attack and some variation for different Reynolds numbers. Normal forces determined from autorotational experiments are higher than the static values at most pitch angles over a cycle. The resulting moment coefficient does not compare well with current analytical formulations which suggest the existence of a flow mechanism that cannot be completely described through static tests.

• Journal of the Korean Magnetics Society
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• v.1 no.1
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• pp.6-11
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• 1991

In order to investigate electronic and magnetic properties of permanent magnets, we have performed self-consistent electronic structure calculations on compounds of rare-earth and transition metals, such as $SmCo_{5},\;NdB_{6},\;NdFe_{5},\;NdFe_{4}B$. Employing the local density LMTO(linearized muffin tin orbital) band method, we have obtained the ground state parameters, such as band structures, density of states, Stoner parameters, and magnetic moments. We have also investigated interactions between d,f-electrons of Nd, Sm rare-earths and d-electrons of Fe, Co transition metals, and the s,p electrons of boron and explored effects of such interactions on the bonding mechanism and the electronic and magnetic structures in these rare-earth compounds.

• Structural Engineering and Mechanics
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• v.89 no.4
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• pp.363-374
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• 2024

Significant changes have been made to estimate the punching shear capacity for edge column-slab joints in the latest editions of most current codes. The revised equations account for axial forces as well as moments conveyed to columns from slabs, which have a substantial impact on the punching resistance of such joints. Many key design parameters, such as reinforcement-ratio, concrete strength, size-effect, and critical-section perimeter, were treated differently or even ignored in various code provisions. Consequently, wide ranges of predicted punching shear strength were detected by applying different code formulas. Therefore, it is essential to assess the various current Codes' design-equations. Because of the similarity in estimated outcomes, only the ACI, EC, and SNiP are used in this study to cover a wide range of estimation ranges from highly conservative to unconservative. This paper is devoted to analyzing the techniques in these code provisions, comparing the estimated punching resistance with available experimental data, and finally developing efficient models predicting the punching capacity of edge column-slab connections. 63 samples from past investigations were chosen for validation. To appropriately predict the punching shear, newly updated equations for ACI and SNiP are provided based on nonlinear regression analysis. The proposed equations'results match the experimental data quite well.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.637-645
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• 2009

The purpose of this study was to investigate the biomechanical alterations in the punching motion of 10 elderly women after 12 weeks of taekwonaerobics training. Seven infrared cameras(Qualisys MCU-240) and 2 force platforms(Kistler-9286AA) were used to acquire raw data. The results were as follows. First, the minimum joint angles of the lower limbs had a statistically significant difference between both the dorsiflexion/plantar flexion(1eft, $p=0.001^*$) and the inversion/eversion(both, $p=0.009^*$, $p=0.04^*$) from the ankle angle. There were differences in abduction/adduction(left, $p=0.04^*$) from the knee angle, as well as internal/external rotation(both, $p=0.07^*$, $p=0.02^*$) from the hip angle. Second, the maximum resultant joint moments of the lower limbs had statistically significant differences in the inversion/eversion moment from the ankle joint(both, $p=0.05^*$, $p=0.05^*$), the abduction/adduction moment(left, $p=0.08^*$) from the knee joint, and the internal/external rotation moment(right, $p=0.09^*$) from the hip joint. Third, the maximum resultant joint powers of the lower limbs had a statistically significant difference both in flexion/extension joint powers(both, $p=0.05^*$, $p=0.01^*$) and in abduction/adduction(both, $p=0.02^*$, $p=0.00^*$) from the hip joint, as well as abduction/adduction(left, $p=0.00^*$) from the knee joint, In conclusion, the elderly women were somewhat changed after 12 weeks of taekwonaerobics training.

• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.645-656
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• 2016

The study performed a regional flood frequency analysis and proposed a regression equation to estimate design floods corresponding to return periods for ungauged basins in Geum-river basin. Five preliminary tests were employed to investigate hydrological independence and homogeneity of streamflow data, i.e. the lag-one autocorrelation test, time homogeneity test, Grubbs-Beck outlier test, discordancy measure test ($D_i$), and regional homogeneity measure (H). The test results showed that streamflow data were time-independent, discordant and homogeneous within the basin. Using five probability distributions (generalized extreme value (GEV), three-parameter log-normal (LN-III), Pearson type 3 (P-III), generalized logistic (GLO), generalized Pareto (GPA)), comparative regional flood frequency analyses were carried out for the region. Based on the L-moment ratio diagram, average weighted distance (AWD) and goodness-of-fit statistics ($Z^{DIST}$), the GLO distribution was selected as the best fit model for Geum-river basin. Using the GLO, a regression equation was developed for estimating regional design floods, and validated by comparing the estimated and observed streamflows at the Ganggyeong station.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.394-410
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• 1993

This study was accomplished for appreciation of the mandibular moments according to antero- posterior movement of pivot placed on the lower natural dentition. For this study, 20 subjects(male, $21\sim30$ yrs., average age 24) in the category of normal occlusion were selected, and the intraoral Vitallium clutches were cast and fabricated for each subjects. A 2-dimension PSD(Position Sensitive Detector, Hamamatsu Photonics Co., Japan) was attached to maxillary clutch in a mode of three dimensional control and LED (Light Emit Diode, Hamamatsu Photonics Co., Japan) was set up on mandibular clutch. Both clutches were set into oral cavity of each subjects and adjusted. Then the subjects were allowed to intercuspated with maximal bite force while the pivoting ball in the mid-line moving from anterior toward posterior position. The displacement scales were recorded by CCD camera(Sony, CCD-TR-705) and VCR, The conclusions were as follows : 1. When the subject was allowed to bite the metal pivoting ball in the midline of lower dentition with maximal bite force voluntarily while moving from lower central incisor to canine, 1st premolar, End premolar, 1st molar and 2nd molar. The lever actions on the pivot were revealed in all subjects. The equilibrium of moment were revealed on the pivots of 1st premolar(14 subjects), End premolar(4 subjects), and canine(2 subjects) areas. 2. The changes of loading on the TMJ according to antero-posterior positional changes of metal pivoting ball were able to recognize as follow. Compression on the TMJ was increased when the pivot moves anteriorly from the equilibrium point, and tension on the TMJ was increased when posteriorly. 3. 13 subjects were recognized their habitual chewing sides(Rights, Left8), and 7 subjects were not. During maximal biting, mandible was displaced toward their habitual chewing sides on the metal pivoting ball in the frontal plane. 4. In cephalometric analysis, the average genial angle of 20 subjects was $116.75^{\circ}$ and the average mandibular body length was 79.77mm. The equilibrium points of mandibular moment were positioned more posteriorly in the subjects having larger Genial angle than in the smaller(p<0.05). Relationships among the angle between FH plane and occlusal plane, the angle between occlusal plane and mandibular plane , and mandibular body length were not significant(p>0.05).

• Geotechnical Engineering
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• v.14 no.6
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• pp.81-92
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• 1998

A beam on elasto-plastic foundation modeling of soldier pile and woodlagging tieback walls or anchored walls was developed and tested. An instrumented full scale tieback wall in sand was constructed at the National Geotechnical Experimentation Bite located on Texas A&M University. The experimental earth pressure deflection relationship (p-y curves) was developed from the measurements. The construction sequence was simulated in the proposed method. The conceptual methodology of an anchored wall design was introduced by using the proposed method. The proposed method was evaluated with the measurements of case histories in sand and clay. A parametric research was performed to study the most influencing factors for the proposed method. It is concluded that the proposed method represents a significant improvement on the prediction of bending moments and deflections of the properly designed walls.

• Journal of the Korean Geotechnical Society
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• v.22 no.8
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• pp.77-88
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• 2006

In this study, the lateral behavior of Pile-Bent structures subjected to lateral loading was evaluated by a load-transfer approach. An analytical method based on the Beam-Column model and nonlinear load transfer curve method was proposed to consider material non-linearity (elastic and yielding) and $P-{\Delta}$ effect. Special attention was given to the lateral deflection of Pile-Bent structures depending on different soil properties, lateral load, slenderness ratio based on pier length and reinforcing effect of casing. From the results of the parametric study, it is shown that the increase of lateral displacement in a pile is much less favorable for an inelastic analysis than for an elastic analysis. It is found that for inelastic analysis, the maximum bending moment is located within a depth approximately 3.5D(D: pile diameter) below ground surface, but within 1.5D when $P-{\Delta}$ effect is considered. It is also found that the magnitude and distribution of the lateral deflections and bending moments on a pile are highly influenced by the inelastic analysis and $P-{\Delta}$ effect, let alone soil properties around an embedded pile.

