• Title/Summary/Keyword: Continuum model

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Behavior of Flexible Hose Connected to Mother Ship (모함에 연결된 탄성 호스의 거동)

  • Kim, Kun-Woo;Lee, Jae-Wook;Kim, Hyung-Ryul;Yoo, Wan-Suk;An, Deuk-Man
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.3
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    • pp.235-240
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    • 2011
  • A flexible hose attached to a mother ship experiences various motions that depend on the movement of the mother ship and that of underwater vehicle. Although the motion of the hose is a very important factor that determines how a mother ship should be steered in a real situation, it is difficult to experimentally obtain information about the hose motion. Therefore, we study the motion of the hose analytically. The ANCF(absolute nodal coordinate formulation) was used to model the hose, because this formulation can relax the Euler-Bernoulli theory and the Timoshenko beam theory and allow the deformation of the cross section. The mother ship is assumed to be a rigid body with 6 degrees of freedom. The motion of the hose is predominantly affected by the behavior of the mother ship and by the fluid flow.

Effect of soil pile structure interaction on dynamic characteristics of jacket type offshore platforms

  • Asgarian, Behrouz;Shokrgozar, Hamed Rahman;Shahcheraghi, Davoud;Ghasemzadeh, Hasan
    • Coupled systems mechanics
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    • v.1 no.4
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    • pp.381-395
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    • 2012
  • Dynamic response of Pile Supported Structures is highly depended on Soil Pile Structure Interaction. In this paper, by comparison of experimental and numerical dynamic responses of a prototype jacket offshore platform for both hinge based and pile supported boundary conditions, effect of soil-pile-structure interaction on dynamic characteristics of this platform is studied. Jacket and deck of a prototype platform is installed on a hinge-based case first and then platform is installed on eight skirt piles embedded on continuum monolayer sand. Dynamic characteristics of platform in term of natural frequencies, mode shapes and modal damping are compared for both cases. Effects of adding and removing vertical bracing members in top bay of jacket on dynamic characteristics of platform for both boundary conditions are also studied. Numerical simulation of responses for the studied platform is also performed for both mentioned cases using capability of ABAQUS and SACS software. The 3D model using ABAQUS software is created using solid elements for soil and beam elements for jacket, deck and pile members. Mohr-Coulomb failure criterion and pile-soil interface element are used for considering nonlinear pile soil structure interaction. Simplified modeling of soil-pile-structure interaction effect is also studied using SACS software. It is observed that dynamic characteristics of the system changes significantly due to soil-pile-structure interaction. Meanwhile, both of complex and simplified (ABAQUS and SACS, respectively) models can predict this effect accurately for such platforms subjected to dynamic loading in small range of deformation.

Evaluation of a theory-based community intervention to increase fruit and vegetable intakes of women with limited incomes

  • Chung, Sang-Jin;Hoerr, Sharon L.
    • Nutrition Research and Practice
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    • v.1 no.1
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    • pp.46-51
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    • 2007
  • The study objectives were to increase both the stage of readiness to eat fruit and vegetables as well as the intakes of women who participated in the Expanded Food and Nutrition Education Program (EFNEP) for families with limited incomes. The intervention was to enhance the currently used curriculum, Eating Right Is Basic III (ERIB3), with stage-specific processes based on the Trans-Theoretical Model of readiness to change. Trained EFNEP community workers taught the enhanced curriculum to 90 mothers in the experimental county and to 53 mothers in the control county. Pre- and post-intervention measures included stages of readiness to eat fruit and vegetables and to intake as assessed by 24-hour dietary recalls and staging questions. Most women recruited into EFNEP were in Action and Preparation Stages (53.5%). Fruit and vegetable intakes showed a linear trend along with the Stage of Change for fruit and vegetable. After intervention, some combination of the ERIB3 and the fruit and vegetables-enhanced ERIB3 resulted in a reported 1/2 servings/day increase in fruits and vegetables in both the control and the experimental counties, although changes were not significant. EFNEP women also moved along the Stage of Change Continuum for fruits and vegetables in both counties. The percentage of people who ate 5 or more servings of fruit and vegetables was significant, however, only in the experimental group. We encourage health professionals to apply lessons learned from this intervention and to continue to pursue theoretically based interventions to change dietary behaviors.

FIR Observations and Simple LVG Modeling Results of L1448-MM

  • Lee, Jin-Hee;Lee, Jeong-Eun;Lee, Seok-Ho;DIGIT Team, DIGIT Team
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.82.2-82.2
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    • 2012
  • We present Herschel-PACS observations of L1448-MM, a Class 0 protostar with a prominent outflow, part of the DIGIT Key Program (PI: N. Evans). We detect numerous emission lines including CO and $H_2O$ rotational transitions, OH transitions, and [OI] forbidden transitions at wavelengths from 55 to 210 ${\mu}m$. The $H_2O$, [OI], mid-J CO (J < 23), and OH emission distributes along the outflow direction although high-J CO and other OH emission peaks at the central spatial pixel. According to our simple excitation analysis, CO seems to have two temperature components of warm and hot, which might be attributed to the PDR and shock, respectively. After exploring a wide range of physical conditions with a non-LTE LVG code, RADEX, we found that either shock alone or the combination of PDR and shock can explain the observations. The relative fraction of observed line luminosities suggest that L1448-MM is shielded from the UV radiation because $H_2O$ and CO are the dominant coolants rather than OH and [OI]. In addition, our observed fluxes match better with C-shock models rather than J-shocks. The non-LTE LVG model supports that the IR pumping process is important for OH transitions because the OH line ratios are fitted much better when the dust thermal continuum is included.

