• Smart Structures and Systems
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• v.13 no.5
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• pp.731-753
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• 2014

In this study, an indirect approach is developed for assessing the state of a bridge on the basis of mode shapes estimated by the responses of passing vehicles. Two types of damages, i.e., immobilization of a support and decrease in beam stiffness at the center, are evaluated with varying degrees of road roughness and measurement noise. The assessment theory's feasibility is verified through numerical simulations of interactive vibration between a two-dimensional beam and passing vehicles modeled simply as sprung mass. It is determined that the damage state can be recognized by the estimated mode shapes when the beam incurs severe damage, such as immobilization of rotational support, and the responses contain no noise. However, the developed theory has low robustness against noise. Therefore, numerous measurements are needed for damage identification when the measurement is contaminated with noise.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.250-253
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• 1998

This paper presents a multi-modal neural network composed of a preprocessing module and a multi-layer neural network module in order to enhance the nonlinear characteristics of neural network. The former module is based on spectral method using Chebyschev polynomials and transforms input data into spectra. The latter module identifies the system using the spectra generated by the preprocessing module. The omnibus numerical experiments show that the method is applicable to many a nonlinear dynamic system in the real world, and that preprocessing using Chebyschev polynomials reduces the number of neurons required for the multi-layer neural network.

• Speech Sciences
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• v.11 no.4
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• pp.207-221
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• 2004

There are two different approaches in studying mapping between syntactic structure and prosody, the 'phonetic approach' and the 'phonological approach'. An experiment to examine which approach is more valid was conducted. In the experiment, syntactically ambiguous Seoul Korean sentences in each of which a noun immediately after an adjective starts with either an H-segment (a segment which triggers the AP-initial H tone) or an L-segment (a segment other than H-segments) were recorded. by 3 Seoul Korean speakers. The F0 values in the syllables containing the consonants in question were then measured. The results show that interaction between the segment type and the branching structure is statistically significant. which suggests that it is difficult to use the phonetic .approach to generalize the relationship between syntax and prosody. Thus, it is concluded that the phonological approach is more valid.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.115.2-115
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1406-1409
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• 1993

This paper describes a model of the subjective reliability analysis, which uses a fuzzy set, natural language expressions and parameterized operations of fuzzy sets, and reflects analysts' subjectivity. The model has the problem of many different analysis results being obtained since the results depend on their subjectivity. As one of the solutions two kinds of mutual agreements based on the analysis results are considered. One is the intersection and the union of the fuzzy sets obtained by the analysis. The other is the weighted average of the fuzzy sets. This paper gives these interpretations from the viewpoint of system reliability analysis. This paper also shows examples of these considerations.

• Wind and Structures
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• v.24 no.6
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• pp.637-656
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• 2017

In Japan, at least 28 local winds are known by name, most of them associated with downslope windstorms and gap winds. To review these windstorms, we categorize them based largely on the atmospheric conditions and formation mechanisms, and then focus on representative examples. These representative cases include the "Yamaji­kaze", a typical downslope windstorm, the "Hirodo-­kaze", a downslope windstorm induced by a nearby typhoon (intense tropical cyclone), and the "Karak-kaze", a downslope wind with a clear diurnal variation. Other downslope winds such as the "Inami-kaze" and the gap wind "Kiyokawa­dashi" are also described. Among these winds, the "Yamaji-kaze", "Hirodo-kaze", and "Kiyokawa-dashi" are considered the three most notorious due to their destructive power. After describing and comparing these winds, we discuss remaining issues to be considered in future studies.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1561-1565
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• 2018

The dielectric properties of the uniaxial relaxor ferroelectric $Sr_xBa_{1-x}Nb_2O_6$ with x = 0.75 were investigated along the polar [001] direction as a function of temperature. The capacitance maximum showed the frequency dispersion commonly observed in relaxors. Additional weak dielectric anomalies were observed in the paraelectric phase; they were only seen during the heating process and disappeared upon subsequent cooling. These were attributed to the existence of large polar clusters strongly pinned at defects and/or to random fields and their metastable characters. Aligning the ferroelectric domains along the polar axis at room temperature removed the high-temperature dielectric anomalies. The dependences of the capacitance and the dielectric maximum temperature on the magnitude of the poling field were investigated.

• East Asian mathematical journal
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• v.35 no.1
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• pp.17-22
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• 2019

A travel groupoid is a pair (V, ${\ast}$) of a set V and a binary operation ${\ast}$ on V satisfying two axioms. For a travel groupoid, we can associate a graph in a certain manner. For a given graph G, we say that a travel groupoid (V, ${\ast}$) is on G if the graph associated with (V, ${\ast}$) is equal to G. There are some results on the classification of travel groupoids which are on a given graph [1, 2, 3, 9]. In this article, we introduce the notion of vertex-indexed partition systems on a graph, and classify the travel groupoids on the graph by the those vertex-indexed partition systems.

• Mycobiology
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• v.46 no.4
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• pp.388-395
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• 2018

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.

• Journal of Public Diplomacy
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• v.1 no.2
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• pp.1-26
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• 2021

Applying discourse analysis of Russia's narrative on humanitarian aid and its perception by the Western collective identity at the beginning of the COVID-19 pandemic, this study identifies several challenges that constructivism poses to the current understanding of public diplomacy (PD). In contrast to the mainstream positivist tendency to evaluate the effectiveness of PD through models, this article expands the PD narrative by inquiring about the role of power, intersubjective knowledge, and collective identities in public diplomacy. In particular, it examines the PD questions often ignored by researchers regarding how collective identities can exercise discursive power to interpret incoming narratives, which challenge domestic intersubjective knowledge. It also argues that, because the Russian political elite failed to ensure a coherent story and provide informational support for its humanitarian aid, the Western intersubjective knowledge on Russia negatively contributed to the perception of PD narratives. Thus, the article underscores the importance for PD practitioners to understand how the socially constructed nature of knowledge can improve or harm PD strategies.