• International Journal of Concrete Structures and Materials
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• v.2 no.1
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• pp.57-62
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• 2008

When the yield line theory is used to estimate the ultimate strength of a concrete barrier, it is of primary importance that the correct assumption is made for the failure mode of the barrier. In this study, a static test was performed on two full-scale concrete barrier specimens of Korean standard shape that simulate the actual behavior of a longitudinally continuous barrier. This was conducted in order to verify the failure mode presented in the AASHTO LRFD specification. The resulting shape of the yield lines differed from that presented in AASHTO when subjected to an equivalent crash load. Furthermore, the ultimate strengths of the specimens were lower than the theoretical prediction. The main causes of these differences can be attributed to the characteristics of the barrier shape and to a number of limitations associated with the classical yield line theory. Therefore, a revised failure mode with corresponding prediction equations of the strength were proposed based on the yield lines observed in the test. As a result, a strength that was more comparable to that of the test could be obtained. The proposed procedure can be used to establish more realistic test levels for barriers that have a similar shape.

• Journal of Information Display
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• v.9 no.3
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• pp.16-22
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• 2008

A novel class of conjugated dendritic molecules bearing N-hexyl-substituted carbazoles as peripheral groups and various conjugative aromatic cores was synthesized through Heck coupling and the Horner-Emmons reaction. A multilayered structure of ITO/PEDOT:PSS (30 nm)/emitting material (50 nm)/BCP (10 nm)/$Alq_3$ (10 nm)/LiF (1 nm)/Al (100 nm) was employed to evaluate the synthesized dendritic materials. The electroluminescence spectrum of the multilayered device made of 3Cz predominantly exhibited blue emissions. Similar emissions were observed in the PL spectra of it's the device's thin film. The multilayered devices made of 3Cz, 3BCz, and 4BCz showed luminance values of 6,250 cd $m^{-2}$ at 24 V, 3,000 cd $m^{-2}$ at 25 V, and 1,970 cd $m^{-2}$ at 36 V, respectively. The smallest molecule, 3Cz, which bore three carbazole peripheral groups, exhibited a blue-like emission with CIE 1931 chromaticity coordinates of x = 0.17 and y = 0.21.

• Journal of Evidence-Based Herbal Medicine
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• v.2 no.1
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• pp.7-12
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• 2009

Velvet antlers from Cervus elaphus species are one of most famous, expensive and commonly used medicinal materials in traditional oriental medicine. Some distributor had illegal practice of disguising the origin of antlers in Korea market. Therefore, a test to distinguish antler essential to ensure the healthy development of the herbal industry. In this study, the variation in DNA sequences of the mitochondrial ATPase8 and cytochrome-coxidaseI (COI) genes of Cervus elaphus from China, the Republic of Altai, and Canada were evaluated. In addition, the sequence variation among, Rein deer and Cervus elaphus species was also evaluated. Although the sequences of deer from the Republic of Altai and Canada were very similar, polymorphisms that were conserved in each species were observed in the ATPase8 and COI genes. Therefore, these polymorphic markers could be used to distinguish Cervus elaphus antlers from different locations.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.1
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• pp.35-45
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• 2012

Polyacrylate dispersion(emulsion) as adhesive material was superior in quality such as preservation characteristics and reversibility. The tapes for repairing archival documents manufactured with four different types of formulation resulted in pH 7~8.8, soluble solid 50~52%, and viscosity 1,300~2,500 cps. Sample 4 of those was most excellent. Probably, sample 4 included inorganic materials such as MgO, silica gel, and zeolite. For selecting carrier of tape, tracing papers, were applied for manufacturing tapes and tested for adhesive strength and peel strength. Adhesive strength of tracing papers, was 3.1~3.8(N/10mm), 2.2~2.8(N/10mm), and 1.7-2.3(N/10mm), respectively. Peel strength was similar in all samples. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $105^{\circ}C$ and $80^{\circ}C$ 65% for 7 days.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.818-823
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• 2012

In order to predict necking behaviour of aluminium sheets, a crystal plasticity model is introduced in the finite element analysis of tensile test. Due to the computational limits of time and memory, only a small part of tensile specimen is subjected to the analysis. Grains having different orientations are subjected to numerical tensile tests and each grain is discretized by many elements. In order to predict the sudden drop of load carrying capacity after necking, a well-known Cockcroft-Latham damage model is introduced. The mismatch of grain orientation causes stress concentration at several points and damage is evolved at these points. This phenomenon is similar to void nucleation. In the same way, void growth and void coalescence behaviours are well predicted in the analysis. For the comparison of prediction capability of necking, same model is subjected to finite element analysis using uniform material properties of polycrystal with and without damage. As a result, it is shown that the crystal plasticity model can be used in prediction of necking and fracture behavior of materials accurately.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.4
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• pp.95-101
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• 2012

In order to explain observed catalytic reactivity of aminophosphine complexes (seven-membered chelate), total energy, net charge, atomic orbital electron population, HOMO and LUMO energy of free ligands are calculated by PM3 methods of HyperChem 6.0. Free ligands are 1,2-bis{(diphosphino)amino}propane{$H_2PNHCH_2CH(CH_3)NHPH_2$;ligand 1},1,2-bis{(dimenylphosphino)amino}propane{$(CH_3)_2PNHCH_2CH(CH_3)NHP(CH_3)_2$;ligand 2},1,2-bis{(diphenylphosphino)amino}propane{$(C_6H_5)_2PNHCH_2CH(CH_3)NHP(C_6H_5)_2$;ligand 3}. The result showed that ligand 3 is stable than ligand 2 and ligand 1 and ligand 2 is stable than ligand 1 in total energy. Net charge of P atom is changed by H atom, methyl groups and phenyl groups in P atoms. Net charge of N atoms in ligands is nagative. The results of atomic orbital electron population are similar net charge data..