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Theoretical Studies on Electronic Structure and Absorption Spectrum of Prototypical Technetium-Diphosphonate Complex 99mTc-MDP

  • Qiu, Ling;Lin, Jian-Guo;Gong, Xue-Dong;Ju, Xue-Hai;Luo, Shi-Neng
    • Bulletin of the Korean Chemical Society
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    • v.32 no.7
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    • pp.2358-2368
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    • 2011
  • Density functional theory (DFT) and time-dependent density functional theory (TDDFT) calculations, employing the B3LYP method and the LANL2DZ, 6-31G$^*$(LANL2DZ for Tc), 6-31G$^*$(cc-pVDZ-pp for Tc) and DGDZVP basis sets, have been performed to investigate the electronic structures and absorption spectra of the technetium-99m-labeled methylenediphosphonate ($^{99m}Tc$-MDP) complex of the simplest diphosphonate ligand. The bonding situations and natural bond orbital compositions were studied by the Mulliken population analysis (MPA) and natural bond orbital (NBO) analysis. The results indicate that the ${\sigma}$ and ${\pi}$ contributions to the Tc-O bonds are strongly polarized towards the oxygen atoms and the ionic contribution to the Tc-O bonding is larger than the covalent contribution. The electronic transitions investigated by TDDFT calculations and molecular orbital analyses show that the origin of all absorption bands is ascribed to the ligand-to-metal charge transfer (LMCT) character. The solvent effect on the electronic structures and absorption spectra has also been studied by performing DFT and TDDFT calculations at the B3LYP/6-31G$^*$(cc-pVDZ-pp for Tc) level with the integral equation formalism polarized continuum model (IEFPCM) in different media. It is found that the absorption spectra display blue shift in different extents with the increase of solvent polarity.

Crystal Structure and Tautomerism Study of the Mono-protonated Metformin Salt

  • Wei, Xiaodan;Fan, Yuhua;Bi, Caifeng;Yan, Xingchen;Zhang, Xia;Li, Xin
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3495-3501
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    • 2014
  • A novel crystal, the mono-protonated metformin acetate (1), was obtained and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. It was found that one of the imino group in the metformin cation was protonated along with the proton transfer from the secondary amino group to the other imino group. Its crystal structure was then compared with the previously reported diprotonated metformin oxalate (2). The difference between them is that the mono-protonated metformin cations can be linked by hydrogen bonding to form dimers while the diprotonated metformin cations cannot. Both of them are stabilized by intermolecular hydrogen bonds to assemble a 3-D supermolecular structure. The four potential tautomer of the mono-protonated metformin cation (tautomers 1a, 1b, 1c and 1d) were optimized and their single point energies were calculated by Density Functional Theory (DFT) B3LYP method based on the Polarized Continuum Model (PCM) in water, which shows that the most likely existed tautomer in human cells is the same in the crystal structure. Based on the optimized structure, their Wiberg bond orders, Natural Population Analysis (NPA) atomic charges, molecular electrostatic potential (MEP) maps were calculated to analyze their electronic structures, which were then compared with the corresponding values of the diprotonated metformin cation (cation 2) and the neutral metformin (compound 3). Finally, the possible tautomeric mechanism of the mono-protonated metformin cation was discussed based on the observed phenomena.

A Study of Galactic Molecular Clouds through Multiwavelength Observations

  • Park, Sung-Joon;Min, Kyoung-Wook;Seon, Kwang-Il;Han, Won-Yong;Lee, Dae-Hee;Edelstein, Jerry;Korpela, Eric;Sankrit, Ravi
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.68.1-68.1
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    • 2010
  • We focus on two Galactic molecular clouds that are located in wholly different environments and both are observed by FIMS instrument onboard STSAT-1. The Draco cloud is known as a translucent molecular cloud at high Galactic latitude. The FUV spectra show important ionic lines of C IV, Si IV+O IV], Si II* and Al II, indicating the existence of hot and warm interstellar gases in the region. The enhanced C IV emission inside the Draco cloud region is attributable to the turbulent mixing of the interacting cold and warm/hot media, which is supported by the detection of the O III] emission line and the $H{\alpha}$ feature in this region. The Si II* emission covers the remainder of the region outside the Draco cloud, in agreement with previous observations of Galactic halos. Additionally, the H2 fluorescent map is consistent with the morphology of the atomic neutral hydrogen and dust emission of the Draco cloud. In the Aquila Rift region near Galactic plane, FIMS observed that the FUV continuum emission from the core of the Aquila Rift suffers heavy dust extinction. The entire field is divided into three sub-regions that are known as the- "halo," "diffuse," and "star-forming" regions. The "diffuse" and "star-forming" regions show various prominent H2 fluorescent emission lines, while the "halo" region indicates the general ubiquitous characteristics of H2. The CLOUD model and the FUV line ratio are included here to investigate the physical conditions of each sub-region. Finally, the development of an infrared imaging system known as the MIRIS instrument onboard STSAT-3 is briefly introduced. It can be used in WIM studies through $Pa{\alpha}$ observations.

