• Journal of the Korean earth science society
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• v.27 no.7
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• pp.757-767
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• 2006

Alluvial-plain deposits in the southeastern part of the Eumsung Basin (Cretaceous) are characterized by coarse-grained channel fills encased in purple siltstone beds. It represents distinct channel geometry, infill organization, and variations in facies distribution. The directions of paleocurrent, sedimentary facies changes, and channel-fill geometry can be used to reconstruct a channel network in the alluvial system developed along the southeastern margin of the basin. The channel-fill facies represent downstream changes: 1) down-sizing and well-sorting in clast and martix of channel fills and 2) internal organization of scour fill or gravel lag and overlying cross-stratified, planar-stratified beds. These findings suggest multiple stages of channel-filling processes according to flooding and subsequent stream flows. In the small-scale pull-apart Eumsung Basin (${\sim}7{\times}33km^2$ in area), vertical-stacked alluvial architecture of the coarse-grained channel fills encased in purple siltstone is expected to result from episodic channel shifting under a rapidly subsiding setting.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.884-888
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• 1991

이 글에서는 1990년 가을 개국하여 운용되고 있는 서울우편물집중국의 우편 물 처리의 자동화 시스템의 적용을 분석, 그의 특징 등을 서술코자 한다. 본 서울우편물집중국의 자동화는 프로그래머블콘트롤러(PLC)를 적용하여 모 든 자동제어기를 통합 NETWORK화하여 1) 계층적제어 SYSTEM을 확립하 였으며 관리용 SYSTEM별의 자율적인 단위 조작과 기능적 독립을 유지하 며, 3) 분산제어 시스템화하여 우편처리에 있어 자동 일관처리 공정을 이루 는데 성공적이였으며, 이는 전적으로 PLC를 적용 계층적 분산제어에 의하여 성취되었다고 본다. 프로그래머블콘트롤러(PLC)는 확장성이 크고 강력한 우 편물 처리의 자동화 장치로서 계속적으로 우편물처리의 자동화 및 기계화 산업에 적용될 것임을 확신하는 바이다.

• Journal of the Korea Society for Simulation
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• v.8 no.4
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• pp.1-8
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• 1999

This paper proposes an ATM switch architecture called Output Queued Batcher-Banyan switch (OQBBS). It consists of a Sorting Module, Expanding Module, and Output Queueing Modules. The principles of channel grouping and output queueing are used to increase the maximum throughput of an ATM switch. One distinctive feature of the OQBBS is that multiple cells can be simultaneously delivered to their desired output. The switch architecture is shown to be modular and easily expandable. The performance of the OQBBS in terms of throughput, cell delays, and cell loss rate under uniform random traffic condition is evaluated by computer simulation. The throughput and the average cell delay are close to the ideal performance behavior of a fully connected output queued crossbar switch. It is also shown that the OQBBS meets the cell loss probability requirement of $10^{-6}$.

• Korean Journal of Child Studies
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• v.27 no.4
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• pp.55-64
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• 2006

The purpose of this study was to investigate the effects of bilingualism on children's selective attentional ability by comparing Korean-Chinese bilingual with Chinese monolinguals in China. The subjects were 71 children, 4 and 5 years of age, 38 of whom were bilingual while 33 were monolingual. Bilingual children spoke Korean at home but Chinese in the community and at preschool. The instrument used to measure children's selective attentional ability was DCCST (Dimensional Change Card Sorting Task) and ANT (Attentional Network Test). Results showed that bilingual children were more advanced than monolingual in selective attentional ability.

• Structural Engineering and Mechanics
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• v.44 no.3
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• pp.325-337
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• 2012

In this article, the multi-objective optimization of cylindrical aluminum tubes under axial impact load is presented. The specific absorbed energy and the maximum crushing force are considered as objective functions. The geometric dimensions of tubes including diameter, length and thickness are chosen as design variables. D/t and L/D ratios are constricted in the range of which collapsing of tubes occurs in concertina or diamond mode. The Non-dominated Sorting Genetic Algorithm-II is applied to obtain the Pareto optimal solutions. A back-propagation neural network is constructed as the surrogate model to formulate the mapping between the design variables and the objective functions. The finite element software ABAQUS/Explicit is used to generate the training and test sets for the artificial neural networks. To validate the results of finite element model, several impact tests are carried out using drop hammer testing machine.

