• Title/Summary/Keyword: Dynamic interaction analysis

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Individual and Family Background Predictors of Nontraditional Career Orientation among U.S. College Women (전통적으로 남성 주도적인 전문직 진출을 희망하는 여대생의 성격 및 가족환경의 특성 연구 : -법률가 및 의사직을 준비하는 미국 여대생을 중심으로-)

  • 김용미
    • Journal of the Korean Home Economics Association
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    • v.27 no.3
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    • pp.173-182
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    • 1989
  • 이 연구의 목적은 전통적으로 남성 주도적인 전문직 진출을 희망하는 여대생(이 연구에서는 법률가 및 의사직, 이하 비 전통적인 여성이라 부름)과 전통적으로 여성 주도적인 전문직 진출을 준비중인 여대생 (이 연구에서는 교사 및 간호사직, 이하 전통적으로 여성 이라 부름)을 구분 할수 있는 개인의 성격 및 가족환경의 특성을 검토하는 것이었다. 남성 주도적인 전문직에 진출을 준비하거나 그 분야에 종사하는 여성들의 특성에 대한 연구가 많이 발표되었으나 그 특징들의 중요성이 상대적으로 얼마나 비중이 있는지는 연구되어 있지 않다. 발단론적 환경이론(Developmental-Contextualism)과 직업 발달에 대한 역동적 상호관계 모델(Dynamic Interaction Model)이 본 연구의 이론적 체계를 이루고 있다. 이 연구에 포함성의 위치, 심리적 남성특성, 출신가정의 사회경제수준, 그리고 부모의 뒷받침과 이해였다. ANOVA 결과에 의하면 비전통적인 여성들이 자아존중감, 학교성적 성취도, 내적 통제성, 심리적 남성특성, 그리고 출신가정의 사회경제수준 면에서 전통적인 여성에 비해 훨씬 높은 수준을 나타내었다. 단계적 분별 분석 (Stepwise Discriminant Analysis) 결과에 따르면, 심리적 남성 특성, 내적 통제성, 학교성적 성취도, 그리고 출신가정의 사회경제수준이 위 두집단의 여성들을 분별하는 가장 뛰어난 특성들이었으며 전체 표본의 76.99%가 이 요인들에 의해 정확하게 분류되었다. 이 연구의 결과를 토대로 볼 때, 역동적 상호관계모델은 여성의 직업발달을 연구하는데 있어서 이론정립과 검사에 유효한 도구로 보이며, 이 연구에 포함한 변수들은 비 전통적인 여성들의 특성을 정확하게 묘사하는데 상당한 공헌을 하고 있었다. 마지막으로, 비전통적인 여성들의 직업발달을 연구하는데 있어서 "능력특성군(Competency-related traits)"의 변수들을 좀 더 정확하게 분류할 필요가 있으며, 이 변수들과 여성의 직업발달의 관계를 자세히 연구할 필요가 있다고 본다.요가 있다고 본다.

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Dynamic analysis of wind turbine wake (풍력 발전 터빈 후류의 동적 분석)

  • Um, Young Han;Kim, Yun Gu;Park, Sung Goon
    • Journal of the Korean Society of Visualization
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    • v.18 no.2
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    • pp.59-65
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    • 2020
  • Vertical axis wind energy systems including 3 and 4 blades are numerically investigated in a two-dimensional (2D) computational domain. The power coefficient (Cp) is adopted to measure the efficiency of the system and the effect of the rotating velocity on the power coefficient is analyzed for the two different systems. The rotating velocity varies from 30 rad/s to 90 rad/s, which corresponds to the tip speed ratio (T.S.R) of 0.5 to 1.5. The torque exerted on the blades is mainly determined by the aerodynamic force in the x-direction and maximized when the blade is positioned at around θ = 186°. The efficiency of the 4-blade system is higher than that of the 3-blade system within the tip speed ratio range between 0.5 and 0.67, besides where the 3-blade system shows a better performance. For the 3-blade system, the maximum efficiency is reached to 0.082 at the tip speed ratio of 1.083. The maximum efficiency of the 4-blade system is 0.071 at T.S.R. = 0.92. The velocity fields in the x-direction, pressure fields, and the vorticity magnitude are analyzed in detail for the optimal cases of the 3- and 4-blades systems, respectively.

