• Proceedings of the Korean Fiber Society Conference
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• 1993.06b
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• pp.704-712
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• 1993

• Wind and Structures
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• v.21 no.2
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• pp.223-239
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• 2015

Open decks are a widely used deck configuration in long-span cable-stayed bridges; however, incorporating aerodynamic countermeasures are advisable to achieve better aerodynamic performance than a bluff body deck alone. A sectional model of an open deck cable-stayed bridge with a main span of 400 m was selected to conduct a series of wind tunnel tests. The influences of five practical aerodynamic countermeasures on flutter and vortex-induced vibration (VIV) performance were investigated and are presented in this paper. The results show that an aerodynamic shape selection procedure can be used to evaluate the flutter stability of decks with respect to different terrain types and structural parameters. In addition, the VIV performance of $\prod$-shaped girders for driving comfortableness and safety requirements were evaluated. Among these aerodynamic countermeasures, apron boards and wind fairings can improve the aerodynamic performance to some extent, while horizontal guide plates with 5% of the total deck width show a significant influence on the flutter stability and VIV. A wind fairing with an angle of $55^{\circ}C$ showed the best overall control effect but led to more lock-in regions of VIV. The combination of vertical stabilisers and airflow-depressing boards was found to be superior to other countermeasures and effectively boosted aerodynamic performance; specifically, vertical stabilisers significantly contribute to improving flutter stability and suppressing vertical VIV, while airflow-depressing boards are helpful in reducing torsional VIV.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.175-182
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• 2019

The study was conducted to verify the effect of basic life support training on the skill ability of police officers. The subjects of this study were 10 experimental group and 10 comparative group with voluntary consent after explaining the theory and significance of the training experiment at the police station located in K. The education program used in this study consists of theoretical education and practical training, and the theoretical education is 60 minutes and the practical training is 30 minutes. The measurement tool for basic resuscitation performance was measured based on the 'CPR and ECG Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care' presented by the American Heart Association. The results are as follows. The experimental group showed higher performance skills than the traditional control group in field confirmation performance skills, primary evaluation performance skills (A, B, C, medical evaluation), and BLS performance skills (heart compression, artificial respiration, medical evaluation) which are the basic resuscitation performance skills. In conclusion, this study confirmed that the theory and practice education program is more effective in improving the clinical performance of police officers than the traditional lectures and practice education, so it is possible to apply this simulation education program to the cardiac arrest patient emergency treatment.

• Journal of Practical Engineering Education
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• v.14 no.2
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• pp.393-404
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• 2022

This study attempted to examine the effect of education and training on organizational performance based on HCCP research through the systematic review of previous studies. For this, 29 papers used HCCP data were selected and analyzed, and the research results are as follows. First, the research results showed that education and training had a positive effect on non-financial performance such as organizational commitment and job satisfaction, and financial performance such as sales and operating profit. Second, in order for education and training to affect organizational performance, job satisfaction, organizational culture, and education transfer were found to be important factors. Third, for effective transfer of education and training, it is necessary to establish a system that can be applied to the field after education and training, finally, it suggested the need for research to be conducted to reveal the practical effectiveness of education and training by measuring the degree to which education and training contributed to financial performance more closely.

• Nuclear Engineering and Technology
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• v.37 no.2
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• pp.167-176
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• 2005

We developed the PERUPS system to aid the on-line performance analysis for the turbine cycle of the YongGwang 3 and 4 nuclear power plants. Procedure of measurement validation is included in the performance calculation to obtain heat balance. Precision of on-line performance calculation is increased via practical modifications of standard calculation algorithms based on the PTC (Performance Test Code). The proposed system also provides useful Web-based aids for performance analysis, including performance data management, a graphic viewer for heat balance and turbine expansion lines, and synthesized reports of performance.

• Earthquakes and Structures
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• v.11 no.2
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• pp.195-215
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• 2016

Rehabilitation of historical unreinforced masonry (URM) buildings is a priority in many parts of the world, since those buildings are a living part of history and a testament of human achievement of the era of their construction. Many of these buildings are still operational; comprising brittle materials with no reinforcements, with spatially distributed mass and stiffness, they are not encompassed by current seismic assessment procedures that have been developed for other structural types. To facilitate the difficult task of selecting a proper rehabilitation strategy - often restricted by international treaties for non-invasiveness and reversibility of the intervention - and given the practical requirements for the buildings' intended reuse, this paper presents a practical procedure for assessment of seismic demands of URM buildings - mainly historical constructions that lack a well-defined diaphragm action. A key ingredient of the method is approximation of the spatial shape of lateral translation, ${\Phi}$, that the building assumes when subjected to a uniform field of lateral acceleration. Using ${\Phi}$ as a 3-D shape function, the dynamic response of the system is evaluated, using the concepts of SDOF approximation of continuous systems. This enables determination of the envelope of the developed deformations and the tendency for deformation and damage localization throughout the examined building for a given design earthquake scenario. Deformation demands are specified in terms of relative drift ratios referring to the in-plane and the out-of-plane seismic response of the building's structural elements. Drift ratio demands are compared with drift capacities associated with predefined performance limits. The accuracy of the introduced procedure is evaluated through (a) comparison of the response profiles with those obtained from detailed time-history dynamic analysis using a suite of ten strong ground motion records, five of which with near-field characteristics, and (b) evaluation of the performance assessment results with observations reported in reconnaissance reports of the field performance of two neoclassical torsionally-sensitive historical buildings, located in Thessaloniki, Greece, which survived a major earthquake in the past.

