• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.1
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• pp.14-24
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• 2011

Purpose: The purpose of this study was to investigate the learning effect of a standardized patient managed instruction program for a clinical maternity nursing course. Methods: The SP managed instruction was made for clinical cases in intrapartum and postpartum nursing care. The SP managed instruction was evaluated by using a quasi-experimental, nonequivalent control group post-test design with separate classes of students attending clinical maternity nursing classes at a nursing school in Incheon. Control groups were taught by traditional lecture/model method and experimental groups were taught by SP managed instruction. Data was collected from September 2009 to February 2010. Results: 1. There was no significant difference between the experimental group and control group in identifying relevant data (z=-1.418, p=.156) and necessary nursing skills performance (z=-.643, p=.520) for intrapartum nursing care. In addition, there was no significant difference between the two groups in identifying relevant data (z=-.264, p=.782) and necessary nursing skill (z=-.342, p=.732) for postpartum nursing care. 2. In clinical nursing skill performances the total score was statistically significantly higher in the experimental group than the control group (intrapartum care z=-4.181, p=.000, postpartum care z=-4.279, p=.000). 3. There was a statistically significant difference between the two groups (intrapartum care z=-3.731, p=.000, postpartum care z=-4.066, p=.000). Conclusion: In conclusion, the SP methodis effective in teaching clinical maternity nursing for student nurses and it is necessary to develop SP instruction courses for many areas in the clinical nursing education field.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.43-52
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• 2021

Purpose : Chronic neck pain negatively impacts the quality of life and causes various problems in daily life due to pain, insomnia, and sleep disturbances in patients with this condition. Therapeutic interventions to solve these problems in rehabilitation and physical therapy are being introduced; however, the evidence of the efficacy of myofascial release (MFR) is still insufficient. This study aimed to investigate the effects of applying MFR on pain, insomnia, and sleep disturbances in patients with chronic neck pain. Methods : Ten patients with chronic neck pain were randomly selected and grouped into the experimental group (n₁ = 10) and control group (n₂ = 10) by cross-over design. Pain was measured before and after MFR intervention. Moreover, insomnia was measured only after MFR intervention. Polysomnography was performed after MFR intervention. Wilcoxon signed rank test and Mann-Whitney U test were used for the visual analog scale (VAS). Independent sample t-test was separately performed to measure insomnia and sleep. Results : After MFR intervention, the VAS score of the experimental group (p = 0.005) significantly decreased than that of the control group (p = 0.002). The insomnia score of the experimental group significantly decreased than that of the control group (p = 0.001). The total sleep time (p = 0.001), sleep efficiency (p = 0.001), and sleep latency (p = 0.001) of the experimental group significantly increased than those of the control group in the polysomnographic measurement. Conclusion : The application of MFR of the neck and upper trunk may have a positive effect on pain, insomnia, and sleep disturbances in patients with chronic neck pain. It was also suggested that an objective and quantitative polysomnography can be used more often in the field of rehabilitation and physical therapy.

• Structural Engineering and Mechanics
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• v.63 no.4
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• pp.509-519
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• 2017

Wind field in mountainous regions demonstrates unique distribution characteristic as compared with the wind field of the flat area, wind load and wind effect are the key considerations in structural design of television towers situated in mountainous regions. The television tower to be constructed is located at the top of Xiushan Mountain in Nanjing, China. In order to investigate the impact of terrain factors of hilltops on wind loads, firstly a wind tunnel test was performed for the mountainous area within 800m from the television tower. Then the tower basal forces such as bending moments and shear strength were obtained based on high frequency force balance (HFFB) test. Based on the experiments, the improved method for determining the load combinations was applied to extract the response distribution patterns of foundation internal force and peak acceleration of the tower top, then the equivalent static wind loads were computed under different wind angles, load conditions and equivalent goals. The impact of terrain factors, damping ratio and equivalent goals on the wind load distribution of a television tower was discussed. Finally the equivalent static wind loads of the television tower under the 5 most adverse wind angles and 5 most adverse load conditions were computed. The experimental method, computations and research findings provide important references for the anti-wind design of high-rise structure built on hilltops.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.675-680
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• 2002