Vibration Analysis of Pears in Packaged Freight Using Finite Element Method (유한요소법을 이용한 골판지 포장화물내 배의 진동해석)

  • Kim M. S.;Jung H. M.;Kim K. B.
    • Journal of Biosystems Engineering
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    • v.29 no.6 s.107
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    • pp.501-507
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    • 2004
  • Fruits we subjected to complex dynamic stresses in the transportation environment. During a long journey from the production area to markets, there is always some degree of vibration present. Vibration inputs are transmitted from the vehicle through the packaging to the fruit. Inside, these cause sustained bouncing of fruits against each other and container wall. These steady state vibration input may cause serious fruit injury, and this damage is particularly severe whenever the fruit inside the package is free to bounce, and is vibrated at its resonant frequency. The determination of the resonant frequencies of the fruit may help the packaging designer to determine the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. The vibration characteristics of the pears in corrugated fiberboard container in transit were analyzed using FEM (finite element method) modeling, and the FEM modeling approach was first validated by comparing the results obtained from simulation and experiment for the pear in the frequency range 3 to 150 Hz and acceleration level of 0.25 G-rms and it was found that between simulated and measured frequencies of the pears have a relatively good agreement. It was observed that the fruit and vegetables in corrugated fiberboard container could be analyzed by finite element method. As the elastic modulus of the cushion materials of corrugated fiberboard pad and tray cup decreased, the first frequencies of upper and lower pears increased and the peak acceleration decreased.

Numerical study on Floor Response Spectrum of a Novel High-rise Timber-concrete Structure

  • Xiong, Haibei;Zheng, Yingda;Chen, Jiawei
    • International Journal of High-Rise Buildings
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    • v.9 no.3
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    • pp.273-282
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    • 2020
  • An innovative high-rise timber-concrete hybrid structure was proposed in previous research, which is composed of the concrete frame-tube structure and the prefabricated timber modules as main structure and substructures, respectively. Considering that the timber substructures are built on the concrete floors at a different height, the floor response spectrum is more effective in estimating the seismic response of substructures. In this paper, the floor response spectra of the hybrid structure with different structural parameters were calculated using dynamic time-history analysis. Firstly, one simplified model that can well predict the seismic response of the hybrid structure was proposed and validated. Then the construction site, the mass ratio and the frequency ratio of the main-sub structure, and the damping ratio of the substructures were discussed. The results demonstrate that the peaks of the floor response spectra usually occur near the vibration periods of the whole structure, among which the first two peaks stand out; In most cases, the acceleration amplification effect on substructures tends to be more evident when the construction site is farther from the fault rupture; On the other hand, the acceleration response of substructures can be effectively reduced with an appropriate increase in the mass ratio of the main-sub structure and the damping ratio of the substructures; However, the frequency ratio of the main-sub structure has no discernible effect on the floor response spectra. This study investigates the characteristics of the floor response spectrum of the novel timber-concrete structure, which supports the future applications of such hybrid structure in high-rise buildings.

$La_{0.7}Ca_{0.3-x}Ba_xMnO_3$ manganites : Local structure and transport properties

  • A.N.Ulyanov;Yang, Dong-Seok;Yu, Seong-Cho
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2003.05a
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    • pp.8-8
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    • 2003
  • Electron-phonon interaction plays a significant role in forming of colossal magnetoresistance effect (CMR). Polaron formation was observed by neutron diffraction and by extended X-ray absorption fine structure (EXAFS) analysis. Local probe as given by the EXAFS is a useful method to study the polaronic charge and its dependence on temperature and ions size. Here we present the EXAFS study of polaronic charge in La/sub 0.7/Ca/sub 0.3-X/Ba/sub X/MnO₃ compositions. The single phase La/sub 0.7/Ca/sub 0.3-X/Ba/sub X/MnO₃ manganites (x=0; 0.03; 0.06, ..., 0.3) were prepared by ceramic technology [1]. The Curie temperature was determined by extrapolation of the temperature dependence of the magnetization (down to zero magnetization). EXAFS experiments were carried out at the 7C EC beam line of the Pohang Light Source (PLS) in Korea. The atomic pair distribution functions (PDF) were obtained by re-regularization method [2] from filtered spectra. The PDF for the x=0.3 sample showed a single peak function and for x=0.0, 0.03, 0.06, 0.09, 0.12 compositions were asymmetric in agreement with a small Jahn-Teller elongation of two (short and long) bonds of the MnO/sub 6/ octahedron. Dispersion, σ/sub Min-O//sup 2/, and asymmetry, σ/sub Min-O//sup 3/, of the Mn-O bond distances varied significantly with x and showed a maximums at x=0.09. The maximum of σ/sub Min-O//sup 2/ is caused by increase of dynamic rms displacements of the Mn-O distances near the T/sub C/. The observed x dependence of σ/sub Min-O//sup 3/ reflects the reduction of charge carriers mobility at approaching to T/sub C/ from low as well as high temperatures.

