• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.235-235
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• 2012

The "Widefield ASKAP L-band Legacy All-sky Blind surveY" (WALLABY) is an extragalactic HI survey which aims to examine HI properties and large-scale distribution of ~500,000 galaxies out to z ~ 0.27, covering a wide range of science goals associated with galaxy formation and evolution (P.I.: B. Koribalski & L. Staveley-Smith). The combination of ASKAP's exquisite column density sensitivity and a large primary beam will make it possible to systematically investigate the rarely explored low column-density HI in the universe. Ultimately, the largest and most homogeneous data set from WALLABY will drastically improve and broaden our knowledge on galaxy formation and evolution. ASKAP will be on-line in 2013, so to ensure timely and efficient reduction and analysis of the large WALLABY data set, we have been developing and testing reliable source finding tools and data analysis pipelines. In this talk I present recent progress of WALLABY, especially on the kinematic parameterisation pipeline for the spatially resolved galaxies detected by WALLABY.

• ETRI Journal
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• v.18 no.4
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• pp.265-286
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• 1997

This paper presents a new software development environment that supports an integrated methodology for covering all phases of software development and gives integrated methods with tools for ITUT (Telecommunication Standardization Section of the International Telecommunication Union) languages. The design of the environment to improve software productivity and quality is based on five main concepts: 1) formal specifications based on SDL (Specification and Description Language) and MSC (Message Sequence Charts) in the design phase, 2) verification and validation of those designs by tools, 3) automatic code generation and a safe separate compilation scheme based on CHILL (CCITT High-Level Language) to facilitate programming-in-the-many and programming-in-the-large. 4) debugging of distributed real-time concurrent CHILL programs, and 5) simulation of application software for integrated testing on the host machine based on CHILL. The application results of the environment compared with other approaches show that the productivity is increased by 19 % because of decreasing implementation and testing cost, and the quality is increased by 83 % because of the formal specifications with its static and dynamic checking facilities.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.6
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• pp.616-625
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• 2011

Ensuring the designed prestress force is very important for the safety of prestressed concrete bridge. The loss of prestress force in tendon could significantly reduce load carrying capacity of the structure. In this study, an automated prestress-loss monitoring system for prestressed concrete girder using PZT-interface and wireless impedance sensor node is presented. The following approaches are carried out to achieve the objective. Firstly, wireless impedance sensor nodes are designed for automated impedance-based monitoring technique. The sensor node is mounted on the high-performance Imote2 sensor platform to fulfill high operating speed, low power requirement and large storage memory. Secondly, a smart PZT-interface designed for monitoring prestress force is described. A linear regression model is established to predict prestress-loss. Finally, a system of the PZT-interface interacted with the wireless sensor node is evaluated from a lab-scale tendon-anchorage connection of a prestressed concrete girder.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.245-252
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• 2001

The ultimate strength testing of a two-story, single-bay, and sway allowed space steel frame was performed. Considering a majority of large-scale frame tests in the past, only two-dimensional frames were experimentally studied. Therefore, three-dimensional experiment is needed to extend the knowledge of this field. The steel frame subjected to non-proportional vertical and horizontal load was tested. The load-displacement curve of the test frame is provided. The experiment results are useful for verification of the three-dimensional numerical analysis. The results obtained from 3D non-linear analysis using ABAQUS were compared with experimental data.

• Journal of the Korean Society for Railway
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• v.7 no.1
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• pp.32-36
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• 2004

Aluminum carbody for rolling stocks is light and perfectly recycled, but includes severe defects which are very dangerous to fatigue strength. Static load test has been performed up to date to assess structural safety of the carbody. However, static load test is not sufficient to evaluate fatigue strength of the carbody, because fatigue failure is caused by dynamic load. In this study, the established load test methods for carbody are described and the characteristics of the methods are discussed. Also, a testing method to simulate dynamic loading condition is proposed for evaluation of fatigue strength of the carbody. The results by the proposed testing method are compared with the results by the static load test and new findings are discussed.

