• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.463-471
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• 2016

A shear strength model for the high-shear ring anchor consisting of a steel ring and a rod was developed based on the shear tests on single high-shear ring anchors. The shear strength was found to be proportional to $f_{ck}{^{0.75}}$ which is a similar characteristic to the strength of shear connectors used in composite structures. The effects of the compressive strength of concrete, edge distance, and embedment length of rod are included in the proposed model. Comparison with 22 tests shows that the average and the coefficient of variation of test-to-prediction ratios are 1.01 and 7.57%, respectively. Push tests on the specimens having four high-shear ring anchors at each face were conducted and the measured shear strengths were compared with the predictions by the proposed model. For the specimen with an edge distance of 100 mm, a splitting failure occurred and for the specimens with an edge distance of 150 mm, a failure mode mixed with splitting and bearing occurred, which were very similar to the failures of shear tests on single high-shear ring anchors. In case of a splitting failure, the overlap of failure surfaces could be prevented by providing the longitudinal spacing of 400 mm which is four times of the edge distance. In case of a bearing failure, the failure area is less than 150 mm from the center of the anchor and therefore the overlap of failure surfaces could be prevented by providing the longitudinal spacing of 200 mm. The average of the test-to-prediction ratios of Push tests is 98%, which means that the proposed mode can be applied to predict the shear strength of the multiple high-shear rings.

• Korean Journal of Hospice Care
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• v.3 no.2
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• pp.19-33
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• 2003

Cancer causes many crises to cancer patients imcluding physical dysfunction and emotional changes such as anxiety, depression as well as a threat of life, fear of death. As it develops, cancer makes people feel powerlessness due to the losses of their own positions, roles and independence. Although occupying a little proportion among all types of cancer, head and neck cancer may cause a wide range of physical transformation by surgical operation, damage to active functions such as eating and speaking, provoke anxiety and depression after its operation, influencing the quality life of head and neck cancer patients. Thus nursing intervention should be developed to provide supportive nursing for head and neck cancer patients and play roles as competent supporters. This study is a nonequivalent, control group, pretest-posttest, non-synchronized quasi-experimental research design to determine, how nursing intervention has effects on anxiety, depressing of head and neck cancer and operated. They were divided into experimental and comparison groups, each consisting of 20 members. The data were collected during the period from December 1, 1999 to April 11, 2000. Tools of the study included the protocol of supportive nursing intervention which was developed by researcher with reference to a literal review and esperts' advice. The measurement tool of anxiety was consisting of totaled 20 question items which was prepared by Spielberger and translated by Kim et al., the device of depression measurement consisting of total 20 question items which was the output of Song's translation the device of depression self-evaluation from Zung. Data were analyzed using the SPSS/PC 9.0 program. The homogeneity of the subjects were tested using x2-test and t-test. 5 hypoteses were tested using t-test. The results of the study can be summarized as follows. 1.The first hypothesis that the experimental group receiving supportive nursing intervention shows a little anxiety than the control group not receiving supportive nursing intervention was supported(t=3.817, P=.000). 2.The second hypothesis that the experimental group receiving supportive nursing intervention shows a little depression than the control group not receiving supportive nursing intervention was supported(t=8.089, P=.000). Consequently, supportive nursing intervention was found an effective nursing intervention strategy to reduce anxiety and depression of head and neck cancer patients. Providing supportive nursing intervention in nursing practice can enhance the quality of life of those cancer patients.

• Composites Research
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• v.30 no.2
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• pp.84-93
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• 2017

This study investigates thermal and mechanical characterization of environmental barrier coating on the $SiC_f-SiC$ composites. The spherical environmental barrier coating (EBC) powders are prepared using a spray drying process for flowing easily during coating process. The powders consisting of mullite and 12 wt% of Ytterbium silicate are air plasma sprayed on the Si bondcoat on the LSI SiC fiber reinforced SiC composite substrate for protecting the composites from oxidation and water vapor reaction. We vary the process parameter of spray distance during air plasma spray of powders, 100, 120 and 140 mm. After that, we performed the thermal durability tests by thermal annealing test at $1100^{\circ}C$ for 100hr and thermal shock test from $1200^{\circ}C$ for 3000 cycles. As a result, the interface delamination of EBC never occur during thermal durability tests while stable cracks are prominent on the coating layer. The crack density and crack length depend on the spray distance during coating. The post indentation test indicates thermal tests influence on the indentation load-displacement mechanical behavior.

• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.31-41
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• 2008

Consolidation characteristics of reclamated ground with dredged soil and methods of evaluating them are investigated in this paper. For a dredged and reclamated ground with a very high water content, self-weight consolidation being progressed, its consolidation characteristics are difficult to find since it is almost impossible to have a undisturbed sample. In order to overcome such a problem, methods of laboratory tests with disturbed sample were studied to obtain consolidation parameters required to analyze consolidation settlement in practices, using the conventional infinitesimal consolidation theory, were evaluated by carrying out various laboratory tests with disturbed soils such as oedometer test, constant rate of deformation test, Rowe-cell tests with ring diameters of 60 mm, 100 mm and 150 mm and the centrifuge model tests with 40 g-levels. Constitutive relations of void ratio - effective vertical stress - permeability were evaluated by using the inverse technique implemented with the finite strain consolidation theory and results of centrifuge model tests. Design soil parameters related to consolidation such as compression index, swelling index, coefficient of volume change and vertical and horizontal consolidation coefficients were proposed properly by analyzing the various test results comprehensively.

• Journal of the Korean Geosynthetics Society
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• v.9 no.2
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• pp.33-40
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• 2010

In this study, the pullout tests are conducted to evaluate pullout resistance of steel strip reinforcement with transverse members. The test results are compared with theoretical equations and then the failure mechanism of transverse members is evaluated. The bearing resistance stress(${\sigma}^{\prime}_b$) of transverse members, which is applied pullout force at 50mm displacement, is closed from punching shear failure to general shear failure. The behavior by increment of a number of transverse members became closer to general shear failure. The behavior of transverse members at maximum pullout force, which is closed to general shear failure, is indicated that it is unrelated to normal stress and a number of transverse members. However, if the allowable displacement of reinforced soil wall is considered, it is impossible to apply in design. The test results are compared with bearing resistance evaluations using Prandtl's plastic theory and cylindrical cavity expansion theory. The analysis results are indicated that the bearing resistance by pullout tests is closed to predicted result by Prandtl's plastic theory, which are located between general shear failure and punching shear failure.

• Korea Journal of Hospital Management
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• v.11 no.3
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• pp.19-41
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• 2006

The Objective of this study was to design the model which predict the future cash flow of hospitals and on the basis of designed model to support sound hospital management by the prediction of future cash flow. The five cash flow measurement variables discussed in financial accrual part were used as variables and these variables were defined as NI, NIDPR, CFO, CFAI, CC. To measure the cash flow B/S related variables, P/L related variables and financial ratio related variables were utilized in this study. To measure cash flow models were designed and to estimate the prediction ability of five cash flow models, the martingale model and the market model were utilized. To estimate relative prediction outcome of cash flow prediction model and simple market model, MAE and MER were used to compare and analyze relative prediction ability of the cash flow model and the market model and to prove superiority of the model of the cash flow prediction model, 32 Regional Public Hospital's cross-section data and 4 year time series data were combined and pooled cross-sectional time series regression model was used for GLS-analysis. To analyze this data, Firstly, each cash flow prediction model, martingale model and market model were made and MAE and MER were estimated. Secondly difference-test was conducted to find the difference between MAE and MER of cash flow prediction model. Thirdly after ranking by size the prediction of cash flow model, martingale model and market model, Friedman-test was evaluated to find prediction ability. The results of this study were as follows: when t-test was conducted to find prediction ability among each model, the error of prediction of cash flow model was smaller than that of martingale and market model, and the difference of prediction error cash flow was significant, so cash flow model was analyzed as excellent compare with other models. This research results can be considered conductive in that present the suitable prediction model of future cash flow to the hospital. This research can provide valuable information in policy-making of hospital's policy decision. This research provide effects as follows; (1) the research is useful to estimate the benefit of hospital, solvency and capital supply ability for substitution of fixed equipment. (2) the research is useful to estimate hospital's liqudity, solvency and financial ability. (3) the research is useful to estimate evaluation ability in hospital management. Furthermore, the research should be continued by sampling all hospitals and constructed advanced cash flow model in dimension, established type and continued by studying unified model which is related each cash flow model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.2100-2108
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• 2015

