• Title/Summary/Keyword: Hybrid Stress Analysis

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Concept Development of Resilience (회복력 (Resilience) 개념 개발)

  • 김혜성
    • Journal of Korean Academy of Nursing
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    • v.28 no.2
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    • pp.403-413
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    • 1998
  • The Resilience is described as the personal capacity which brings psychosocial comeback. The role of nursing is to do its best to rehabilitate patients and to explore the individual in order to promote patients psychosocial change. However, as the current nursing is heavily physical nursing oriented, the identity of the nursing would be lost. Therefore this researcher reviewed if the concept of resilience can be applied to the nursing after examing the concept of resilience by Documents and Fieldwork. The methodology of this research is Hybrid Model developed by Schwartz-Barcott and Kim for the concept development and analysis. The process and procedure consist of The Theoretical Phase, The Fieldwork Phase and The Final Analytical Phase in accodance with the Hybrid Model. The followings the summary of the Research. 1. The Concept of Resilience Finally Analyzed by Documents and Fieldwork (1) The Redefinition of Resilience The resilience is the latent psychosocial capacity which minimize the negative emotion and promote the adaptation under adversity. Resilience appears as cognitive, emotional and behavioral response in the course of changing from negative response to positive response through the interaction of the individual and the enviroments in a given time. Resilience changes and decreases according to time and situation and it can be nurtured. Resilience is the higher concept including hardiness, sense of coherence and self-strength which maintain the health under stress. (2) The Attribute of Resilience The attribute of resilience was devided into psychological and social dimension. In psychological attributes, there are admittion of reality of situation, denial of negative emotion, desire to live, responsibility, confidence, courage, hope, pursuit of positive meaning, identification and pursuit of goal, self-esteem, reception, spontaneity, planning, positiveness, will power, flexibility and creativity. In social attributes, there are a sense of belonging, perception of social support and active social relations. (3) The Process of Resilience There are 4 resilience phases which were the process minimizing the possibility of the negative chain reactions under adversity, the process minimizing the negative emotion under adversity, the process gaining the desire to live and the process exposing the active social relations. 2. The Application Possibility of Resilience Concept to Nursing The resilience concept is the psychosocial capacity with which an individual manages adversity. As many nursing scientists have developed nursing theory based on this capacity and the identification of nursing has been established in this field, resilience is not the new conception in nursing. However, since resilience appears in the attributes related with the resilience process concretely, it would help a lot when nurses execute psychosocial nursing.

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THE EFFECT OF MOISTENING OF ETCHED DENTIN AND ENAMEL SURFACE ON THE MICROLEAKAGE OF COMPOSITE RESINS (복합레진 수복시 상아질 표면 처리가 미세 변연 누출에 미치는 영향에 관한 연구)

  • Jeon, Cheol-Min;Kwon, Hyuk-Choon;Lee, Chung-Sik;Lee, Myung-Jon;Um, Chung-Moon
    • Restorative Dentistry and Endodontics
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    • v.21 no.1
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    • pp.321-338
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    • 1996
  • The purpose of this study was to evaluate the effect of moistening and air-drying of acid conditioned dentin and enamel on the marginal microleakage. In this study, Class V cavity were prepared on both buccal and lingual surface of sixty extracted human premolars with cementum margin. These specimens were randomly devided into three groups and three dentin adhesives(Scotchbond Multi-Purpose, All bond 2, Prisma Universal Bond 3) were applied to each group. The specimens in each group were subdevided into four groups (Wet/primed, Dry/primed, Wet/not primed, Dry/not primed) and the etched dentin and enamel surface were treated these four surface treatments prior to the placement of a bonding agent or adhesive. Wet/primed group was simply blot-dried with a damp facial tissue before primer placement ; Dry/primed group was air dried for 30 seconds before the placement of a primer ; Wet/not primed group and Dry/not primed group were not primed after blot dried and air dried for 30 seconds each group. The bonding agent and composite resin were applied for each group. All specimens were exposed to 500 cycle of thermal stress. Specimens were placed in a silver nitrate solution and then sectioned buccolingually through the center of the restoration. The dye penetrations of the specimens were observed with a stereo microscope. The statistical test were applied to the results using a one way analysis variance (ANOVA) and Duncan's multiple range test. The aspects of silver ion penetration into the resin/dentin interface were examined under scanning electron microscopy. The results were as follows. 1. In all groups, the enamel margin showed significantly lower leakage value than the cementum margin (p<0.05). 2. Regardless of various surface treatment and dentin adhesives, there was no significant difference at the enamel margins (p>0.05). 3. At the dentin margins, the leakage values of Dry/not primed group showed significantly higher than that of the other groups (p<0.05). The leakage values of Wet/primed group showed significantly lower than that of the other groups, but, there was no significant difference between Wet group and Dry group. 4. There was no significantly difference between the dentin adhesives regarding the surface treatments in all groups(p>0.05). 5. On the backscatterd scanning electron microscopy observation, the penetration of the silver ion occured at the bonding resin/dentin interface. In the Wet/primed group, resindentin hybrid zone and resin penetration into the dentin was observed. The resin tags were compactively formed to a thickness of $3\sim4{\mu}m$ at the upper part of dentinal tubules. In the Dry/primed group, the thickness of the hybrid zone and the diameter, depth of the resin tags diminished. In the Non-primed groups, the hybrid zone was not identified and few resin tag was observed. There was the gap formation in the resin/dentin interface.

