• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.513-518
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• 2003

The quantity of container transportation of the world habors is constantly increasing by 8.8 per year until 2011. Present port facilities will not satisfy it. So facility expansion is necessary. Because the processing cost in the harbor becomes to 30% of total transportation expense, major pors inthe world are making an effort in the automation facilities to solve the problems of higher labor costs and indufficient labor and to maximize the efficiency of the work and use of the land. Especially, the automation of the gate, which is the place of cargo's appearance and disappearance, the node which creates the information, is now rising as the important issue. In this study suggest more efficient design for port gate automation. First, calculate scale of gate complex, and compare of 1 step gate and 2 step, and optimal design for automated operation method of gate process.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.145-154
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• 2003

In this study, the variation in excess pore pressure during dissipation is estimated by using successive cavity expansion theory and finite difference technique based on axisymmetric uncoupled linear consolidation theory with separate consideration of magnitude and initial distribution $\Delta{u}_{oct}$induced by changes of octahedral normal stress, and $\Delta{u}_{shear}$ induced by changes of octahedral shear stress. The coefficient of consolidation is also estimated by trial and error procedure until the predicted dissipation curve matches the measured curve at a typical degree of dissipation. The proposed method is applied to the results of miniature piezocone tests at Louisiana State University calibration chamber system. Based on the results of interpretation and the comparison with experimental measurements and those from other solutions, the prediction dissipation curves show a good match with those measured during dissipation tests and the values of coefficient of consolidation estimated by proposed method are more close to the range of laboratory measurements than those of other theories.

• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.155-162
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• 2004

An analytical method to predict the time dependent flexural behavior of composite girder is presented based on sectional analysis. The time dependent constitutive relation accounting for the early-age concrete properties including maturing of elastic modulus, creep and shrinkage is derived in an incremental format by the first order Taylor series expansion. The sectional analysis calculates the axial and curvature strains based on the force and moment equilibriums. The deflection curve of the girder approximated by the quadratic polynomial function is calculated by applying to the proper boundary conditions in the consecutive segments. Numerical applications are made for the 3-span double composite steel box girder which is a composite bridge girder filled with concrete at the bottom of the steel box in the negative moment region. The calculated results are compared with those by finite element analysis results. Close agreement is observed between the two approaches.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.285-291
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• 2020

There is a growing interest in breast augmentation surgery, which can most effectively maximize femininity, among modern women around the world. However, breast augmentation surgery is considered one of the most terrifying surgeries many women are afraid of, as many cases of its side effects have been reported. As a way to provide a complementary method to deal with it, this study investigated the effects of a non-surgical breast enhancement program by stretching soft tissue of the breast. According to the results, there was no change in body weight and breast elasticity, but there were marked increases in breast cup size, breast diameter and volume of the women who used this program. The external soft tissue expansion system was found to be effective in Korean women's change of breast shape. On the other hand, users should use this system regularly for some period of time, and this would limit their social activities. Therefore, for the effective use of this system, its users should make individual efforts.

• Journal of Ocean Engineering and Technology
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• v.21 no.5
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• pp.55-60
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• 2007

Bellows are mechanical components which prevent the damage of system by absorption of the vibration and the displacement of axle and radial direction. Thermal piping system is expanded by the fluid of the high temperature from the heat engine inside. At this time, bellows prevent the damage of the piping due to the thermal expansion. Recently, design of bellows is required to fit some other operational environments which are not suggested in the E.J.M.A code book. And it is difficult to produce and to maintain bellows of high temperature and high pressure bemuse of its complicated shape and this causes the manufacturing cost to rise. The objective of this study is to determine optimum shape of bellows which can endure in the high temperature and high pressure. The maximum stress has an effect on the fatigue life of bellows, therefore it needs to be minimized. This study attempts to find a shape which minimizes the stress occurring in the bellows by the design of experiment. The model used in this study is not presented in the E.J.M.A code book, therefore, from the result of design of experiment we find the factors which give effects on the characteristic value and we presents the recession model using the RSM, which can predict the characteristic values depending on the change of factor values.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.25-32
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• 2012

In this paper, we propose a method for improving the performance of low complexity LS channel estimation for OFDM in fast time varying channels. The CE-BEM channel model used for the low complexity LS channel estimation has a problem on its own and deteriorates channel estimation performance. In this paper, we first use time domain windowing in order to remove the effect of ICI caused by data symbols. Then samples are taken from the results of the LS channel estimation and the effects of the windowing are removed from them. For resolving the defect of CE-BEM, the channel responses are recovered by interpolating the resultant samples with DPSS employed as basis functions the characteristics of which is well matched to the time variation of the channel. Computer simulations show that the proposed channel estimation method gives rise to performance improvement over conventional methods especially when channel variation is very fast and confirm that not only which type of functions is selected for the basis but how many functions are used for the basis is another key factor to performance improvement.

