• Journal of the Korean Geotechnical Society
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• v.34 no.11
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• pp.57-70
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• 2018

In this study, verification of the nonlinear effective stress analysis is performed for introducing performance based earthquake resistance design of port and harbor structures. Seismic response of gravitational caisson quay wall in numerical analysis is compared directly with dynamic centrifuge test results in prototype scale. Inside of the rigid box, model of the gravitational quay wall is placed above the saturated sand layer which can show the increase of excess pore water pressure. The model represents caisson quay wall with a height of 10 m, width of 6 m under centrifugal acceleration of 60 g. The numerical model is made in the same dimension with the prototype scale of the test in two dimensional plane strain condition. Byrne's liquefaction model is adopted together with a nonlinear constitutive model. Interface element is used for sliding and tensional separation between quay wall and the adjacent soils. Verification results show good agreement for permanent displacement of the quay wall, horizontal acceleration at quay wall and soil layer, and excess pore water pressure increment beneath the quay wall foundation.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.884-887
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• 2009

Social Network Service has been extremely popular these days and providing diverse features and functions to users. Social networking and interest sharing in between users are key factors of SNS and this circles back to draw more users to the service. Web is the first media to provide SNS and mobile is the next. The service based on mobile environmental uniqueness such as Location-based-service(LBS) is the key success factors to convert users to web SNS to mobile SNS. TV has also been a possible SSN market to draw users to share interests and participation. However TV has been always community electronics in family members and personalization to provide SNS has been barrier to overcome. In this study, we explorer ideas of key factors of personalization in TV environment and conducted a field study to define characteristics of TV personalization in terms of depth, method, style and structure. Research finds out that there are significant differences in these categories.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.545-551
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• 2016

In this study, we evaluate the braking performance of an urban railway vehicle to verify its basic safety condition. The braking performance evaluation methods, deceleration measurement and braked weight percentage, were compared for trains with different numbers of cars, in order to assess the advantages of each method and their compatibility. With a probabilistic braking model, the effect of the adhesion coefficient distribution was analyzed in accordance with the train composition. A train with many cars has a narrower deceleration distribution width than one with few cars. The braked weight percentage method is expected to be useful in the design of train signal systems, because it allows the braking distance to be calculated for various initial brake velocities. The deceleration distribution model and its results are expected to be useful as a basis for precise train signal design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.9-18
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• 1983

In many geological investigation, a data sequence may be created which consisted of a succession of mutually exclusive state. However, now our interest lie in the nature of transition from one state to another, rather than in the position of states in the sequence. In this paper, authors studied for the deformation of HAEUNDAE beach by transition matrices and empirical eigenfunction method. In this paper, 5-yr. set of profile data from HAEUNDAE beach measured at several monthly or yearly intervals are analyzed by using the transition matrices and empirical eigen-function. Results of this study indicate that the transition matrices and empirical eigenfunctions are useful in the analysis of beach profile data and provide objective insight in the nature of profile configuration.

• Composites Research
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• v.24 no.1
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• pp.37-44
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• 2011

In this paper, Particle Swarm Optimization(PSO) is applied to the design of the Frequency Selective Surface(FSS) and residual stresses of hybrid radome is predicted. An equivalent circuit model with Square Loops arrays was derived and then PSO was applied for acquiring the optimized geometrical parameters with proper resonant frequency. Residual stresses occur in the FSS embedded composite structures after cocuring and have a great influence on the strength of the FSS embedded composite structures. They also effect transmission quality because of delamination. Therefore, the thermal residual stresses of FSS embedded composite structures were analyzed using finite element analysis with considering the effects of FSS pattern, and composite stacking sequence.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.12
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• pp.1343-1352
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• 1992

This paper presents a new and easy method to obtain the Fourier transforms of the n-th order cosine-pulses whose maximum amplitudes are uniform. The new method is focused on deriving a formula which is recursively related following their orders and can be well applied to some numerical solutions. On the other hand, this method also offers more compact procedures in view of analytical solutions than the conventional methods because the results are consist of the sum of two functions which are easily calculated. Especially, the formula can be represented as a complete recursion by the separation of coefficients originated by the authors and the resulting difference equation is given by the sum of the original 'sinc' functions shifted by some symmetrical factors and multiplied by some constants. The constants are easily decided from the binomial coefficients and the shifting factors from the corresponding exponential differences in the expansion of $(a+b)^n$.

• Journal of the HCI Society of Korea
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• v.4 no.1
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• pp.11-15
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• 2009

Social Network Service has been extremely popular these days and providing diverse features and functions to users. Social networking and interest sharing in between users are key factors of SNS and this circles back to draw more users to the service. Web is the first media to provide SNS and mobile is the next. The service based on mobile environmental uniqueness such as Location-based-service(LBS) is the key success factors to convert users to web SNS to mobile SNS. TV has also been a possible SSN market to draw users to share interests and participation. However TV has been always community electronics in family members and personalization to provide SNS has been barrier to overcome. In this study, we explorer ideas of key factors of personalization in TV environment and conducted a field study to define characteristics of TV personalization in terms of depth, method, style and structure. Research finds out that there are significant differences in these categories.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.80-84
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• 2010

Satellite structure should be designed to accommodate and support safely the payload and equipments necessary for its own missions and to secure satellite and payloads from severe laucnch enviroments. The lauch environments imposed on satellites are quasi-static accelerations, aerodynamic loads, acoustic loads and shock loads. To qualify the structure design against low-frequency dyanmic enviromnent, sine vibration test should be performed. During sine vibration test, the notchings are implemented in order to keep the payloads and equipments from excessive loading at their own main modes. This paper deals with sine test prediction, sine vibration test results, comparison of predicted values and tested values, and verification of Finite Element Model.

• Membrane Journal
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• v.29 no.1
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• pp.37-43
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• 2019

In this study, we investigated how the force-field, which is the most important factor to define atomic motion in molecular dynamics (MD), affects the motion of the polymer and gas molecules. The repeat units and the polymer structure were well simulated in all five force-fields, and the distribution of the polymer linear chain in the final polymer 3D model did not show any significant difference. However, the movement of actual gas molecules showed a very different tendency, which was also observed in COMPASS and pcff using the same functional form. Therefore, even if the same structure is used, it can be seen that the motion of the gas molecule moves under the influence of the force-field continuously over time, so that the effect is much larger than that of macromolecules such as a polymer linear chain. Accordingly, in case of using different force-fields, it is necessary to be very careful in comparison of those results.

• Journal of The Korean Association of Information Education
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• v.24 no.5
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• pp.453-462
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• 2020

With the development of artificial intelligence, a lot of platforms have emerged that enable anyone to easily access and learn about artificial intelligence or create artificial intelligence models. Therefore, in this study, we analyzed various artificial intelligence education platforms and developed and proposed a SW education class plan using a framework-based artificial intelligence education platform for activating artificial intelligence based SW education. The artificial intelligence-based SW education framework aims to cultivate artificial intelligence literacy on the basis of computational thinking. In addition, a learner-centered project class was formed to include elements that could be fused with real life contexts or other subjects. Using this, with the theme of creating an artificial intelligence program to help separate garbage collection, a six-hour project-based class was developed and proposed using practical arts, social studies, and creative experiential activities. This project class was organized using a platform that is not difficult, such as AI Oceans and Entry.