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Fish-trait Simulator for Constructing Virtual Aquarium System (가상수족관 시스템 구축을 위한 어류 생태 시뮬레이터)

  • Jeong, Seung-Moon;Lee, Hyeon-Cheol;Kim, Eun-Seok;Hur, Gi-Taek;Gang, Gyeong-Heon
    • The Journal of the Korea Contents Association
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    • v.7 no.3
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    • pp.68-78
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    • 2007
  • In a virtual aquarium, the behavior of fish objects is the most important factor in respect of visual effects. In addition to the individual behavior of fish object, the interactions between objects due to their attributes, can improve the dynamics and reality of the virtual world. In this paper, we analyze the principal habits of fish objects such as the vitality, the range of movement, the maximum depth of water they can live, and the cycle of eating. Then, we suggest a method for simulating the stable marine ecosystem with controlling the behaviors, the interaction with other species, the average span of life, and all that sort of thing based on the result of analysis. Because we can freely modify the behavior of fish object by altering the values of attributes, it can be utilized in the dynamic virtual aquarium, the 3D aquarium screen saver, and the virtual fish game, and so on.

Pavement condition assessment through jointly estimated road roughness and vehicle parameters

  • Shereena, O.A.;Rao, B.N.
    • Structural Monitoring and Maintenance
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    • v.6 no.4
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    • pp.317-346
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    • 2019
  • Performance assessment of pavements proves useful, in terms of handling the ride quality, controlling the travel time of vehicles and adequate maintenance of pavements. Roughness profiles provide a good measure of the deteriorating condition of the pavement. For the accurate estimates of pavement roughness from dynamic vehicle responses, vehicle parameters should be known accurately. Information on vehicle parameters is uncertain, due to the wear and tear over time. Hence, condition monitoring of pavement requires the identification of pavement roughness along with vehicle parameters. The present study proposes a scheme which estimates the roughness profile of the pavement with the use of accurate estimates of vehicle parameters computed in parallel. Pavement model used in this study is a two-layer Euler-Bernoulli beam resting on a nonlinear Pasternak foundation. The asphalt topping of the pavement in the top layer is modeled as viscoelastic, and the base course bottom layer is modeled as elastic. The viscoelastic response of the top layer is modeled with the help of the Burgers model. The vehicle model considered in this study is a half car model, fitted with accelerometers at specified points. The identification of the coupled system of vehicle-pavement interaction employs a coupled scheme of an unbiased minimum variance estimator and an optimization scheme. The partitioning of observed noisy quantities to be used in the two schemes is investigated in detail before the analysis. The unbiased minimum variance estimator (MVE) make use of a linear state-space formulation including roughness, to overcome the linearization difficulties as in conventional nonlinear filters. MVE gives estimates for the unknown input and fed into the optimization scheme to yield estimates of vehicle parameters. The issue of ill-posedness of the problem is dealt with by introducing a regularization equivalent term in the objective function, specifically where a large number of parameters are to be estimated. Effect of different objective functions is also studied. The outcome of this research is an overall measure of pavement condition.

Habitat Potential Evaluation Using Maxent Model - Focused on Riparian Distance, Stream Order and Land Use - (Maxent 모형을 이용한 서식지 잠재력 평가 - 하천으로부터의 거리, 하천의 차수, 토지이용을 중심으로-)

