• Journal of the Korean Geotechnical Society
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• v.32 no.6
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• pp.27-40
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• 2016

Conventional warning criteria for landslides due to rainfall in broad regions have limitations, because they did not have proper reflection of topography, forest physiognomy, and unsaturated soil properties, et al. This study suggested a new stability model for unsaturated slope analyses during rainfall, considering rainfall pattern, geomorphological characteristics (slope angle, soil depth), engineering properties of unsaturated soils, and tree surcharge and root reinforcement. Stability analysis not considering root reinforcement and tree surcharge tends to over-predict a factor of safety in unsaturated slopes. Developed slope stability model was used to build database on the factor of safety in unsaturated slopes during rainfall, and it was integrated with GIS to do quantitative risk analysis in landslide risk areas specified in Ulju. Landslide risk areas were located at downstream of the point with sudden drop in safety factor, as well as at regions with low safety factor during rainfall.

• Journal of Soil and Groundwater Environment
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• v.25 no.3
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• pp.65-73
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• 2020

Exposure assessment methodology for outdoor air inhalation pathways (i.e., inhalation of volatile compounds and fugitive dust in outdoor air) was investigated. Default values of several parameters currently used in Korea (e.g., Q/C; inverse value of concentration per unit flux, and frs; soil fraction in PM10) may not be suitable and lack site-specificity, as they have been adopted from the risk assessment guidance of the United States or the Netherlands. Such limitation can be addressed to a certain degree by incorporating the volatilization factor (VF) and the particulate emission factor (PEF) with Box model. This approach was applied to an exposure assessment of a site contaminated with petroleum hydrocarbons in Korea. The result indicated that the suggested methodology led to more accurate site-specific exposure assessment for outdoor inhalation pathways. Further work to establish methodology to determine site-specific Q/C values in Korea needs to be done to secure the reliability of the exposure assessment for outdoor air inhalation pathways.

• The Korean Journal of Health Service Management
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• v.6 no.1
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• pp.27-38
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• 2012

This study is to find out the correlation among the predisposing, enabling, and need factors in Anderson Behavioral Model using the data from Korea Medical Panel Survey conducted in the early part (April 1 - October 31) of 2008. The findings are as follows. It was found that the utilization rate of western medical service was far higher. the influential factor to choose western or oriental medical service taking western medical institutions as the reference group, the influential factor to choose oriental medical institution has significantly increased when the patient who have covered by medical insurance has one accompanied disease and their age was between 45 - 74, compared to the people less than 45 years old. It also increased when the age of the patient was between 45-54 years old, and in the event those who are not covered by medical insurance have accompanied disease and that the disease mobility period is 2-4 years. reviewing the several characteristics of the utilization of western and oriental medical services by the patient with musculoskeletal system disorders, the number of accompanied disease is an influential factor for the utilization of oriental medical services. And, disease mobility period is a significant factor for the utilization of both western and oriental medical services together, though it is not identified in this study. Therefore, it is expected that mutual cooperation between western and oriental medical services is more required for the patient with musculoskeletal system disorders as the aging society rapidly develops. In order to foster oriental medicine, it is required to specialize in competitive disease such as musculoskeletal system disorders.

• Polymer(Korea)
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• v.33 no.5
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• pp.485-489
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• 2009

The temperature dependence of the structure of micelles formed by a deuterated polystyrene-poly(ethylene oxide) diblock copolymer (dPS-PEO) in heavy water were investigated with small-angle neutron scattering (SANS). SANS data were analyzed using the hard-sphere structure factor in combination with the form factor of a core-shell model. The micelle aggregation number and corona radius were obtained from the fits to the SANS data. The micelle aggregation numbers varied with temperature from 229 at $25^{\circ}C$ to 240 at $45^{\circ}C$, with a corresponding increase in the core radius. However, the shell thickness of micelles decreased with increasing temperature from 6.2 to 5.8 nm. These structural changes of micelles might be ascribed to the decrease in the hydration volume per hydrophilic group in the corona because of the increase in hydrophobicity of the PEO block with increasing temperature.