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Effect of the Inner Pressure on a Hybrid Composite Flywheel Retor (하이브리드 복합재 플라이휠 로터에 작용하는 내압의 효과)

  • Oh Je-Hoon;Han Sang-Chul;Kim Myung-Hoon;Ha Sung Kyu
    • Composites Research
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    • v.18 no.1
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    • pp.45-54
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    • 2005
  • The delamination in the filament-wound composite flywheel rotor often lowers the performance of the flywheel energy storage system. A conventional ring type hub usually causes tensile stresses on the inner surface of the composite rotor, resulting in lowering the maximum rotational speed of the rotor. In this work, the stress and strain distributions within a hybrid composite rotor were derived from the two-dimensional governing equation with the specified boundary conditions, and an optimum pressure at the inner surface of the rotor was proposed to minimize the strength ratio and maximize the storage energy. A split type hub was introduced to apply the calculated optimum pressure at the inner surface, and a spin test was performed up to 40,000 rpm to demonstrate the performance of the split type hub with radial and circumferential strains measured using a wireless telemetry system. From the analysis and the test, it was found that the split type hub successfully generates a compressive pressure on the inner surface of the rotor, which can enhance the performance of the composite rotor by lowering the strength ratio within the rotor.

Variation of Seismic Behavior of Continuous Skew Plate Girder Bridges According to the Arrangement of Bearings (받침배치에 따른 연속 플레이트 거더 사교의 지진거동 변화)

  • Moon, Seong Kwon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.5
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    • pp.124-135
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    • 2011
  • The capacity of bearings installed at abutments and piers for continuous bridges is usually determined by the magnitude of the maximum vertical reaction at each support and the capacity of bearings placed at piers is higher than that at abutments. In this study, the possibility of the improved seismic performance of base-isolated continuous skew bridges was investigated by analysing the variation of the seismic behavior of them according to three arrangements of bearings. Based on the conventional arrangement of bearings(Case A), three arrangements of bearings such as Case A, Case B and Case C were selected considering the variation of the horizontal stiffness of the lead rubber bearing(LRB) installed at the pier. The seismic behavior of the total 36 skew bridges was investigated by conducting the response spectrum analysis using the hybrid response spectrum considered the effect of LRB's damping. Results of analyses show that a more desirable seismic behavior of base-isolated continuous skew bridges can be obtained by reducing the magnitude of the horizontal stiffness of LRB placed at the pier to similar to or less than that of LRB installed at abutments. The variation of LRB's stiffness at the pier brings about period elongation and the change of mode shapes of base-isolated skew bridges and results in the reduction of the total base shear, the maximum base shear at the pier and the girder stresses. Although positive effects on the seismic behavior of base-isolated skew bridges caused by the change of arrangement of bearings decreased slighty with an increase in the flexibility of the substructure, the proposed arrangements of bearings bring about the improved seismic performance of base-isolated continuous skew plate girder bridges with less than 10m height of piers.