• Journal of the Korean Home Economics Association
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• v.45 no.4
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• pp.43-51
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• 2007

This study analyzed the knit wear trend, which has gained attention as a sensuous and luxury item, through collection magazines, and used the technique of hand-knit to produce and present the knit wear that was designed based on the study results. Accordingly, the purpose of this study is to raise awareness of the expansion of hand knit's new expression techniques and expression areas and to verify its possibility as a higher value-added product. The trends of hand-knit wear resulted from the analysis of collections divided into the following four groups, and the knit designs were also grouped accordingly: First was "The design using object." The trend survey showed the results that the form of drops or flowers was often used as a factor of object. Accordingly, as for the study design, the drop-knitting technique, which is one of the pattern knitting techniques, was used to present a design that employed drops as the object. Second was "The design matched with woven material." It is a way to emphasize aesthetic formativeness and at the same time to activate the area of knit design by matching woven material, which is different from knit in texture, with knit. This study presented a design that tried to combine knit texture and woven material by connecting denim material with various textures and colors. Third was "The design to express see-through." A sense of showing through knit wear was expressed through changes in the type of thread or knitting technique. In this study, the sense of see-through was expressed using piano wires and wool threads and through changes in the thickness of needle. Fourth was "The design to emphasize coloring." It was analyzed that regarding the production of hand knit, the method of coloring expression was to express points, lines and sides or to create harmony by changing the material's color or texture to show particular objects or shapes. In this study, a jacket was designed using the method to express points, lines and sides by changing the material's color.

• Journal of Broadcast Engineering
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• v.20 no.5
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• pp.667-675
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• 2015

As the interest on the high-definition and high-quality broadcasting is increased, the request on the high quality sound signal is enlarged as well as on the video signal's quality. One factor contributing to the high-quality of audio signal is an expansion of reproduction channels like 10.2channel and 22.2channel, but there is a problem of speaker installation issue of these many channels. One solution to solve this problem, we can use frontal loudspeaker array reproduction technique making virtual surround sound. So in this paper, we introduce theocratical analysis on the Wave Field Synthesis used for speaker array based sound reproduction and also present the result about the subjective listening test of reproduction performance based on this technique to check the perfoemance of this system. As a result, we showed WFS based frontal loudspeaker array reproduction method could provide sufficient performance compared to conventional discrete 5.1 channel reproduction method.

• The Mathematical Education
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• v.58 no.4
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• pp.609-625
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• 2019

While research projects and reports on values in mathematics education increased in the international community over the years, little has been known about the topic and research findings in South Korea. The purpose of this study was to analyze the trends of value research in mathematics education focused on the "mathematical values" and "mathematics educational values" as defined by Bishop (1996) through a systematic review of the literature. A total of 66 research papers related to value research were analyzed in terms of the following four areas: research period, projects, target research population, and research method. The results of this study showed that the value research that was carried out was project-driven. There was an increase in both the number of papers published and countries that were studied, which encouraged the continuous expansion of the field. Furthermore, the topic of mathematics educational values was studied more than mathematical values. It was also observed that the survey method, among others, was frequently used to explore mathematics educational values of middle school teachers. Finally, research methods related to the measurement of value were gradually refined over time. Based on these results, this paper describes implications to conduct and advance value research in South Korea in various aspects, including in the field of mathematics education.

• The Mathematical Education
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• v.59 no.3
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• pp.255-269
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• 2020

In this study, how to instruct the computational estimation of addition and subtraction was considered from the perspective of a 'intended-written-implemented' multi-dimensional curriculum. To this end, the 2015 revised elementary school mathematics curriculum as a intended curriculum and the 2015 revised first~sixth grade textbook as a written curriculum were analyzed with respect to how to instruct the computational estimation of addition and subtraction. As an implemented curriculum, a research study was conducted in relation to the method of instructing teachers about the computational estimation of addition and subtraction. As a result, first, it is necessary to discuss how to develop the ability to estimate and set it as a teaching goal and achievement standard in a separate curriculum to instruct it with learning content. Second, it is necessary to provide an opportunity to learn about various estimation methods by presenting specific activities so that students can learn the estimation itself in a separate operation method. Third, in order to improve the computational estimating ability of addition and subtraction, contents related to the computational estimation need to be included in the achievement criteria, and discussions on the expansion of the areas, and the diversification of the instructing time will be needed.