  • Lee, Dong-Kun;Kim, Ho-Gul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.6
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    • pp.161-172
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    • 2010
  • As the interest on biodiversity has increased around the world, researches about evaluating potential for habitat are also increasing to find and comprehend the valuable habitats. This study focus on comprehending the significance of stream in evaluating habitat's potential. The purpose of this study is to evaluate habitat potential with applying stream as a main variable, and to comprehend the relationship between the variables and habitat potential. Basin is a unit that has hydrological properties and dynamic interaction with ecosystem. Especially, biodiversity and suitability of habitat in basin area has direct correlation with stream. Existing studies also are proposing for habitat potential evaluation in basin unit, they applied forest, slope and road as main variables. Despite stream is considered the most important factor in basin area, researchers haven't applied stream as a main variable. Therefore, in this study, three variables that can demonstrate hydrological properties are selected, which are, riparian distance, stream order and land use disturbance, and evaluate habitat potential. Habitat potential is analyzed by using Maxent (Maximum entropy model), and vertebrate's presence data is used as dependent variables and stream order map and land cover map is used as base data of independent variables. As a result of analysis, habitat potential is higher at riparian and upstream area, and lower at frequently disturbed area. Result indicates that adjacent to stream, upstream, and less disturbed area is the habitat that vertebrate prefer. In particular, mammals prefer adjacent area of stream and forest and reptiles prefer upriver area. Birds prefer adjacent area of stream and midstream and amphibians prefer adjacent area of stream and upriver. The result of this research could help to establish habitat conservation strategy around basin unit in the future.

A cost-effective method to prepare size-controlled nanoscale zero-valent iron for nitrate reduction

  • Ruiz-Torres, Claudio Adrian;Araujo-Martinez, Rene Fernando;Martinez-Castanon, Gabriel Alejandro;Morales-Sanchez, J. Elpidio;Lee, Tae-Jin;Shin, Hyun-Sang;Hwang, Yuhoon;Hurtado-Macias, Abel;Ruiz, Facundo
    • Environmental Engineering Research
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    • v.24 no.3
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    • pp.463-473
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    • 2019
  • Nanoscale zero-valent iron (nZVI) has proved to be an effective tool in applied environmental nanotechnology, where the decreased particle diameter provides a drastic change in the properties and efficiency of nanomaterials used in water purification. However, the agglomeration and colloidal instability represent a problematic and a remarkable reduction in nZVI reactivity. In view of that, this study reports a simple and cost-effective new strategy for ultra-small (< 7.5%) distributed functionalized nZVI-EG (1-9 nm), with high colloidal stability and reduction capacity. These were obtained without inert conditions, using a simple, economical synthesis methodology employing two stabilization mechanisms based on the use of non-aqueous solvent (methanol) and ethylene glycol (EG) as a stabilizer. The information from UV-Vis absorption spectroscopy and Fourier transform infrared spectroscopy suggests iron ion coordination by interaction with methanol molecules. Subsequently, after nZVI formation, particle-surface modification occurs by the addition of the EG. Size distribution analysis shows an average diameter of 4.23 nm and the predominance (> 90%) of particles with sizes < 6.10 nm. Evaluation of the stability of functionalized nZVI by sedimentation test and a dynamic light-scattering technique, demonstrated very high colloidal stability. The ultra-small particles displayed a rapid and high nitrate removal capacity from water.

Identification of Serial DNA Methylation Changes in the Blood Samples of Patients with Lung Cancer

  • Moon, Da Hye;Kwon, Sung Ok;Kim, Woo Jin;Hong, Yoonki
    • Tuberculosis and Respiratory Diseases
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    • v.82 no.2
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    • pp.126-132
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    • 2019
  • Background: The development of lung cancer results from the interaction between genetic mutations and dynamic epigenetic alterations, although the exact mechanisms are not completely understood. Changes in DNA methylation may be a promising biomarker for early detection and prognosis of lung cancer. We evaluated the serial changes in genome-wide DNA methylation patterns in blood samples of lung cancer patients. Methods: Blood samples were obtained for three consecutive years from three patients (2 years before, 1 year before, and after lung cancer detection) and from three control subjects (without lung cancer). We used the MethylationEPIC BeadChip method, which covers the 850,000 bp cytosine-phosphate-guanine (CpG) site, to conduct an epigenome-wide analysis. Significant differentially methylated regions (DMRs) were identified using p-values <0.05 in a correlation test identifying serial methylation changes and serial increase or decrease in ${\beta}$ value above 0.1 for three consecutive years. Results: We found three significant CpG sites with differentially methylated ${\beta}$ values and 7,105 CpG sites with significant correlation from control patients without lung cancer. However, there were no significant DMRs. In contrast, we found 11 significant CpG sites with differentially methylated ${\beta}$ values and 10,562 CpG sites with significant correlation from patients with lung cancer. There were two significant DMRs: cg21126229 (RNF212) and cg27098574 (BCAR1). Conclusion: This study revealed DNA methylation changes that might be implicated in lung cancer development. The DNA methylation changes may be the possible candidate target regions for the early detection and prevention of lung cancer.