• Journal of the Korean Geotechnical Society
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• v.21 no.6
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• pp.81-91
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• 2005

'Coarse grained material' refers to crushed stones or gravels, and the behaviour of soil containing coarse grained material is not easily defined using the conventional soil mechanics theory due to the influences of large particles, therefore large scale test is essential to investigate their effects. Previous studies have identified the major factors affecting the properties of coarse grained materials by using large scale shear testing apparatus, such as maximum particle size, water content, density and uniformity coefficients. In this paper, the effect of variation of maximum particle size and water content on shear strength was analyzed from the results of large scale shear test. In addition, the fiction coefficient at critical state per vertical load was estimated using the equation proposed by Wood (1998). The sample for the test was obtained from the local quarry sites. Tests results show that the shear strength for 50.8 m maximum particle size is relatively larger than that of 76.3 m and air-dry sample has larger shear strength than saturated sample. In the meantime, the friction coefficient at critical state shows $1.0\sim1.6$ according to the test conditions.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.19-29
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• 2008

In case of unit testing, White-box test can be used to closely check source code and to analyze logic and statement errors. On the other hand, in case of function testing of system level, Black-box test can be mainly used to compare actual and expected results by inputting test data because the scale of function is large. This Black-Box test in system testing level has problem in tracing errors in source code when we find errors. Moreover applying White-box test is not easy for system testing level because the levels of test target are different. Therefore this paper suggests the vertical test method of a practical and integrated system level which can checks up to source code level using White-box test style although it aims to test the highly abstract level like a system function. In addition, the experiment explains how to apply the vertical test by displaying an example which traces from UML specification model to the source code and also shows efficiency of error trace.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.2
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• pp.135-145
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• 2023

Developing high-fidelity Computational Fluid Dynamics (CFD) simulation methods used to evaluate the airwake characteristics along a flight deck of a large ship, the various kind of data such as actual ship measurement and wind tunnel results are required to verify the accuracy of CFD simulation. Inflow velocity profile at the bow, local unsteady flow field data around the flight deck, and highly reliable wind tunnel data which were measured after reviewing Atmospheric Boundary Layer (ABL) simulation and Reynolds Number effects were also used to determine the key parameters such as turbulence model, time resolution and accuracy, grid resolution and type, inflow condition, domain size, simulation length, and so on in STAR CCM⁺. Velocity ratio and turbulent intensity difference between Full-scale CFD and actual ship measurement at the measurement points show less than 2% and 1.7% respectively. And differences in velocity ratio and turbulence intensity between wind tunnel test and small-scale CFD are both less than 2.2%. Based upon this fact, the selected parameters in CFD simulation are highly reliable for a specific wind condition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.5
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• pp.465-474
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• 2008

The real-time hybrid testing method(RT-HYTEM) is a structural testing technique in which the numerical integration of the equation of motion for a numerical substructure and the physical testing for an experimental substructure are performed simultaneously in real-time. This study presents the quantitative evaluation of the seismic performance of a building structure installed with an passive and semi-active MR damper by using RT-HYTEM. The building model that was identified from the force-vibration testing results of a real-scaled 5-story building is used as the numerical substructure, and an MR damper corresponding to an experimental substructure is physically tested by using the universal testing machine(UTM). The RT-HYTEM implemented in this study is validated because the real-time hybrid testing results obtained by application of sinusoidal and earthquake excitations and the corresponding analytical results obtained by using the Bouc-Wen model as the control force of the MR damper respect to input currents were in good agreement. Also for preliminary study, some semi-active control algorithms were applied to the MR damper in order to control the structural responses optimally. Comparing between the test results of semi-active control using RT-HYTEM and numerical analysis results show that the RT-HYTEM is more resonable than numerical analysis to evaluate the performance of semi-active control algorithms.

• Structural Engineering and Mechanics
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• v.53 no.1
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• pp.173-188
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• 2015

Several structural calamities in the second half of the 20th century have shown that adequate collapse-resistance cannot be achieved by designing the individual elements of a structure without taking their interconnectivity into consideration. It has long been acknowledged that membrane behaviour of reinforced concrete structures can significantly increase the robustness of a structure and delay a complete collapse. An experimental large-scale test was conducted on a horizontally restrained, continuous reinforced concrete slab exposed to an artificial failure of the central support and subsequent loading until collapse of the specimen. Within this investigation the development of catenary action associated with the formation of large displacements was observed to increase the ultimate load capacity of the specimen significantly. The development of displacements, strains and horizontal forces within this investigation confirmed a load transfer process from an elastic bending mechanism to a tension controlled catenary mechanism. In this contribution a special focus is directed towards strain and crack development at critical sections. The results of this contribution are of particular importance when validating numerical models related to the development of catenary action in concrete slabs.