• Phonetics and Speech Sciences
• /
• v.1 no.3
• /
• pp.3-18
• /
• 2009

Do loanword properties emerge in the acquisition of a foreign language and if so, how? Classic studies in adult language learning assumed loanword properties that range from near-ceiling to near-chance level of appearance depending on speech proficiency. The present research argues that such variations reflect different phonological types, rather than speech proficiency. To investigate the difference between learner speech and loanword phonology, the current research analyzes the speech data from five different proficiency levels of 92 Korean speakers who read 19 pairs of English words and sentences that contained loanwords. The experimental method is primarily an acoustical one, by which the phonological cause in the loanwords (e.g., the insertion of [$\Box$] at the end of the word stamp) would be attested to appear in learner speech, in comparison with native speech from 11 English speakers and 11 Korean speakers. The data investigated for the research are of segment deletion, insertion, substitution, and alternation in both learner speech and the native speech. The results indicate that learner speech does not present the loanword properties in many cases, but depends on the types of phonological causes. The relatively easy acquisition of target pronunciation is evidenced in the cases of segment deletion, insertion, substitution, and alternation, except when the loanword property involves the successful command of the target phonology such as the de-aspiration of [p] in apple. Such a case of difficult learning draws a sharp distinction from the cases of easy learning in the development of learner speech, particularly beyond the intermediate level of proficiency. Overall, learner speech departs from loanword phonology and develops toward the native speech value, depending on phonological contrasts in the native and foreign languages.

• Ocean and Polar Research
• /
• v.30 no.2
• /
• pp.181-191
• /
• 2008

This study aims at assessment of spatio-temporal distribution of demersal fish aggregations near the west coast of Jeju Island using hydroacoustic survey. A 200 kHz split beam transducer attached to a small towed body was used for all acoustic investigations. The received acoustic data were in situ acoustic target strength (TS, dB) for all pings and nautical area scattering coefficient(NASC, $m^2/mile^2$) for 0.1 mile along 12 acoustic transects. Demersal fish aggregations are distributed around the coastal slope having 20 to 30 m depth throughout all seasons. The concentration is higher during the summer season. With regard spatial distribution, higher demersal fish aggregations have been detected near the West coast of Shinchang and especially near Chagwi-do. Pelagic fish aggregations were higher to the south of Chagwi-do during the spring season. Additionally, standing stock of demersal fish aggregations from the NASC data, TS function, and length-weight function of dominant species was estimated as follows: 3.2 ton (CV 21.8%) in December 2006, 17.9 ton (CV 21.6%) in April 2007, 30.8 ton (CV 17.8%) in June 2007, and 22.5 ton (CV 24.2%) in October 2007. The application of hydroacoustic methods offers a new approach to understanding spatiotemporal structure and estimate the biomass of demersal fish aggregations in the coastal area. And the results can be made up limitations of qualitative analysis through net and diving for fisheries resources survey in coastal area.

• The Bulletin of The Korean Astronomical Society
• /
• v.46 no.1
• /
• pp.45.1-45.1
• /
• 2021

The polarization degree as a function of phase angle (the Sun-target-observer's angle), so-called the polarimetric phase curves (PPC), have provided priceless information on asteroids' albedos since B. Lyot (1929). Succeeding experimental works in 1970s have confirmed the Umow law: There is a universal and strong correlation between the albedo and the PPC slope (slope of the tangential line at the zero of the PPC at phase angle ~ 20 degrees). Experiments in 1990s (ref [1]), on the other hand, have demonstrated that the negative branch of PPC is dependent on the size parameter (X ~ π * particle-size / wavelength), especially when X <~5. The change in particle size changed the minimum polarization degree, location of the minimum, and the width of the negative branch (called the inversion angle). From polarimetry[2] and spectroscopy[3], large asteroids are expected to be covered with fine (<~ 10 ㎛ size) particles due to the gravity. The size parameters are X ~ 30 at the optical wavelength (λ ~ 0.5 ㎛) and X ~ 10 in near-infrared (J, H, Ks bands; λ ~ 1.2-2.2 ㎛), if the representative particle size of 5 ㎛ is considered. Accordingly, the near-infrared polarimetry has a great potential to validate the idea in ref[1]. We conducted near-infrared photopolarimetry of the large asteroid (4) Vesta using the Nishiharima Infrared Camera (NIC) at Nishi-Harima Astronomical Observatory (NHAO). NIC allows simultaneous polarimetric measurements in J, H, and Ks bands, and thus the change of PPC is obtained for three different size parameters. As a result, we found a signature of the change in the negative branch in the PPC of asteroid (4) Vesta. We will introduce our observation and the results and give an interpretation of the regolith on Vesta.

