• Geomechanics and Engineering
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• v.6 no.3
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• pp.293-320
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• 2014

In this study, in order to evaluate adequacy of considering local site effect, excluding soil-structure interaction (SSI) effects in inelastic dynamic analysis and design of mid-rise moment resisting building frames, three structural models including 5, 10, and 15 storey buildings are simulated in conjunction with two soil types with the shear wave velocities less than 600 m/s, representing soil classes $D_e$ and $E_e$ according to the classification of AS1170.4-2007 (Earthquake actions in Australia) having 30 m bedrock depth. Structural sections of the selected frames were designed according to AS3600:2009 (Australian Standard for Concrete Structures) after undertaking inelastic dynamic analysis under the influence of four different earthquake ground motions. Then the above mentioned frames were analysed under three different boundary conditions: (i) fixed base under direct influence of earthquake records; (ii) fixed base considering local site effect modifying the earthquake record only; and (iii) flexible-base (considering full soil-structure interaction). The results of the analyses in terms of base shears and structural drifts for the above mentioned boundary conditions are compared and discussed. It is concluded that the conventional inelastic design procedure by only including the local site effect excluding SSI cannot adequately guarantee the structural safety for mid-rise moment resisting buildings higher than 5 storeys resting on soft soil deposits.

• Steel and Composite Structures
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• v.22 no.3
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• pp.537-565
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• 2016

Australian railway networks possess a large amount of aging timber components and need to replace them in excess of 280 thousands $m^3$ per year. The relatively high turnover of timber sleepers (crossties in a plain track), bearers (skeleton ties in a turnout), and transoms (bridge cross beams) is responsible for producing greenhouse gas emissions 6 times greater than an equivalent reinforced concrete counterparts. This paper presents an innovative solution for the replacement of aging timber transoms installed on existing railway bridges along with the incorporation of a continuous walkway platform, which is proven to provide environmental, safety and financial benefits. Recent developments for alternative composite materials to replace timber components in railway infrastructure construction and maintenance demonstrate some compatibility issues with track stiffness as well as structural and geometrical track systems. Structural concrete are generally used for new railway bridges where the comparatively thicker and heavier fixed slab track systems can be accommodated. This study firstly demonstrates a novel and resilient alterative by incorporating steel-concrete composite slab theory and combines the capabilities of being precast and modulated, in order to reduce the depth, weight and required installation time relative to conventional concrete direct-fixation track slab systems. Clear benefits of the new steel-concrete composites are the maintainability and constructability, especially for existing railway bridges (or brown fields). Critical considerations in the design and finite element modelling for performance benchmarking of composite structures and their failure modes are highlighted in this paper, altogether with risks, compatibilities and compliances.

• Steel and Composite Structures
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• v.28 no.2
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• pp.233-250
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• 2018

Back-to-back built-up cold-formed steel un-lipped channel sections are used in cold-formed steel structures; such as trusses, wall frames and portal frames. In such built-up columns, intermediate fasteners resist the buckling of individual channel-sections. No experimental tests or finite element analyses have been reported in the literature for back-to-back built-up cold-formed steel un-lipped channel sections and specially investigated the effect of screw spacing on axial strength of such columns. The issue is addressed in this paper. The results of 95 finite element analyses are presented covering stub to slender columns. The finite element model is validated against the experimental tests recently conducted by authors for back-to-back built-up cold-formed steel lipped channel sections. The verified finite element model is then used for the purposes of a parametric study to investigate the effect of screw spacing on axial strength of back-to-back built-up cold-formed steel un-lipped channel sections. Results are compared against the built-up lipped channel sections and it is shown that the axial strength of un-lipped built-up sections are 31% lesser on average than the built-up lipped channel sections. It was also found that the American Iron and Steel Institute (AISI) and the Australian and New Zealand Standards were over-conservative by around 15% for built-up columns failed through overall buckling, however AISI and AS/NZS were un-conservative by around 8% for built-up columns mainly failed by local buckling.

• The Journal of the Petrological Society of Korea
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• v.17 no.1
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• pp.44-50
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• 2008

A geochemical technique based on rare earth element geochemistry was used to clarity the source of the Asian dust (Yellow sand) in the Daejeon area. The Asian dusts were collected 4 times during 31th March- 2nd April and 25th May-27th May 2007. The Yellow sand shows PAAS (Post Archean Australian Shale)-normalized REE pattern of the flattened LREE and slightly depleted LREE without Eu anomaly, whereas the Daejeon soil has slightly enriched LREE and depleted HREE with negative Eu anomaly. Our results show that REE patterns of the Asian dust are LREE-flattened similar to those of the sediment from the south-eastern part of Ordos desert. This suggests that Asian dust in the Daejeon area might be derived from the south-eastern part of Ordos desert.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.532-536
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• 2005

GC-NPD analysis was performed on residues of aluminium phosphide in raw wheat and wheat products by trapping gaseous phosphine in the headspace of vessel. In Australian wheat, over 95% of samples were detected below 1 ppb, considered as safe level, whereas in American wheat, about 70% of 58 samples were detected within 1-10 ppb with 4 showing over 10 ppb. About 14-22% phosphine residues of raw wheat were retained after milling process. Wheat samples of same origin showed significant varying levels of phosphine.

