• Speech Sciences
• /
• v.15 no.3
• /
• pp.203-217
• /
• 2008

The number of Asian women immigrants in Korea is getting bigger and it's important to note that their communication problem in Korean causes not only the difficulty of adapting to Korean society but their children's speech-language disorder. To date there is little research on their acoustics characters and articulatory errors. Therefore, this study focuses on acoustic characters and articulatory error patterns of the women immigrants from Japan and Philippine based on the theory of "contrastive analysis". The subjects were 16 Japanese women immigrants(age: 42.5$\pm$4.4) and 14 Philippine women immigrants(age: 31.64$\pm$6.7) and control group consisted of 10 Korean women(age: 28.3$\pm$1.2). Speech and hearing of all subjects and control group were within normal limits. Speech samples were analyzed in a computer using CSL and data analysis was done on FFT widow for F1, F2, F3 of vowels and on wideband spectrogram for VOT of plosives and africatives. The results of this study were like this; For Japanese women immigrants, they had different articulatory patterns of /e/, /a/, /u/, /o/, /$\varepsilon$/, /m/ from those of Koreans and showed articulatory errors on the fortis and aspirated sounds. The reason is Japanese has only two distinctive characters for plosives and affricates; voicing and voiceless. The Philippine women immigrants also showed the same error patterns as the Japanese women immigrants. Especially the errors on aspirated sounds were prominent because their mother tongue has no distinctive characters about aspirated sounds. For vowels, they showed errors of /a/, /o/, /c/.

• Journal of the Korean Society of Safety
• /
• v.34 no.5
• /
• pp.7-14
• /
• 2019

The type III vessel, which is used to store high-pressure hydrogen gas, is made by wrapping the vessel's liner with carbon fiber composite materials for strength performance and lightening. The liner seals the internal gas and the composite resists the internal pressure. The properties of the fiber composite material depends on the angle and thickness of the fiber. Thus, engineers should consider these various design variables. However, it significantly increases the design cost due to the trial and error under designing based on experience or experiments. And, for aluminum liners, fatigue loads due to using and charging could give a huge impact on the performance of the structure. However, fatigue failure does not necessarily occur in the position under the highest load in use. Therefore, for hydrogen storage vessel, fatigue evaluation according to design patterns is essential because stress distribution varies depend on composite layer patterns. This study performed an optimization analysis and evaluated a high-pressure hydrogen storage vessel to minimize these trial and error and improve the reliability of the structure, while simultaneously conducting fatigue assessment of all patterns derived from the optimization analysis process. The results of this study are thought to be useful in the strength improvement and life design of composite reinforced high-pressure storage vessels.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.12C
• /
• pp.965-970
• /
• 2010

In the NAND flash memory storing two bits per cell, data is discriminated among four levels of electrical charges. We refer to these four levels as E, P1, P2, and P3 from the low voltage. In the statistics, many errors occur when E and P3 are stored at the next cells. Therefore, we propose a coding scheme for avoiding E-P3 or P3-E data patterns. We investigate two modulation codes for 9/10 code (9 bit input and 5 symbol codeword) and 11/12 code (11 bit input and 6 symbol codeword).

• Journal of the Korea Convergence Society
• /
• v.9 no.6
• /
• pp.125-132
• /
• 2018

This study was to investigate the speech sound production characteristics and evaluation aspects of preschool children through word test and connected speech test. For this, the authors conducted Assessment of Phonology and Articulation for Children(APAC) to 72 normal children(24 three-, four-, and five-year-olds each) and analyzed difference in percent of correct consonant(PCC) and intelligibility according to age and sex, correlation between PCC and intelligibility, and speech sound error patterns. PCC and intelligibility increased with age but there was no difference according to sex. The correlation was statistically significant in 5-year-old group. Speech sound error patterns were different in the two tests. This study showed that children's speech sound production varied according to language unit. Therefore, both types of tests should be done to grasp their speech sound production ability properly. This suggests that current standard to identify language impairment only by PCC of word level requires review and further studies.

• Proceedings of the Korean Association for Survey Research Conference
• /
• 2002.11a
• /
• pp.255-274
• /
• 2002

We classify rotation sampling designs into two classes. The first class replaces sample units within the same rotation group while the second class replaces sample units between different rotation groups. The first class is specified by the three-way balanced design which is a multi-level version of previous balanced designs. We introduce an extended generalized composite estimator (EGCE) and derive its variance and mean squared error for each of the two classes of design, cooperating two types of correlations and three types of biases. Unbiased estimators are derived for difference between interview time biases, between recall time biases, and between rotation group biases. Using the variance and mean squared error, since any rotation design belongs to one of the two classes and the EGCE is a most general estimator for rotation design, we evaluate the efficiency of EGCE to simple weighted estimator and the effects of levels, design gaps, and rotation patterns on variance and mean squared error.