• Geophysics and Geophysical Exploration
• /
• v.8 no.1
• /
• pp.7-17
• /
• 2005

The determination of seismic velocities in refractors for near-surface seismic refraction investigations is an ill-posed problem. Small variations in the computed time parameters can result in quite large lateral variations in the derived velocities, which are often artefacts of the inversion algorithms. Such artefacts are usually not recognized or corrected with forward modelling. Therefore, if detailed refractor models are sought with model based inversion, then detailed starting models are required. The usual source of artefacts in seismic velocities is irregular refractors. Under most circumstances, the variable migration of the generalized reciprocal method (GRM) is able to accommodate irregular interfaces and generate detailed starting models of the refractor. However, where the very-near-surface environment of the Earth is also irregular, the efficacy of the GRM is reduced, and weathering corrections can be necessary. Standard methods for correcting for surface irregularities are usually not practical where the very-near-surface irregularities are of limited lateral extent. In such circumstances, the GRM smoothing statics method (SSM) is a simple and robust approach, which can facilitate more-accurate estimates of refractor velocities. The GRM SSM generates a smoothing 'statics' correction by subtracting an average of the time-depths computed with a range of XY values from the time-depths computed with a zero XY value (where the XY value is the separation between the receivers used to compute the time-depth). The time-depths to the deeper target refractors do not vary greatly with varying XY values, and therefore an average is much the same as the optimum value. However, the time-depths for the very-near-surface irregularities migrate laterally with increasing XY values and they are substantially reduced with the averaging process. As a result, the time-depth profile averaged over a range of XY values is effectively corrected for the near-surface irregularities. In addition, the time-depths computed with a Bero XY value are the sum of both the near-surface effects and the time-depths to the target refractor. Therefore, their subtraction generates an approximate 'statics' correction, which in turn, is subtracted from the traveltimes The GRM SSM is essentially a smoothing procedure, rather than a deterministic weathering correction approach, and it is most effective with near-surface irregularities of quite limited lateral extent. Model and case studies demonstrate that the GRM SSM substantially improves the reliability in determining detailed seismic velocities in irregular refractors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.4 s.119
• /
• pp.398-407
• /
• 2007

In this paper we proposed the tag antenna with a low performance distortion from an attached surface material using the asymmetric dual-arm dipole antenna(ADDA) structure. The tag is designed to exhibit low performance changes when the tag is attached on a target object(the medical litter receptacle, ${\varepsilon}_r=1.7,\;tan\;{\delta}=0.002$). Detail design parameters for the proposed antenna are optimized to maintain a good readable range in free-space as well as on a target object. The size of the optimized antenna is $100\;mm{\times}50\;mm$. The antenna shows the matching bandwidth($S_{11}$< -10 dB) of 3.7 % and the radiation efficiency of 80 % at the operating frequency. Finally we confirmed the readable range of the tag antenna by measurement and it shows about 5.3 m in free space and 5.5 m on the target object.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.7
• /
• pp.578-583
• /
• 2011

We report on the design of a holographic homogenizer composed of a periodic hologram and a condensing lens. If the hologram is periodic, the homogenizer is free from the alignment error of the incident laser beam. Holographic homogenizer also has an advantage of the flexibility in the size of the target beam. We calculated theoretically the Fraunhofer diffracted wave function when a rectangular laser beam is incident on a periodic hologram. The diffracted wave is the sum of sinc functions at regular distance. The width of each sinc function depends on the size of the incident laser beam and the distance between the sinc functions depends on the period of the hologram. We calculated numerically the diffracted light intensity for various ratios of the size of the incident laser beam to the period of the hologram. The results show that it is possible to make the diffracted beam uniform at a certain value of the ratio. The uniformity is high at the central part of the target area and low near the edge. The more sinc functions are included in the target area, the larger portion of the area becomes uniform and the higher is the uniformity at the central part. Therefore, we can make efficient homogenizer if we design a hologram so that the maximum number of the diffracted beams may be included in the target area.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.92.1-92.1
• /
• 2014