This study was conducted to examine the effects of a simulation-based learning scenario using standardized respiratory patients regarding emergency care on learning satisfaction, and self efficacy, clinical skill competency of health related department students. A quasi-experimental non-equivalent control group pre-post test design was used. A total of 50 students, 25 students for the experimental group and 25 students for the control group, The experimental group received the 2 educations sessions and 1 evaluation session with 180 minutes for each session. It was implemented in November, 2013. Data were analysed using frequency, ratio and t-test by the SPSS/Win 18.0. The experimental group who had the simulation-based learning scenario using standardized respiratory patients showed significantly higher learning satisfaction and self efficacy, clinical skill competency compared with the control group who had a traditional simulation education. Through this study, simulation-based learning scenario using standardized patients was verified to be an effective teaching method to be grow up on professional competency of health related department students. Also the simulation-based learning scenario using standardized patients should be developed in the various fields.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.413-418
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• 2016

Recently, a mega project such as Korea-China or Korea-Japan undersea tunnel project has been emerged for detail discussion and the interest in undersea tunnel is on the rise. More severe damage by train fire is expected in undersea tunnel comparing to ground tunnel and thus the study on more efficient fire extinguishing system, besides existing disaster prevention design is underway. To that end, a full-scale fire tests using CAF fire extinguishing system which has been developed by modifying traditional foam fire extinguishing system for fire suppression at rescue station in timely manner were conducted over 7 times. The test was conducted after setting the rescue station in virtual tunnel with a car of KTX. As a result of using compressed air foam directly to the fire source, 30 liter of Heptane combustibles was extinguished within 1 minutes. Applicability of compressed air foam to train fire at rescue station in undersea tunnel was has been proven and further study is considered required while changing the nozzle angle and location so as to achieve quick and easy extinguishing goal, making use of the advantage of CAF, as well as to reduce the fire water and chemicals required.

• Journal of Korean Society of Steel Construction
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• v.20 no.6
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• pp.817-827
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• 2008

The seismic performance of a column splice fabricated with PJP (partial joint penetration) welds for special moment frames was experimentally evaluated in this study. The steel materials that were used for the specimens included SHN490 and SN490 steel, or the newly developed structural steel for seismic application. Fabricating the column splice with PJP welds is highly attractive from the perspective of reducing the welding cost and the construction time. PJP welds in column splices are viewed apprehensively, however, because several tests have shown that PJP welds in thick members tend to become brittle under tensile loads. The column splices in this testing program were designed for the expected plastic moment of the column that current seismic codes typically require. The design strength of partial-penetration welded joints was determined according to the 2005 AISC-LRFD Specification. Three-point loading was applied monotonically, using a universal testing machine, such thatthe column splice joints were subjected to pure tension. The test results showed that the PJP welded splices, if designed properly, can develop a strength exceeding that of the actual plastic moment of the column. The specimen made of the SM490 rolled section, however, showed a brittle fracture at the splice soon after achieving the actual plastic moment of the column. The tensile coupon test results also showed that the material properties of SM490 steel are more unpredictable. Overall, although the test data are limited, the SHN490 and SN490 steel specimens showed a superior and reliable performance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.88-98
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• 2011

Masonry structure is a style of building which has been widely applied as residential facilities of low and middle stories, commercial and public facilities etc. But it is possible to destroy by loss of adhesive strength or sliding when lateral forces, such as earthquake, occurs. This study proposes a seismic retrofit method for masonry structure and its seismic performance is demonstrated by shaking table test. Two specimens per each shaking direction were made, having out-of-plane(weak axis) and in-plane(strong axis) direction. External load of 1 ton was also applied for each specimen during the test, to model the behavior of reinforced masonry wall. As a result of shaking table tests, it is shown that the specimen applying the proposed seismic retrofit method showed acceptable behaviors in both of Korea building design criteria(0.14g) and USA seismic criteria suggested by IBC(0.4g). However, it was observed that stiffness of the specimen toward out-of-plane was rapidly decreasing when seismic excitations over 0.14g were loaded. In comparison of relative displacements, maximum relative displacement of specimens which were accelerated toward out-of-plane with 0.4g at once was 29~31% of maximum relative displacement when specimens were gradually accelerated from 0.08g to 0.4g, while the maximum relative displacement of specimens accelerated toward in-plane has similar value in both cases. Therefore, it is concluded that the wall accelerated toward out-of-plane is more affected by hair crack or possible fatigues caused by seismic excitation.