• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.2
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• pp.185-191
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• 2012

Typically, a wedge is involved to generate effectively high inspection angle in pipe weld inspection using phased array ultrasonic technique. But the usage of this wedge for weld or access limited area can cause coverage limitation for the examination volume because of the wedge front length. Therefore, the shear wave phased array probe which can generate high inspection angle without wedge is essentially necessary. In this paper, the shear wave phased array ultrasonic probe which can generate high inspection angle designed by modeling and manufactured from the modelling result. And this shear wave probe tested whether it can detect and sizing for EDM test block that contains various depth. As results, the experimental results show that the designed shear wave phased array probe can detect and size with reliable accuracy. Therefore if this phased array probe apply in field inspection, it is expected that it show more reliable inspection result for plant structure having access limitation.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.179-184
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• 2015

The purpose of this study is to provide appropriate methodology to ensure the safety and integrity of the production riser in offshore structure. In order to select integrity estimation methodology for production riser, level I and II Non-destructive Damage Evaluation (NDE) methods that were applied to existing structures are classified and reviewed. Numerical analysis is performed to verify the applicability and capability on damage detection of reviewed methods. As a result, the damage detection methodology using modal strain energy is more sensitive in detection of the damage than other methods. In practice, the number of sensors is limited due to the environmental and financial conditions. The impact on damage detection performance by reducing the number of sensors is systematically investigated through a series of numerical analyses and the results are discussed. The optimal number of sensor for the integrity estimation of production riser is recommended.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.2
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• pp.163-168
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• 2001

Due to aging, adhesively bonded and riveted aircraft lap joints can contain distends, cracks around rivet holes, fatigue induced flaws, and corrosion. It is required for the safety of aircraft to inspect these defects through the whole region of mint in rapid speed. Bond quality or adhesively bonded and riveted aluminum lap splice joints is investigated using non-contact remote ultrasonic nondestructive evaluation (NDE). Non-contact ultrasonic tests are performed using laser generation and air-coupled transducer detection. A Q-switched Nd:YAG laser and a periodic transmission mask are used to generate a selected Lamb mode. The Lamb wave is generated on one side of the lap splice joint, propagates along the plate, interacts with the joint and is detected on the other side by a micromachined air-coupled capacitance transducer. Analysis of recorded signals allows to evaluate the condition of the bond.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.1
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• pp.229-245
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• 1999

Mehrere Sprachen insgesamt oder in Ausschnitten miteinander zu vergleichen, hat die Sprachwissenschaft mit je unterschiedlichen Erkenntnisinteressen wenigstens seit dem 17. Jahrhundert unternommen. Bis in diese Zeit reichen die Versuche einer inhaltlichen, d.h. auf die Inhalte sprachlicher Formen bezogene Sprachtypologie zuruck. Im 19. jahrhundert entstand und entwickelte sich die historisch-vergleichende (komparatistische) Sprachwissenschaft mit dem vorrangigen Bestreben, Ursprung, Entwicklungsgeschichte und Verwandtschaftsbeziehungen einzelner Sprachen durch vergleichende Untersuchungen zu rekonstruieren. Die sprachtypologischen $Bem\"{u}hungen\;fr\"{u}herer$ Zeiten haben ihre Forsetzung in der neueren, etwa in den 60er Jahren $verst\"{a}rkt$ einsetzenden Unversalienforschung. In den meiseten $europ\"{a}ischen$ Sprachen gibt es nicht geringe und $auff\"{a}llige$ Lehnwortbestande. Diese $Wortbest\"{a}nde$ beruhen nicht auf $Zuf\"{a}lligkeiten$, sondern sie sind Ergebnisse internationaler Kontakte mit politischen, kulturellen, okonomischen und anderen Voraussetzungen. Diese sprachlichen Gemeinsamkeiten in verschiedenen Sprachen werden mit dem Begriff des Internationalismus $erfa{\ss}t$. Obwohl die $europ\"{a}ischen$ Sprachen sich immer mehr von den gemeinsamen Ursprungssprachen entfernt haben, verraten die $Wortbest\"{a}nde$ der Internationalismen Tendenzen der $Ann\"{a}herungen$ und der Gemeinsarnkeiten, vor allem auf der Ebene des Wortschatzes. Im Ausblick auf $M\"{o}glichkeiten$ der Verwertung von nationalen $Wortsch\ddpt{a}tzen$ kann man so fomulieren: Internatonalismen 1) $k\"{o}nnen$ die Alltags­kommunikation zwischen Menschen verschiedener Herkunftssprachen erleichtern; sie offenbaren, $da\ss$ viele Fremdsprachen gar nicht so fremdartig sind; 2) haben im Hinblick auf den Fremdsprachenerwerb und den Fremdsprachenunterricht multiplizierten Gebrauchwert: Viele Interlexeme $geh\"{o}ren$ zum festen Bestand $europ\"{a}ischer$ Sprachen; 3) geben $Aufschlu\ss\;\"{u}ber$ geschichtliche und kulturelle $Kontaktvorg\"{a}nge$ und Kontaktergebnisse in Europa; 4) $k\"{o}nnen\;als\;Wortsch\"{a}tze\;einer\;m\"{o}glichen\;europ\"{a}ischen$ Integration betrachtet werden'.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.5
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• pp.369-377
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• 1999