Cracking and bulging in welded and internally lined pressure vessels that work in thermal-mechanical cycling service have been well known problems in the petrochemical, power and nuclear industries. However, published literature and industry surveys show that similar problems have been occurring during the last 50 years. A better understanding of the causes of cracking and bulging causes is needed to improve the reliability of these pressure vessels. This study attempts to add information required for increasing the knowledge and fundamental understanding required. Typical examples of this problem are the coke drums in the delayed coking units refinery process. This case was selected for experimental work, field study and results comparison. Delayed coking units are among the refinery units that have higher economical yields. To shut down these units represents a high negative economical impact in refinery operations. Also, the maintenance costs associated with repairs are commonly very high. Cracking and bulging occurrences in the coke drums, most often at the weld areas, characterize the history of the operation of delayed coking units. To design and operate more robust coke drums with fewer problems, an improved metallurgical understanding of the cracking and bulging mechanisms is required. A methodology that is based field experience revision and metallurgical analyses for the screening of the most important variables, and subsequent finite element analyses to verify hypotheses and to rank the variables according to their impact on the coke drum lives has been developed. This indicated approach provides useful information for increasing coke drum reliability. The results of this work not only order the most important variables according to their impact in the life of the vessels, but also permit estimation of the life spans of coke drums. In conclusion, the current work shows that coke drums may fail as a combination of thermal fatigue and other degradation mechanisms such as: corrosion at high and low temperatures, detrimental metallurgical transformations and plastic deformation. It was also found that FEA is a very valuable tool for understanding cracking and bulging mechanisms in these services and for ranking the design, fabrication, operation and maintenance variables that affect coke drum reliability.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.739-742
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• 2002

The supersonic, dual, coaxial jet impinging upon a vertical flat plate has recently been applied to a variety of industrial manufacturing processes, since it has several advantages over a conventional supersonic impinging jet. In the present study, experimentation is carried out to investigate the effects of the impinging angle of the annular flow and the design Mach number on the flow field formed over the vertical flat plate. A convergent-divergent nozzle is used to obtain the inner jet flow, its design Mach number being changed between $1.0\;and\;2.0$. The outer annular nozzle has a constant area of the Mach number of 1.0, and its impinging angle of $0^{\circ}\;and\;20^{\circ}$. The primary jet pressure ratio is changed in the range from 6.0 to 10.0 and for the annular flow, the assistant jet pressure ratio is changed from 1.0 to 4.0. The distance between the dual, coaxial nozzle and flat plate is also changed. Detailed pressure measurements are conducted along the axis of the jet and on the flat plate as well. The impinging coaxial Jet flows are visualized using the Schlieren and Shadow optical methods. The results show that the flow field on the plate is not strongly dependent only on the primary and assistant pressure ratios but also the impinging angle of the annular nozzle.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.79-92
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• 2002

This paper describes a research work of developing computer-aided design of a product with bending and piercing for progressive working. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout and die layout modules. The system is designed by considering several factors, such as bending sequences by fuzzy set theory, complexities of blank geometry, punch profiles, and the availability of a press equipment. Strip layout drawing generated in the strip layout module is presented in 3-D graphic farms, including bending sequences and piercing processes with punch profiles divided into for external area. The die layout module carries out die design for each process obtained from the results of the strip layout. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.

• Journal of The Korean Association For Science Education
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• v.24 no.1
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• pp.29-47
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• 2004

Two project-centered secondary school programs were studied as part of an effort to elucidate successful components for science reform-based curriculum development. The Teachers for Exciting Science (TES), and Foundational Approaches in Science Teaching (FAST) programs in Korea and U.S., respectively, are project-centered programs because their curricula are centered on the activities initiated and engaged in by the students. Students serve as principal investigators in their projects, and teachers serve as guides. Both programs were analyzed based on criteria such as curriculum design, teaching, lives of students, lives of teachers, evaluation of program, from the Third International Mathematics and Science Study (TIMSS). In the programs, teachers and students directed the development of curricula and their implementation. Students assumed teacher roles as mentors of other students. And emphasis was on development of communication skills through student-delivered talks and written papers, and professional development of teachers as educators and scientists. Participation in TES stimulated secondary school student interest in science, encouraged inquiry thinking, increased achievement in learning science, and promoted better awareness of science related to real life. FAST students practice laboratory and field techniques, experimental design, hypothesis formation, generalization, and practical implications of research as academic and applied disciplinarians. These project-centered programs have been successfully implemented in field, lab, and classroom curricula for secondary science education. Comparison of these programs will provide an opportunity for identifying key elements instrumental in successful implementation of guidelines for science education, as measured through successful outcomes.