Hybrid Integration of P-Wave Velocity and Resistivity for High-Quality Investigation of In Situ Shear-Wave Velocities at Urban Areas (도심지 지반 전단파속도 탐사를 위한 P-파 속도와 전기비저항의 이종 결합)

  • Joh, Sung-Ho;Kim, Bong-Chan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1C
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    • pp.45-51
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    • 2010
  • In urban area, design and construction of civil engineering structures such as subway tunnel, underground space and deep excavation is impeded by unreliable site investigation. Variety of embedded objects, electric noises and traffic vibrations degrades the quality of site investigation, whatever the site-investigation technique would be. In this research, a preliminary research was performed to develop a dedicated site investigation technique for urban geotechnical sites, which can overcome the limitations of urban sites. HiRAS (Hybrid Integration of Surface Waves and Resistivity) technique which is the first outcome of the preliminary research was proposed in this paper. The technique combines surface wave as well as electrical resistivity. CapSASW method for surface-wave technique and PDC-R technique for electrical resistivity survey were incorporated to develop HiRAS technique. CapSASW method is a good method for evaluating material stiffness and PDC-R technique is a reliable method for determination of underground stratification even in a site with electrical noise. For the inversion analysis of HiRAS techniuqe, a site-specific relationship between stress-wave velocity and resistivity was employed. As for outgrowth of this research, the 2-D distribution of Poisson's ratio could be also determined.

Comparison of Stress Cognition for Siren of Paramedics (구급대원의 출동벨에 대한 스트레스 인지 비교)

  • Kim, Sung-Lyoung;Lee, Nam-Jong;Shin, Gyo-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.4
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    • pp.156-163
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    • 2020
  • This study was conducted to provide basic data for realistic applicable changes of sirens by identifying the stress due to the currently used sirens and the need for improving siren. The data was collected from an online survey of 267 subjects who voluntarily agreed to join this study from August 2019 to September, 2019. A structured questionnaire was used as a research tool. The results were analyzed by means and standard deviations, percentages and frequency analysis, and independent t-tests using SPSS. For the current workplace emergency siren type, it is believed that the number of hybrid formats was 143, the most negative opinion of the siren is high at 132, so periodic replacement is needed. For contextual stresses, the highest was 4.35 ± 0.94, when the siren was heard during bedtime. In the stress during sleep, which was based on the daily mean number of movements,, a statistically significant difference was shown between groups of 9 or more movements and below 9 movements (p <0.05). The type of siren paramedics wanted was 'soft music' and 'sound of nature'. More than half of 168 people (62.9%) wanted to replace the current siren, and 163 (91.6%) wanted that periodically within 24 months. Therefore, it is necessary to improve the siren.

Numerical Evaluation of Stress Loss Rates and Adjusting Coefficients due to Internal and External Constraints of Concrete Long-Term Deformation (콘크리트 장기변형의 내·외부 구속에 의한 응력 손실률 및 수정계수 평가의 전산구조해석)

  • Yon, Jung-Heum;Kim, Hyun-Jin
    • Journal of the Korea Concrete Institute
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    • v.25 no.4
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    • pp.429-438
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    • 2013
  • An object oriented numerical analysis program of axial-flexural elements and the step-by-step method (SSM) has been developed to analyze concrete long-term behaviors of structures constrained internally and externally. The results of the numerical analysis for simple and continuous prestressed (PS) concrete box and composite girders, pre-cast slab of continuous steel composite girder, and simple preflex composite girder show that the adjusting coefficient decreases by increasing constraint. The loss rates of pre-tension force were not sensitive but those of pre-compression force were increased rapidly by decreasing adjusting coefficient. This indicates that the design based on the loss rate of pre-tension can over-estimate the pre-compression force in a concrete section constrained internally and externally. The adjusting coefficients which satisfy results of the numerical analysis are 0.35~0.95, and it can be used as an index of constraint of concrete long-term deformation. The adjusting coefficient 0.5 of Bridge Design Specifications can under-estimate residual stress of PS concrete slab, and the coefficient 0.7 or 0.8 of LRFD Bridge Designing Specifications can under-estimate the loss rates of continuous PS concrete girders. The adjusting coefficient of hybrid structures should be less then 0.4.

Effect of utilizing pressurized ring beam system in modern rock TBM: I. Numerical study (현대식 Rock TBM에서 가압형 링빔의 효과 연구: I. 수치해석적 연구)

  • Kwak, Yun-Suk;Kang, Gi-Don;Kim, Do-Hoon;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.1
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    • pp.55-77
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    • 2012
  • A Modern Rock TBM is a tunnel excavation method combining the conventional tunnelling method with the mechanized tunnelling method. It is a hybrid system that excavates a tunnel with TBM and supports the ground by ring beam, wire mesh, rock bolt, shotcrete, i.e., conventional tunnelling method. In the Modern Rock TBM, a ring beam is similar to a steel rib in NATM in the way that uses H-beam. But using a ring beam is more effective than a steel rib because it is installed in a closed-circle. Therefore, improving the performance of the ring beam is a key factor for achieving tunnel stability. In this respect, this study introduces a pressurized ring beam that might be functioning more effectively by confining convergence during tunnel excavation. In order to verify the effect of the pressurized ring beam, a three-dimensional numerical analysis was conducted. The numerical analysis confirms an increase in the minimum principal stress and reduction in the plastic strain that triggers excessive displacement. The analysis result also indicates a decrease in the relative displacement occurring after installing the ring beam, and expansion in spacing between the ring beams.

