• Composites Research
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• v.32 no.1
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• pp.29-36
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• 2019

The purpose of this paper is to suggest a lightweight design for the aluminum extrusion carbody structure of a double deck high-speed train using material substitution and size optimization method. In order to conduct material substitution, the topology optimization was used to determine the application parts of sandwich composites at the carbody structures. The results of analysis showed that sandwich composites could be applied at roof and 2nd underframe. The size optimization was used to determine thickness of the aluminum extruded and carbon/epoxy composite. The design variable, state constraint and objective function were formulated to solve the size optimization, and then, the feasible design was presented by these conditions. The results of the lightweight design showed that the weight of double deck high-speed train hybrid carbody could be reduced by 2.18(17.70%) tons.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.980-983
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• 2012

Nowadays, with increasing in difficulty level of elementary, junior high and high school education, we are growing more and more interested in the national history. We intend to develop the mobile App to make the people have the concern and interest in the national cultural assets to introduce the information about them. The game can be learned easily and we are increased the interest in the national cultural assets by game speed. We intent to develop the mobile App to be able to search the information about the national cultural assets at anytime and anywhere. This App uses the Model2 Architecture MVC method.

• Journal of the Korean Geotechnical Society
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• v.15 no.3
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• pp.17-25
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• 1999

The feasibility of using waste lime, which is produced as a byproduct during the manufacture of sodium carbonate in Inchon, Korea. as a stabilization admixture with weathered granite soil was investigated. Laboratory tests were conducted to determine the chemical composition, pH, compaction characteristics, unconfined compression strength. X-ray diffraction analysis of waste lime and weathered granite soil admixtures. Based on the present tests, it appears that the admixtures are environmentally safe and can be used as landfill material.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.202-202
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• 2022

SWAT모형은 장기간에 모의가 가능하며 다양한 토양이용과 토지특성을 고려할 수 있는 유역 단위 모형으로 많은 연구에서 이용된다. 이러한 유역단위 수문모형의 평가는 통계적 지수(NSE, R2)들로 모형의 적합성을 평가한다. NSE, R2는 상대적으로 큰 값에 대한 영향을 많이 받는다. 따라서 많은 강우량이 발생하는 시점에서의 유출량과 SS농도가 중요시되었다. 하지만 강우시에 하천으로 유입된 토양 중 일부는 하천에 퇴적물로 침전된다. 이 침전된 토양이 비강우시 바람 등과 같은 이유로 재부유되며 이로 인해 수중 DO를 고갈시켜 수생태계 악영향을 미친다. 이에 따라 비점오염저감시설 평가는 강우시 발생하는 SS농도도 중요하지만 비강우시 재부유되는 SS농도도 중요한 부분이다. SWAT모형에서는 하천 SS농도를 계산하는데 사용되는 매개변수가 강우시와 비강우시에 동일하게 적용되어 비강우시에 과대 산정되어 비강우시 SS농도가 증가되도록 sediment routing이 진행되고 있었다. 본 연구에서는 sediment routing을 수정하여 비강우시 SS농도를 실측 농도와 비슷하게 보정할 수 있도록 개선하였다. 비점오염관리지역 중 하나인 자운천 유역에 개선된 sediment routing을 적용하였다. 개선된 모형은 비강우시 농도가 잘 반영하는 것으로 확인되었다.

• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.25-32
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• 2020

The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.90-98
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• 2013

The stereo system based on local matching is very popular due to its algorithmic simplicity, however it is limited to apply to various applications because it shows poor quality with low matching rates. In this paper, we propose and design a realtime stereo system based on an adaptive support-weight and the system shows low error rates and realtime performance. Generally, in the adaptive support-weight algorithm the intermediate computing results can not be reused to reduce the number of computations. In this research we modify the scheduling to reuse the intermediate results for the better performance by processing rows and columns separately. The nonlinear functions such as exponential or arc tangent have been designed with piecewise linear and step functions by empirical simulations and error analysis. The proposed architecture is composed of 9 processing elements for realtime performance. The proposed stereo system has been designed and synthesized using Donbu Hitek 0.18um standard cell library and can run up to 350Mhz operation frequency (33 frames per second) with 424K gates.