Recently, it is gradually raised necessity that thickness of thin film is measured accuracy and managed in industrial circles and medical world. Ultrasonic signal processing method is likely to become a very powerful method for NDE method of detection of microdefects and thickness measurement of thin film below the limit of ultrasonic distance resolution in the opaque materials, provides useful information that cannot be obtained by a conventional measuring system. In the present research. considering a thin film below the limit of ultrasonic distance resolution sandwiched between three substances as acoustical analysis model, demonstrated the usefulness of ultrasonic signal processing technique using information of ultrasonic frequency for NDE of measurements of thin film thickness. Accordingly, for the detection of delamination between the junction condition of boundary microdefect of thin film sandwiched between three substances the results from digital image processing.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.10
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• pp.45-66
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• 2004

Die relationale Stelle und Bewegung der $Gegenst\"{a}nde$ lassen sick mil Hilfe anderer $Gegenst\"{a}nde$ beschreiben, die in den $diesbez\"{u}glichen$ Untersuchungen jeweils als 'Thema'und 'Relatum' gekennzeichnet wurden. Neben dem Thema und dem Relatum ist zur Beschreibung der $Raumausdr\"{u}cke$ ein driller Begriff 'Origo', bzw. 'Betrachtspunkt', notwendig, weil dabei der subjektive Aspekt des Sprechers bzw. $H\"{o}rers$ u.a. eine wichtige Rolle spielt. Die Stelle eines Gegenstandes ist durch einen Bezug zu seinem Relatum $auszudr\"{u}cken$. Wenn das Relatum keine intrinsische Orientierung kennt, wird im Deutschen und such im Koreanischen eine deiktische Strategie verwendet, in der sich der Sprecher aus seiner Sicht zwischen rechts (von/neben) und links (von/neben), bzw. vor und hinter entscheidet. Falls das Relatum eine intrinsische Orientierung kennt, wird im Deutschen die deiktische Strategie zwar bevorzugt, ist aber nicht dominant, In einem solchen Fall gilt im Koreanischen sowohl der Sprecher wie auch das Relatum als Betrachtspunkt Bei der Beschreibung der Bewegung sind nicht nor der betreffende Cegenstand (=das Thema) und der Zielort (=das Relatum), sondern auch die Stelle des Sprechers, eventuell auch des $H\"{o}rers$ zu $ber\"{u}cksichtigen$. Im Koreanischen spielt der Sprecher konsistent die Rolle des Betrachtspunktes. Auch im Deutschen fungiert normalerweise der Sprecher als Betrachtspunkt; aber im Falle der Bewegung zum Horer fungiert der Horer als Betrachtspunkt Die Bewegung zum Betrachtspunkt wird durch ein Annaherungsverb wie kommen und oda (오다) bezeichnet, $w\"{a}hrend$ die vom Betrachtspunkt $wegf\"{u}hrende$ Bewegung durch ein Entfernungsverb wie gehen und gada (가다) bezeichnet wird. In diesem Zusammenhang wird die Bewegung zum Sprecher durch kommen und oda $ausgedr\"{u}ckt$. Die Bewegung zum $H\"{o}rer$ wird im Koreanischen auch durch gada ausgedruckt, da es sich hierbei um die vom Betrachtspunkt $wegf\"{u}hrende$ Bewegung handelt; in einem solchen Fall wird aber im Deutschen kommen gebraucht, da der $H\"{o}rer$ als Betrachtspunkt fungiert und es sich hier um die Bewegung zum Betrachtspunkt handelt.