• Journal of Korean Academy of Nursing
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• v.48 no.3
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• pp.362-374
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• 2018

Purpose: This study aimed to develop a triage competency scale (TCS) for emergency nurses, and to evaluate its validity and reliability. Methods: Preliminary items were derived based on the attributes and indicators elicited from a concept analysis study on triage competency. Ten experts assessed whether the preliminary items belonged to the construct factor and determined the appropriateness of each item. A revised questionnaire was administered to 250 nurses in 18 emergency departments to evaluate the reliability and validity of the scale. Data analysis comprised item analysis, confirmatory factor analysis, contrasted group validity, and criterion-related validity, including criterion-related validity of the problem solving method using video scenarios. Results: The item analysis and confirmatory factor analysis yielded 5 factors with 30 items; the fit index of the derived model was good (${\chi}^2/df=2.46$, Root Mean squared Residual=.04, Root Mean Squared Error of Approximation=.08). Additionally, contrasted group validity was assessed. Participants were classified as novice, advanced beginner, competent, and proficient, and significant differences were observed in the mean score for each group (F=6.02, p=.001). With reference to criterion-related validity, there was a positive correlation between scores on the TCS and the Clinical Decision Making in Nursing Scale (r=.48, p<.001). Further, the total score on the problem solving method using video scenarios was positively correlated with the TCS score (r=.13, p=.04). The Cronbach's ${\alpha}$ of the final model was .91. Conclusion: Our TCS is useful for the objective assessment of triage competency among emergency nurses and the evaluation of triage education programs.

• Journal of Korean Academy of Nursing
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• v.48 no.3
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• pp.375-388
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• 2018

Purpose: This study was conducted to assess the reliability and validity of the Korean version of the Coping and Adaptation Processing Scale-Short- Form in patients with cancer. Methods: The original scale was translated into Korean using Brislin's translation model. The Korean Short-Form and the Functional Assessment Cancer Therapy-General were administered to 164 Korean patients with cancer using convenience sampling method. The collected data were analyzed using SPSS 23.0 and AMOS 23.0. Construct validity, criterion validity, test-retest reliability, and internal consistency reliability of the Korean Coping and Adaptation Processing Scale-Short-Form were evaluated. Results: Exploratory factor analysis supported the construct validity with a four-factor solution that explained 60.6% of the total variance. Factor loadings of the 15 items on the four subscales ranged .52~.86. The four-subscale model was validated by confirmatory factor analysis (Normed ${\chi}^2=1.38$ (p=.013), GFI=.92, SRMR=.02, RMSEA=.05, TLI=.94, and CFI=.95), and criterion validity was demonstrated with the Functional Assessment Cancer Therapy-General. Cronbach's alpha for internal consistency of the total scale was .83 and ranged .68~.81 for all subscales, demonstrating sufficient test-retest reliability. Conclusion: The Korean version showed satisfactory construct and criterion validity, as well as internal consistency and test-retest reliability.

• Geotechnical Engineering
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• v.3 no.2
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• pp.17-28
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• 1987

Reliability of the cone penetration test (CPT) for estimating shear strength of marine soils is investigated in this paper. For sands, the uncertainty about the angle of internal friction is analyzed. It includes the spatial variation of the soil and the model error in the equation used for interpretation. The most serious uncertainty encountered was the error in the interpretative models. Different methods of interpretation gave quite different values. Subjective opinion was introduced to combine all the interpretative models in a systematic manner. For clays, the undrained Shear Strength from the CPT results is usually =derived by empirical correlations between cone resistance and untrained shear strength from laboratory tests or field vane tests, expressed in terms of cone factor and function of overburden pressure. The uncertainty of the undrained shear strength is caused by data scatter of the cone factor in the correlation, model error of the cone factor, effect of anisotropy, and spatial variability of cone resistance. Among these uncertainties, the most serious one was the data scatter of the cone factor in the .correlation. Between the laboratory test and the field vane test used for correlation, the field vane test was more reliable.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.3
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• pp.71-87
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• 2020

