• Journal of Convergence for Information Technology
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• v.7 no.5
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• pp.95-102
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• 2017

Modular toys for creative education require functional blocks to create various types of movements. An active drive module and a lot of passive connection blocks are needed to express motion with combination. In this paper, we propose the design of modular toys to produce various creative movements and controller structure working with them. In order to facilitate the connection between the designed modules, a connection method and a suitable mechanism are suggested. We also dealt with the design of various types of sensor modules that can work in conjunction with modular toys. Using these toys, typical standard application form that can be imitated educationally is suggested and showed the usefulness of the modular toy by actually applying it with designed modules and components. The proposed method is applied to actual educational toys, and the operation is effectively performed by recording operation and playing repetitive operation.

• Geophysics and Geophysical Exploration
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• v.11 no.1
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• pp.60-67
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• 2008

In this paper we consider an application of the method of electromagnetic (EM) migration to the interpretation of a typical marine controlled-source (MCSEM) survey consisting of a set of sea-bottom receivers and a moving electrical bipole transmitter. Three-dimensional interpretation of MCSEM data is a very challenging problem because of the enormous number of computations required in the case of the multi-transmitter and multi-receiver data acquisition systems used in these surveys. At the same time, we demonstrate that the MCSEM surveys with their dense system of transmitters and receivers are extremely well suited for application of the migration method. In order to speed up the computation of the migration field, we apply a fast form of integral equation (IE) solution based on the multigrid quasi-linear (MGQL) approximation which we have developed. The principles of migration imaging formulated in this paper are tested on a typical model of a sea-bottom petroleum reservoir.

• Nuclear Engineering and Technology
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• v.23 no.3
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• pp.285-298
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• 1991

An example application of the fuzzy set theory is first made to a simple portion of a given accident progression event tree with typical qualitative fuzzy input data, and thereby computational algorithms suitable for application of the fuzzy set theory to the accident progression event tree analysis are identified and illustrated with example applications. Then the procedure used in the simple example is extended to extremely complex accident progression event trees with a number of phenomenological uncertainty issues, i.e., a typical plant damage state‘SEC’of the Zion Nuclear Power Plant risk assessment. The results show that the fuzzy averages of the fuzzy outcomes are very close to the mean values obtained by current methods. The main purpose of this paper is to provide a formal procedure for application of the fuzzy set theory to accident progression event trees with imprecise and qualitative branch probabilities and/or with a number of phenomenological uncertainty issues.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1221-1225
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• 2006

문산천 하구와 임진강 장단반도 부근은 일반 하천과는 달리 특이한 하도특성을 지니는 구간이다. 문산천의 종단특성은 전형적인 상시 퇴적구간이다. 유사레짐에서도 실제 문산천 하구와 임진강 반구정 구간의 흐름특성 또한 감조구간으로서 밀물, 썰물에 민감하게 작용하여 거시적으로 유사이동이 정체성을 띠는 구간인 것이 확인되었다. 평면특성으로서는 임진강 반구정 구간에서 만곡하도 구간으로서 그 만곡 정도가 매우 크며(곡률 반경 709 m), 이에 따른 양안의 수위차가 실제 약 30 cm 이상 발생하는 것으로 평가되었다. 그리고 문산천 하구역의 하상경사가 1/5,400으로 임진강의 1/3,000보다 완만하다. 문산천 합류부 부근의 하상재료를 살펴 볼때도 임진강보다 문산천에서 더 작은 입경이 비교적 널리 분포하고 있다. 따라서, 홍수시 특히 조석이 창조기나 정체기에 임진강으로 직각 유입하는 형태를 취하고 있는 문산천 하구에서 문산천 홍수량이 유하하지 못하여 배수영향이 가중되고 임진강의 우안이 상대적으로 높은 홍수위가 역류하고 있다고 추정되었다. 이와 같은 현상들은 평균하상고의 변화에서도 나타나듯이 문산천 하구에서 외견상 하구막힘과 같은 사주 형태가 발달하는 양상에서도 찾을 수 있었다. 결국 문산천 하구에서 수위 및 하상변동량 저감을 위한 궁극적인 대책으로서 새로운 문산천 방수로 건설 및 현 문산천 하구에서의 배수기장 도입이 필요한 것으로 분석 되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2023-2027
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• 2009

본 연구는 현재와 과거의 하도 지형자료 분석을 통하여 만경강에서 나타나는 폐천(Abandoned channel)을 파악하고, 유형을 폐쇄형, 개방형, 육화형 폐천으로 구분하여 각각의 본류구간과 함께 식물상 및 식생분포 특성을 비교하였다. 만경강의 경우 1918년 하도 형태가 경지정리 및 치수사업에 따른 제방축조 등 인위적인 절단(Engineered cutoff)으로 8개소 이상의 구간에서 하도 선형이 크게 변경됨으로써 폐천이 형성되는 것으로 나타났다. 현재 폐천부지는 육화형태의 농지 이용 및 개방형 또는 폐쇄형의 습지로 유지되는 것으로 조사되었다. 폐천 유형에 따라 나타난 식물상은 폐쇄형 56종류, 개방형 31종류로 조사되었다. 육화형의 본류의 경우 보에 의한 영향으로 달뿌리풀 (Phragmites japonica)과 저수로 검정말(Hydrilla verticillata) 등의 수생식물이 우점하는 정체수역이 나타났다. 개방형 폐천은 갈수기에도 수심이 깊은 수역이 확보되어 본류에 비하여 출현종수가 높았다. 폐쇄형 폐천은 연꽃(Nelumbo nucifera), 애기부들(Typha angustifolia) 등의 다양한 수생식물이 출현하여 본류에 비해 안정된 습지 생태계를 유지하였다. 만경강의 개방형과 폐쇄형 폐천은 수생식물의 증가와 전형적인 습지생태계를 유지하고 있었으며 본류의 정체수역이 관찰되었다. 본래 하천의 연속성을 향상하기 위한 유수생태계의 복원은 하천의 건강성을 향상하기 위한 방안이 될 것이다.