• Management & Information Systems Review
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• v.24
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• pp.155-185
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• 2008

This study tries to find out the resonable improvement method of the export logistics system for fresh agriculture products. Export logistics system improvement of fresh agriculture products rationalized the export network covering the export and import of fresh agriculture products from producers to end customers and realized cost reduction and profit maximization. We are also operating our very own comprehensive logistics system that maximizes customer satisfaction. Supporting the entire logistics process starting from the collection, unloading, sorting, packaging, customs clearing, and information up to comprehensive logistics services, the export logistics system of fresh agriculture products realized a comprehensive transport system that uses 12 feet cool container. We have successfully reduced logistics costs through efficient operation in the export logistics system of fresh agriculture products.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1293-1296
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• 2002

본 연구에서는 서브 스위치를 이용한 오류허용 정렬 네트워크를 제안한다. 기존의 정렬 네트워크에서는 여분의 경로와 네트워크의 복잡성문제가 있었다. 제안된 구조에서는 여분 경로를 확장시키기 위해서 각 스테이지마다 $\frac{N}{4}\sum\limits_{i=0}^{n=2}{(\frac{1}{2})}^i$ (N=입 출력수) 서브 스위치를 추가함으로써 여분의 경로가 $3^{n(n+1)/2}$만큼 증가하였다. 또한 제안된 정렬 네트워크는 기존의 네트워크의 이중 네트워크 plane 개념에서 사용한 스위치 소자와 링크 수와 비교해 볼 때 제안된 구조의 단일 plane을 이용한 구조가 복잡도에서 낮다. 결론적으로 제안된 서브 스위치를 이용한 오류 허용 정렬 네트워크는 여분의 경로를 증가시키면서 하드웨어적 복잡도를 감소시킬 수 있다.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.503-510
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• 2020

The importance of DC breakers as key protection equipment is increasing in accordance with growing concerns on MVDC distribution network systems without DC/AC conversion. Different from the situation in AC systems, no natural zero-crossing point exists in DC systems. Thus, DC breaker technology is more difficult than AC breaker technology. The solutions for DC breakers can be divided into three types: mechanical, power electronics, and hybrid. In this study, the operating principles of several topologies of hybrid circuit breakers and that of the proposed DC breaker are analyzed and simulated by sorting two types. The breakers are compared in terms of the type and number of semiconductors, volume, power loss, auxiliary components, isolation, and other aspects. The advantages and disadvantages of the breakers are also analyzed.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.113-125
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• 2002

Although there are several empirical and semi-empirical formulae available for predicting ground surface settlement, most of them do not simultaneously take into consideration all the relevant factors, resulting in inaccurate predictions. In this study, an artificial neural network (ANN) is incorporated with 113 of monitored field results to predict surface settlement for a tunnel site with prescribed conditions. To achieve this, a format for a database of monitored field data is first proposed and then used for sorting out a variety of monitored data sets available in Korea Institute of Construction Technology. An optimal neural network model is suggested through preliminary parametric studies and introduces a concept of RSE (Yang and Zhang, 1997) in sensitivity analysis for various major factors affecting the surface settlement in tunnelling. It is seen in some examples that the RSE rationally enables to recognize the most significant factors of all the contributing factors. Two verification examples are undertaken with the trained ANN using the database created in this study. It is shown from the examples that the ANN has adequately recognized the characteristics of the monitored data sets retaining a generality fur further prediction.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.7
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• pp.1131-1140
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• 2017

This study is concerned with a design methodology of optimized fuzzy clustering-based neural network classifier for classifying black plastic. Since the amount of waste plastic is increased every year, the technique for recycling waste plastic is getting more attention. The proposed classifier is on a basis of architecture of radial basis function neural network. The hidden layer of the proposed classifier is composed to FCM clustering instead of activation functions, while connection weights are formed as the linear functions and their coefficients are estimated by the local least squares estimator (LLSE)-based learning. Because the raw dataset collected from Raman spectroscopy include high-dimensional variables over about three thousands, principal component analysis(PCA) is applied for the dimensional reduction. In addition, artificial bee colony(ABC), which is one of the evolutionary algorithm, is used in order to identify the architecture and parameters of the proposed network. In experiment, the proposed classifier sorts the three kinds of plastics which is the most largely discharged in the real world. The effectiveness of the proposed classifier is proved through a comparison of performance between dataset obtained from chemical analysis and entire dataset extracted directly from Raman spectroscopy.