• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.277-284
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• 1998

The purpose of this study was to evaluate the propriety of making use of the light-cured resin base in indirect bracket bonding technique by study of shear bond strength and failure patterns according to the material of resin base. Metal brackets were bonded to the stone models of specimens involving bovine lower incisor with chemical-cured(Excel), light-cured(Light-Bond) and thermal-cured(Therma-Cure) resin. They were transferred to the specimens and bonded using sealant. The shear bond strength was tested on Instron. After bracket removal, the bracket base was examined and assessed with the adhesive remnant index(ARI). The results were as follows : 1. No significant differences in shear bond strength were found among the three groups (P>0.05). 2. No significant differences in ARI score were found among the three groups (P>0.05). The above results suggest that light-cured resin base in addition to chemical-cured and thermal-cured resin bases is useful in the indirect bonding technique.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.264-271
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• 2017

Purpose: The purpose of this study is to investigate the differences in bond strength of four different indirect composites to the gold alloy and Ni-Cr alloy according to type of metal surface treatment after water storage. Materials and methods: Type IV gold alloy and Ni-Cr alloy were used for casting alloy while four types of indirect composite resins (Gradia, Tescera Sinfony and in;joy) were used in this study. Metal specimens were produced by casting and total of 240 specimens (60 specimens per one indirect composite group) were prepared. After bonding indirect composite resin and undergoing 24 hours of polymerization, customized jig was attached to the metal specimen and shear bond strength were measured using universal testing machine. Also, differences in shear bond strength before and after water storage for 240 hours were also measured. Results: In the measurement of shear bond strength according to the metal surface treatments, bead group showed high strength followed by loop and flatting group (P<.05). After being stored in water bath for 240 hours, Gradia showed statistically significant high bond strength compared to other indirect composite resins in all groups (P<.05). Conclusion: Shearbond strength was found to be different according to type of metal surface treatment and type of metal used after storage in water. Further studies need to be developed for clinical practices as three are still problems of microleakage, stain or wear.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.115-130
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• 2005

This paper presents the effects of indirect costs on Life-Cycle-Cost(LCC) effective optimum design of steel-box girder bridges. The LCC formulations considered in the LCC optimization of the bridges consist of initial cost and expected rehabilitation costs including repair/replacement costs, loss of contents or fatality and injury losses, and indirect costs such as road user costs and indirect socio-economic losses. To demonstrate the LCC-effectiveness for optimum design of the bridges, an actual steel box girder bridge having two continuous spans(2@50m=100m) is considered as a numerical example. And also, in this paper, various sensitivity analyses are performed to investigate the effects of indirect costs caused by traffic conditions such as number of detour route, number of lane on detour route, length of detour route, and traffic volumes on the LCC-effective optimum design. From the numerical investigations, it may be concluded that indirect costs caused by traffic network may sensitively influence on the LCC-effective optimum design of steel-box girder bridges. Therefore, it may be stated that the traffic conditions should be considered as one of the important items in the LCC-effective optimum design of the bridges.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.599-608
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• 2001

Many papers which deal with the dynamic instability of shell-like structures under the STEP load has been published but there have been few papers related to the dynamic instability of hybrid cable domes. And also there are a few researches which treat the essential phenomenon of the dynamic buckling using the phase for investigating occurrence of chaos. In this study the indirect buckling of hybrid cable domes considering geometric nonlinearity are investigated numerically and compared it with the static critical load The dynamic critical loads are determined by the numerical integration of the geometric nonlinear equation of motion and the mechanism of the indirect buckling is examined by using the phase curves.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.133-141
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• 2002

Isotropic rock and anisotropic rock have different tensile strength which has the greatest influence on rock failure. In this study, elastic modulus of anisotropic rock is obtained through uniaxial compression test, and tensile strength and tension failure behavior are analyzed through indirect tensile strength test. Stress concentration factor of a specimen at the center is obtained from anisotropic elastic modulus and strain by indirect tensile strength test. Theoretical solutions for tensile strength of isotropic and anisotropic rock are compared. Stress concentration factor of anisotropic rock is either higher or lower than isotropic rock depending on the inclination angle of bedding plane. The use of stress concentration factor of isotropic rock resulted in overestimation or underestimation of tensile strength.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.11
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• pp.1914-1922
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• 2008