• The Journal of Information Technology
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• v.5 no.1
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• pp.29-37
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• 2002

Distributed programming can be greatly simplified by language support for distributed communication. Many web browsers now offer some form of distributed objects and the number and types of them are growing daily in interesting and innovative ways CORBA IDL and Java RMI, the representative of distributed object model, support different approaches for distributed computing environments. CORBA approach does not support the application generated by java RMI, even though it supports multiple programming languages. Object translation system between RMI to CORBA is designed and implemented for interoperability of distributed objects on the two different distributed programming environments. Suggested system is considered binding, inheritance, polymorphism, object passing, and callback which are key properties on the distributed objects. Translation System we suggested is implemented on the Window/NT(version 4.0) with Java Development Kit(version 1.1.6).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.3
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• pp.173-180
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• 1992

A feature typical of natural rivers is the bend. The purpose of this study is to examine hydraulic and morphometric characteristics in channel bend reach by the deterministic approach. Cross section shape factor, "As" is suggested for a new cahracteristic factor of channel bend reach analysis. The variation of this new factor along the river reach showed the location of the concentration of the force due to the current all over the reach, that is curved or not. Some general meander factors are used for correlation with new factor suggested, and the applicability of "As" is verified. The range R/W values are concentrated 2~4, the meanning of this value can be regarded to the warning for bank erosion or breaking. And this paper dealt with prediction of cross section bed shape variation.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.110.1-110.1
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• 2011

오리온 A 분자운은 별탄생이 활발하게 일어나는 영역이다. 때문에 분자운 연구를 통해서 별탄생을 연구하기에는 최적의 곳이다. 특기할 것은 Orion A에는 필라멘트 구조가 있다는 점이다. 필라멘트는 전형적으로는 길이 4.8pc, 너비 1.4 pc 로 제시되었다(Nagahama et al. 1998). 많은 미지의 조건들 가운데 필라멘트 구조는 별탄생에 대한 새로운 조명을 던져주는 데, 가령 분자운이 수축, 분열하며 작은 덩어리를 만드는 과정에 이런 기다란 구조가 별탄생에 어떤 과정에서 나타나며 이것이 별탄생이 어떤 효과를 발생하는지 연구되어야 하는 문제들이다. 대덕전파안테나의 1분의 분해능(Channel resolution 63 KHz/ Band Width 25 MHz) 의 12CO, 13CO(J=1-0) 분자선 관측으로 필라멘트를 이전 연구보다 자세하게 관측하여 이것 안에 있을 것으로 보이는 substructure들 연구하고자 한다. 관측영역은 적경: 5h 32m ~ 5h 37m, 적위: $-5^{\circ}$ 14' ~ $-5^{\circ}$ 37'으로 ($1^{\circ}{\times}1^{\circ}$) 영역을 관측하였다. 그 결과 필라멘트구조를 확인할 수 있었으며 약 0.7pc,약 $1000\;M_{\odot}$의 덩어리들이 이전관측에서 보여진 X자형태가 아니라 일자형태로 분포되어있는 것을 알 수 있었다. 관측된 최소덩어리는 star cluster mass이고 stellar size 의 덩어리는 별탄생 과정 이후 소멸된 것으로 보인다. 관측으로 확인된 덩어리들의 물리적인 성질과 분포를 깊이 연구해 보고자 한다. 향후 Orion A 전체를 추가로 관측하고자 한다.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.277-286
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• 2020

In this paper, we propose a new educational approach to help learners form concepts by identifying the properties of programming concepts targeting a group of experts in programming education. Therefore, we confirmed the typical properties of concepts by programming education experts for programming learning elements through conceptual metaphor analysis, which is a qualitative research method, and confirmed the validity through the delphi method. As a result of this study, we identified 17 typical properties of programming concepts that learners should form in programming education. The conclusions of this study are that need to compose the educational content more specifically for the conceptualization of learners' programming as follows: 1)the concept of a variable is to understand how to store data, how to set a name, what an address has, how to change a value, various types of variables, and the meaning of the size of a variable, 2)the concept of operator is to understand how to operate the four rules, how to deal with it logically, how to connect according to priority, meaning of operation symbols, and how to compare, 3)the concept of the control structure is to understand how to control the execution flow, how to make a logical judgment, how to set an execution rule, meaning of sequential execution, and how to repeat executing.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.152-158
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• 2007

Micromorphological and chemical characteristics of living Castanea spp. and Tamarix spp. attacked by a brown-rot fungus were examined. Micromorphological features of brown-rotted hardwood species were similar to those observed in softwoods such as losses in birefringence under polarized microscopy, preferential degradation of $S_2$ layer and cracks in the $S_3$ layer. Thinning of the secondary cell wall in fibers was also observed, although it did not seem to be the main symptom. FT-IR analysis showed that bands assigned to cellulose and hemicelluloses decreased or disappeared, whereas the bands assigned to lignin increased. X-ray diffraction analysis exhibited the decrease of relative crystallinity, indicating that degradation of hardwood by a brown-rot fungus was in the advanced stages.