• Steel and Composite Structures
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• v.9 no.6
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• pp.569-584
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• 2009

Corrosion of steel rebars in bridge decks which are faced to harsh conditions, is a common problem in construction industries due to the porosity of concrete. In this research, the behavior of one-way concrete slabs reinforced with Glass fiber reinforced polymer (GFRP) molded grating is investigated both theoretically and experimentally. In the analytical method, a closed-form solution for load-deflection behavior of a slab under four-point bending condition is developed by considering a concrete slab as an orthotropic plate and defining stiffness coefficients in principal directions. The available formulation for concrete reinforced with steel is expanded for concrete reinforced with GFRP molded grating to predict ultimate failure load. In finite element modeling, an exact nonlinear behavior of concrete along with a 3-D failure criterion for cracking and crushing are considered in order to estimate the ultimate failure load and the initial cracking load. Eight concrete slabs reinforced with steel and GFRP grating in various thicknesses are also tested to verify the results. The obtained results from the models and experiments are relatively satisfactory.

• Structural Engineering and Mechanics
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• v.50 no.6
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• pp.817-834
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• 2014

An experimental program was designed in the current work to examine the structural behavior of ferrocement beams reinforced with composite materials under three point loadings up to failure. The experimental program comprised casting and testing of twelve ferrocement beams having the dimensions of 120 mm width, 200 mm depth and 1600 mm length. The twelve beams were different in the type of reinforcements; steel bars, traditional wire meshes (welded and expanded wire meshes) and composite materials (fiberglass wire meshes and polypropylene wire meshes). The flexural performances of the all tested beams in terms of strength, ductility, cracking behavior and energy absorption were investigated. Also all the tested beams were simulated using ANSYS program. The results of the experimental tests concluded that the beam with fiber glass meshes gives the lowest first crack load and ultimate load. The ferrocement beam reinforced with four layers of welded wire meshes has better structural behavior than those beams reinforced with other types of wire meshes. Also the beams reinforced with metal wire meshes give smaller cracks width in comparing with those reinforced with non-metal wire meshes. Also the Finite Element (FE) simulations gave good results comparing with the experimental results.

• The Research Journal of the Costume Culture
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• v.18 no.6
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• pp.1112-1128
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• 2010

This study aims to know the trace of Korean musical, consider musical depending on its type, arrange characteristic of musical costume and find out the developmental direction of Korean musical costume with potentials as a culture industry. For study method, the data were collected from thesis, academic journal, book and internet web-site concerning musical costume, literatures were considered and performance costume photos, which were captured via musical performance site, were analyzed. The history of Korean modern-day musical is regarded as starting with (1966) in the full scale. Although foreign musical was imitated in 1970s~1980s, it may be called the growth period of Korean musical because the period showed the commercial possibility. Since 1990s, large-scaled musical securing good work and popularity was popular. In 2000s, musical industry was abundant quantitatively and qualitatively as investment or popularity was significantly expanded. The type of Korean musical are divided to opera musical of European, Broadway musical of American and creative musical of Korean. The costumes used in opera musical of European and Broadway musical of American are borrowed from original works through license or were manufactured in Korea by referring to the costumes of original works and using similar materials or fabrics. The costumes used in creative musical of Korea are designed by either domestic or foreign designers and produced in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.393-400
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• 1992

The DC(Direct-Current) servo motor has widely used for many application areas, FA(Factory Automation), OA(Office Automation) and home applications. But DC servo motor needs periodical inspection because it has brush and commutator. Recently, AC servo motor has expanded it's application areas due to for the development of the power semi-conductor and control technology. But it has large torque ripple for it's small number of commutation. And it also has cogging torque due to permanent magenet rotor. Therefore it can't run balence rotarion. Many torque ripple reduction methods are published. In this paper, phase advanced method adopted for torque ripple reduction of AC servo motor. In this research, AC servo motor torque characteristic variation surveied under the phase advance control through the computer simulation. Under the simulation, the load inertia varied from 0.0001[Kg.m$^{2}$] to 0.0314[Kg.m$^{2}$]. The result os nonlinear simulation, torque and speed ripple of AC servo motor under the phase advance control reduced approximately 50[%] and 10[%]. And maximum torque of AC servo motor under phase advance control condition increased about 5[%] as compare with fixed switching time.

• Solar Energy
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• v.17 no.1
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• pp.35-46
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• 1997

In this study comparison of experiment results with the computed results of linear theory and nonlinear theory using singularity method was obtainable. Specially singularity points like sources and vortexes on hydrofoil and freestreamline were distributed to analyze two dimensional flow field of supercavitating cascade using nonlinear theory, and governing equations of flow field were derived and hydraulic characteristics of cascade were calculated by numerical analysis of the governing equations. The results compared linear theory and nonlinear theory with the experiment results of the study are as follows: The tolerances of nonlinear theory were larger than those of linear theory in case of ${\alpha}<10^{\circ}$. Moreover the computational range of attack angles could be expanded from ${\alpha}=10^{\circ}$ to ${\alpha}=25^{\circ}$, the flow field of supercavitating cascade could be analyzed in the condition which the wake thickness and the length of cavity are a variable. The shapes of cavity were changed sensitively according to various variable such as attack angles, pitches and wake thickness, and the pressure distribution of hydrofoil surface was identical almost disregarding wake thickness but changed largely according to attack angle and the length of cavity. Lift coefficient and drag coefficient were reduced according to increasing of wake thickness but the influences of wake thickness were very little in the situation of small pitch and long cavity.