• Journal of the Korean Society for Precision Engineering
• /
• v.10 no.2
• /
• pp.126-137
• /
• 1993

This paper presents an efficient method for the identification of motion error sources in NC machine tools by making use of the circular interpolation test, which is often used in estimating the motion accuracy of NC machine tools. Mathematical formulae are described for motion errors due to various kinds of error sources. Two identification formulae are proposed: one is based on the frequency analysis and the other is formulated with the weithted residual method. Motion error signal is classified into two patterns, mean errors(mean of CW and CCW test signals from mean errors). The sources of the mean errors are identified by using the frequency analysis technique and the sources of the deviation errors by the weighted residual formulaltion. A menu driven, user oriented, computer program is written to realize the full steps of the proposed identificationprocedure. Then, the identification method is applied to two NC machine tools.

• Korean Journal of Optics and Photonics
• /
• v.15 no.1
• /
• pp.79-85
• /
• 2004

We report on a transmittance controlled photomask with phase patterns on the back quartz surface. Theoretical analysis for changes in illumination pupil shape with respect to the variation of size and density of backside phase patterns and experimental results for improvement of critical dimension uniformity on a wafer by using the transmittance controlled photomask are presented. As phase patterns for controlling transmittance of the photomask we used etched contact-hole type patterns with 180" rotative phase with respect to the unetched region. It is shown that pattern size on the backside of the photomask must be made as small as possible in order to keep the illumination pupil shape as close as possible to the original pupil shape and to achieve as large an illumination intensity drop as possible at a same pattern density. The distribution of illumination intensity drop suitable for correcting critical dimension error was realized by controlling pattern density of the contact-hole type phase patterns. We applied this transmittance controlled photomask to a critical layer of DRAM (Dynamic Random Access Memory) having a 140nm design rule and could achieve improvement of the critical dimension uniformity value from 24.0 nm to 10.7 nm in 3$\sigma$.TEX>.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.4 s.304
• /
• pp.13-20
• /
• 2005

In this paper, we propose new smoothing filters, i.e., occluding patterns that can accurately correct disparities of occluded areas in the estimated disparity map. An image is composed of several layers and each layer presents similar disparity. Furthermore, the distribution of the estimated disparities has a specific direction around the boundary of the occlusion, and this distribution presents the different direction with respect to the left- and the right-based disparity map. However, typical smoothing filters, such as mean filter and median filter, did not take into account those characteristic. So, they can decrease some error, but they cannot guarantee the accuracy of the corrected disparity. On the contrary, occluding patterns can accurately correct disparities of occluded areas because they consider both the characteristic that occlusion occurs and the characteristic that disparities of the occlusion are ranged, from estimated disparity maps with respect to the left and the right images. We made experiments on occluding patterns with some real stereo image set, and as a result, we can correct disparities of occluded areas more accurately than typical smoothing filters did.

• Education of Primary School Mathematics
• /
• v.22 no.4
• /
• pp.281-294
• /
• 2019

The purpose of this study is to analyze errors and treatment behavior during the course of mathematics learning of academic achievement by applying reflective activities in the second semester of the third year of elementary school. The study participants are students from two classes, 21 from the third-grade S elementary school in Seoul and 20 from the comparative class. In the case of the experiment group, the multiplication unit was reconstructed into a mathematics class that applied reflective activities. They were pre-post-test to examine the changes in students' mathematics performance, and mathematical communication was recorded and analyzed for the focus group to analyze the patterns of learners' error handling in the reflective activities. In addition, they recorded and analyzed students' activities and conversations for error type and error handling. As a result of the study, the student's mathematics achievement was increased using reflective activities. When learning double digit multiplication, the error types varied. It was also confirmed that the reflective activities helped learners reflect on the multiplication algorithm and analyze the error-ridden calculations to reflect on and deal with their errors.

• Journal of Korea Society of Industrial Information Systems
• /
• v.14 no.4
• /
• pp.116-127
• /
• 2009

This research aims to improve the efficiency of production by selecting production configuration with high yield rate and lower error rate based on production history of steel pipe. To achieve this, we identify the properties of various types of MTO(make-to-order) steel pipe products and determine properties affecting yield rate and error rate using decision tree technique. From experimental results, we find out that specification is critical to determine yield rate and error rate of ERW steel pipes with mostly small and medium caliber, and an external diameter range in case of roll benders or spiral steel pipes with mostly large caliber. This research classified and embodied the patterns of yield rate and error rate mathematically by product properties.