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.4091-4094
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• 2014

Background: This study used the receiver operating characteristic curve (ROC) to analyze Surveillance, Epidemiology and End Results (SEER) bronchioaveolar carcinoma data to identify predictive models and potential disparity in outcomes. Materials and Methods: Socio-economic, staging and treatment factors were assessed. For the risk modeling, each factor was fitted by a Generalized Linear Model to predict cause specific survival. The area under the ROC was computed. Similar strata were combined to construct the most parsimonious models. A random sampling algorithm was used to estimate modeling errors. Risk of cause specific death was computed for the predictors for comparison. Results: There were 7,309 patients included in this study. The mean follow up time (S.D.) was 24.2 (20) months. Female patients outnumbered male ones 3:2. The mean (S.D.) age was 70.1 (10.6) years. Stage was the most predictive factor of outcome (ROC area of 0.76). After optimization, several strata were fused, with a comparable ROC area of 0.75. There was a 4% additional risk of death associated with lower county family income, African American race, rural residency and lower than 25% county college graduate. Radiotherapy had not been used in 2/3 of patients with stage III disease. Conclusions: There are socio-economic disparities in cause specific survival. Under-use of radiotherapy may have contributed to poor outcome. Improving education, access and rates of radiotherapy use may improve outcome.

• Journal of architectural history
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• v.23 no.4
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• pp.7-17
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• 2014

This paper aims at researching the cave concept of the Japanese architect Terunobu Fujimori and the result could be summarised as follows. First, a cave is Fujimori's only theme related to the interior space. He set some design guidelines for practice concerning openings of the wall and finishing materials of the interior, following the two major characteristics of a cave: 'comfortability' and 'homogeneity in material'. And 'fire' was also the premise in the cave as a 'spirit' of the space. Second, Fujimori applied the concrete guidelines to Tanpopo House (1994~95), which had in fact borne the ideas. Yakisugi House (2005~07) that took the cave as its design theme showed the transition of his cave concept, from closedness to openness. Third, though his cave concept might deserve the criticism that it is inclined to 'image' rather than 'essence', it illustrates that he seeks after an archetype of human dwelling before the purity of the original space was tarnished with rationality and abstraction. And the cave idea allows the seemingly contradictory 'sachlich' and 'surrealistic' features to coexist. Summing up, Fujimori's cave concept proves that his architecture is a rejection of the Cartesian modernist ideal and the contemporary architects' desire for dematerialisation. In a fundamental level, however, it is a result of his strategic choice induced by his own primary principle that his building must not be similar to any styles in history or any other architects' works in the world.

• International Journal of Concrete Structures and Materials
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• v.8 no.2
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• pp.129-139
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• 2014

In this study, the concrete fracture energy was obtained using the three point notched beam test method developed by Hillerborg et al. (Cem Concr Res 6(6):773-782, 1976). A total of 12 notched concrete beams were tested under two different loading conditions: constant stroke control and constant crack mouth opening displacement (CMOD) control. Despite individual fracture energies obtained from the two different loading conditions showing some variation, the average fracture energy from both loading conditions was very similar. Furthermore, the results obtained support the idea that a far tail constant "A" could change the true fracture energy by up to 11 %, if it is calculated using CMOD instead of LVDT. The far tail constant "A" is determined using a least squares fit onto a straight line according to Elices et al. (Mater Struct 25(148):212-218, 1992) and RILEM report (2007). It was also observed that the selection of the end point can produce variations of the true fracture energy. The end point indicates the point in the experiment at which to stop. An end point of 2 mm has been recommended, however, in this study other end points were also considered. The final form of the bilinear softening curve was determined based on Elices and Guinea's methods (1992, 1994) and RILEM report (2007). This paper proposes a bilinear stress-crack opening displacement curve according to test results as well as the CEB-FIP model code.

• KIEAE Journal
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• v.8 no.5
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• pp.3-10
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• 2008

The Korean traditional architecture has developed by adapting to the natural environment, and has successfully created a comfortable indoor settings by using the surrounding natural resources. This is reflected in the building layout, space design and even materials. Our traditional wooden windows adjusting ambient temperature and humidity have both the functions of window and door, although they are clearly divided in the West. The opening and closing method of our traditional windows is similar and their dimensions are shown not to be standardized but diverse in terms of the characteristic of wooden furniture and that of components placed between columns. Thus this study aims to research the sound insulation and absorption performance of traditional windows to be varied with thickness, finishing method of window paper and thickness of air layer. Despite increase of the thickness of window paper, sound absorption was reduced, and the same result was shown when both sides of the structure were finished with thick window paper. The sound insulation performance of the windows could be evaluated to be inappropriate with $R_w$ 0 ~ $R_w$ 14.