• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.3
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• pp.157-162
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• 2005

In order to evaluate the corrosion of reinforcing steel-bars (rebar) in concrete, a nondestructive evaluation by the half-cell potential method is currently applied. In this study, potentials measured on a concrete surface are compensated into those on the concrete-rebar interface by the inverse boundary element method (IBEM). Because these potentials are obtained three-dimensionally (3-D), 3-D visualization is desirable. To this end, a visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, results of a reinforced concrete (RC) slab with corroded rebars are visualized and discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.195-200
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• 2001

Composites have wide applications in aerospace vehicles and automobiles because of the inherent flexibility in their design for improved material properties. Composite tribes in particular, are potential candidates for their use as energy absorbing elements in crashworthiness applications due to their high specific energy absorbing capacity and the stroke efficiency. Their failure mechanism however is highly complicated and rather difficult to analyze. This includes fracture in fibres, in the matrix and in the fibre-matrix interface in tension, compression and shear. The purpose of this study is to investigate the energy absorption characteristics of CFRP(Carbon Fiber Reinforced Plastics) tubes on static and impact tests. Static compression tests have been carried out using the static testing machine and impact tests have been carried out using the vertical crushing testing machine. Interlaminar number affect the energy absorption capability of CFRP tubes. Also, theoretical and experimental have the same value.

• Journal of the Korean Society for Railway
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• v.5 no.3
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• pp.158-166
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• 2002

In this paper, we introduce the software and hardware of the measurement system for on-line testing and evaluation of high speed railway. The test items focus on the verification of the performance and acquirement of the technical data of the high speed railway system. The software controls the hardware of the measurement system, perform the analysis and calculation of measurement data and acts as interface between users and the system hardware. For this purpose, three programs a measuring program, a monitoring program and post-processing program are developed. The detailed test scenario is in the process of development to closely follow the process of development and design of the system.

• Journal of Applied Reliability
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• v.2 no.1
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• pp.23-32
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• 2002

As the function of digital products gets diverse and complex, more than 30~40% job of software developing and testing group within its development cycle, concentrates on the software testing[1]. To cope with consumers'quickly changing needs, development cycle time gets short, and the number of model and test items increase steadily This is why automating software basic function and UI(User Interface) verification is needed [4][5][6]. This paper draws many strength and weakness defines Input/Output through integrating mobile phone, DVDP, PDA, and Black-Box (Intrusive (mobile) or Non-Intrusive(DVDP, PDA)) testing systematically, which brought above the 64% average of automation rate, and ensure 80% of test coverage [4][5][6].

• Proceedings of the Korea Society of Design Studies Conference
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• 2003.05a
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• pp.32-33
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• 2003

• International Journal of Automotive Technology
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• v.3 no.4
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• pp.157-163
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• 2002

It is well recognized that the ultrasonic method is one of the most common and reliable nondestructive testing (NDT) methods for the quantitative estimation of defects in welded structures. However, NDT techniques applying for adhesively bonded joints have not been clearly established yet. In this paper, the detection of interface crack by the ultrasonic method was applied for the measurement of interfacial crack length in the adhesively bonded joints of double-cantilever beam (DCB). An optimal condition of transmission coefficients and experimental accuracy by the ultrasonic method in the adhesively bonded joints have been investigated and discussed. The experimental values are in good agreement with the computed results by boundary element method (BEM) and Ripling's equation.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.3
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• pp.451-460
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• 2006

While sludge settles down in a batch column, sludge concentration becomes high. Sludge concentration change is one of the most critical causes of the sludge settling velocity variation. Therefore, sludge concentration change causes sludge index to change. SVI is more sensitive than other sludge indexes to the change of sludge concentration. And if sludge-water interface has reached final height within 30minutes, SVI is not suitable for prediction of sludge settling characteristic, Therefore, SVIs of each sludge are, in some cases, different although each sludge has the same settling velocity. But SVI has been widely used to interpret sludge settling characteristic by a simple testing method. This work has two purposes. The first purpose is to predict sludge settling velocity by using sludge-water interface settling velocity. And the second purpose is to develop new sludge settling characteristic index to exactly interpret sludge settling characteristic by overcoming the limit of SVI.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.90-95
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• 2015

This paper describes IEC 61727 standard of Photovoltaic (PV) systems -Characteristics of the utility interface. IEC 61727 standard tests include utility compatibility and personnel safety and equipment protection of PV inverter performance functions. Especially utility compatibility part includes test items of 1) voltage, current and frequency, 2) normal voltage operating range, 3) flicker, 4) DC injection, 5) normal frequency operating range, 6) harmonics and 7) waveform distortion, 8) power factor of PV inverter. Also personnel safety and equipment protection part includes test items 1)loss of utility voltage, 2)over/under voltage and frequency, 3)Islanding protection, 4)response to utility recovery, 5)earthing, 6)short circuit protection, 7)Isolation and switching of PV inverter. In this paper, each item of IEC 61727 standard test is studied and analyzed and finally full tested by PV inverter performance function.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.1049-1052
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• 1999

We present a use. interface(UI) simulator for developing a mobile phone. This simulator consists of 3 major modules: Graphic Tool Editor, User Interface Software(UI), and Network Command Processor(NCP). The Graphic Tool Editor can design a virtual mobile terminal. The NCP sends a command to the phone and then receives its status from the phone after completion of the command. We can add or modify lots of features easily to the phone using the UI module. These modules can interact each other by sharing the common area in the memory. By doing so, these modules can exchange their status and data to operate in real-time. We have designed and tested a virtual prototyping phone for the LGP 3200 manufactured by LGIC by using the simulator. Through a series of experiment, we have believed that our virtual prototyping interactive simulator can do shorten its development and testing cycle by applying it in the early design phase.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.97-102
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• 2000

It is well recognized that the ultrasonic methods is one of the most common and reliable nondestructive testing(NDT) methods for the quantitative estimation of defects in welded structures. However, NDT techniques applying for adhesively bonded joints have not been clearly established yet. In this paper, the detection of interface crack by the ultrasonic method was applied for the measurement of interfacial crack length in the adhesively bonded joints of double-cantilever beam(DCB). The optimum condition of transmission coefficients in the adhesively bonded joints and it's experimental accuracy by the ultrasonic method have been investigated. The experimental values are in good agreement with the computed results by boundary element method(BEM) and Ripling's equation.