• Journal of The Korean Astronomical Society
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• v.51 no.5
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• pp.129-142
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• 2018

The DEEP-South (the Deep Ecliptic Patrol of the Southern Sky) photometric census of small Solar System bodies produces massive time-series data of variable, transient or moving objects as a by-product. To fully investigate unexplored variable phenomena, we present an application of multi-aperture photometry and FastBit indexing techniques for faster access to a portion of the DEEP-South year-one data. Our new pipeline is designed to perform automated point source detection, robust high-precision photometry and calibration of non-crowded fields which have overlap with previously surveyed areas. In this paper, we show some examples of catalog-based variability searches to find new variable stars and to recover targeted asteroids. We discover 21 new periodic variables with period ranging between 0.1 and 31 days, including four eclipsing binary systems (detached, over-contact, and ellipsoidal variables), one white dwarf/M dwarf pair candidate, and rotating variable stars. We also recover astrometry (< ${\pm}1-2$ arcsec level accuracy) and photometry of two targeted near-earth asteroids, 2006 DZ169 and 1996 SK, along with the small- (~0.12 mag) and relatively large-amplitude (~0.5 mag) variations of their dominant rotational signals in R-band.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.155.2-155.2
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• 2012

CTIO 4m 및 CTIO 1m 망원경으로 Westerlund 2의 UBVI 관측을 수행하여, CTIO 4m SDSS $u$ filter의 적색광누출 현상을 발견하였고 그 영향을 분석하였다. 적색광누출 현상은 filter의 투과함수가 설계와는 달리 장파장 영역에서 투과 존재하는 현상으로, CTIO 4m SDSS $u$ filter의 경우 B-V>1.4, V-I>2.0에서 그 영향이 나타나기 시작한다. SDSS $u$ filter의 적색광누출 현상은 별의 고유색지수와 상관없이 관측된 색지수가 클수록 영향이 크며, $B-V{\leq}1.8$, $V-I{\leq}2.8$의 범위에서는 보정이 가능하다. CTIO 1m B filter에서는 성간소광을 받지 않은 별과 성간소광을 많이 받은 별의 표준계변환 결과, $B_{CTIO1m}=B_{Standard}-0.055{\times}E(V-V)$에 해당하는 차이를 보였다. 이러한 차이는 CTIO 1m B filter의 투과함수의 단파장 쪽 날개부분이 표준 Johnson B filter에 비하여 단파장 쪽으로 많이 치우쳐있기 때문으로 보인다. 특히 Ballmer jump에 해당하는 파장인 370 nm에서 filter의 최대투과율에 비하여 32.2%에 달하는 투과율을 보이는데, 이는 Bessell B filter의 3.1%에 비하여 매우 큰 값이다. CTIO 1m 망원경의 Y4KCam CCD에서는 포화된 화소에 의한 crosstalk 뿐 아니라 포화되지 않은 화소에 의한 crosstalk 현상도 보였다. 짧은 노출을 준 영상에서는 5000 ADU 이상에서는 육안에 의한 crosstalk 확인이 가능하며, 포화되지 않은 밝은 별에 의한 crosstalk을 확인하지 않고 측광할 경우 백색왜성으로 오인할 가능성이 있으므로 측광 과정에서 좌표를 통하여 확인할 필요가 있다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.7
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• pp.627-633
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• 2003

The effects of alloying-element additions to Ag sheath on thermal conductivity and mechanical properties of Bi-2223 superconductor tapes have been evaluated. In order to evaluate the effects of sheath alloys and their configuration on the properties of tape, various combinations of Ag and Ag alloys were selected as the inner and outer sheath. Thermal conductivity of the tapes was evaluated by using thermal integral method at 10 ∼120 K. It was observed that the addition of Mg, Sb, and Au to Ag sheath significantly decreased the thermal conductivity at low temperature probably due to the alloying effect. Specifically, the thermal conductivity of AgMg, AgSb, and AgAu at 40 K were 411.4, 142.3, and 109.7 W/(m·K), respectly, which is about 2∼9 times lower than that of Ag (1004.6 W/(m·K)). In addition, the thermal conductivity of alloy-sheathed tape was significantly dependent on their thermal conductivities of constituent sheath materials. The mechanical properties of alloy-sheathed tapes were also evaluated. Yield strength and tensile strength were improved but workability decreased for alloy-sheathed tapes.

• School Mathematics
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• v.18 no.2
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• pp.349-373
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• 2016

Comparison of curriculum between various countries is a major research method for studying a course and content quoted on Korea's national curriculum. Therefore this research focuses on comparing and analyzing a new curriculum which Australia has announced on 2012 and conducting since 2015. From this research result, we found that Australia's curriculum achievement shows some unique characteristics. Such examples can be dealing a concept with real life context and proposing a mathematical content specifically. Also they introduce the definite integral by defining to the sum of series. There are other characteristics such as modelling motion, and numerical integration which Korea's highschool curriculum achievement doesn't deal with, and the content of vector calculus is handled more deeply. As a result of analyzing Australia's textbook, it fully deals with the supplementary notion to help understand mathematical definition. Hence further research will be needed later on to relieve the aspect of cognitive burden on Korean learners.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.1-9
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• 2002

Evolutionary artificial neural networks (EANNs) are towards the near optimal ANN using the global search of evolutionary instead of trial-and-error process. However, many real-world problems are too hard to be solved by only one ANN. Recently there has been plenty of interest on combining ANNs in the last generation to improve the performance and reliability. This paper proposes a new approach of constructing multiple ANNs which complement each other by speciation. Also, we develop a multiple ANN to combine the results in abstract, rank, and measurement levels. The experimental results on Australian credit approval data from UCI benchmark data set have shown that combining of the speciated EANNs have better recognition ability than EANNs which are not speciated, and the average error rate of 0.105 proves the superiority of the proposed EANNs.