In astronomical spectroscopy, stable auto-guiding and accurate target centering capabilities are critical to increase the achievement of high observation efficiency and sensitivity. We developed an instrument control software for the Immersion GRating INfrared Spectrograph (IGRINS), a high spectral resolution near-infrared slit spectrograph with (R=40,000). IGRINS is currently installed on the McDonald 2.7 m telescope in Texas, USA. We had successful commissioning observations in March, May, and July of 2014. The role of the IGRINS slit-viewing camera (SVC) is to move the target onto the slit, and to provide feedback about the tracking offsets for the auto-guiding. For a point source, we guide the telescope with the target on the slit. While for an extended source, we use another a guide star in the field offset from the slit. Since the slit blocks the center of the point spread function, it is challenging to fit the Gaussian function to guide and center the target on slit. We developed several center finding algorithms, e.g., 2D-Gaussian Fitting, 1D-Gaussian Fitting, and Center Balancing methods. In this presentation, we show the results of auto-guiding performances with these algorithms.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.5
• /
• pp.83-91
• /
• 2001

This paper proposes the Focused beamforming to estimate the location of target residing near to the observation platform in the underwater environment. The Focused beamforming technique provides the location of target by the coherent summation of a series of incident spherical waveforms considering distinct propagation delay times at the sensor array. But due to the movement of the observation platform and the variation of the underwater environment, the shape of the sensor array is no longer to be linear but it becomes distorted as the platform moves. Thus the Focused beamforming should be peformed regarding to the geometric shape variation at each time. To estimate the target location, the artificial image plane comprised of cells is constructed, and the delays are calculated from each cell where the target could be proximity to sensors for the coherent summation. After the coherent combining, the beam pattern can be obtained through the Focused beamforming on the image plane. Futhermore to compensate the variation of the shape of the sensor array, the paper utilizes the Nth-order polynomial approximation to estimate the shape of the sensor array obeying the water pulley modeling. Simulation results show the performance of the Focused beamforming for different frequency bands of the radiated signal.

• Korean Journal of Materials Research
• /
• v.1 no.4
• /
• pp.191-197
• /
• 1991

The surface roughnesses of titanium silicide films and the diffusion behaviours of dopants in single crystal and polycrystalline silicon substrates durng titanium silicide formation by rapid thermal annealing(RTA) of sputter deposited Ti-filicide film from the composite $TiSi_{2.6}$ target were investigated by the secondary ion mass spectrometry(SIMS), a four-point probe, X-ray diffraction, and surface roughness measurements. The as-deposited films were amorphous but film prepared on single silicon substrate crystallized to the orthorhombic $TiSi_2$(C54 structure) upon rapid thermal annealing(RTA) at $800^{\circ}C$ for 20sec. There was no significant out-diffusion of dopants from both single crystal and polycrystalline silicon substrate into titanum silicide layers during annealing. Most of the implanted dopants piled up near the titanium silicide/silicon interface. The surface roughnesses of titanium silicide films were in the range between 16 and 22nm.

• Korean Journal of Community Nutrition
• /
• v.16 no.3
• /
• pp.375-385
• /
• 2011

The nutritional balance of the menu plans prepared according to the target pattern was examined. Total of 81 home economics teachers throughout the nation and 161 3rd-grade middle-school girls in Chungnam area participated. The data was collected by questionnaire and analyzed by using SPSS WIN 12.0. Although both teacher and student groups had fairly good knowledge on preparing menu plans related concepts, they rarely make use any menu planning currently. More than 85% of menu plans investigated exceeded their energy goal in the target pattern. The energy contribution ratios of carbohydrate: protein: fat were 56.1%: 17.4%: 26.5% in teachers' menu plan and 55.1%: 17.2%: 27.7% in students' menu plan. The NAR of the protein, phosphorous, iron, zinc, vitamin A and C, thiamin, riboflavin, niacin, B6 was 1 or near 1. But in case of calcium, 56.5% of the menu plan prepared by the students was less than 1, and in case of folate 75.3% of teachers', and 85.1% of students' were less than NAR 1. The MAR of the 12 nutrients examined were 0.98, 0.97, and the DVS were 51, 49 for menu plan prepared by teachers and students, respectively.