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Numerical estimation for safety factors of tunnels considering the failure of supports (지보재 파괴를 고려한 터널 안전율의 수치해석적 산정 연구)

  • You, Kwang-Ho;Park, Yeon-Jun;Hong, Keun-Young;Lee, Hyun-Koo;Kim, Jea-Kwon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.7 no.1
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    • pp.37-49
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    • 2005
  • In a tunnel, failure of its supports can cause failure of the tunnel. Therefore it is important to estimate safety factor of the tunnel which the failure of its supports is taken into account. In previous studies, supports of tunnels were usually modelled as beam elements. The failure of the supports was decided by comparing the allowable stress and the calculated bending stresses inside the beam elements in estimating safety factor of the tunnel considering the failure of its supports. In this study, it is suggested how to model the supports properly. To this end, supports of a tunnel were modelled by both beam (elastic) elements and continuum (elasto-plastic) elements in two dimensional numerical analyses. Meanwhile, it was analyzed how rock mass class, coefficient of lateral pressure, shotcrete thickness, the existence of rock bolt, and excavation method had an effect on the safety factor of a tunnel.

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Embarrassment; a concept analysis (당혹감(embarrassment); 개념분석)

  • Cho, Eun-Jung;Chung, Bok-Yae
    • Korean Journal of Adult Nursing
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    • v.14 no.2
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    • pp.276-286
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    • 2002
  • Purpose: The concept of embarrassment as an unpleasant emotion is important in caring for those who are in the continuum of illness and health requiring body care and facing sexual problems. In spite of its nursing implication, embarrassment has not been focused in nursing research. Therefore, the purpose of this paper is to develope a conceptual analysis of embarrassment. This analysis would help to understand comprehensively an embarrassing situation in which an intimate relationship between nurse and patient regarding body care of the patient could develope. Futhermore, it would be a basis for developing strategies for prevention of embarrassment which could lead for both patient and nurse to emotionally vulnerable situation because of their failure of self-presentation (impression management). Method: The concept analysis model suggested by Walker and Avant (1988) is used to clarify what is meant by the term 'embarrassment'. Result: This analysis defines the attributes of embarrassment such as follows. First, embarrassment is often attributed to situational factors interrupting a smooth interaction such as intimacy, confusion, vulnerability, exposure of interaction and characteristics of audience. Second, embarrassment is closely related with cognitive factor such as fear of losing face resulted from a behaviour being out of line. Third, embarrassment is closely associated with dispositional factor such as embarrassability. Fourth, embarrassment is an unpleasant and unwanted emotion arising reactively after an interaction had occurred. Fifth, embarrassment encloses physical, physiological and behavioral aspects such as a variety of unique and easily noticeable reactions and a pattern of verbal and non-verbal behaviour for coping in an embarrassing situation. The antecedents were normally socialized adolescents with normal cognitive ability, concern of losing face, embarrassability, embarrassing events related with situational intimacy, confusion, vulnerability, exposure of interaction and characteristics of audience, physical, behavioral blunders resulting in a failure of impression management. The consequences were an emotional coping behaviour, audience's embarrassment responses, and verbal and non-verbal coping strategies of interactional participants. Conclusion: It is hoped that this analysis will stimulate further exploration of this concept and study for developing systematic assessment and nursing practice that diminishes embarrassment of interactional participants.

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A Study on Factors of Elderly Residential Care Service Utilization for using Decision Tree Regression (의사결정분석을 이용한 우리나라 노인의 요양시설서비스 이용 결정요인에 관한 연구)

  • Lim, Jeong-Gi
    • Korean Journal of Social Welfare
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    • v.60 no.3
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    • pp.129-150
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    • 2008
  • This study examined the factors affecting service utilization of elderly residential care among long term care services recipients during long term care insurance pilot project period in Korea. Help-seeking Behavior model developed by Andersen and Newman(1973) was used to analyze the factors affecting their utilization residential care service among 1,939 long term care services recipients. Frequency and Decision Tree Regression analysis on SPSS 13.0 used. Analyses show strong significant factor is service preference(predisposing factors), and then significant factors are enabling factors such as co-residence type, household income. According to this results, need factors such as cognition disorder, problem behavior, ADL and IADL disabilities are affecting utilization behavior of elderly residential care services. These findings provide implications and suggestions about how long term care service system would be settled in Korea. And these finding provide information about target-efficient long term care continuum system to policy makers and helping professionals.

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