Objectives Even though the various alternative herbal medicine has applied for osteoarthritis (OA) treatment, its scientific proof remains uncertain. The aim of the present study evaluates the effects of Chulbu-tang on inflammatory responses in a monosodium iodoacetate (MIA)-induced osteoarthritis rat model. Methods OA rat model was established by MIA injection in intra-joint of rats. 7 days after, OA rats except OA control rats were administrated Chulbu-tang (100 or 200 mg/kg) or Indomathacin (5 mg/kg) once a day for 14 days. The weight-bearing ability of hind paws were measured when group isolation 0, 7, and 14 days. Western blotting was performed to examine the knockdown/overexpressing efficiency of Chulbu-tang. In addition, cartilage destruction was measured histologically. Results Chulbu-tang treatment significantly reduced the protein expressions of inflammatory mediators such as inducible nitric oxide synthase and cyclooxygenase 2, and inhibited inflammatory cytokines including tumor necrosis factor alpha, interleukin (IL)-1β, and IL-6 through nuclear factor-kappa B (NF-κB) inactivation. Moreover, anti-oxidant enzymes such as superoxide dismutase and glutathione peroxidase-1/2 through nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway significantly increased. Our findings indicate that Chulbu-tang has the potential therapeutic effect on OA through inhibiting the inflammatory responses via inactivating NF-κB signaling pathway. In addition, upregulation of Nrf2 led to anti-oxidant effects. Conclusions Taken together, Chulbu-tang is believed to have antioxidant, anti-inflammatory effects, and cartilage protection for arthritis-causing rats.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.1904-1911
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• 1999

The most effective material in the shape memory alloy(SMA) is the TiNi alloy, because its shape recovery characteristics are very excellent. We molded the composite material with shape memory function. The fiber of it is $Ti_{50}-Ni_{50}$ shape memory alloy and matrix of it is epoxy resin(Araldite B41, Hardner HT903. Ciba Geigy), its adhesive and optical sensitivity are very excellent. It was assured that the composite material could be used as model material of photoelastic experiment for intelligent materials or structures. In this research, the composite material with shape memory function is used as model material of photoelastic experiment. Photoelastic experimental hybrid method is developed in this research, it is assured that it is useful on the obtaining stress intensity factor and the separation of stress components from only isochromatic data. The measuring method of stress intensity factor of intelligent material by photoelastic experiment is introduced. In the mode I state, we can know that stress intensity factors are decreased more than 50% of stress intensity factor of room temperature when temperature of fiber is greater than 4$0^{\circ}C$, prestrain greater than 5% and fiber volume ratio greater than 0.42% and that stress intensity factors are decreased by 100% when fiber volume ratio is greater than 0.84%, prestrain greater than 5% and temperature greater than 60 $^{\circ}C$.

• Steel and Composite Structures
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• v.33 no.6
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• pp.891-906
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• 2019

This study considers the instability behavior of sandwich plates considering magnetorheological (MR) fluid core and piezoelectric reinforced facesheets. As facesheets at the top and bottom of structure have piezoelectric properties they are subjected to 3D electric field therefore they can be used as actuator and sensor, respectively and in order to control the vibration responses and loss factor of the structure a proportional-derivative (PD) controller is applied. Furthermore, Halpin-Tsai model is used to determine the material properties of facesheets which are reinforced by graphene platelets (GPLs). Moreover, because the core has magnetic property, it is exposed to magnetic field. In addition, Kelvin-Voigt theory is applied to calculate the structural damping of the piezoelectric layers. In order to consider environmental forces applied to structure, the visco-Pasternak model is assumed. In order to consider the mechanical behavior of structure, sinusoidal shear deformation theory (SSDT) is assumed and Hamilton's principle according to piezoelasticity theory is employed to calculate motion equations and these equations are solved based on differential cubature method (DCM) to obtain the vibration and modal loss factor of the structure subsequently. The effect of different factors such as GPLs distribution, dimensions of structure, electro-magnetic field, damping of structure, viscoelastic environment and boundary conditions of the structure on the vibration and loss factor of the system are considered. In order to indicate the accuracy of the obtained results, the results are validated with other published work. It is concluded from results that exposing magnetic field to the MR fluid core has positive effect on the behavior of the system.