• Journal of Conservation Science
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• v.11 no.1 s.14
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• pp.38-51
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• 2002

The first priority we face in the conservation of wall paintings, is the conservation of painting layer. The 'painting layer' is sometimes called the pigment layer, and refers to the painted surface. For the consolidation of this painting layer we use 'fixative'. Fixative is a common adhesive which has been used in various field and conservators have made up for the weak points in the consolidation of wall paintings. In my thesis, I will summarise the range of use, standards of selection, and results of research on the use of fixative in the conservation of European paintings. In addition, I will describe various kinds of our traditional fixatives. As synthetic resins have proved that it is not ideal as a fixative for wall painting, conservators have studied to find an alternative. Same as European conservators, Asian scientists has researched to find alternative fixative which is more suitable to the wall paintings in Asia based on their traditional techniques and materials. Therefore, 1 have studied to find an adequate fixative for our own wall paintings and I could conclude that we can consider traditional fixative which is made of 'seaweeds' as an alternative and it is very important to proceed research and experiment on this material.

• Convergence Security Journal
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• v.24 no.2
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• pp.55-61
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• 2024

With the development of IoT technology, wearable services have also developed rapidly. Wearable devices required for this service are used as sensors and controllers in the form of smart bands. Wearable devices implement very concise SWlogic for possible long-term use and use wireless communication protocols to improve convenience. However, because this wearable device aims to be lightweight, it is more vulnerable to security than terminals used for other information services. Many smart healthcare or smart medical services are passive or do not apply security technology. By exploiting this security environment, attackers can obtain or modify important information through access to wearable devices. In this study, we analyzed the technical operating environment of wearable services and identified authentication information reuse attacks, BIAS attacks, battery drain attacks and firmware attacks on wearable devices. And we analyzed the mechanism of each security threat and confirmed the attack effect. In this study, we presented a response plan to respond to the identified security threats. When developing wearable services, it is expected that safer services can be built if the response plan proposed in this study is considered.

• Analytical Science and Technology
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• v.14 no.4
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• pp.311-316
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• 2001

We have investigated the trace amount in an oriental medicine in oder to determine the geographical origin by using inductively coupled plasma-atomic emission spectrometry(ICP-AES) and chemometric anlysis with principal component analysis(PCA) and pattern recognition. Astragali Radix from several agricultural places in Korea was selected as an example of the oriental medicine and analyzed by ICP-AES. The dried Astragali Radix sample was treated with $HNO_3$ and $H_2O_2$, then digested using microwave oven. Elements such as Mg, Al, K, Ca, Ti, Mn, Fe, Cu, Zn, and Ba with different concentrations were found an used for the identification of the origin of agriculture places. Especially, the concentration of Al, Fe, Zn and Ti were employed to investigate the relationship between. Astragali Radix and the agricultural places by PCA and pattern recognition. We have made a program that is based on chemometrics in analytical spectroscopy. The results of the chemometrics analysis indicated that a distinction among Yechon and Chechon, Chungson, Kurye and Chinese Astragali Radix could be made. We believe that principal component analysis(PCA) and pattern recognition is a valuable tool to identify the origin of Astragali Radix in terms of the agricultural place.

• Journal of KIISE:Software and Applications
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• v.36 no.6
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• pp.431-442
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• 2009

The Software Product Line (SPL) engineering is one of the most promising software development paradigms. With Feature-Oriented Reuse Method (FORM), reusable and flexible components can be built to aid the delivery of various software products such as mobile phone and digital TV applications based on commonalities and variabilities identified during Feature modeling. Model Driven Architecture (MDA) is also an emerging technology which supports developing software products to work on different platforms with platform independent models (PIM). Combining advantages of these two approaches is helpful to build a group of software products which share common Features while working on various platforms. As first step to combine FORM with MDA, we extend UML2.0 with profiles by which FORM architectures and parameterized Statecharts can be modeled. Secondly, we provide rules to examine whether Features are allocated at positions of elements of Statecharts consistently between a Feature model and a parameterized Statechart. Some rules are designed to check the consistency between FORM architectures and parameterized Statecharts. A case study on an elevator control system is provided to demonstrate the feasibility of our modeling approach and consistency checking rules.