• Fire Science and Engineering
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• v.20 no.3 s.63
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• pp.85-95
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• 2006

Because the average span of human life is expanded by developing economy growth and medicine science elder population increases rapidly. According to that A first aid patient of demands grow, too so in a fire station. We have to prepare following these. First that the silver ambulance is in process of service is widely. second, medical teams and fire fighters construct unity Third, New curni culum makes under modern operating course. Forth, the problem that wireless paging system sets up and rums already. advances more effective. Fifth furthermore, we organize a private volunteer for an old age To connect that we enlarge total service for silver age. Through this fire fighting service. we are neloom to get more confidence and love.

• Fire Science and Engineering
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• v.6 no.1
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• pp.90-98
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• 1992

Over the last 100 years since the introduction of electricity, the nation has faced ever increasing demand for electricity as consequence of the rapid economic growth. The expanded consumption ratio for electricity naturally increased the possibility for electricity related accident mainly iii the form of electrically ignited fire and human injuries from electric shock. Under such circumstances, the presented study sets a focus on analysing the causes of the electrically related fire accidents happened in the nation over the last 10 years(in the 80's) to provide a scientific basis for identifying the cause of electric fires. Identification of the cause of fire ignited electrically may be approached either by studying accident related electrical properties or by investigating power instruments at the place of the accient. In the present paper, the former approach is taken especially on investigating the consequences of over current induced by short circuiting of high power instruments which is reported as the primary cause electricity related fire accidents. In order to provide reliability of the identification method, microscopic photograph's are taken for the cross sections of the electrical materials(fuse, wire, plug socket and plug) after being exposed to over current and heated by external means respectively. The results are consequently compared and analysed.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.61-68
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• 2012

The main objective of this study is to develop an analytical model for the resilient modulus of EPS geofoam when it is applied for flexible pavement as a subgrade material. This analytical model has been developed based on the results from triaxial compression tests. And this model can be used to analyze the flexible pavement structure using the finite element method by developing a program or modifying an existing program for any desired purposes. The results of this study show that the EPS geofoam as a replacement material for subgrade in flexible pavement is a feasible alternative to natural weak soils.

• Structural Engineering and Mechanics
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• v.64 no.2
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• pp.155-171
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• 2017

This paper presents a proposed method for producing reinforced composite concrete columns reinforced with various types of metallic and non metallic mesh reinforcement. The experimental program includes casting and testing of twelve square columns having the dimensions of $100mm{\times}100mm{\times}1000mm$ under concentric compression loadings. The test samples comprise all designation specimens to make comparative study between conventionally reinforced concrete column and concrete columns reinforced with welded steel mesh, expanded steel mesh, fiber glass mesh and tensar mesh. The main variables are the type of innovative reinforcing materials, metallic or non metallic, the number of layers and volume fraction of reinforcement. The main objective is to evaluate the effectiveness of employing the new innovative materials in reinforcing the composite concrete columns. The results of an experimental investigation to examine the effectiveness of these produced columns are reported and discussed including strength, deformation, cracking, and ductility properties. Non-linear finite element analysis; (NLFEA) was carried out to simulate the behavior of the reinforced concrete composite columns. The numerical model could agree the behavior level of the test results. ANSYS-10.0 Software. Also, parametric study is presented to look at the variables that can mainly affect the mechanical behaviors of the model such as the change of column dimensions. The results proved that new reinforced concrete columns can be developed with high strength, crack resistance, and high ductility properties using the innovative composite materials.

• Korean Journal of Adult Nursing
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• v.17 no.1
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• pp.128-138
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• 2005

Purpose: As population of elderly people continues to grow, successful aging has risen to the top of the nursing science agenda. The successful aging includes maintenance of the cognitive and physical functions, as well as emotional well-beings. This study was carried out to evaluate effects of the environmental enrichments on cognition of institutionalized elderly. Method: The population was selected among the elderly aging over 65 residing at two of institutions. A quasi experimental design was used with non-equivalent control group. Study subjects were thirteen for each group. For the experimental group, physical, social and symbolic environmental enrichment program was provided for six weeks. The data were analyzed by repeated measure ANOVA and repeated measure ANCOVA using SPSS Win 11.0. Result: Compared to control group, the experimental group showed a significant difference on DSF(F=3.29, p=.046), and TMTA(F=4.76, p=.013) of cognitive function, and depression (F=5.56, p=.007) of emotional distress after 1 and 12 weeks of environmental enrichment program. Conclusion: Findings indicate that physical, social, and symbolic environmental enrichment was effective to partially prevent from cognitive decline, and to decrease emotional distress of elderly. As a nursing intervention, environmental enrichment program for elderly should be expanded for nursing practice to promote healthy aging and to offer support to the growing population of elderly. Further research should be conducted to evaluate the effect on the community elderly.