Multi-scale Process-structural Analysis Considering the Stochastic Distribution of Material Properties in the Microstructure (미소 구조 물성의 확률적 분포를 고려한 하이브리드 성형 공정 연계 멀티스케일 구조 해석)

  • Jang, Kyung Suk;Kim, Tae Ri;Kim, Jeong Hwan;Yun, Gun Jin
    • Composites Research
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    • v.35 no.3
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    • pp.188-195
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    • 2022
  • This paper proposes a multiscale process-structural analysis methodology and applies to a battery housing part made of the short fiber-reinforced and fabric-reinforced composite layers. In particular, uncertainties of the material properties within the microscale representative volume element (RVE) were considered. The random spatial distribution of matrix properties in the microscale RVE was realized by the Karhunen-Loeve Expansion (KLE) method. Then, effective properties of the RVE reflecting on spatially varying matrix properties were obtained by the computational homogenization and mapped to a macroscale FE (finite element) model. Morever, through the hybrid process simulation, a FE (finite element) model mapping residual stress and fiber orientation from compression molding simulation is combined with one mapping fiber orientation from the draping process simulation. The proposed method is expected to rigorously evaluate the design requirements of the battery housing part and composite materials having various material configurations.

The Concept Analysis of Hope : Among Cancer Patients Undergoing Chemotherapy (희망의 개념 분석 -항암화학요법을 받는 암환자를 대상으로-)

  • Song, Mi-Sun;Lee, Eun-Ok;Park, Yeong-Suk;Ha, Yang-Suk;Sim, Yeong-Suk;Yu, Su-Jeong
    • Journal of Korean Academy of Nursing
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    • v.30 no.5
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    • pp.1279-1291
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    • 2000
  • The main objectives of this study were to analyze the concept of hope, so to provide basic data to develop a valid instrument to measure hope, and to develop hope enhancing nursing intervention a program for cancer patients. The hybrid model approach was applied in three phases, the theoretical phase, the empirical phase, and the analytic phase. The study was developed on universal attributes explaining generalized hope and specific hope, which were revealed in a comprehensive review of the literature. In the empirical phase, eight cancer patients undergoing chemotherapy were interviewed to reveal causes, motivation, and their resource of hope according to The Hope Assessment Guide (Farren, Herth, & Popovich, 1995). In the analytical phase, the results of the two previous stages of the study were compared. The results were as follows : In the theoretical phase, six dimensions of hope emerged; affective, cognitive, behavioral, affiliative, temporal and contextual dimension. The antecedent of hope was loss, crisis, uncertainity, and stress. The consequences were renewal, development of new methods, safety, peace and transcendental competence. In the empirical phase, these six dimensions emerged as theoretical phases were verified and specified as these descriptive terms: feeling, intention, expectation, activity, relation, future- orientation, reality and goal-setting. The antecedent factor of hope was occurrence or recurrence of cancer. The consequence of hope was ability to cope with real condition, feeling of safety and comfort, peace, development of new strategy and recovery of disease. The major content of hope in this phase was related to specific hope, but it was also influenced on by general hope. In the analytic phase, general and specific hope was renamed as trait and state hope. All attributes emerged at the empirical phases, and also emerged at the theoretical phase. However, cognitive and contextual dimensions were revised and specified. In conclusion, the concept of hope is divided into trait hope and state hope, and state hope is an anticipatory expectation that occurs at the time of a stressful stimulus, such as being diagnosed with cancer. Hope is a multidimensional dynamic energized mental state which has the dimensions of affective, cognitive, behavioral, affiliative, temporal and contextual. There should be further studies to develope the state and trait hope scale according to definition and attributes of hope investigated in this study. In addition, considering results of the empirical phase, the family is very a important factor as a resource of hope, so it is necessary to consider family in implementing a nursing intervention program to enhance hope.

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