In this paper, examined characteristics of EEG(electroencephalogram) variation when the stimulation was given to lung-wan(CV12), Shin-gwol(CV8) and Gwan-won(CV4) which were some of the acupuncture point, through indirect moxibustion and No stimulation. The EEG signals were measured before the stimulation, during the stimulation, and 1 hour after the stimulation. The measured time domain data were converted to the frequency domain data FFT(Fast Fourier Transform) and frequency power spectrum. Then the $\alpha,\beta,\delta$, and $\theta$ waves were analyzed for variation to the amplitude of vibration according to the stages of stimulation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.4
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• pp.127-134
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• 2005

Design and construction of long-span bridge are recently increasing by development of computer technology. Specially, cable stayed bridge and suspension bridge having cable component are representative of long-span bridge may do. Therefore, this paper a present a methodology for cable tension force monitoring in cable-stayed bridge under construction using acceleration data acquired by the vibration method. To improve accuracy construction, all stay cables are measured, according to 4-step construction stage and change of temperature.

• Korean Journal of Environment and Ecology
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• v.31 no.4
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• pp.420-427
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• 2017

The purpose of this study was to investigate the indirect effects of forest using the forest healing factors such as landscape and hearing factors on mood improvement. The experiment was conducted for about 2 months from October 5, 2016 to November 30, 2016 targeting 30 healthy college students ($23.6{\pm}1.7$ years old). After making 3 factors(image factor, sound factor and image+sound factor) using scenery and sound of both forest and urban space, participants undergone the test in a room. And the effects of these 3 factors on the mood improvement were compared and analyzed using SPSS 18.0 program. Profile of Mood State test (POMS) and Semantic Differential method (SD) were used to measure mood improvement as a psychological test. As a result, indirect forest stimulation showed effects of suppressing tension, fatigue, anger, confusion, depression, and enhancement of vitality. No significant difference was observed in the comparison between forest stimuli. However, Compared with the urban stimuli, the stimulation of the forests has the effect of enhancing pleasant, natural feeling and calmness.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.203-209
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• 2010

The base asphalt mixtures that used the waste recycle asphalt correcting from the four different overlay construction sites in Seoul city were made using the foamed asphalt method. The sample mixtures were made in different ratio of the recycle asphalt and new asphalt material and the performance of the mixtures of the different ratio was investigated in the laboratory. The laboratory tests includes the Marshall test, the indirect tensile test, the resilient modulus test, the creep test and the wheel tracking test. The test of the recycle foamed asphalt mixtures(RFA) were compared with the those of the recycle hot mix asphalt(RHA) mixtures. The performance of the RFA is comparable to that of the RHA. On the other hand, the indirect tensile strength of the RFA in dry condition is lower than that of RHA and the indirect tensile strength of the RFA in wet condition is much lower than that of the RHA.

• Journal of the Korean GEO-environmental Society
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• v.4 no.3
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• pp.5-17
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• 2003

Using Rowe cell for vertical and lateral consolidate test, we concerned characteristics of vertical and lateral consolidation, and permeability on the remolded Decompoed Mudstone Soil in Phoang, and then, compared it with Oedometer test results. Indirect coefficients of permeability were calculated by the results of the coefficient of consolidation that were derived from 9 different kinds of methods. The values of indirect coefficients of permeability derived from ${\sqrt{t}}$ method and hyperbolic method were similar to the results of direct coefficients of permeability with respect to vertical drainage, but, in the case of lateral drainage, for all kinds of methods, the values of indirect coefficients of permeability showed overestimated ones. With vertical and lateral direct coefficient of permeability, by investigating the anisotropic effect with respect to permeability on Decomposed mudstone soil, we obtained average value, 13, with respect to anisotropic characteristics for all kinds of consolidation loadings.