• Journal of the Korean Society for Nondestructive Testing
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• v.17 no.1
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• pp.23-30
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• 1997

Recently high frequency ultrasonic transducers to employ polyvinylidene fluoride(PVDF) or polyvinylidene fluoride trifluoroethylene P(VDF-TrFE) have been used to detect small flaws in immersion testing. The detection field depending on the water path between the transducer and a specimen and the path in a tested specimen was measured using a PVDF transducer with nominal frequency 80MHz. Also, C-scan and B-scan were performed for the specimens made of Cr-Ni steel with the artificial flaws, the flat-bottom holes with diameter ranging from $50{\mu}m$ to $560{\mu}m$ at 12mm depth. As the result, the flaws with diameter larger than $280{\mu}m$ were detected, but the flaws with the ratio of diameter to wavelength smaller than about 0.48 were not detected. That the smaller flaws could not be detected was attributed to the attenuation of high frequency components in the steel specimens.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.6
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• pp.426-432
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• 1999

A plus-point eddy current test(ECT) probe was developed to examine the defects on the welds of pumps, valves, and pipings which are the major components of the electric power plants, non-destructive evaluation (NDE) techniques for detecting and sizing the flaws were studied adapting this probe. Differential plus-point ECT probe is consists of two "I"-type coils crossed each other and has an advantage having a small influence on the sensitivity by lift-off variation to the conventional types of probe. The specimens with crack-like electro discharge machining(EDM) notches on the weld of type 304 stainless-steel were fabricated in order to evaluate the plus-point ECT probe response to the flaws. NDE techniques to detect and size the flaws and estimate the flaw type were established with this specimens.

• Journal of Plant Biology
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• v.35 no.3
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• pp.265-271
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• 1992

Vie investigated the effect of indole acetic acid (IAA) on diamine oxidase (DAO; EC 1.4.3.6) in the seedling of soybean (Glycine max L. forma Paldalkong). DAO activity was not detected in the resting soybean seeds. During germination it appeared in the elongating zone on day 3, increased up to day 4 and decreased thereafter. Endogenous IAA content has been shown the same pattern as DAO activity. However, cadaverine content was reduced on day 4. To investigate the effect of IAA on DAO activity, the segments of hypocotyl on day 3 were soaked in various concentration of IAA. The activity increased at low concentrations ($10^{-7}-10^{-6}M$) of 1M as compared to that of control but not at high concentrations ($10^{-5}-10^{-4}M$) of IAA. Differing from DAO activity, cadaverine content increased as concentrations of IAA increased. On the other hand, ethylene was induced by IAA at high concentrations. To study the effect of ethylene on DAO activity, we cotreated IAA and 2,S-Norbonadiene (NDE). In this case, DAO activity was not affected.fected.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.6
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• pp.103-111
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• 2015

To evaluate the compressive strength of concrete, rebound test and ultra pulse velocity methods as well as core test were widely used. The predicted strength effected by age, maturity and degradation of concrete, is a slight difference between in-situ concrete strength. The compressive strength of standard cylinder specimens and core samples by obtained from drilling will have a difference since the concrete is disturbed during the drilling by machinery. And the rebound number and ultra pulse velocity are also changed according to the age and maturity of concrete that effected to the surface hardness and microscpic minuteness. The authors performed the experimental work to reflect the age and core effect to the results from NDE test. The test results considering on the core and age of concrete were compaired with the proposed equation to predict the compressive strength.