• Journal of ILASS-Korea
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• v.14 no.2
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• pp.77-83
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• 2009

In this study, the effect of important parameters such as the pixel size and number of a CCD, the object distance, the wavelength of laser, and the particle diameter on the depth of focus in digital in-line particle holography were investigated. The depth of focus in several different cases was calculated using simulation holograms and detailed description of the depth of focus in digital particle holography was presented. The depth of focus is directly proportional to the object distance and the particle size. With the increase of the wavelength of laser, the depth of focus is decreased. The depth of focus is also inversely proportional to the pixel size and number of a CCD. Using the data of depth of focus from simulation holograms and a data-fitting software, we obtained the prediction equations of depth of focus for typical CCD cameras. Finally, the prediction equations of depth of focus in digital particle holography were verified by investigating real holograms of the calibration target in different cases and satisfied agreement between measured values and predicted values was confirmed.

• Korean Journal of English Language and Linguistics
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• v.4 no.2
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• pp.195-227
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• 2004

This paper concerns the issue related to the focus phenomena with a particular reference to the two alternating orders (continuous vs. discontinuous orders) in particle constructions in English. To explain the alternation of word order in particle constructions, I will argue that the choice of word order is closely related to the focus property of the object DPs. Following Drubig (2003), I will assume that focus-feature is taken to be a syntactic feature assigned freely to a lexical head in the process of the mapping into Lexical Array (LA) from the lexicon (LEX). I argue that the focus-marked object DP cannot move out of its focus domain and thus the continuous order is derived. In the case of non-focus-marked object DP, however, the object DP moves out of VP in order to receive an appropriate interpretation. As a result, the discontinuous order is derived.

• Speech Sciences
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• v.8 no.4
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• pp.275-288
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• 2001

The sentences with the same surface word order may be realized with the pragmatically different meanings, depending on the contexts under which they could appear. Semantically, their meaning differences have been explained in terms of the different information structures (Steedman 2000), whereas prosodically, they can be explained in terms of the different compositions of intonational components which make their own semantic contributions (Pierrehumbert and Hirschberg 1990). In other words, the different intonation realizations of the sentences with the same word order reflect the different information structures. In this paper, we investigate the relationship between the information structure and the intonational meaning by way of analysing the production of the sentences with ambiguous scopes of the English focus particle 'only'. In contrast to the previous quantitative approaches to the scopes of the focus particle 'only', two independent levels of information structure (Steedman 2000)-theme/rheme, and focus/ background-make it possible to consistently explain the intonational phenomena.

• Speech Sciences
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• v.5 no.2
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• pp.77-91
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• 1999

The purpose of this paper is to investigate the phonetic characteristics of the 'focus' phrases associated with the particle '-man' in Korean. The particle '-man' is a bound morpheme which, like other postpositions such as the subject marker '-ka' and the object marker '-lil', the so-called 'case markers' in Korean, typically attaches to a noun (phrase). The semantics of '-man' roughly corresponds to that of only, its counterpart in English, and is thus classified as a 'delimiter' (Yang 1973). It is assumed in this paper that '-man', like only in English, should have a 'focus' associated with it (von Stechow 1991, Rooth 1992). In general, '-man' attached phrases get the focus, but sometimes the association is not clear-cut, especially in the cases of emphatic use of '-man' or when the context strongly favors other phrase as the focus (Choe 1996). In this paper, we compare the phonetic characteristics of the '-man' marked phrases with those to which '-ka'/'-lil' is attached, and conclude that the focused '-man' phrases show higher fundamental frequencies than their equally focused 'case' -marked counterparts. However, when the context clearly forces the focus to fall on phrases other than the '-man' or '-ka'/'-lil' attached ones, there is no meaningful difference in fundamental frequency between the '-man' and '-ka'/'-lil' attached phrases. We also compare the phonetic characteristics of the regular use of '-man' with those of the emphatic '-man'. According to our experiments, the emphatic '-man' does not bring forth its phonetic effects, namely, higher fundamental frequencies, on the' -man' attached words or phrases but rather in various other ways such as higher fundamental frequencies in '-man', lengthening of the following word-initial syllable, or the inclusion of the following word in the same accentual phrase. Finally, it is claimed that '-man' associated focus phenomena, especially the emphatic use of '-man', show some typical acoustic characteristics of the other well-known focus phenomena, namely, wh-interrogatives.

• Speech Sciences
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• v.9 no.4
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• pp.149-163
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• 2002

Focal parts of utterance can be determined by new/contrastive information, a focus particle, a contrastive topic marker, or a nominative case marker in Busan Korean. Among these factors, new or contrastive information is the most important element in determining the intonational nucleus of an utterance. However, unlike Seoul Korean, when a focus particle, a topic marker, or a case marker contributes to the placement of the most prominent peak of an utterance, the peak is on the noun to which they are attached. Moreover, the case marker-ga shows more prominent pitch on the preceding noun than the noun followed by the topic marker-nun when-ga is used as emphatic or contrastive. This is one of the major problems for Busan Korean users in commanding natural and fluent Seoul Korean intonation even if they use standard written form of Seoul Korean in their speech.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.398-407
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• 1999