• Geomechanics and Engineering
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• v.10 no.6
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• pp.737-755
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• 2016

The load transfer depth of a ground anchor is the minimum length required to transfer the initial prestressing to the grout column through the bonded part. A thorough understanding of the mechanism of load transfer as well as accurate prediction of the load transfer depth are essential for designing an anchorage that has an adequate factor of safety and satisfies implicit economic criteria. In the current research, experimental and numerical studies were conducted to investigate the load transfer mechanism of ground anchors based on a series of laboratory and field load tests. Optical FBG sensors embedded in the central king cable of a seven-wire strand were successfully employed to monitor the changes in tensile force and its distribution along the tendons. Moreover, results from laboratory and in-situ pullout tests were compared with those from equivalent case studies simulated using the finite difference method in the FLAC 3D program. All the results obtained from the two proposed methods were remarkably consistent with respect to the load increments. They were similar not only in trend but also in magnitude and showed more consistency at higher pullout loading stages, especially the final loading stage. Furthermore, the estimated load transfer depth demonstrated a pronounced dependency on the surrounding ground condition, being shorter in hard ground conditions and longer in weaker ones. Finally, considering the safety factor and cost-effective design, the required bonded length of a ground anchor was formulated in terms of the load transfer depth.

• Wind and Structures
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• v.30 no.4
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• pp.339-366
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• 2020

This study aims at modeling boundary layers (BLs) encountered in sparse and built environments (i.e. open, suburban and urban) at the subsonic Wind Tunnel (WT) at Ryerson University (RU). This WT has an insignificant turbulence intensity and requires a flow-conditioning system consisting of turbulence generating elements (i.e., spires, roughness blocks, barriers) to achieve proper turbulent characteristics. This system was developed and validated in the current study in three phases. In phase I, several Computational Fluid Dynamic (CFD) simulations of the tunnel with generating elements were conducted to understand the effect of each element on the flow. This led to a preliminary design of the system, in which horizontal barriers (slats) are added to the spires to introduce turbulence at higher levels of the tunnel. This design was revisited in phase II, to specify slat dimensions leading to target BLs encountered by tall buildings. It was found that rougher BLs require deeper slats and, therefore, two-layer slats (one fixed and one movable) were implemented to provide the required range of slat depth to model most BLs. This system only involves slat movement to change the BL, which is very useful for automatic wind tunnel testing of tall buildings. The system was validated in phase III by conducting experimental wind tunnel testingof the system and comparing the resulting flow field with the target BL fields considering two length scales typically used for wind tunnel testing. A very good match was obtained for all wind field characteristics which confirms accuracy of the system.

• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.24-32
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• 2002

The modified compression field theory is already applied in shear problem at some code(AASHTO-1998) partly. Nominal shear strength of concrete beam is sum of the concrete shcar strength and the steel shear strength in the current design code. But Torsional moment strength of concrete is neglected in the calculation of the nominal torsional moment strength of concrete beam In the current revised code. Tensile stress of concrete strut between cracks is still in effect due to tension stiffening effect. But The tensile stresses of concrete after cracking are neglected in bending and torsion In design. The torsional behavior is similar to the shear behavior in mechanics. Therefore the torsional moment strength of concrete should be concluded in the nominal torsional moment strength of reinforced concrete beam. This paper shows that the torsional moment strength of concrete is caused by the average principal tensile stress of concrete. To verify the validity of the proposed model, the nominal torsional moment strengths according to two ACI codes (89, 99) and proposed model are compared to experimental torsional moment strengths of 55 test specimens found in literature. The nominal torsional moment strengths by the proposed model show the best results.