• Journal of the Korean Geotechnical Society
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• v.23 no.6
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• pp.37-51
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• 2007

In this study, pile load tests have been carried out to develop new P-y curves and then, to investigate the effects of pile rigidities on laterally loaded offshore drilled shafts in Incheon marine clay. This paper consists mainly of two parts: the first part, performance of a series of lateral load tests on small- and full-scale piles under one- and two-way loadings and the second part, comparison between the measured and predicted results by using O'Neill's and Matlock's clay models. Based on the results obtained, it is shown that relatively good agreements in bending moments and lateral displacements were obtained between the measured results using calculated P-y curves and predicted ones by O'Neill's and Matlock's clay models. The cases were considered with varying rigidity factors based on pile diameter, length and subgrade soil reaction. Through comparisons, it is found that soil P-y curve influences highly the behavior of flexible pile rather than that of rigid pile.

• Journal of Korean Academy of Nursing
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• v.10 no.2
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• pp.95-115
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• 1980

Current statistics reveal remarkable prolongation of the average longevity in this country for the past decade. Welfare of the aged is no longer sole concern of the person or/and family. but has aroused social concern on the community and national level. This study was designed to assess social, economic and emotional needs of the aged. and to identify problems they are confronting. Data were gathered through questioning 273 subjects living in Seoul from July 25, to August 31. 19 80. Frequencies and percentile scores were analysed to describe the fact. and the significance of int or-variable differences was tested by Chi-square method. Results are : 1. Majority of the subjects (male : 65.38%). (female : 62.13%)“talk about past experiences”to re-collect their past days, the difference between male and female respondents was not significant. 2. Except few who earn their pocket money (4.21%). majority were doing household errands (34.52% ) and looking after their garnd children (29.26 ％）. Main sources of their pocket money revealed to be their children (84.02%) and their own savings (24.64% ). Except few (15％）engaged with social activities directly or indirectly. leisure hours are spent in chatting with aged neighbors (44.81%). Highest in the rank order on the joyous moments for the aged revealed to be when the members of family living apart paying a visit (male : 37.5%, female : 63.72%)difference of male and female was significant ( P<0.05). Among female respondents. significant difference between age group was revealed (p<0.05). 3. Majority prefered sin91e houses (84.30% ). as residential environment. the suburban (36.26% ) area was the filet in the rank order : difference between age group and the educational status were not significant. Majority of respondents revealed to have their own room in the house. The first preference was given to live with their children (68.86%). Memory of the past (37.36% )revealed to be the highest in the rank order among the reasons why they dislike moving the house. 4. Majority favored current welfare benefts provided for the old age. however. the ideal way to live at their old age they responded was to live on their own savings (50.54%). 5. Majority revealed to be daunted occasionally (62.27%) by not being less active (34.16%) socially and by poor physical health(29.75%). Male and female differ in the causes of loneliness significantly (P <0.001) : retirement (37.89%) in ale and helpessness (43.05%) in female revealed the highest in the rank order. Majority talk over their feelings with aged neighbors to overcome the loneliness. 6 Majority were in favor of planting and looking after pet animal in the house. however. male and female differ in the kind significantly (p <0.001), 7. Majority think about death and dying occasionally or more (84.11% ). Many of the respondents believes in the life after life (53.49%) : female revealed to be significantly higher (p <0.01). and subjects with christian belief were significantly higher than non-christians (P<0.001). Attitude towards death and dying differs significantly between male and female (P <0. 001) and between christians ans and nonchristians (p <0.001). Highest preference was given to simple funeral (69.85%). Precious heritage that they would pass on to their descendants was onoscience and ethical value(57. 51%) : christian response as the first value was christian belief (52.38%).