In the present image processing technique, the concept of the gradient indicator(GI) has been introduced to find out the depth-of-field in sizing large particles ranging from $30{\mu}m$ to $30{\mu}m$ where using of the concept of the normalized contrast value(VC) is not appropriate. The gradient indicator is defined as the ratio of the local value to the maximum possible value of the gray-level gradient in an image frame. The gradient indicator decreases with the increases of the particle size and the distance from the exact focal plane. A particle is considered to be in focus when the value of the gradient indicator at its image boundary stays above a critical value. This critical gradient indicator($GI_{critical}$) is defined as the maximum gradient indicator($GI_{max}$) subtracted by a constant ${\Delta}GI$ which is to account for the particle-size effect. In the present ca.so, the value of ${\Delta}GI$ was set to 0.28 to keep the standard deviation of the measured particles mostly within 0.1. It was also confirmed that, to find the depth-of-field for small particles(${\leq}30{\mu}m$) with the same measurement accuracy, tho concept of the critical normalized contrast($VC_{critical}$) is applicable with 85% of the maximum normalized contrast value($VC_{max}$). Finally, the depth-of-field was checked for the size range between $10{\mu}m$ and $300{\mu}m$ when the both in-focus criteria ($GI_{critical}$ and $VC_{critical}$) were adopted. The change of the depth-of-field with the particle size shows good linearity in both the VC-applicable and the GI-applicable ranges with a reasonable accuracy.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.808-809
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• 2006

The decrease of the distance between particle centers due to the growth of the sinter necks can be explained by the well known two-particle model. Unfortunately this model fails to provide a comprehensive description of the processes for 3D specimens. Furthermore, there is a significant discrepancy between the calculated and the measured shrinkage because particle rearrangements are not considered. Only the recently developed analysis of the particle movements inside of 3D specimens using micro focus computed tomography $({\mu}CT)$, combined with photogrammetric image analysis, can deliver the necessary experimental data to improve existing sintering theories. In this work, ${\mu}CT$ analysis was applied to spherical copper powders. Based on photogrammetric image analysis, it is possible to determine the positions of all particle centers for tracking the particles over the entire sintering process and to follow the formation and breaking of the particle bonds. In this paper, we present an in-depth analysis of the obtained data. In the future, high resolution synchrotron radiation tomography will be utilized to obtain in-situ data and images of higher resolution.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.69-76
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• 2006

TRISO(tri-isotropic)-coated fuel particle technology is utilized owing to its higher stability at a high temperature and Its efficient retention capability for fission products In the HTGR(high temperature gas-reeled reactor). The typical spherical TRISO fuel panicle with a diameter of about 1mm is composed of a nuclear fuel kernel and outer coating layers. The outer coating layers consist of a buffer PyC(pyrolytic carbon) layer, Inner PyC(1-PyC) layer, SiC layer, and outer PyC(O-PyC) layer Most of the Inspection Items for the TRTSO-coated fuel particle depend on destructive methods. The coating thickness of the TRISO fuel particle can be nondestructively measured by the X-ray radiography without generating radioactive wastel. In this study, the coaling thickness for the simulated TRISO-coated fuel particle with $ZrO_2$ kernel Instead of $%UO_2$ kernel was measured by using micro-focus X-ray radiography with micro-focus X-ray generator and flat panel detector The radiographic image was also enhanced by image processing technique to acquire clear boundary lines between coating layers. The coaling thickness wat effectively measured by applying the micro-focus X-ray radiography The inspection process for the TRISO-coated fuel particles will be improved by the developed micro-focus X-ray radiography and digital image processing technology.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.4
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• pp.599-607
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• 2000

In this study, experiments have been performed to examine the effects of background gray-level on the depth-of-field and on the in-focus criteria. The normalized value of contrast(VC) and the gradient indicator(GI) were used as the in-focus criteria for the small and the large size-ranges of particles, respectively. The slightly larger number of pixels were detected with the brighter background. The maximum of the normalized value of contrast(VCmax) is decreased with the brighter background and its deviation from that with the background gray-level of 160 turned out to be about $pm$15% when the background gray-level changes from 100 to 200. However, the maximum gradient indicator(GImax) changes with the background gray-level within only $pm$5%. The depth-of-field for the VC-applicable particle-size range is largely dependent on the background gray-level. On the other hand, the depth-of-field for the GI-applicable particle-size range changes only slightly with the background gray-level. To keep the normalized standard deviation of the particle size within 0.1, the background gray-level should be set 160$pm$20 for both the VC-applicable and GI-applicable ranges which cover the particle size between $10{\mu}m$ and $300{\mu}m$.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.4
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• pp.31-36
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• 2001

A spin coater is a machine to coat wafer or LCD display with thin film. Vibration in the spin coater may be one of main troubles in the coating process. In this paper, we focus on the difference between two spin coaters. Vibration sources are identified by experimental approach and are compared to find the difference between the two spin coaters. Also, the particle concentration is observed by laser particle counter (LPC) for the two spin coaters, when the spin coaxers are working. It is also considered whether the defect rate is proportional to the particle concentration. The result shows that particle generation in the coating process is related to excessive vibration of the spin coater shaft and the particles influence the defect rate of the thin film product.