• Design & Manufacturing
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• v.10 no.3
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• pp.14-19
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• 2016

Thermally or electrically conductive filler reinforced polymer composites are extensively being developed as the demand for light weight material increases rapidly in industiral applications need good conductivity such as heat sink of the electronics or light. Carbon or ceramic materials like graphite, carbon nanotube or boron nitride are typical conductive fillers with good thermal or electical conductivity. Using these conductive fillers, the polymer composites in the market show wide range of thermal conductivity from approximately 1 W/mK to 20 W/mK, which is quite enhanced considering the thermal conductivity lower than 0.5 W/mK for most polymeric materials. The practical use of these composites, however, is yet limited to specific applications because most composites are still not conductive enough or too difficult to process, too brittle, too expensive for higher conductivity. For practical use of conductive composite, the thermal conductivity required depending on the heat releasing mode are studied first for simplified unit cooling geometry to propose thermal conductivities of the composites for reasonable cooling performance comparing with the metal heat sink as a reference. Also, as a practical design for heat sink based on polymer composite, composite and metal sheet hybrid structures are investigated for LED lamp heat sink and audio amplication module housing to find that this hybrid structure can be a good solution considering all of the cooling performance, manufacturing, mechanical performance, cost and weight.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.4B
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• pp.378-385
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• 2011

The three-dimensional triangulation algorithm that the beacon nodes can be allocated to dynamically in not the experimental region but the practical region is suggested, and the performance of the localization system adapting the suggested algorithm is analyzed. The suggested algorithm adapts the computation method of the three dimensional point that the surfaces of three spheres overlapped, while the traditional triangulation algorithm adapts the computation method of the two dimensional point that three circles are overlapped in order to compute the distance between beacon nodes and mobile node that means a radius. In addition to this, to analyze the performance of the localization system adapting the suggested algorithm, first of all, the allocation layout of beacon nodes is made, and the allocation layout is modeled by selection of ten random distance values between mobile node and beacon nodes for computer simulation of the practical model. Next, the two dimensional coordinator of mobile node that is calculated by the suggested algorithm and the traditional triangulation algorithm is compared with each other. The localization measuring performance about three dimensional coordinator(z axis) of the suggested algorithm is also obtained by comparing with that of the practical model.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.15-21
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• 2008

The internally confined hollow-concrete filled tube (ICH-CFT) column has two tubes on the both sides (hollow part and outer part) of the concrete. The inner tube and the outer tube perform great seismic abilities, ductility and absorption of energy due to the steel tubes and the hollow part. So, the study of this column type for the practical use is needed. In this study, the qualitative analysis about seismic capacities depending on parameters is performed for the practical design of the ICH-CFT column. The parameters are diameter of column, hollow ratio and thickness of tubes with the same resistance of the moment. Also, the economical evaluation of ductility and comparison with CFT column make this study to be of practical use. Especially, a change of seismic performance depends on the hollow ratio and the thickness of the outer tube, and the economical hollow ratios according to the thickness of the outer tube in the ICH-CFT column are suggested.

• Convergence Security Journal
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• v.17 no.5
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• pp.179-186
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• 2017

The purpose of this study is to analyze the relation of security officers' martial arts training and job performance. To this end, we conducted surveys on security practitioners. The questionnaire consisted of three variables, "necessity of martial arts training, application to practical security work, improvement of job satisfaction". In this study for reliability analysis, Chronbach's Alpha coefficient was calculated. In order to verify the validity of the measured variables, exploratory factors were analyzed using the Berimax method. Both AVE and CR values of the measured variables were above the reference value of 0.5, indicating that the convergence validity was good. As a result of the hypothesis test, the standardization coefficient is 0.636 for "need for training in martial arts training${\Rightarrow}$practical security work", 0.986 for "practical security work${\Rightarrow}$job satisfaction improving", and the relationship between the two hypotheses is positive(+). In order to improve the job satisfaction of security-related practitioners, it seems necessary to raise the need for martial arts training.